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--------------------------------------------------------------------------------

1	Internet-draft       Media Server Markup Language        February 2006
2	                                 (MSML)

4	   SIPPING                                                    A. Saleem
5	   Internet Draft                                           G. Sharratt
6	   Expires: August 26, 2006                                    Convedia

8	                                                      February 26, 2006

10	                    Media Server Markup Language (MSML)
11	                           draft-saleem-msml-00

13	Status of this Memo

15	   By submitting this Internet-Draft, each author represents that any
16	   applicable patent or other IPR claims of which he or she is aware
17	   have been or will be disclosed, and any of which he or she becomes
18	   aware will be disclosed, in accordance with Section 6 of BCP 79.

20	   Internet-Drafts are working documents of the Internet Engineering
21	   Task Force (IETF), its areas, and its working groups. Note that other
22	   groups may also distribute working documents as Internet-Drafts.

24	   Internet-Drafts are draft documents valid for a maximum of six months
25	   and may be updated, replaced, or obsoleted by other documents at any
26	   time. It is inappropriate to use Internet-Drafts as reference
27	   material or to cite them other than as "work in progress."

29	   The list of current Internet-Drafts can be accessed at
30	   http://www.ietf.org/ietf/1id-abstracts.txt.

32	   The list of Internet-Draft Shadow Directories can be accessed at
33	   http://www.ietf.org/shadow.html.

35	   This Internet-Draft will expire on August 26, 2006.

37	Copyright Notice

39	   Copyright (C) The Internet Society (2006). All Rights Reserved.

41	Abstract

43	   The Media Server Markup Language (MSML) is used to control and invoke
44	   many different types of services on IP Media Servers. Clients can use
45	   it to define how multimedia sessions interact on a Media Server and
46	   to apply services to individuals or groups of users. MSML can be
47	                                 (MSML)

49	   used, for example, to control Media Server conferencing features such
50	   as video layout and audio mixing, create sidebar conferences or
51	   personal mixes, and set the properties of media streams. As well,
52	   clients can use MSML to define media processing dialogs, which may be
53	   used as parts of application interactions with users or conferences.
54	   Transformation of media streams to and from users or conferences as
55	   well as IVR dialogs are examples of such interactions, which are
56	   specified using MSML. MSML clients may also invoke dialogs with
57	   individual users or with groups of conference participants using
58	   VoiceXML.

60	Table of Contents

62	   1. Introduction...................................................5
63	   2. Conventions used in this document..............................6
64	   3. Glossary.......................................................6
65	   4. MSML SIP Usage.................................................7
66	   5. Language Structure.............................................9
67	      5.1 Package Scheme.............................................9
68	      5.2 Profile Scheme............................................12
69	   6. Execution Flow................................................13
70	   7. Media Server Object Model.....................................14
71	      7.1 Objects...................................................15
72	      7.2 Identifiers...............................................17
73	   8. MSML Core Package.............................................19
74	      8.1 <msml>....................................................20
75	      8.2 <send>....................................................20
76	      8.3 <result>..................................................21
77	      8.4 <event>...................................................21
78	   9. MSML Conference Core Package..................................22
79	      9.1 Conferences...............................................22
80	      9.2 Media Streams.............................................23
81	      9.3 <createconference>........................................24
82	         9.3.1 <reserve>............................................26
83	            9.3.1.1 <resource>......................................26
84	      9.4 <modifyconference>........................................27
85	      9.5 <destroyconference>.......................................29
86	      9.6 <audiomix>................................................29
87	         9.6.1 <n-loudest>..........................................30
88	         9.6.2 <asn>................................................30
89	      9.7 <videolayout>.............................................31
90	         9.7.1 <root>...............................................31
91	         9.7.2 <region>.............................................32
92	         9.7.3 <selector>...........................................35
93	            9.7.3.1 <vas> Voice Activate Switching..................37
94	      9.8 <join>....................................................38
95	                                 (MSML)

97	      9.9 <modifystream>............................................40
98	      9.10 <unjoin>.................................................41
99	      9.11 <monitor>................................................42
100	      9.12 <stream>.................................................42
101	         9.12.1 Audio Stream Properties.............................43
102	            9.12.1.1 <gain>.........................................44
103	            9.12.1.2 <clamp>........................................44
104	         9.12.2 Video Stream Properties.............................44
105	            9.12.2.1 <visual>.......................................45
106	   10. MSML Dialog Packages.........................................45
107	      10.1 Overview.................................................45
108	      10.2 Primitives...............................................47
109	      10.3 Events...................................................49
110	      10.4 MSML Dialog Usage with SIP...............................50
111	      10.5 MSML Dialog Structure and Modularity.....................52
112	      10.6 MSML Dialog Core Package.................................52
113	         10.6.1 <dialogstart>.......................................53
114	         10.6.2 <dialogend>.........................................55
115	         10.6.3 <send>..............................................56
116	         10.6.4 <exit>..............................................57
117	         10.6.5 <disconnect>........................................57
118	      10.7 MSML Dialog Base Package.................................57
119	         10.7.1 <play>..............................................58
120	            10.7.1.1 <audio>........................................60
121	            10.7.1.2 <video>........................................61
122	            10.7.1.3 <media>........................................62
123	            10.7.1.4 <var>..........................................62
124	            10.7.1.5 <playexit>.....................................63
125	         10.7.2 <dtmfgen>...........................................63
126	            10.7.2.1 <dtmfgenexit>..................................64
127	         10.7.3 <record>............................................64
128	            10.7.3.1 <play>.........................................68
129	            10.7.3.2 <recordexit>...................................68
130	         10.7.4 <dtmf> or <collect>.................................68
131	            10.7.4.1 <play>.........................................70
132	            10.7.4.2 <pattern>......................................70
133	            10.7.4.3 <detect>.......................................71
134	            10.7.4.4 <noinput>......................................71
135	            10.7.4.5 <nomatch>......................................71
136	            10.7.4.6 <dtmfexit>.....................................72
137	         10.7.5 <moml>..............................................72
138	      10.8 MSML Dialog Group Package................................72
139	         10.8.1 <group>.............................................76
140	         10.8.2 <groupexit>.........................................76
141	      10.9 MSML Dialog Transform Package............................76
142	         10.9.1 <vad>...............................................77
143	            10.9.1.1 <voice>, <silence>, <tvoice>, <tsilence>.......77
144	         10.9.2 <gain>..............................................78
145	                                 (MSML)

147	         10.9.3 <agc>...............................................78
148	         10.9.4 <gate>..............................................79
149	         10.9.5 <clamp>.............................................79
150	         10.9.6 <relay>.............................................79
151	      10.10 MSML Dialog Speech Package..............................79
152	         10.10.1 <speech>...........................................80
153	            10.10.1.1 <grammar>.....................................81
154	            10.10.1.2 <match>.......................................82
155	            10.10.1.3 <noinput>.....................................82
156	            10.10.1.4 <nomatch>.....................................82
157	            10.10.1.5 <speechexit>..................................82
158	         10.10.2 <play>.............................................83
159	            10.10.2.1 <tts>.........................................83
160	      10.11 MSML Dialog Fax Detection Package.......................83
161	         10.11.1 <faxdetect>........................................83
162	      10.12 MSML Dialog Fax Send/Receive Package....................84
163	         10.12.1 <faxsend>..........................................84
164	            10.12.1.1 <sendobj>.....................................86
165	            10.12.1.2 <hdrfooter>...................................86
166	            10.12.1.3 <rxpoll>......................................87
167	            10.12.1.4 <faxstart>....................................87
168	            10.12.1.5 <faxnegotiate>................................88
169	            10.12.1.6 <faxpagedone>.................................88
170	            10.12.1.7 <faxobjectdone>...............................88
171	            10.12.1.8 <faxopcomplete>...............................88
172	            10.12.1.9 <faxpollstarted>..............................89
173	         10.12.2 <faxrcv>...........................................89
174	            10.12.2.1 <rcvobj>......................................90
175	            10.12.2.2 <txpoll>......................................91
176	   11. Response Codes...............................................91
177	   12. MSML Conference Examples.....................................93
178	      12.1 Establishing a Dial-in Conference........................93
179	      12.2 Example of a Sidebar Audio Conference....................97
180	      12.3 Example of Removing a Conference.........................99
181	      12.4 Example of Modifying Video Layout........................99
182	   13. MSML Dialog Examples........................................100
183	      13.1 Announcement............................................100
184	      13.2 Voice Mail Retrieval....................................101
185	      13.3 Play and Record.........................................102
186	      13.4 Speech Recognition......................................103
187	      13.5 Play and Collect........................................104
188	      13.6 User Controlled Gain....................................106
189	   14. Change Summary..............................................106
190	   15. Future Work.................................................107
191	   16. XML Schema - MSML Core and MSML Conference Core Packages....107
192	   17. XML Schema � MSML Dialog/Transform/Speech/Fax Packages......118
193	   18. Security Considerations.....................................138
194	   19. IANA Considerations.........................................138
195	                                 (MSML)

197	   20. URN Sub-Namespace Registration..............................139
198	   21. XML Schema Registration.....................................139
199	   22. References..................................................139
200	   Acknowledgments.................................................141
201	   Authors' Addresses..............................................141
202	   Intellectual Property Statement.................................142
203	   Copyright Statement.............................................142
204	   Disclaimer of Validity..........................................143
205	   Acknowledgement.................................................143

207	1. Introduction

209	   Media servers contain dynamic pools of media resources. Control
210	   Agents and other users of media servers (called media server clients)
211	   can define and create many different services based on how they
212	   configure and use those resources. Often, that configuration and the
213	   ways in which those resources interact will be changed dynamically
214	   over the course of a call, to reflect changes in the way that an
215	   application interacts with a user.

217	   For example, a call may undergo an initial IVR dialog before being
218	   placed into a conference. Calls may be moved from a main conference
219	   to a sidebar conference and then back again. Individual calls may be
220	   directly bridged to create small n-way calls or simple sidebars. None
221	   of these change the SIP [1] dialog or RTP [15] session. Yet these do
222	   affect the media flow and processing internal to the media server.

224	   The Media Server Markup Language (MSML) is an XML [4] language used
225	   to change the flow of and services on media streams within a media
226	   server. It is used to invoke many different types of services on
227	   individual sessions, groups of sessions, and conferences. MSML allows
228	   the creation of conferences, bridging different sessions together,
229	   and bridging sessions into conferences.

231	   MSML may also be used to create user interaction dialogs and allows
232	   the application of media transforms to media streams. Media
233	   interaction dialogs created using MSML allow construction of IVR
234	   dialog sessions to individual users as well as to groups of users
235	   participating in a conference. Dialogs may also be specified using
236	   other languages, VoiceXML [7], which support complete single-party
237	   application logic to be executed on the Media Server.

239	   MSML is a transport independent language, such that it does not rely
240	   on underlying transport mechanisms and language semantics are
241	   independent of transport. However, SIP is a typical and commonly used
242	   transport mechanism for MSML, invoked using the SIP URI scheme. This
243	                                 (MSML)

245	   specification defines using MSML Dialogs using SIP as the transport
246	   mechanism.

248	   A network connection may be established with the media server using
249	   SIP. Media received and transmitted on that connection will flow
250	   through different media resources on the media server depending on
251	   the requested service. Basic Network Media Services with SIP [9]
252	   defines conventions for associating a basic service with a SIP
253	   Request-URI. MSML allows services to be dynamically applied and
254	   changed by a Control Agent during the lifetime of the SIP dialog.

256	   MSML has been designed to address the control and manipulation of
257	   media processing operations (e.g., announcement, IVR, play and
258	   record, ASR/TTS, fax, video), as well as control and relationships of
259	   media streams (e.g., simple and advanced conferencing). It provides a
260	   general-purpose media server control architecture. MSML can
261	   additionally be used to invoke other more complex IVR languages such
262	   as VoiceXML.

264	2. Conventions used in this document

266	   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
267	   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
268	   document are to be interpreted as described in RFC 2119 [7].

270	3. Glossary

272	   Media Server: a general-purpose platform for executing real-time
273	   media processing tasks. This is a logical function that maps either
274	   to a single physical device or to a portion of a physical device.

276	   Media Server Client: an application which originates MSML requests to
277	   a media server and also referred to as a Control Agent in this
278	   specification.

280	   Network Connection: a participant that represents the termination on
281	   a media server of one or more RTP [15] sessions (for example audio
282	   and video) associated with a call. Network connections are
283	   established and removed using a session establishment protocol such
284	   as SIP. An instance of a network connection is independent of MSML
285	   processing instructions applied to it.

287	   Dialog: an automated IVR participant. Examples of dialogs may be
288	   announcement players, IVR interfaces, or voice recorders. Dialogs may
289	   be defined in MSML or using VoiceXML [7].

291	   Conference: an intermediary function that provides multimedia mixing
292	   and other advanced conferencing services. This specification
293	                                 (MSML)

295	   currently considers conferences with audio and/or video media types,
296	   but is extensible to other media types.

298	   Identifier: a name that is used to refer to a specific instance of an
299	   object on the media server, such as a conference or a dialog.
300	   Identifiers are composed of one or more terms where each term
301	   identifies an object class and instance.

303	   Object: the generic term for a media server entity that terminates,
304	   originates, or processes media. This specification defines four
305	   classes of objects and specifies mechanisms to create them, join them
306	   together, and destroy them.

308	   Participant Object: an object in a media server that sources original
309	   media in a call and/or receives and terminates media in a call.

311	   Intermediary Object: an object in a media server that acts on media
312	   within a call for the benefit of the participants.

314	   Independent Object: an object that can exist on a media server
315	   independent of other objects.

317	   Operator: an intermediary object class that modifies or transforms a
318	   media stream. Examples of operators may be audio gain controls, video
319	   scaling, or voice masking. MSML defines operators as implicit
320	   objects, which transform media when operations, such as gain control,
321	   are applied to media streams.

323	   Media Stream: a single media flow between two objects. A media stream
324	   has a media type and may be unidirectional or bidirectional.

326	4. MSML SIP Usage

328	   SIP is used to create and modify media sessions with a media server
329	   according to the procedures defined in RFC 3261 [1]. Often, SIP third
330	   party call control [16] will be used to create sessions to a media
331	   server on behalf of end users. MSML is used to define and change the
332	   service which a user connected to a media server will receive. MSML
333	   clients are application servers, softswitches, or other forms of
334	   control agents, and SHOULD have an authorized security relationship
335	   with the media server. MSML itself does not define authorization
336	   mechanisms.

338	   MSML transactions are originated based upon events that occur in the
339	   application domain. These events may be independent from any media or
340	   user interaction. For example, an application may wish to play an
341	   announcement to a conference warning that its scheduled completion
342	   time is approaching. Applications themselves are structured in many
343	                                 (MSML)

345	   different ways. Their structure and requirements contribute to their
346	   selection of protocols and languages. To accommodate differing
347	   application needs, MSML has been designed to be neutral to other
348	   languages and independent of the transport used to carry it.

350	   Many alternatives exist for a transport mechanism for MSML. There may
351	   be one or many transport channels used to carry MSML based upon the
352	   requirements and structure of applications. SIP INVITE and INFO [17]
353	   requests and responses have been chosen to carry MSML in this release
354	   of the specification. INFO requests allow asynchronous mid-call
355	   messages within SIP with few additional semantics. In addition, there
356	   are existing widely deployed implementations of that method, it aids
357	   in initial developments which are closely coupled with SIP session
358	   establishment, and it allows MSML to be directly associated with user
359	   dialogs when third party call control is used.

361	   Although INFO is sometimes considered to not be a suitable general-
362	   purpose transport mechanism for messages within SIP, there have been
363	   proposals to make it more acceptable. MSML may evolve to include
364	   other SIP usage and/or to work with other protocols or as a stand-
365	   alone protocol established through SIP, in future releases of this
366	   document.

368	   MSML supports several models for client interaction. When clients use
369	   3PCC to establish media sessions on behalf of end users, clients will
370	   have a SIP dialog for each media session. MSML MAY be sent on these
371	   dialogs. However the targets of MSML actions are not inferred from
372	   the session associated with the SIP dialog. The targets of MSML
373	   actions are always explicitly specified using identifiers as
374	   previously defined.

376	   An application, after interacting with a user, may want to affect
377	   multiple objects within a media server. For example, tones or
378	   messages are often played to a conference when connections are added
379	   or removed. A separate message may also be played to a participant as
380	   they are joined, or to moderators. Explicit identifiers, that is, not
381	   inferred from a transport mechanism allow these multiple actions to
382	   be easily grouped into a single transaction sent on any SIP dialog.

384	   MSML also supports a model of dedicated control associations. This
385	   supports decoupled application architectures where a client can
386	   control media server services without also establishing all of the
387	   media sessions itself. Control associations are created using SIP but
388	   they do not have any associated media session. Although initially
389	   INFO messages will be sent on this SIP dialog, just as with dialogs
390	   associated with media sessions, it is possible that in the future,
391	   the SIP dialog will be used to establish a separate control session
392	                                 (MSML)

394	   (defined in SDP [18]) that does not use SIP as the transport for MSML
395	   messages.

397	   A media server using MSML also sends asynchronous events to a client
398	   using MSML scripts in SIP INFO. Events are sent based on previous
399	   MSML requests and are sent within the SIP dialog on which the MSML
400	   request that caused the event to be generated was received. If this
401	   dialog no longer exists when the event is generated, the event is
402	   discarded.

404	   Events may be generated during the execution of a dialog created by a
405	   <dialogstart> element. For example, dialogs can send events based on
406	   user input. VoiceXML dialogs, on the other hand, generally interact
407	   with other servers outside of MSML using HTTP.

409	   An event is also generated when the execution of a dialog terminates,
410	   either because of completion or failure. The exact information
411	   returned is dependent on the dialog language, the capabilities of the
412	   dialog execution environment, and what was requested by the dialog.
413	   Both MSML and VoiceXML [7] allow information to be returned when they
414	   exit. These events may be sent in a SIP INFO or a SIP BYE. SIP BYE is
415	   used when the dialog itself specifies that the connection should be
416	   disconnected, for example through the use of the <disconnect>
417	   element.

419	   Conferences may also generate events based upon their configuration.
420	   An example of this is the notification of the set of active speakers.

422	5. Language Structure

424	5.1 Package Scheme

426	   The primary mechanism for extending MSML is the "package". A package
427	   is an integrated set of one or more XML schemas that define
428	   additional features and functions via new or extended use of elements
429	   and attributes. Each package, except for those defined in the current
430	   document, is defined in a separate standards document, e.g., an
431	   Internet Draft or an RFC. All packages, that extend the base MSML
432	   functionality, MUST include references to the MSML base set of
433	   schemas provided in the Internet drafts. A schema in a package MUST
434	   only extend MSML, this is, it must not alter the existing
435	   specification.

437	   A particular MSML script will include references to all the schemas
438	   defining the packages whose elements and attributes it makes use of.
439	   A particular script MUST reference MSML base and optionally extension
440	   package(s). See IANA Considerations section.

442	                                 (MSML)

444	   Each package MUST define its own namespace so that elements or
445	   attributes with the same name in different packages do not conflict.
446	   A script using a particular element or attribute MUST prefix the
447	   namespace name on that element or attribute's name if it is defined
448	   in a package (as opposed to being defined in the base).

450	   MSML consists of a core package which provides structure without
451	   support for any specific feature set. Additional packages, relying on
452	   the core package, provide functional features. Any combination of
453	   additional packages may be used along with the core package. The
454	   following describes the set of MSML packages defined in this
455	   document.

457	                  +----------------------------------------------+
458	                  |                  MSML Core                   |
459	                  +----------------------------------------------+
460	                      /                                     \
461	                  +--------+                            +--------+
462	                  | Dialog |                            | Conf   |
463	                  | Core   |                            | Core   |
464	             -  - +--------+ - -  -  -  -  -   -   -    +--------+
465	            /        /          \           \       \
466	       +--------+  +--------+ +---------+ +------+ +------+
467	       | Dialog |  | Dialog | |Dialog   | |Dialog| |Dialog|
468	       | Base   |  | Group  | |Transform| |Speech| |Fax   |
469	       +--------+  +--------+ +---------+ +------+ +------+

471	      o MSML Core package (Mandatory)

473	         Describes the minimum base framework which MUST be implemented
474	         to support additional core packages.

476	      o MSML Conference Core package (Conditionally Mandatory, for
477	         Conferencing)

479	         Describes the audio and multimedia basic and advanced
480	         conferencing package, which MAY be implemented.

482	      o MSML Dialog Core package (Conditionally Mandatory, for Dialogs)

484	         Describes the dialog core package which MUST be implemented for
485	         any dialog services. However, systems supporting conferencing
486	         only, MAY omit support for MSML dialogs. The MSML dialog core
487	         package specifies the framework within which additional dialog
488	         packages are supported. The MSML dialog base package MUST be
489	         supported, while all other dialog packages MAY be supported.

491	                                 (MSML)

493	         o MSML Dialog Base package (Conditionally Mandatory, for
494	         Dialogs)

496	         o MSML Dialog Group package (Optional)

498	         o MSML Dialog Transform package (Optional)

500	         o MSML Dialog Fax Detection package (Optional)

502	         o MSML Dialog Fax Send/Receive package (Optional)

504	         o MSML Dialog Speech package (Optional)

506	   The formal process for defining extensions to MSML Dialogs is to
507	   define a new package. The new package MUST provide a text description
508	   of what extensions are included and how they work. It MUST also
509	   define an XML schema file (if applicable) that defines the new
510	   package (which may be through extension, restriction of an existing
511	   package, or a specific profile of an existing package). Dependencies
512	   upon other packages MUST be stated. For example a package that
513	   extends or restricts has a dependency on the original package
514	   specification. Finally, the new package MUST be assigned a unique
515	   name and version.

517	   The types of things which can be defined in new packages are:

519	      o  new primitives

521	      o  extensions to existing primitives (events, shadow variables,
522	         attributes, content)

524	      o  new recognition grammars for existing primitives

526	      o  new markup languages for speech generation

528	      o  languages for specifying a topology schema

530	      o  new pre-defined topology schemas

532	      o  new variables / segment types (sets & languages)

534	      o  new control flow elements

536	   MSML Packages are assembled together to form a specific MSML profile
537	   that is shared between different implementations. The base MSML
538	   Dialog profiles which are defined in this document consist of the
539	   MSML Core package, MSML Dialog Core package, MSML Dialog Base
540	                                 (MSML)

542	   package, MSML Dialog Group package, MSML Transform package, MSML Fax
543	   packages, and the MSML Speech package.

545	   MSML extension packages, which define primitives, MUST define the
546	   following for each primitive within the package:

548	      o  the function which the primitive performs

550	      o  the attributes which may be used to tailor its behavior

552	      o  the events which it is capable of understanding

554	      o  the shadow variables which provide access to information
555	         determined as a result of the primitive's operation.

557	   The mechanism used to insure that a media server and its client share
558	   a compatible set of packages is not defined. Currently it is expected
559	   that provisioning will be used, possibly coupled with a future
560	   auditing capability. Additionally, when used in SIP networks,
561	   packages could be defined using feature tags and the procedures
562	   defined for Indicating User Agent Capabilities in SIP [2] used to
563	   allow a media server to describe its capabilities to other user
564	   agents and its domain registrar.

566	5.2 Profile Scheme

568	   Not all devices and applications using MSML will need to support the
569	   entire MSML schema. For example, a media processing device might
570	   support only audio announcements, only audio simple conferencing, or
571	   only multimedia IVR. It is highly desirable to have a system for
572	   describing what portion of MSML a particular media processing device
573	   or Control Agent supports.

575	   The Package scheme described earlier allows MSML functionality to be
576	   functionally grouped, relying on the MSML core package. This scheme
577	   allows a portion of the complete MSML specification to be
578	   implemented, on a per package basis and also creates a framework for
579	   future extension packages. However, within a given package, in some
580	   cases, only a subset of the package functionality may be required. In
581	   order to support subsets of packages, with greater degree of
582	   granularity than at the package level, a profile scheme is required.

584	   MSML package profiles would identify a subset of a given MSML package
585	   with specific definitions of elements and attributes. Each MSML
586	   package profile MUST be accompanied by one or more corresponding
587	   schemas. To use the examples above, there could be an audio
588	   announcements profile of the MSML Dialog Base package, an audio
589	                                 (MSML)

591	   simple conferencing profile of the MSML Conference Core package, and
592	   a multimedia IVR profile of the MSML Dialog Base package.

594	   MSML package profiles MUST be published separately from the MSML
595	   specification, in one or more standards documents (e.g., Internet
596	   Drafts or RFCs) dedicated to MSML package profiles. Profiles would
597	   not be registered with IANA and any organization would additionally
598	   be free to create its own profile(s) if required.

600	6. Execution Flow

602	   MSML assumes a model where there is a single control context within a
603	   media server for MSML processing. That context may have one or many
604	   SIP [1] dialogs associated with it. It is assumed that any SIP
605	   dialogs associated with the MSML control context have been
606	   authorized, as appropriate, by mechanisms outside the scope of MSML.

608	   A media server control context maintains information about the state
609	   of all media objects and media streams within a media server. It
610	   receives and processes all MSML requests from authorized SIP dialogs
611	   and receives all events generated internally by media objects and
612	   sends them on the appropriate SIP dialog. An MSML request is able to
613	   create new media objects and streams, and to modify or destroy any
614	   existing media objects and streams.

616	   An MSML request may simply specify a single action for a media server
617	   to undertake. In this case, the document is very similar to a simple
618	   command request. Often, though, it may be more natural for a client
619	   to request multiple actions at one time, or the client would like
620	   several actions to be closely coordinated by the media server.
621	   Multiple MSML elements received in a single request MUST be processed
622	   sequentially in document order.

624	   An example of the first scenario would be to create a conference and
625	   join it with an initial participant. An example of the second case
626	   would be to unjoin one or more participants from a main conference
627	   and join them to a sidebar conference. In the first scenario, network
628	   latencies may not be an issue, but it is simpler for the client to
629	   combine the requests. In the second case, the added network latency
630	   between separate requests could mean perceptible audio loss to the
631	   participant.

633	   Each MSML request is processed as a single transaction. A media
634	   server MUST ensure that it has the necessary resources available to
635	   carry out the complete transaction before executing any elements of
636	   the request. If it does not have sufficient resources, it MUST return
637	   a 520 response and MUST NOT execute the transaction.

639	                                 (MSML)

641	   The MSML request MUST be checked for well-formedness and validated
642	   against the schema prior to executing any elements. This allows XML
643	   [4] errors to reported immediately and minimizes failures within a
644	   transaction and the corresponding execution of only part of the
645	   transaction.

647	   Each element is expected to execute immediately. Elements such as
648	   <dialogstart>, which take an unpredictable amount of time, are
649	   "forked" and executed in a separate thread (see MSML Dialog
650	   packages). Once successfully forked, execution continues with the
651	   element following the </dialogstart>. As such, MSML does not provide
652	   mechanisms to sequence or coordinate other operations with dialog
653	   elements.

655	   Processing within a transaction MUST stop if any errors occur.
656	   Elements that were executed prior to the error are not rolled back.
657	   It is the responsibility of the client to determine appropriate
658	   actions based upon the results indicated in the response. Most
659	   elements MAY contain an optional "mark" attribute. The value of that
660	   attribute from the last successfully executed element MUST be
661	   returned in an error response. Note that errors that occur during the
662	   execution of a dialog occur outside the context of an MSML
663	   transaction. These errors will be indicated in an asynchronous event.

665	   Transaction results are returned as part of the SIP request response.
666	   The transaction results indicate the success or failure of the
667	   transaction. The result MUST also include identifiers for any objects
668	   created by a media server for which the client did not provide an
669	   instance name. Additionally, if the transaction fails, the reason for
670	   the failure MUST be returned, as well as an indication of how much of
671	   the transaction was executed before the failure occurred SHOULD be
672	   returned.

674	7. Media Server Object Model

676	   Media servers are general-purpose platforms for executing real-time
677	   media processing tasks. These tasks range in complexity from simple
678	   ones such as serving announcements, to complex ones, such as speech
679	   interfaces, centralized multimedia conferencing, and sophisticated
680	   gaming applications.

682	   Calls are established to a media server using SIP. Clients will often
683	   use SIP third party call control (3PCC) [16] to establish calls to a
684	   media server on behalf of end users. However MSML does not require
685	   that 3PCC be used; only that the client and the media server share a
686	   common identifier for the call and its associated RTP [15] sessions.

688	                                 (MSML)

690	   Objects represent entities which source, sink, or modify media
691	   streams. A media streams is a bidirectional or unidirectional media
692	   flow between objects on a media server. The following subsections
693	   define the classes of objects that exist on a media server and the
694	   way these are identified in MSML.

696	7.1 Objects

698	   A media object is an endpoint of one or more media streams. It may be
699	   a connection that terminates RTP sessions from the network or a
700	   resource that transforms or manipulates media. MSML defines four
701	   classes of media objects. Each class defines the basic properties of
702	   how object instances are used within a media server. However most
703	   classes require that the function of specific instances be defined by
704	   the client, using MSML or other languages such as VoiceXML.

706	   The following classes of media processing objects are defined. The
707	   class names are given in parentheses:

709	         o network connection (conn)

711	         o conference (conf)

713	         o dialog (dialog)

715	         o operator (oper)

717	   Network connection is an abstraction for the media processing
718	   resources involved in terminating the RTP session(s) of a call. For
719	   audio services a connection instance presents a full-duplex audio
720	   stream interface within a media server. Multimedia connections have
721	   multiple media streams of different media types, each corresponding
722	   to an RTP session. Network connections get instantiated through SIP
723	   [1].

725	   A conference represents the media resources and state information
726	   required for a single logical mix of each media type in the
727	   conference (e.g. audio and video). MSML models multiple mixes/views
728	   of the same media type as separate conferences. Each conference has
729	   multiple inputs. Inputs may be divided into classes that allow an
730	   application to request different media treatment for different
731	   participants. For example, the video streams for some participants
732	   may be assigned to fixed regions of the screen while those for other
733	   participants may only be shown when they are speaking.

735	                                 (MSML)

737	   A conference has a single logical output per media type. For each
738	   participant, it consists of the audio conference mix, less any
739	   contributed audio of the participant, and the video mix shared by all
740	   conference participants. Video conferences using voice activated
741	   switching have an optional ability to show the previous speaker to
742	   the current speaker.

744	   Conferences are instantiated using the <createconference> element.
745	   The content of the <createconference> element specifies the
746	   parameters of the audio and/or video mixes.

748	   Dialogs are a class of objects that represent automated participants.
749	   They are similar to network connections from a media flow perspective
750	   and may have one or more media streams as the abstraction for their
751	   interface within a media server. Unlike connections however, dialogs
752	   are created and destroyed through MSML, and the media server itself
753	   implements the dialog participant. Dialogs are instantiated through
754	   the <dialogstart> element. Contents of the <dialogstart> element
755	   define the desired or expected dialog behavior. Dialogs may also be
756	   invoked by referencing VoiceXML as the dialog description language.

758	   Operators are implicit functions that are used to filter or transform
759	   a media stream. The function that an instance of an operator fulfills
760	   is defined as a property of the media stream. Operators may be
761	   unidirectional or bidirectional and have a media type. Unidirectional
762	   operators reflect simple atomic functions such as automatic gain
763	   control, filtering tones from conferences, or applying specific gain
764	   values to a stream. Unidirectional operators have a single media
765	   input, which is connected to the media stream from one object, and a
766	   single media output, which is connected to the media stream of a
767	   different object.

769	   Bidirectional operators have two media inputs and two media outputs.
770	   One media input and output is associated with the stream to one
771	   object and the other input and output is associated with a stream to
772	   a different object. Bidirectional objects may treat the media
773	   differently in each direction. For example, an operator could be
774	   defined which changed the media sent to a connection based upon
775	   recognized speech or DTMF received from the connection. Operators are
776	   implicitly instantiated when streams are created or modified using
777	   the elements <join> element and elements <modifystream> respectively.

779	   The relationships between the different object classes is shown in
780	   the figure below.

782	                                 (MSML)

784	                   +--------------------------------------+
785	                   |           Media Server               |
786	                   |                                      |
787	                   |------+                      ,---.    |
788	                   |      |      +------+       /     \   |
789	        <== RTP ==>| conn |<---->| oper |<---->( conf  )  |
790	                   |      |      +------+       \     /   |
791	                   |------+                      `---'    |
792	                   |   ^                           ^      |
793	                   |   |                           |      |
794	                   |   |   +------+    +------+    |      |
795	                   |   |   |      |    |      |    |      |
796	                   |   +-->|dialog|    |dialog|<---+      |
797	                   |       |      |    |      |           |
798	                   |       +------+    +------+           |
799	                   +--------------------------------------+

801	   A single, full-duplex instance of each object class is shown together
802	   with common relationships between them. An operator (such as gain) is
803	   shown between a connection and a conference and dialogs are shown
804	   participating both with an individual connection and with a
805	   conference. The figure is not meant to imply only one to one
806	   relationships. Conferences will often have hundreds of participants,
807	   and either connections or conferences may be interacting with more
808	   than one dialog. For example, one dialog may be recording a
809	   conference while other dialogs announce participants joining or
810	   leaving the conference.

812	7.2 Identifiers

814	   Objects are referenced using identifiers that are composed of one or
815	   more terms. Each term specifies an object class and names a specific
816	   instance within that class. The object class and instance are
817	   separated by a colon ":" in an identifier term.

819	   Identifiers are assigned to objects when they are first created. In
820	   general, either the MSML client or a media server may specify the
821	   instance name for an object. Objects for which a client does not
822	   assign an instance name will be assigned one by a media server. Media
823	   server assigned instance names are returned to the client as a
824	   complete object identifier in the response to the request that
825	   created the object.

827	   It is meaningful for some classes of objects to exist independently
828	   on a media server. Network connections may be created through SIP at
829	   any time. MSML can then be used to associate their media with other
830	   objects as required to create services. Conferences may be created
831	                                 (MSML)

833	   and have specific resources reserved waiting for participant
834	   connections.

836	   Objects from these two classes, connections and conferences, are
837	   considered independent objects since they can exist on a standalone
838	   basis. Identifiers for independent objects consist of single term as
839	   defined above. For example, identifiers for a conference and
840	   connection could be "conf:abc" or "conn:1234" respectively. Clients
841	   which choose to assign instance names to independent objects must use
842	   globally unique instance names. One way to create globally unique
843	   names is to include the domain name of the client as part of the
844	   name.

846	   Dialogs are created to provide a service to independent objects.
847	   Dialogs may act as a participant in a conference or interact with a
848	   connection similar to a two participant call. Dialogs depend upon the
849	   existence of independent objects and this is reflected in the
850	   composition of their identifiers. Operators modify the media flow
851	   between other objects, such as application of gain between a
852	   connection and a conference. As operators are merely media transform
853	   primitives defined as properties of the media stream, they are not
854	   represented by identifiers and created implicitly.

856	   Identifiers for dialogs are composed of a structured list of slash
857	   ('/') separated terms. The left-most term of the identifier must
858	   specify a conference or connection. This serves as the root for the
859	   identifier. An example of an identifier for a dialog acting as a
860	   conference participant could be:

862	         conf:abc/dialog:recorder

864	   All objects except connections are created using MSML. Connections
865	   are created when media sessions get established through SIP. There
866	   are several options clients and media servers can use to establish a
867	   shared instance name for a connection and its media streams.

869	   When media servers support multiple media types, the instance name
870	   SHOULD be a call identifier that can be used to identify the
871	   collection of RTP sessions associated with a call. When MSML is used
872	   in conjunction with SIP and third party call control, the call
873	   identifier MUST be the same as the local tag assigned by the media
874	   server to identify the SIP dialog. This will be the tag the media
875	   server adds to the "To" header in its response to an initial invite
876	   transaction. RFC 3261 requires the tag values to be globally unique.

878	   An example of a connection identifier is: conn:74jgd63956ts.

880	                                 (MSML)

882	   With third party call control, the MSML client acts as a back to back
883	   user agent (B2BUA) to establish the media sessions. SIP dialogs are
884	   established between the client and the media server allowing the use
885	   of the media server local tag as a connection identifier. If third
886	   party call control is not used, a SIP event package MAY be used to
887	   allow a media server to notify new sessions to a client that has
888	   subscribed to this information.

890	   Identifiers as described above allow every object in a media server
891	   to be uniquely addressed. They can also be used to refer to multiple
892	   objects. There are two ways in which this can currently be done:

894	         wildcards

896	         common instance names

898	   An identifier can reference multiple objects when a wildcard is used
899	   as an instance name. MSML reserves the instance name comprised of a
900	   single asterisk ('*') to mean all objects that have the same
901	   identifier root and class. Instance names containing an asterisk
902	   cannot be created. Wildcards MUST only be used as the right most term
903	   of an identifier and MUST NOT be used as part of the root for dialog
904	   identifiers. Wildcards are only allowed where explicitly indicated
905	   below.

907	   The following are examples of valid wildcards:

909	         conf:abc/dialog:*

911	         conn:*

913	   Examples of illegal wildcard usage are:

915	         conf:*/dialog:73849

917	   Although identifiers share a common syntax, MSML elements restrict
918	   the class of objects which are valid in a given context. As an
919	   example, although it is valid to join two connections together, it is
920	   not valid to join two IVR dialogs.

922	8. MSML Core Package

924	   This section describes the core MSML package which MUST be supported
925	   in order to use any other MSML packages. The core MSML package
926	   defines a framework, without explicit functionality, over which
927	   functional packages are used.

929	                                 (MSML)

931	8.1 <msml>

933	   <msml> is the root element. When received by a media server, it
934	   defines the set of operations that form a single MSML request.
935	   Operations are requested by the contents of the element. Each
936	   operation MAY appear zero or more times as children of <msml>.
937	   Specific operations are defined within the Conference package and in
938	   the set of Dialog packages.

940	   The results of a request or the contents of events sent by a media
941	   server are also enclosed within the <msml> element. The results of
942	   the transaction are included as a body in the response to the SIP
943	   request that contained the transaction. This response will contain
944	   any identifiers that the media server assigned to newly created
945	   objects. All messages that a media server generates are correlated to
946	   an object identifier. Objects and identifiers are discussed in
947	   section 7 (Media Server Object Model).

949	   Attributes:

951	         version: "1.1" Mandatory

953	8.2 <send>

955	   Events are used to affect the behavior of different objects within a
956	   media server. The <send> element is used to send an event to the
957	   specified recipient within the Media Server.

959	   Attributes:

961	         event: the name of an event. Mandatory.

963	         target: an object identifier. When the identifier is for a
964	         dialog, it may optionally be appended with a slash "/" followed
965	         by the target to be included in a MSML Dialog <send>.
966	         Mandatory.

968	         valuelist: a list of zero or more parameters that are included
969	         with the event.

971	         mark: a token that can be used to identify execution progress
972	         in the case of errors. The value of the mark attribute from the
973	         last successfully executed MSML element is returned in an error
974	         response. Therefore the value of all mark attributes within an
975	         MSML document should be unique.

977	                                 (MSML)

979	8.3 <result>

981	   The <result> element is used to report the results of an MSML
982	   transaction. It is included as a body in the final response to the
983	   SIP request which initiated the transaction. An optional child
984	   element <description> may include text which expands on the meaning
985	   of error responses. Response codes are defined in section 11
986	   (Response Codes).

988	   attributes:

990	         response: a numeric code indicating the overall success or
991	         failure of the transaction, and in the case of failure, an
992	         indication of the reason. Mandatory.

994	         mark: in the case of an error, the value of the mark attribute
995	         from the last successfully executed element that included the
996	         mark attribute.

998	   In the case of failure, a description of the reason SHOULD be
999	   provided using the child element <description>.

1001	   Three other child elements allow the response to include identifiers
1002	   for objects created by the request but which did not have instance
1003	   names specified by the client. Those elements are <confid> and
1004	   <dialogid>, for objects created though a <createconference> and
1005	   <dialogstart> respectively.

1007	8.4 <event>

1009	   The <event> element is used to notify an event to a media server
1010	   client. Three types of events are defined by MSML Core package;
1011	   "msml.dialog.exit", "msml.conf.nomedia", and "msml.conf.asn". These
1012	   correspond to the termination of an executing dialog, a conference
1013	   being automatically deleted when the last participant has left, and
1014	   the notification of the current set of active speakers for a
1015	   conference, respectively. Events may also be generated by an
1016	   executing dialog. In this case the event type is specified by the
1017	   dialog. (see MSML Dialog Core Package <send>).

1019	   attributes:

1021	         name: the type of event. If the event is generated because of
1022	         the execution MSML Dialog <send>, the value MUST be the value
1023	         of the "event" attribute from the <send> element within the
1024	         MSML Dialog Core package. If the event is generated because of
1025	         the execution of an <exit>, the value MUST be "moml.exit". If
1026	         the event is generated because of the execution of a
1027	                                 (MSML)

1029	         <disconnect>, the value MUST be "moml.disconnect". If the event
1030	         is generated because of an error, the value must be
1031	         "moml.error". Mandatory.

1033	         id: the identifier of the conference or dialog that generated
1034	         the event or caused the event to be generated. Mandatory.

1036	         <event> has two children, <name> and <value>, which contain the
1037	         name and value respectively of each namelist item associated
1038	         with the event.

1040	9. MSML Conference Core Package

1042	9.1 Conferences

1044	   A conference has a mixer for each type of media that the conference
1045	   supports. Each mix has a corresponding description that defines how
1046	   the media from participants contributes to that mix. A mixer has
1047	   multiple inputs that are combined in a media specific way to create a
1048	   single logical output.

1050	   The elements that describe the mix for each media type are called
1051	   mixer description elements. They are:

1053	   <audiomix> defines the parameters for mixing audio media.

1055	   <videolayout> defines the composition of a video window.

1057	   These elements, defined in sections 9.6 (Audio Mix) and 9.7 (Video
1058	   Layout) respectively, are used as content of the <createconference>
1059	   element to establish the initial properties of a conference. The
1060	   elements are used within the <modifyconference> element to change the
1061	   properties of a conference once it has been created, or within the
1062	   <destroyconference> element to remove individual mixes from the
1063	   conference.

1065	   Conferences may be terminated by an MSML client using the
1066	   <destroyconference> element to remove the entire conference or by
1067	   removing the last mixer(s) associated with the conference.
1068	   Conferences can also be terminated automatically by a media server
1069	   based on criteria specified when the conference is created. When the
1070	   conference is deleted, any remaining participants will have their
1071	   associated SIP dialogs left unchanged or deleted based on the value
1072	   of the "term" attribute specified when the conference was created.

1074	                                 (MSML)

1076	9.2 Media Streams

1078	   Objects have at least one media input and output for each type of
1079	   media that they support. Each object class defines the number of
1080	   inputs and outputs objects of that class support. Media streams are
1081	   created when objects are joined, either explicitly using <join>, or
1082	   implicitly when dialogs are created using <dialogstart>. Dialog
1083	   creation has two stages, allocating and configuring the resources
1084	   required for the dialog instance, and implicitly joining those
1085	   resources to the dialog target during the dialog execution. Refer to
1086	   MSML Dialog Base package.

1088	   A join operation by default creates a bidirectional audio stream
1089	   between two objects. Video and unidirectional streams may also be
1090	   created. A media stream is created by connecting the output from one
1091	   object to the input of another object and vice versa (assuming a
1092	   bidirectional or full-duplex join).

1094	   Many objects may only support a single input for each type of media.
1095	   Within this specification, only the conference object class supports
1096	   an arbitrary number of inputs. When a stream is requested to be
1097	   created to an object that already has a stream of the same type
1098	   connected to its single input, the result of the request depends upon
1099	   the type of the media stream.

1101	   Audio mixing is done by summing audio signals. Automatically mixing
1102	   audio streams has common and straight forward applications. For
1103	   example, the ability to bridge two streams allows for the easy
1104	   creation of simple three-way calls or to bridge private announcements
1105	   with a [whispered] conference mix for an individual participant. In
1106	   the case of general conferences however, an MSML client SHOULD create
1107	   an audio conference and then join participants to the conference.
1108	   Conference mixers SHOULD subtract the audio of each participant from
1109	   the mix so that they do not hear themselves.

1111	   A media server that receives a request that requires joining an audio
1112	   stream to the single audio input of an object that already has an
1113	   audio stream connected, SHOULD automatically bridge the new stream
1114	   with the existing stream, creating a mix of the two audio streams.
1115	   The maximum number of streams that may be bridged in this manner is
1116	   implementation-specific. It is RECOMMENDED that a media server
1117	   support bridging at least two streams. A media server that cannot
1118	   bridge a new stream with any existing streams MUST fail the operation
1119	   requesting the join.

1121	   Unlike audio mixing, there are many different ways that two video
1122	   streams may be combined and presented. For example, they may be
1123	   presented side by side in separate panes, picture in picture, or in a
1124	                                 (MSML)

1126	   single pane which displays only a single stream at a time based on a
1127	   heuristic such as active speaker. Each of these options creates a
1128	   very different presentation and require significantly different media
1129	   resources.

1131	   A join operation does not describe how a new stream can be combined
1132	   with an existing stream. Therefore automatic bridging of video is not
1133	   supported. A media server MUST fail requests to join a new video
1134	   stream to an object that only supports a single video input and
1135	   already has a video stream connected to that input. For an object to
1136	   have multiple video streams joined to it, the object itself must be
1137	   capable in supporting multiple video streams. Conference objects can
1138	   support multiple video streams and provide a way to specify the
1139	   mixing presentation for the video streams.

1141	   A media server MUST NOT establish any streams unless the media server
1142	   is able to create all the streams requested by an operation. Streams
1143	   are only able to be created if both objects support a media type and
1144	   at least one of the following conditions is true:

1146	      1. each object that is to receive media is not already receiving a
1147	         stream of that type.

1149	      2. any object that is to receive media and is already receiving a
1150	         stream of that type supports receiving an additional stream of
1151	         that type. The only class of objects defined in this
1152	         specification that directly support receiving multiple streams
1153	         of the same type are conferences.

1155	      3. the media server is able to automatically bridge media streams
1156	         for an object that is to receive media and that is already
1157	         receiving a stream of the requested type. The only type of
1158	         media defined in this specification that MAY be automatically
1159	         bridged is audio.

1161	   The directionality of media streams associated with a connection are
1162	   modeled independently from what SDP [18] allows for the corresponding
1163	   RTP [15] sessions. Media servers MUST respect the SDP in what they
1164	   actually transmit but MUST NOT allow the SDP to affect the
1165	   directionality when joining streams internal to the media server.

1167	9.3 <createconference>

1169	   <createconference> is used to allocate and configure the media mixing
1170	   resources for conferences. A description of the properties for each
1171	   type of media mix required for the conference is defined within the
1172	   content of the <createconference> element. Mixer descriptions are
1173	   described in Audio Mix and Video Layout sections. When no mixer
1174	                                 (MSML)

1176	   descriptions are specified, the default behavior MUST be equivalent
1177	   to inclusion of a single <audiomix>.

1179	   Clients can request that a media server automatically delete a
1180	   conference when a specified condition occurs by using the
1181	   "deletewhen" attribute. A value of "nomedia" indicates that the
1182	   conference MUST be deleted when no participants remain into the
1183	   conference. When this occurs, an "msml.conf.nomedia" event MUST be
1184	   notified to the MSML client. A value of "nocontrol" indicates the
1185	   conference MUST be deleted when the SIP [1] dialog that carries the
1186	   <createconference> element is terminated. When this occurs, a media
1187	   server MUST terminate all participant dialogs by sending a BYE for
1188	   their associated SIP dialog. A value of "never" MUST leave the
1189	   ability to delete a conference under the control of the MSML client.

1191	   attributes:

1193	         name: the instance name of the conference. If the attribute is
1194	         not present, the media server MUST assign a globally unique
1195	         name for the conference. If the attribute is present but the
1196	         name is already in use, an error (432) will result and MSML
1197	         document execution MUST stop. Events which the conference
1198	         generates use this name as the value of their "id" attribute
1199	         (see section 5.6.2 (<event>)).

1201	         deletewhen: defines whether a media server should automatically
1202	         delete the conference. Possible values are "nomedia",
1203	         "nocontrol", and "never". Default is "nomedia".

1205	         term: when true, the media server MUST send a BYE request on
1206	         all SIP dialogs still associated with the conference when the
1207	         conference is deleted. Setting term equal to false allows
1208	         clients to start dialogs on connections once the conference has
1209	         completed. Default true.

1211	         mark: a token which MAY be used to identify execution progress
1212	         in the case of errors. The value of the mark attribute from the
1213	         last successfully executed MSML element is returned in an error
1214	         response. Therefore the value of all mark attributes within an
1215	         MSML document should be unique.

1217	   An example of creating an audio conference is shown below. This
1218	   conference allows at most two participants to contend to be heard and
1219	   reports the set of active speakers no more frequently than every ten
1220	   seconds.

1222	            <?xml version="1.0" encoding="UTF-8"?>
1223	                                 (MSML)

1225	            <msml version="1.1">
1226	               <createconference name="example">
1227	                  <audiomix>
1228	                     <n-loudest n="3"/>
1229	                     <asn ri="10s"/>
1230	                  </audiomix>
1231	               </createconference>
1232	            </msml>

1234	9.3.1 <reserve>

1236	   Conference resources may be reserved by including the <reserve>
1237	   element as a child of <createconference>. <reserve> allows the
1238	   specification of a set of resources which a media server will reserve
1239	   for the conference. Any requests for resources beyond those that have
1240	   been reserved should be honored on a best-effort basis by a media
1241	   server.

1243	   attributes:

1245	         required: boolean that specifies whether <createconference>
1246	         should fail if the requested resources are not available. When
1247	         set to false, the conference will be created, with no reserved
1248	         resources, if the complete reservation cannot be honored.
1249	         Default true.

1251	9.3.1.1 <resource>

1253	   The resources to be reserved are defined using <resource>. The
1254	   contents of these elements describe a resource that is to be
1255	   reserved. Descriptions are implementation-dependent. Media servers
1256	   that support MSML Dialogs may use the elements from that package as
1257	   the basis for resource descriptions. Each resource element may use
1258	   the attribute "n" to define the quantity of the resource to reserve.

1260	   For example, the following creates a conference and reserves two
1261	   types of resources. One resource element may represent resources that
1262	   are shared by all participants of the conference while the other may
1263	   represent resources that are reserved for each of the expected
1264	   participants.

1266	   attributes:

1268	                                 (MSML)

1270	         n: number of resources to be reserved. Default 1.

1272	         type: specifies whether the resource is to be reserved by each
1273	         individual participant or reserved as a shared conference
1274	         resource. Valid values for this attribute are �individual� or
1275	         �shared�. Default �individual�.

1277	      <createconference>
1278	         <reserve>
1279	            <resource n="20">
1280	              <!--description of resources used by each participant-->
1281	            </resource>
1282	            <resource n="2" type=�shared�>
1283	              <!--description of the shared conference resources-->
1284	            </resource>
1285	         </reserve>
1286	      </createconference>

1288	9.4 <modifyconference>

1290	   All of the properties of an audio mix or the presentation of a video
1291	   mix may be changed during the life of a conference using the
1292	   <modifyconference> element. Changes to an audio mix are requested by
1293	   including an <audiomix> element as a child of <modifyconference>.
1294	   This may also be used to add an audio mixer to the conference if none
1295	   was previously allocated. Changes to a video presentation are
1296	   requested by including a <videolayout> element as a child of
1297	   <modifyconference>. Similar to an audio mixer, this may be used to
1298	   add a video mixer if none was previously allocated.

1300	   Mixers are removed by including a mixer description element within
1301	   <destroyconference/>.

1303	   Features and presentation aspects are enabled/added or modified by
1304	   including the element(s) that define the feature or presentation
1305	   aspect within a mixer description. The complete specification of the
1306	   element must be included just as it would be included when the
1307	   conference is created. The new definition completely replaces any
1308	   previous definition that existed. Only things that are defined by
1309	   elements included in the mixer descriptions are affected. Any
1310	   existing configuration aspects of a conference, which are not
1311	                                 (MSML)

1313	   specified within the <modifyconference/> element, MUST maintain their
1314	   current state in the Media Server.

1316	   For example, if an MSML client wanted to change the minimum reporting
1317	   interval for active speaker notification from that shown in the
1318	   Conference Examples section (<createconference>) it would send the
1319	   following to the media server:

1321	            <?xml version="1.0" encoding="UTF-8"?>
1322	            <msml version="1.1">
1323	               <modifyconference id="conf:example">
1324	                  <audiomix>
1325	                     <asn ri="4"/>
1326	                  </audiomix>
1327	               </modifyconference>
1328	            </msml>

1330	   This would also enable active speaker notification if it had not
1331	   previously been enabled. The N-loudest mixing is unaffected.

1333	   Multiple elements MAY be included in the mixer descriptions similar
1334	   to when conferences are created. For example, in a video conference,
1335	   the video mix description (<videolayout>) could specify that the
1336	   layout of the video being displayed should change such that the
1337	   regions currently displaying participants get smaller and new
1338	   region(s) are created to support additional participants. A media
1339	   server MUST make all of the requested changes or none of the
1340	   requested changes.

1342	   Additional examples of modifying conferences are presented in the
1343	   Conference Examples section.

1345	   attributes:

1347	         id: the identifier for a conference. Wildcards MUST NOT be
1348	         used. Mandatory.

1350	         mark: a token which can be used to identify execution progress
1351	         in the case of errors. The value of the mark attribute from the
1352	         last successfully executed MSML element is returned in an error
1353	         response. Therefore the value of all "mark" attributes within
1354	         an MSML document SHOULD be unique.

1356	                                 (MSML)

1358	9.5 <destroyconference>

1360	   Destroy conference is used to delete mixers or to delete the entire
1361	   conference and all state and shared resources. When a mixer is
1362	   removed, all of the streams joined to that mixer are unjoined. When a
1363	   conference is destroyed, SIP dialogs for any remaining participants
1364	   MUST be maintained or removed based on the value of the "term"
1365	   attribute when the conference was created.

1367	   When there is no element content, <destroyconference/> deletes the
1368	   entire conference. Individual mixer(s) are removed by including a
1369	   mixer description element identifying the mix(es) to be removed as
1370	   content to <destroyconference/>. <audiomix/> is used remove audio
1371	   mixers and <videolayout/> is used remove video mixers. When one or
1372	   more mixer descriptions are specified, then Media Server MUST only
1373	   delete the specified mixer and MUST NOT affect any other existing
1374	   mixers. When <audiomix/> or <videolayout/> are identified for
1375	   individual removal, other feature aspects of the mix MUST NOT be
1376	   included. If specified, the Media Server MUST ignore any such
1377	   elements. When the last mixer is removed from a conference, a media
1378	   server MUST remove all conference state, leaving or removing any
1379	   remaining SIP dialogs as described above.

1381	   attributes:

1383	         id: the identifier for a conference. Mandatory.

1385	         mark: a token which can be used to identify execution progress
1386	         in the case of errors. The value of the mark attribute from the
1387	         last successfully executed MSML element is returned in an error
1388	         response. Therefore the value of all "mark" attributes within
1389	         an MSML document SHOULD be unique.

1391	9.6 <audiomix>

1393	   The properties of the overall audio mix are specified using the
1394	   <audiomix> element.

1396	   Attributes:

1398	         id: an optional identifier for the audio mix.

1400	   An example of the description for an audio mix is:

1402	      <audiomix id="mix1">
1403	         <asn ri="10s"/>
1404	         <n-loudest n="3">
1405	                                 (MSML)

1407	      </audiomix>

1409	9.6.1 <n-loudest>

1411	   The <n-loudest> element defines that participants contend to be
1412	   included in the conference mix based upon their audio energy. When
1413	   the element is not present, all participants are mixed.

1415	   Attributes:

1417	         n: the number of participants that will be included in the
1418	         audio mix based upon having the greatest audio energy.

1420	9.6.2 <asn>

1422	   The <asn> element enables notification of active speakers. Active
1423	   speakers MUST be notified using the <event> element with an event
1424	   name of "msml.conf.asn". The namelist of the event consists of the
1425	   set of active speakers. The name of each item is the string "speaker"
1426	   with a value of the connection identifier for the connection.

1428	   Attributes:

1430	         ri: the minimum reporting interval defines the minimum duration
1431	         of time which must pass before changes to active speakers will
1432	         be reported. A value of zero disables active speaker
1433	         notification.

1435	   An example of an active speaker notification is:

1437	      <event name="msml.conf.asn" id="conf:example">
1438	         <name>speaker</name>
1439	         <value>conn:hd93tg5hdf</value>
1440	         <name>speaker</name>
1441	         <value>conn:w8cn59vei7</value>
1442	         <name>speaker</name>
1443	         <value>conn:p78fnh6sek47fg</value>
1444	      </event>
1445	                                 (MSML)

1447	9.7 <videolayout>

1449	   A video layout is specified using the <videolayout> element. It is
1450	   used as a container to hold elements that describe all of the
1451	   properties of a video mix. The parameters of the window that displays
1452	   the video mix are defined by the <root> element. When the video mix
1453	   in composed of multiple panes, the location and characteristics of
1454	   the panes are defined by one or more <region> elements. A <region>
1455	   element is not required when only a single video stream is displayed
1456	   at one time and none of the visual attributes of regions are
1457	   required.

1459	   Some regions may be used to display a video stream based on a
1460	   selection criteria rather than having a video stream of a single
1461	   participant continuously presented in the region. One such an example
1462	   is a distance learning lecture where the instructor sees each of the
1463	   students periodically displayed in a region. When a region is used to
1464	   display one of a number of streams, it is placed as a child of a
1465	   <selector> element.

1467	   Attributes:

1469	         type: specifies the language used to define the layout. Layouts
1470	         defined using MSML MUST use the value "text/msml-basic-layout".
1471	         This is the same convention as defined for the layout package
1472	         from the W3C SMIL 2.0 specification [19]. The default when
1473	         omitted is "text/msml-basic-layout".

1475	         id: an optional identifier for the video layout.

1477	9.7.1 <root>

1479	   The <root> element describes the root window or virtual screen in
1480	   which the conference video mix will be displayed. Simple conferences
1481	   can display participant video directly within the root window but
1482	   more complex conferences will use regions for this purpose. Areas of
1483	   the window which are not used to display video will show the root
1484	   window background.

1486	   All video presentations require a root window. It MUST be present
1487	   when a video mix is created and it cannot be deleted, however its
1488	   attributes MAY be changed using the <modifyconference> element.

1490	   Attributes:

1492	         size: the size of the root window specified as one of the five
1493	         standard common intermediate formats (e.g. CIF, QCIF, etc.).

1495	                                 (MSML)

1497	         backgroundcolor: the color for the root window background
1498	         defined using the values for the "background-color" property of
1499	         the CSS2 specification [20].

1501	         backgroundimage: the URI for an image to be displayed as the
1502	         root window background. Transparent portions of the image allow
1503	         the background color to show through.

1505	9.7.2 <region>

1507	   <region> elements define video panes that are used to display
1508	   participant video streams. Regions are rendered on top of the root
1509	   window.

1511	   The size of a region is specified relative to the size of the root
1512	   window using the "relativesize" attribute. Relative sizes are
1513	   expressed as fractions (e.g. 1/4, 1/3) that preserve the aspect ratio
1514	   of the original video stream while allowing for efficient scaling
1515	   implementations.

1517	   Regions are located on the root window based on the value of the
1518	   position attributes "top" and "left". These attributes define the
1519	   position of the top left corner of the region as an offset from the
1520	   top left corner of the root window. Their values may be expressed
1521	   either as a number of pixels or as a percent of the vertical or
1522	   horizontal dimension of the root window. Percent values are appended
1523	   with a percent ('%') character. Percent values of "33%" and "67%"
1524	   should be interpreted as "1/3" and "2/3" to allow easy alignment of
1525	   regions whose size is expressed relative to the size of the root
1526	   window.

1528	   An example of a video layout with six regions is:

1530	         +-------+---+
1531	         |       | 2 |
1532	         |   1   +---+
1533	         |       | 3 |
1534	         +---+---+---+
1535	         | 6 | 5 | 4 |
1536	         +---+---+---+

1538	      <videolayout type="text/msml-basic-layout">
1539	         <root size="CIF"/>
1540	         <region id="1" left="0" top="0" size="2/3"/>
1541	         <region id="2" left="67%" top="0" size="1/3"/>
1542	                                 (MSML)

1544	         <region id="3" left="67%" top="33%" size="1/3">
1545	         <region id="4" left="67%" top="67%" size="1/3"/>
1546	         <region id="5" left="33%" top="67%" size="1/3"/>
1547	         <region id="6" left="0" top="67%" size="1/3"/>
1548	      </videolayout>

1550	   The area of the root window covered by a region is a function of the
1551	   region's position and its size. When areas of different regions
1552	   overlap, they are layered in order of their "priority" attribute. The
1553	   region with the highest value for the "priority" attribute is below
1554	   all other regions and will be hidden by overlapping regions. The
1555	   region with the lowest non-zero value for the "priority" attribute is
1556	   on top of all other regions and will not be hidden by overlapping
1557	   regions. The priority attribute may be assigned values between 0 and
1558	   1. A value of zero disables the region, freeing any resources
1559	   associated with the region, and unjoining any video stream displayed
1560	   in the region.

1562	   Regions that do not specify a priority will be assigned a priority by
1563	   a media server when a conference is created. The first region within
1564	   the <videolayout> element that does not specify a priority will be
1565	   assigned a priority of one, the second a priority of two, etc. In
1566	   this way, all regions that do not explicitly specify a priority will
1567	   be underneath all regions that do specify a priority. As well, within
1568	   those regions that do not specify a priority, they will be layered
1569	   from top to bottom, in the order they appear within the <videolayout>
1570	   element.

1572	   For example, if a layout was specified as follows:

1574	      <videolayout>
1575	         <root size="CIF"/>
1576	         <region id="a" ... priority=".3" .../>
1577	         <region id="b" ... />
1578	         <region id="c" ... priority=".2" ...>
1579	         <region id="d" ... />
1580	      </videolayout>

1582	   Then the regions would be layered, from top to bottom, c,a,b,d.

1584	                                 (MSML)

1586	   Portions of regions that extend beyond the root window will be
1587	   cropped. For example, a layout specified as:

1589	      <videolayout>
1590	         <root size="CIF"/>
1591	         <region id="foo" left="50%" top="50%" size="2/3"/>
1592	      </videolayout>

1594	   would appear similar to:

1596	         +-----------+
1597	         |   root    |
1598	         |background |
1599	         |     +-----+--
1600	         |     |     |//
1601	         |     | foo |//
1602	         +-----+-----+//
1603	               |////////

1605	   Visual attributes are used to define aspects of the visual appearance
1606	   of individual regions. A border may be defined together with a title
1607	   and/or logo. Text and logos are displayed as images on top of the
1608	   region's video, below all regions with a lower priority. The visual
1609	   attributes are "title", "titletextcolor", "titlebackgroundcolor",
1610	   "bordercolor", "borderwidth", and "logo".

1612	   Visual attributes can also be defined for individual streams (Video
1613	   Stream Properties). When visual attributes are specified as part of
1614	   both a region and a stream, those associated with the stream MUST
1615	   take precedence. This allows streams that are chosen for display
1616	   automatically (Stream Selection) to have proper text and logos
1617	   displayed. The region visual attributes are displayed when no stream
1618	   is associated with the region.

1620	   Two other attributes associated with a region, "blank" and "freeze",
1621	   define the state of the video displayed in the region. When the blank
1622	   or freeze attribute is assigned the value "true", then the Media
1623	   Server MUST display the region either as a blank region, or the video
1624	   image frozen at the last received frame.

1626	   Open Issue: these attributes are specified for a region and not
1627	   allowed for streams because that appears to be the common use case.

1629	                                 (MSML)

1631	   Applying them to streams would allow only that stream to be affected
1632	   within a selector while other streams continue to display normally.
1633	   Except for personal mixing scenarios, the same effect can be achieved
1634	   by having the participant mute their own transmission to the media
1635	   server.

1637	   Attributes associated with each region are:

1639	         id: a name that can be used to refer to the region.

1641	         left: the position of the region from the left side of the root
1642	         window.

1644	         top: the position of the region from the top of the root
1645	         window.

1647	         relativesize: the size of the region expressed as a fraction of
1648	         the root window size.

1650	         priority: a number between 0 and 1 that is used to define the
1651	         precedence when rendering overlapping regions. A value of zero
1652	         disables the region.

1654	         title: text to be displayed as the title for the region

1656	         titletextcolor: the color of the text

1658	         titlebackgroundcolor: the color of the text background

1660	         bordercolor: the color of the region border

1662	         borderwidth: the width of the region border

1664	         logo: the URI of an image file to be displayed

1666	         freeze: a boolean value, with a default of false, that defines
1667	         whether the video image should be frozen at the currently
1668	         displayed frame

1670	         blank: a boolean value, with a default of false, that defines
1671	         whether the region should display black instead of the
1672	         associated video stream

1674	9.7.3 <selector>

1676	   It is often desired that one of several video streams be
1677	   automatically selected to be displayed. The <selector> element is
1678	   used to define the selection criteria and its associated parameters.

1680	                                 (MSML)

1682	   The selection algorithm is specified by the "method" attribute.
1683	   Currently defined selection methods allow for voice activated
1684	   switching and to iterate sequentially through the set of associated
1685	   video streams.

1687	   The regions that will display the selected video stream are placed as
1688	   child elements of the <selector> element. Including regions within a
1689	   <selector> element does not affect their layout with respect to
1690	   regions not subject to the selection. For simple video conferences
1691	   that display the video directly in the root window, the <root>
1692	   element can be placed as a child of <selector>. Region elements MUST
1693	   NOT be used in this case.

1695	   For example, below is a common video layout that allows the video
1696	   stream from the currently active speaker to be displayed in the large
1697	   region ("1") at the top left of the layout while the streams from
1698	   five other participants are displayed in regions located at the
1699	   layout periphery.

1701	         +-------+---+
1702	         |       | 2 |
1703	         |   1   +---+
1704	         |       | 3 |
1705	         +---+---+---+
1706	         | 6 | 5 | 4 |
1707	         +---+---+---+

1709	      <videolayout type="text/msml-basic-layout">
1710	         <root size="CIF"/>
1711	         <selector id="switch" method="vas">
1712	            <region id="1" left="0" top="0" size="2/3"/>
1713	         </selector>
1714	         <region id="2" left="67%" top="0" size="1/3"/>
1715	         <region id="3" left="67%" top="33%" size="1/3">
1716	         <region id="4" left="67%" top="67%" size="1/3"/>
1717	         <region id="5" left="33%" top="67%" size="1/3"/>
1718	         <region id="6" left="0" top="67%" size="1/3"/>
1719	      </videolayout>
1720	                                 (MSML)

1722	   All selector methods must be defined so that they work if only a
1723	   single region is a child of the selector. Selector methods that
1724	   support more than one child region MUST specify how the method works
1725	   across multiple regions. Media server implementations MAY support
1726	   only a single region for methods that are defined to allow multiple
1727	   regions.

1729	   The selector or region for a participant's video is defined using the
1730	   "display" attribute of <stream> during a join operation. Specifying a
1731	   selector allows the stream to be displayed according to the criteria
1732	   defined by the selector method. Specifying a region supports
1733	   continuous presence display of participants. Some streams may be
1734	   joined with both a selector and a region. In this case, the value of
1735	   <blankothers> attribute defines whether the streams associated with a
1736	   continuous presence region should be blanked when the stream is
1737	   selected for display in one of the selector regions.

1739	   Attributes common to all selector methods are:

1741	         id: a name that can be used to refer to the selector.

1743	         method: the name of the method used to select the video stream.

1745	         status: specifies whether the selector is "active" or
1746	         "disabled".

1748	         blankothers: when "true", video streams that are also displayed
1749	         in continuous presence regions will have the continuous
1750	         presence regions blanked when the stream is displayed in a
1751	         selection region.

1753	9.7.3.1 <vas> Voice Activate Switching

1755	   Voice activated switching (VAS) is used to display the video stream
1756	   that correlates with the participant who is currently speaking. It is
1757	   specified using a selector method value of "vas".

1759	   If the video stream associated with the active speaker is not
1760	   currently displayed in a selection region, then it replaces the video
1761	   in the region that is displaying the video of the speaker that was
1762	   least recently active. If the video of the active speaker is
1763	   currently displayed in a selection region, then there is no change to
1764	   any region. When VAS is applied to a single region, this has the
1765	   effect that the current speaker is displayed in that region.

1767	   Attributes associated with voice activated switching are:

1769	                                 (MSML)

1771	         si: switching interval is the minimum period of time that must
1772	         elapse before allowing the video to switch to the active
1773	         speaker.

1775	         speakersees: defines whether the active speaker sees the
1776	         "current" speaker (themselves) or the "previous" speaker.

1778	9.8 <join>

1780	   <join> is used to create one or more streams between two independent
1781	   objects. Streams may be audio or video and may be bidirectional or
1782	   unidirectional. A bidirectional stream is implicitly composed of two
1783	   unidirectional streams that can be manipulated independently. The
1784	   streams to be established are specified by <stream> elements (section
1785	   <stream>) as the content of <join>.

1787	   Without any content, <join> by default establishes a bidirectional
1788	   audio stream. When only a stream of a single type has previously been
1789	   created between two objects, or when only a unidirectional stream
1790	   exists, <join> can be used to add a stream of another media type or
1791	   make the stream bidirectional by including the necessary <stream>
1792	   elements. Bidirectional streams are made unidirectional by using
1793	   <unjoin> (section <unjoin>) to remove the unidirectional stream for
1794	   the direction that is no longer required.

1796	   In addition to defining the media type and direction of streams,
1797	   <stream> elements are also used to establish the properties of
1798	   streams, such as gain, voice masking, or tone clamping of audio
1799	   streams, or labels and other visual characteristics of video streams.
1800	   Properties are often defined asymmetrically for a single direction of
1801	   a stream. Creating a bidirectional stream requires two <stream>
1802	   elements within the <join>, one for each direction, if one direction
1803	   is to have different properties from the other direction.

1805	   If a media server can provide services using both compressed or
1806	   uncompressed media, the MSML client may need to distinguish within
1807	   requests which format is to be used. When compressed streams are
1808	   created, both objects must use the same media format or an error
1809	   response (450) is generated.

1811	   attributes:

1813	         id1: an identifier of either a connection or conference.
1814	         Wildcards MUST NOT be used. Any other object class results in a
1815	         440 error.

1817	                                 (MSML)

1819	         id2: an identifier of either a connection or conference.
1820	         Wildcards MUST NOT be used. Any other object class results in a
1821	         440 error.

1823	         mark: a token which can be used to identify execution progress
1824	         in the case of errors. The value of the mark attribute from the
1825	         last successfully executed MSML element is returned in an error
1826	         response. Therefore the value of all mark attributes within an
1827	         MSML document SHOULD be unique.

1829	   For example, consider a call center coaching scenario where a
1830	   supervisor can listen to the conversation between an agent and a
1831	   customer, and provide hints to the agent, which are not heard by the
1832	   customer. One join establishes a stream between the agent and the
1833	   customer and another join establishes a stream between the agent and
1834	   the supervisor. A third join is used to establish a half-duplex
1835	   stream from the customer to the supervisor. The media server
1836	   automatically bridges the media streams from the customer and the
1837	   supervisor for the agent, and from the customer and the agent for the
1838	   supervisor.

1840	   Assuming the following connections, each with a single audio stream:

1842	         conn:supervisor

1844	         conn:agent

1846	         conn:customer

1848	   The following would create the media flows previously described:

1850	      <?xml version="1.0" encoding="UTF-8"?>
1851	      <msml version="1.1">
1852	         <join id1="conn:supervisor" id2="conn:agent"/>
1853	         <join id1="conn:agent" id2="conn:customer"/>
1854	         <join id1="conn:supervisor" id2="conn:customer">
1855	            <stream media="audio" dir="to-id1"/>
1856	         </join>
1857	      </msml>

1859	   The following example, shows joining a participant to a multimedia
1860	   conference. It assumes that the conference has a video presentation
1861	                                 (MSML)

1863	   region named "topright". The "display" attribute is explained in
1864	   section Video Stream Properties.

1866	      <?xml version="1.0" encoding="UTF-8"?>
1867	      <msml version="1.1">
1868	         <join id1="conn:hd83t5hf7g3" id2="conf:example">
1869	            <stream type="audio"/>
1870	            <stream type="video" dir="from-id1" display="topright"/>
1871	            <stream type="video" dir="to-id1"/>
1872	      </msml>

1874	9.9 <modifystream>

1876	   Media streams can have different properties such as the gain for an
1877	   audio stream or a visual label for a video stream. These properties
1878	   are specified as the content of <stream> elements (section <stream>).
1879	   <modifystream> is used to change the properties of a stream by
1880	   including one or more <stream> elements that are to have their
1881	   properties changed.

1883	   Stream properties MUST be set as specified by the element <stream> as
1884	   a child element of <modifystream> element. Any properties not
1885	   included in the <stream> element when modifying a stream MUST remain
1886	   unchanged. Setting a property for only one direction of a
1887	   bidirectional stream MUST NOT affect the other direction. The
1888	   directionality of streams can be changed using issuing an <unjoin>
1889	   followed by a <join>. Any streams that exist between the two objects
1890	   that are not included within <modifystream> MUST NOT be affected.

1892	   attributes:

1894	         id1: an identifier of either a conference or a connection. The
1895	         instance name MUST NOT contain a wildcard if "id2" contains a
1896	         wildcard. Mandatory.

1898	         id2: an identifier of either a conference or a connection. The
1899	         instance name MUST NOT contain a wildcard if "id1" contains a
1900	         wildcard. Mandatory.

1902	         mark: a token which can be used to identify execution progress
1903	         in the case of errors. The value of the mark attribute from the
1904	         last successfully executed MSML element is returned in an error
1905	         response. Therefore the value of all mark attributes within an
1906	         MSML document are RECOMMENDED to be unique.

1908	                                 (MSML)

1910	9.10 <unjoin>

1912	   Unjoin removes one or more media streams between two objects. In the
1913	   absence of any content in <stream> element, all media streams between
1914	   the objects MUST be removed. Individual streams may be removed by
1915	   specifying them using <stream> elements, while the unspecified
1916	   streams MUST NOT be removed. A bidirectional stream is changed to a
1917	   unidirectional stream by unjoining the direction that is no longer
1918	   required, using the <unjoin> element. Operator elements MUST NOT be
1919	   specified within <stream> elements when streams are being unjoined
1920	   using the <unjoin> element. Any specified stream operators MUST be
1921	   ignored.

1923	   <unjoin> and <join> may be used together to move a media stream, such
1924	   as from a main conference to a sidebar conference.

1926	   attributes:

1928	         id1: an identifier of either a conference or a connection. The
1929	         instance name MUST NOT contain a wildcard if "id2" contains a
1930	         wildcard. Mandatory.

1932	         id2: an identifier of either a conference or a connection. The
1933	         instance name MUST NOT contain a wildcard if "id1" contains a
1934	         wildcard. Mandatory.

1936	         mark: a token which can be used to identify execution progress
1937	         in the case of errors. The value of the mark attribute from the
1938	         last successfully executed MSML element is returned in an error
1939	         response. Therefore the value of all mark attributes within an
1940	         MSML document SHOULD be unique.

1942	   The following removes a participant from a conference and plays a
1943	   leave tone for the remaining participants in the conference.

1945	            <?xml version="1.0" encoding="UTF-8"?>
1946	            <msml version="1.1">
1947	               <unjoin id1="conn:jd73ht89sf489f" id2="conf:1"/>
1948	               <dialogstart target="conf:1" type="application/moml+xml">
1949	                  <play>
1950	                     <audio uri="file://leave_tone.wav"/>
1951	                  </play>
1952	               </dialogstart>
1953	            </msml>
1954	                                 (MSML)

1956	9.11 <monitor>

1958	   Monitor is a specialized unidirectional join that copies the media
1959	   that is destined for a connection object. One example of the use for
1960	   <monitor> may be quality monitoring within a conference. The media
1961	   stream may be removed using the <unjoin> element (see section
1962	   <unjoin>).

1964	   attributes:

1966	         id1: an identifier of the connection to be monitored. Any other
1967	         object class results in a 440 error. Wildcards MUST NOT be
1968	         used.

1970	         id2: an identifier of the object which is to receive the copy
1971	         of the media destined to id1. id2 may be a connection or a
1972	         conference. Any other object class results in a 440 error.
1973	         Wildcards MUST NOT be used.

1975	         compressed: "true" or "false". Specifies whether the join
1976	         should occur before or after compression. When "true", id2 must
1977	         be a connection using the same media format as id1 or an error
1978	         response (450) is generated. Default is "false.

1980	         mark: a token which can be used to identify execution progress
1981	         in the case of errors. The value of the mark attribute from the
1982	         last successfully executed MSML element is returned in an error
1983	         response. Therefore the value of all mark attributes within an
1984	         MSML document SHOULD be unique.

1986	9.12 <stream>

1988	   Individual streams are specified using the <stream> element. They MAY
1989	   be included as a child element in any of the stream manipulation
1990	   elements <join>, <modifystream>, or <unjoin>.

1992	   The type of the stream is specified using a "media" attribute that
1993	   uses values corresponding to the top-level MIME media types as
1994	   defined in RFC 2046 [21]. This specification only addresses audio and
1995	   video media. Other specifications may define procedures for
1996	   additional types.

1998	   A bidirectional stream is identified when no direction attribute
1999	   "dir" is present. A unidirectional stream is identified when a
2000	   direction attribute is present. The "dir" attribute MUST have a value
2001	   of "from-id1" or "to-id1" depending on the required direction. These
2002	                                 (MSML)

2004	   values are relative to the identifier attributes of the parent
2005	   element.

2007	   The compressed attribute is used to distinguish the compressed nature
2008	   of the stream when necessary. It is implementation specific what is
2009	   used when the attribute is not present. Joining compressed streams
2010	   acts much like an RTP [15] relay.

2012	   The properties of the media streams are specified as the content of
2013	   <stream> elements when the element is used as a child of <join> or
2014	   <modifystream>. Stream elements MUST NOT have any content when they
2015	   are used as a child of <unjoin> to identify specific streams to
2016	   remove.

2018	   Some properties are defined within MSML as additional attributes or
2019	   child elements of <stream> that are media type specific. Ones for
2020	   audio streams and video streams are defined in the following two sub-
2021	   sections. Operators, viewed as properties of the media stream, MAY be
2022	   specified as child elements of the <stream> element.

2024	   attributes:

2026	         media: "audio" or video". Mandatory

2028	         dir: "from-id1" or "to-id1".

2030	         compressed: "true" or "false". Specifies whether the stream
2031	         uses compressed media. Default is implementation specific.

2033	9.12.1 Audio Stream Properties

2035	   Audio mixes can be specified to only mix the N-loudest participants.
2036	   However there may be some "preferred" participants that are always
2037	   able to contribute. When audio streams are joined to a conference
2038	   that uses N-loudest audio mixing, preferred streams need to be
2039	   identified.

2041	   A preferred audio stream is identified using the "preferred"
2042	   attribute. The "preferred" attribute MAY be used for an audio stream
2043	   that is input to a conference and MUST NOT be used for other streams.

2045	   Additional attributes of the <stream> element for audio streams are:

2047	         preferred: a boolean value that defines whether the stream does
2048	         not contend for N-loudest mixing. A value of "true" means that
2049	         the stream MUST always be mixed while a value of "false" means
2050	         that the stream MAY contend for mixing into a conference when
2051	         N-loudest mixing is enabled. Default "false".

2053	                                 (MSML)

2055	   There are two elements that can be used to change the characteristics
2056	   of an audio stream as defined below.

2058	9.12.1.1 <gain>

2060	   The <gain> element may be used to adjust the volume of an audio media
2061	   stream. It may be set to a specific gain amount, to automatically
2062	   adjust the gain to a desired target level, or to mute the stream.

2064	   Attributes of the <gain> element are:

2066	         amt: a specific gain to apply specified in dB or the string
2067	         "mute" indicating that the stream should be muted. This
2068	         attribute MUST NOT be used if "agc" is present.

2070	         agc: boolean indicating whether automatic gain control is to be
2071	         used. This attribute MUST NOT be used if "amt" is present.

2073	         tgtlvl: the desired target level for AGC specified in dBm0.
2074	         This attribute MUST be specified if "agc" is set to "true".
2075	         This attribute MUST NOT be specified if "agc" is not present.

2077	         maxgain: the maximum gain that AGC may apply. Maxgain is
2078	         specified in dB. This attribute MUST be used if "agc" is
2079	         present and MUST NOT be used when "agc" is not present.

2081	9.12.1.2 <clamp>

2083	   The <clamp> element is used to filter tones and/or audio-band dtmf
2084	   from a media stream.

2086	   Attributes of the <clamp> element are:

2088	         dtmf: boolean indicating whether DTMF tones should be removed.

2090	         tone: boolean indicating whether other tones should be removed.

2092	9.12.2 Video Stream Properties

2094	   Video mixes define a presentation that may have multiple regions,
2095	   such as a quad-split. Each region displays the video from one or more
2096	   participants. When video streams are joined to such a conference, the
2097	   region that will display the video needs to be specified as part of
2098	   the join operation.

2100	   The region that will display the video is specified using the
2101	   "display" attribute. The "display" attribute MUST be used for a video
2102	   stream that is input to a conference and MUST NOT be used for other
2103	                                 (MSML)

2105	   streams. The value of the attribute MUST identify a <region> (see
2106	   section <region>) or a <selector> (see section <selector>) that is
2107	   defined for the conference. A stream MUST NOT be directly joined to a
2108	   region that is defined within a selector. Changing the value of the
2109	   "display" attribute can be used to change where in a video
2110	   presentation layout a video stream is displayed.

2112	   Additional attributes of the <stream> element for video streams are:

2114	         display: the identifier of a video layout region or selector
2115	         that is to be used to display the video stream.

2117	9.12.2.1 <visual>

2119	   Some regions of video conferences may display different streams
2120	   automatically, such as when voice activated switching is used.
2121	   Connections MAY also be joined directly without the use of video
2122	   mixing. In these cases, the <visual> element may be used to define
2123	   visual display properties for a stream.

2125	   The <visual> element MAY use any of the visual attributes defined for
2126	   regions (see section <region>). This allows the visual aspects of
2127	   regions within a <selector> to be tailored to the selected video
2128	   stream, or for streams that are directly joined to display a name or
2129	   logo.

2131	10. MSML Dialog Packages

2133	10.1 Overview

2135	   MSML Dialog Packages define an XML [4] language for composing complex
2136	   media objects from a vocabulary of simple media resource objects
2137	   called primitives. It is primarily a descriptive or declarative
2138	   language to describe media processing objects. MSML dialogs operate
2139	   on a single or multiple streams which are identified by the MSML
2140	   document outside the scope of the MSML dialog package.

2142	   MSML Dialogs are intended to be used in different environments. As
2143	   such, the language itself does not define how an MSML Dialog is used.
2144	   Each environment in which MSML Dialog is used must define how it is
2145	   used, the set of services provided and the mechanism for passing
2146	   information between the environment and MSML Dialog. The specific
2147	   mechanisms used to realize the interface between MSML Dialog and its
2148	   environment are platform specific.

2150	   MSML Dialog packages provide two models for access to media resources
2151	   and service creation building blocks. Both models MAY be used in
2152	   conjunction with each other in a complementary manner. The first
2153	                                 (MSML)

2155	   model (referred to as �Media Primitives and Composites�, part of the
2156	   mandatory MSML Dialog Base package) contains media primitives (such
2157	   as digit collection and announcements) and composite functions (such
2158	   as play and collect combined as a single operation). The second model
2159	   (referred to as �Media Groups�, part of the optional MSML Dialog
2160	   Group package) allows the ability to define complex customized
2161	   interactions, via event passing mechanisms, between media primitives,
2162	   if required.

2164	      MSML Dialog Core Package

2166	         Defines core framework over which all MSML dialog packages
2167	         operate.

2169	      MSML Dialog Base Package

2171	         Media Primitives
2172	            <dtmf> or <collect>
2173	                        DTMF digit collection
2174	            <play>
2175	                        Playing of Announcements
2176	            <dtmfgen>
2177	                        Generation of DTMF digits
2178	            <record>
2179	                        Media recording

2181	         Media Composites
2182	            <collect>
2183	                        Supports play and collect operation.
2184	                        Composite function with inclusion of play.
2185	            <record>
2186	                        Supports play and record operation.
2187	                        Composite function with inclusion of play.

2189	      MSML Dialog Group Package

2191	            <group>
2192	                        Allows grouping of media primitives for parallel
2193	                        execution, with an event exchange mechanism
2194	                        between the media primitives to achieve
2195	                        customized media operations. All the above media
2196	                        primitive elements are accepted within the
2197	                        group.

2199	   Following operations MUST be supported using elements described above
2200	   using either the MSML Dialog Base Package or MSML Dialog Group
2201	   Package.

2203	                                 (MSML)

2205	         Announcement only
2206	                           <play>

2208	         Collection only
2209	                           <dtmf> or <collect>

2211	         Recording only
2212	                           <record>

2214	         Play and Collect
2215	                           <collect>
2216	                              <play/>
2217	                           </collect>

2219	         Play and Record
2220	                           <record>
2221	                              <play/>
2222	                           </record>

2224	   Additional MSML Dialog packages are:

2226	      O MSML Dialog Transform Package

2228	      O MSML Dialog Speech Package

2230	      O MSML Fax Detection Package

2232	      O MSML Fax Send/Receive Package

2234	   MSML Dialogs MAY be used to simply expose primitive media resource
2235	   objects but will be used more often to describe dialog operations and
2236	   media transformation objects which can be controlled via user
2237	   interaction.

2239	   MSML Dialogs do not contain any computation or flow control
2240	   constructs. There are no results automatically generated when media
2241	   operations complete. Results MUST be explicitly requested using a
2242	   <send> or <exit> element within the definition of the MSML Dialog.

2244	10.2 Primitives

2246	   Primitives perform a single function on a media stream or multiple
2247	   streams such as generating audio/video, recognizing speech or DTMF,
2248	   or adjusting the gain. They may be composed so that primitives
2249	   execute concurrently. Primitives not composed for concurrent
2250	   execution MUST simply execute sequentially in the order they occur in
2251	   a MSML document. All concurrently executing primitives in the same
2252	   MSML object (defined in one MSML document) MAY interact with each
2253	   other through events (see MSML Dialog Group package).

2255	                                 (MSML)

2257	   Currently all primitives use audio media; primitives for text and
2258	   video will be defined in future versions of this specification.
2259	   Primitives can roughly be considered to fall into one of three
2260	   descriptive categories.

2262	      o  recognizers have a media input but no output. They allow
2263	         different things within a media stream to be recognized or
2264	         detected and for events to be generated based upon received
2265	         media.

2267	      o  transformers have one media input and output and may send and
2268	         receive events;

2270	      o  sources and sinks generate or consume media. They have either a
2271	         media input or a media output but not both. They may receive
2272	         and generate events.

2274	      o  composites combine underlying primitives to provide higher-
2275	         level user interaction, without the need for specific event
2276	         based exchange between the primitives. The composite elements
2277	         provide a simpler mechanism for more commonly used services,
2278	         such as play and collect or play and record.

2280	   Primitives may define different media processing behavior (states)
2281	   based upon the events which they receive. Primitives which support
2282	   different processing states must define their default starting state
2283	   and should support the "initial" attribute to allow that state to be
2284	   specified when the primitive is instantiated. All primitives must
2285	   support the "terminate" event class.

2287	   The following types of primitives are defined within this
2288	   specification:

2290	       Recognizers    Transformers   Source/Sink   Composites
2291	       ------------------------------------------------------
2292	         dtmf           agc           play          collect
2293	         faxtone        clamp         record        record
2294	         speech         gain          dtmfgen
2295	         vad            gate          faxsend
2296	                        relay         faxrcv

2298	   Primitives have shadow variables, similar to those within VoiceXML
2299	   [7], which are automatically assigned values when the primitives are
2300	   used. Upon initialization of an MSML Dialog context, all shadow
2301	   variables have the string value "undefined". Each primitive has its
2302	   own instance of shadow variables which are global in scope to the
2303	   entire MSML Dialog context.

2305	                                 (MSML)

2307	   Names SHOULD be assigned to individual primitives when more than one
2308	   primitive of the same type is used within one MSML document. Shadow
2309	   variables are overwritten if the primitive has not been named and is
2310	   instantiated a second time.

2312	   Shadow variables cannot be modified under user control. They may be
2313	   returned from the MSML Dialog context using the <send> element.

2315	10.3 Events

2317	   Events provide the mechanism for primitives to interact with each
2318	   other and for a MSML context to interact with its external
2319	   environment. The external environment is defined by the way in which
2320	   a MSML context has been invoked. This will often be through MSML but
2321	   other languages and protocols such as SIP may also be used.

2323	   Every primitive and group conceptually implements their own event
2324	   queue. Events sent to them get placed into their associated queue.
2325	   Events are removed from their queues and processed in order.
2326	   Primitives within a group conceptually have their own thread of
2327	   execution. Due to the asynchronous nature of servicing events from
2328	   multiple queues, it cannot be assumed that several events sent in
2329	   sequence to different queues, will be processed in the order in which
2330	   they were sent. For example, if recognition of something led to
2331	   sending events to both a <play> and a <record> in that order, it is
2332	   possible that the <record> may process its event before the <play>.

2334	   Primitives each define the set of events which they support and the
2335	   behavior associated with their handling of each event. This allows
2336	   many types of behaviors to be defined. For example, VCR type controls
2337	   can be constructed by defining primitives which support events
2338	   corresponding to each control. Media recognition/detection can be
2339	   used to cause those events to be generated.

2341	   Alternatively, events can be originated elsewhere, such as from a
2342	   Control Agent, and simply received by the primitive implementing the
2343	   control. Examples of the use of events include adjusting volume
2344	   (gain) and pause and resume of both announcement playout and record
2345	   creation.

2347	   Primitives act on events based upon the longest match of an event
2348	   name. Event names are a period '.' delimited sequence of tokens. The
2349	   first token, or the root of the name, can be considered an event
2350	   class. Matching allows a standard meaning to be defined and then
2351	   extended based upon what triggers an event's generation. For example,
2352	   a record primitive has different behavior depending upon whether it
2353	   completed because a user stopped speaking or because it was
2354	                                 (MSML)

2356	   cancelled. The recording is retained in the first case but not the
2357	   second.

2359	   Longest match allows new recognizers to be created and used without
2360	   changing how existing primitives are defined. For example, a face
2361	   recognition capability could be created which generates a
2362	   terminate.frowning event when a user looks puzzled. Although no
2363	   primitive directly defines this event, it will still effect a generic
2364	   terminate action. Primitives which require specialized behavior based
2365	   upon frowning may be extended to support this. As well, the event can
2366	   still be exported from the MSML context without requiring that
2367	   primitives receiving the event understand facial expressions.

2369	10.4 MSML Dialog Usage with SIP

2371	   MSML Dialogs MAY be used directly with SIP for dialog interactions
2372	   (e.g., IVR or fax). It can be initially invoked as part of the
2373	   "Prompt and Collect" service described in "Basic Network Media
2374	   Services with SIP" [9]. That defines service indicators for a small
2375	   number of well defined services using the user part of the SIP
2376	   Request-URI (R-URI).

2378	   The prompt and collect service uses "dialog" as the service
2379	   indicator. URI parameters further refine the specific IVR request.
2380	   This document defines an additional parameter "msml-param" for the
2381	   dialog service indicator as follows:

2383	   dialog-parameters = ";" ( dialog-param [ vxml-parameters ] )
2384	                           | moml-param
2385	   dialog-param      = "voicexml=" dialog-url
2386	   moml-param        = "moml=" moml-url

2388	   There are no additional URI parameters when MSML is used as the
2389	   dialog language.

2391	   MSML Dialogs defines discrete IVR dialog commands. These commands MAY
2392	   be included directly in the body of the INVITE to the "dialog"
2393	   service indicator by using the "cid" [12] URL scheme. This scheme
2394	   identifies a message body part which in this case would contain the
2395	   MSML Dialog request. Note that a multipart message body, containing a
2396	   single part, MUST be present even if the INVITE does not contain an
2397	   SDP offer. Subsequent MSML Dialog requests are sent in the body of
2398	   SIP INFO messages as are all messages from a media server.

2400	   An example of SIP URI as described above is:

2402	      sip:dialog@mediaserver.example.net;\
2403	          moml=cid:14864099865376@appserver.example.net
2404	                                 (MSML)

2406	   The body part that contained the MSML Dialog referenced by the URL
2407	   would have a Content-Id header of:

2409	      Content-Id: <14864099865376@appserver.example.net>

2411	   The results of executing an <exit> or <disconnect>, or of executing a
2412	   <send> which has a "target" attribute value equal to "source", are
2413	   notified in SIP INFO messages using the <event> element from MSML
2414	   Core package. No messages are sent if execution completes normally
2415	   without executing one of these elements.

2417	   If there is an error during validation or execution, then a media
2418	   server MUST notify the error as described above and must include the
2419	   namelist items "moml.error.status" and "moml.error.description". The
2420	   values for these items are defined in section 11.

2422	   A restricted subset of MSML Dialogs can also be used with the
2423	   "Announcement" service defined in [9]. This service uses "annc" as
2424	   the service indicator and defines parameters that describe an
2425	   announcement. The "play=" parameter identifies the URL of a prompt or
2426	   a provisioned announcement sequence. The value of the "play="
2427	   parameter can refer to a MSML Dialog body part using a "cid" URL as
2428	   described above. That body part must only contain the <play>
2429	   primitive.

2431	   Using MSML Dialogs enhances the announcement service by allowing the
2432	   client to specify a sequence of audio segments rather than requiring
2433	   each sequence to be provisioned as well as support for video.
2434	   Moreover, MSML Dialogs define a standard set of variables in contrast
2435	   to [9] which defines a parameterization mechanism but does not
2436	   formally specify any semantics.

2438	   If a media server does not understand the "cid" scheme or does not
2439	   understand MSML Dialogs, it must respond with the SIP response code
2440	   "488 -  not acceptable here". If the MSML Dialog body contains
2441	   elements other than the <play> primitive, or there are errors during
2442	   validation, a media server must respond with a SIP response code "400
2443	   - bad request". Finally, if there is a discrepancy between parameters
2444	   specified in the Request-URI and corresponding attributes defined in
2445	   the MSML Dialog body, the Request-URI parameters must be silently
2446	   ignored.

2448	   MSML Dialogs MUST NOT change the operation of the announcement
2449	   service from that defined in [9]. When the announcement completes, a
2450	   media server issues a SIP BYE request. The INFO method MUST NOT used
2451	   with the announcement service.

2453	                                 (MSML)

2455	10.5 MSML Dialog Structure and Modularity

2457	   MSML is structured as a set of packages. Only the core and base
2458	   packages are required. The Dialog Core package, defines the framework
2459	   for MSML requests to a media server, without specific functionality.
2460	   It consists of the �primitive� abstraction, an abstract element for
2461	   control flow, the sequential execution model, and the <send> element.
2462	   That is, the MSML Dialog Core package allows for the execution of a
2463	   sequence of one or more media processing primitives with the ability
2464	   to notify events to the invocation environment.

2466	   Primitives are contained within the MSML Dialog Base package, which
2467	   defines the basic <play>, <record>, <dtmf>, <dtmfgen> and <collect>
2468	   elements. Another package, the MSML Dialog Transform package, defines
2469	   the simple half duplex filters. More advanced primitives are defined
2470	   in the speech and fax packages. The MSML speech package depends on
2471	   the MSML Dialog base package as it extends the capability of <play>
2472	   by adding synthesized speech. Finally, the group execution model,
2473	   which is currently the only element which changes the flow of control
2474	   is defined in a separate MSML Dialog Group package. All of these
2475	   packages are optional with the exception that MSML Dialog Core and
2476	   MSML Dialog Base packages MUST be implemented to provide the minimal
2477	   functionality.

2479	10.6 MSML Dialog Core Package

2481	   The MSML Dialog Core package defines the structural framework and
2482	   abstractions for MSML Dialogs(via its schema). It also defines the
2483	   basic elements which are not part of the core primitive or control
2484	   abstractions. This package is dependent on the MSML Core package.
2485	   Events generated by MSML Dialogs, such as prompt completion, digits
2486	   collected, or dialog termination, etc, are communicated by the Media
2487	   Server via the MSML Core Package (see MSML Core Package <event>).

2489	   MSML Dialogs are executed independently from the MSML core context.
2490	   When an MSML Dialog is started, MSML allocates the dialog control
2491	   resources, and if successful, starts those resources executing. MSML
2492	   core execution then continues without waiting for the MSML dialog to
2493	   complete. This forking of MSML dialog invocation from the MSML core
2494	   context is done via the <dialogstart> element. Media streams are
2495	   created between the MSML dialog target and other internal media
2496	   server resources as part of dialog execution. Stream creation is
2497	   subject to the requirements defined in MSML Core package and media
2498	   streams as defined in MSML Conference Core package.

2500	                                 (MSML)

2502	10.6.1 <dialogstart>

2504	   The <dialogstart> element is used to instantiate an MSML media dialog
2505	   on connections or conferences. The dialog is specified either inline
2506	   or by a URI [8]. Inline dialogs MUST be composed of any of the MSML
2507	   Dialog packages. MSML dialogs MAY be defined externally as VoiceXML
2508	   [7]. The MSML dialog description MUST NOT be inline if the src
2509	   attribute, containing a URI, is present.

2511	   The originator of the MSML dialog is notified using a
2512	   "msml.dialog.exit" event when the dialog completes. Any results
2513	   returned by the dialog when it exits are sent as a namelist to the
2514	   event.

2516	   The "msml.dialog.exit" event is also used when dialogs fail due to
2517	   errors encountered fetching external documents or errors that occur
2518	   within the dialog execution thread. In this case, a namelist
2519	   containing the items "dialog.exit.status" and
2520	   "dialog.exit.description" is returned with the event to inform the
2521	   client of the failure and the failure reason. The values of these
2522	   items are defined within this package and the MSML Core package.
2523	   Information from the failed dialog may be returned as additional
2524	   namelist items.

2526	   attributes:

2528	         target: an identifier of a connection or a conference which
2529	         will interact with the dialog. The identifier must not contain
2530	         wildcards. Mandatory.

2532	         src: the URL of the dialog description. MUST NOT be used if the
2533	         MSML dialog description is inline. Otherwise an error (422)
2534	         will result and MSML document execution will stop.

2536	         type: a MIME type which identifies the type of language used to
2537	         describe the dialog. application/moml+xml and
2538	         application/vxml+xml are used to identify MSML Dialogs and
2539	         VoiceXML [7] respectively.

2541	         name: an instance name for the dialog. If the attribute is not
2542	         present, the media server will assign an identifier to the
2543	         dialog. If the attribute is present but the name is already
2544	         associated with the target, an error (431) will result and MSML
2545	         document execution will stop. Any results that a dialog
2546	         generates will be correlated to its identifier.

2548	         mark: a token which can be used to identify execution progress
2549	         in the case of errors. The value of the mark attribute from the
2550	                                 (MSML)

2552	         last successfully executed MSML element is returned in an error
2553	         response. Therefore the value of all "mark" attributes within
2554	         an MSML document should be unique.

2556	   The following sections show examples of initiating an external MSML
2557	   dialog, an in-line embedded MSML dialog, and an MSML initiated
2558	   VoiceXML dialog.

2560	   The following example starts a MSML dialog on a connection.

2562	        <?xml version="1.0" encoding="UTF-8"?>
2563	        <msml version="1.1">
2564	           <dialogstart target="conn:abcd1234"
2565	                 type="application/moml+xml"
2566	                 name="sample"
2567	                 src="http://server.example.com/scripts/foo.moml"/>
2568	         </msml>

2570	   The following example starts an in-line embedded MSML dialog on a
2571	   connection.
2572	         <?xml version="1.0" encoding="UTF-8"?>
2573	         <msml version="1.1">
2574	           <dialogstart target=�conn:abcd1234� name=�sample�>
2575	              <play>
2576	                 <audio uri="file://clip1.wav"/>
2577	                 <audio uri="http://host1/clip2.wav"/>
2578	                 <tts uri="http://host2/text.ssml"/>
2579	                 <var type="date" subtype="mdy" value="20030601"/>
2580	              </play>
2581	              <send target="source"
2582	                     event="done"
2583	                     namelist="play.amt play.end"/>
2584	            </dialogstart>
2585	         </msml>

2587	   The following example starts a VoiceXML dialog on a connection.

2589	                                 (MSML)

2591	         <?xml version="1.0" encoding="UTF-8"?>
2592	         <msml version="1.1">
2593	            <dialogstart target="conn:abcd1234"
2594	                type="application/vxml+xml"
2595	                name="sample"
2596	                src="http://server.example.com/scripts/foo.vxml"/>
2597	         </msml>

2599	   If this dialog fails once its execution thread had begun, for example
2600	   the fetch of the VoiceXML document failed, an example of the event
2601	   which would be returned would be:

2603	         <?xml version="1.0" encoding="UTF-8"?>
2604	         <event name="msml.dialog.exit"
2605	                id="conn:abcd1234/dialog:sample">
2606	            <name>dialog.exit.status</name>
2607	            <value>423</value>
2608	            <name>dialog.exit.description</name>
2609	            <value>External document fetch error</value>
2610	         </event>

2612	10.6.2 <dialogend>

2614	   Dialog end is used to terminate a MSML dialog created through
2615	   <dialogstart> before it completes of its own accord. The operation of
2616	   <dialogend> depends on the dialog language being used by the
2617	   executing context. When that context is VoiceXML, a
2618	   "connection.disconnected" event will be thrown to the VoiceXML
2619	   application. When that context is MSML Dialog, a "terminate" event
2620	   will be sent to the MSML core context.

2622	   <dialogend> allows the executing dialog the opportunity to gracefully
2623	   complete before generating a "msml.dialog.exit" event. Dialog results
2624	   may be returned and will be contained as a namelist to that event.

2626	   attributes:

2628	         id: the identifier of a dialog. Mandatory.

2630	                                 (MSML)

2632	         mark: a token which can be used to identify execution progress
2633	         in the case of errors. The value of the mark attribute from the
2634	         last successfully executed MSML Dialog element is returned in
2635	         an error response. Therefore the value of all "mark" attributes
2636	         within an MSML document should be unique.

2638	   For example, if the dialog from the previous example was still
2639	   executing, the following would terminate the dialog and generate a
2640	   "msml.dialog.exit" event.

2642	            <?xml version="1.0" encoding="UTF-8"?>
2643	            <msml version="1.1">
2644	               <dialogend id="conn:abcd1234/dialog:sample"/>
2645	            </msml>

2647	10.6.3 <send>

2649	   Sends an event and optional namelist to the recipient identified by
2650	   the target attribute. Event names are defined by the recipient. In
2651	   the case where the recipient is an MSML Dialog group or primitive,
2652	   the events are defined within this document. Other recipients MAY use
2653	   names that are suitable for their environment.

2655	   The "target" attribute specifies the recipient of the event.
2656	   Recipients MAY be other MSML Dialog primitives or groups executing
2657	   within the object, the object itself, or the environment which
2658	   invoked the MSML Dialog. Sending events to media primitives or groups
2659	   is supported by the MSML Dialog Group package. Any target which is
2660	   unknown within the object is assumed to be destined to the external
2661	   environment. By convention, the string "source" SHOULD used to
2662	   address that environment but any target name distinct from the MSML
2663	   Dialog namespace MAY be used.

2665	      Attributes:

2667	         event: the name of an event.

2669	         target: the recipient of the event. The recipient MUST be a
2670	         MSML Dialog primitive, the currently executing group, or the
2671	         MSML Dialog environment. A primitive is specified by a
2672	         primitive type, optionally appended by a period '.' followed by
2673	         the identifier of a primitive. Identifiers are only needed when
2674	         more than one primitive of the same type exists in the object.
2675	         The executing group is specified using the token "group". The
2676	         environment is specified using the token "source", optionally
2677	                                 (MSML)

2679	         appended by a period '.' followed by any environment specific
2680	         target.

2682	         namelist: a list of zero or more shadow variables which are
2683	         included with the event.

2685	10.6.4 <exit>

2687	   Exit causes execution of the MSML Dialog to terminate.

2689	      Attributes:

2691	         namelist: a list of one or more shadow variables which MAY
2692	         optionally be sent to the context which invoked the MSML Dialog
2693	         object.

2695	10.6.5 <disconnect>

2697	   Disconnect is similar to <exit> but has the additional semantics of
2698	   indicating to the context which invoked the MSML Dialog, that it
2699	   should disconnect from a media server, the media stream associated
2700	   with the object. The method of disconnection depends upon how the
2701	   media stream was initially established. If SIP was used, a
2702	   <disconnect> would cause a media server to issue a BYE request. The
2703	   request would be sent for the SIP dialog associated with media
2704	   session on which the MSML Dialog was operating.

2706	      Attributes:

2708	         namelist: a list of one or more shadow variables which MAY
2709	         optionally be sent to the context which invoked the MSML Dialog
2710	         object.

2712	10.7 MSML Dialog Base Package

2714	   The MSML Dialog Base package defines a required set of base
2715	   functionality for Media Server. It support individual media
2716	   primitives, such as playing an announcement or collection digits, as
2717	   well as composite operations such as play and collect. When this
2718	   package is used in conjunction with MSML Dialog Group package the
2719	   event based mechanism is used to control primitives. This package may
2720	   also be used in conjunction with MSML Speech package to extend the
2721	   functionality of prompts to include TTS and user input collection to
2722	   include ASR.

2724	   In the following sections, subsections of a primitive define child
2725	   elements of that primitive and are not themselves considered
2726	   primitives. They do not receive events or populate shadow variables.

2728	                                 (MSML)

2730	10.7.1 <play>

2732	   Play is used to generate an audio or video stream. It MUST play in
2733	   sequence the media created by the child media elements <audio>,
2734	   <video>, <media>, <tts>, and <var>. When the play stops, either
2735	   because the terminate event is received or all media generation has
2736	   completed, the <playexit> element, if present, is executed. At least
2737	   one media generation element must be present.

2739	   Play supports two states; generate and suspend. Media generation
2740	   occurs in the generate state and is suspended in the suspend state.
2741	   Once in the suspend state, media generation continues upon receiving
2742	   the generate event. The default initial state is generate.

2744	   Audio MAY be generated in different languages by specifying the
2745	   xml:lang attribute for <play> and/or the child elements of <play>.
2746	   The language is inherited by the child elements but each child MAY
2747	   specify its own language. Except for physical audio clips, it is an
2748	   error if a language is specified but the media server can not render
2749	   the audio in the requested language.

2751	      Attributes:

2753	         id: an optional identifier which may be referenced elsewhere
2754	         for sending events to the play primitive.

2756	         interval: specifies the delay between stopping one iteration
2757	         and beginning another. The attribute has no effect if
2758	         iterations is not also specified. Default is no interval.

2760	         iterate: specifies the number of times the media specified by
2761	         the child media elements should be played. Each iteration is a
2762	         complete play of each of the child media elements in document
2763	         order. Defaults to once '1'.

2765	         initial: defines the initial state for the play element.
2766	         Default is "generate".

2768	         maxtime: defines the maximum allowed time for the <play> to
2769	         complete.

2771	         barge: defines whether or not audio announcements MAY be
2772	         interrupted by DTMF detection during play-out. The DTMF digit
2773	         barging the announcement is stored in the digit buffer. Valid
2774	         values for barge are �true� or �false�, and the attribute is
2775	         mandatory.

2777	                                 (MSML)

2779	         cleardb: defines whether the digit buffer is cleared or not,
2780	         prior to starting the announcement. Valid values for cleardb
2781	         are �true� or �false�, and the attribute is mandatory.

2783	         offset: defines an offset, measured in units of time, where the
2784	         <play> is to begin media generation. Offset is only valid when
2785	         all child media elements are <audio>.

2787	         skip: an amount, expressed in time, which will be used to skip
2788	         through the media when "forward" and "backward" events are
2789	         received. Default is 3s (three seconds).

2791	         xml:lang: specifies the language to use for content which can
2792	         be rendered in different languages.

2794	      Events:

2796	         Following describes input events to the media primitive object.
2797	         The MSML Dialog Group package allows an event exchange
2798	         mechanism between primitives.

2800	         pause: causes the play to enter the suspend state.

2802	         resume: causes play to enter the generate state.

2804	         forward: skips forward through the media. Only has effect when
2805	         all child media elements are <audio>.

2807	         backward: skips backward through the media. Only has effect
2808	         when all child media elements are <audio>.

2810	         restart: skips to the beginning of the media. Only has effect
2811	         when all child media elements are <audio>.

2813	         toggle-state: causes the suspend / generate state to toggle.

2815	         terminate: terminates the play and assigns values to the shadow
2816	         variables.

2818	      Shadow Variables:

2820	         play.amt: identifies the length of time for which media was
2821	         generated before the play was stopped. This does not include
2822	         time which may have elapsed while the play was in the suspend
2823	         state.

2825	                                 (MSML)

2827	         play.end: contains the event which caused the play to stop.
2828	         When the play stops because all media generation has completed,
2829	         end is assigned the value "play.complete".

2831	   Note: Attributes barge and cleardb provide a simplified mechanism for
2832	   controlling play operations with implicit DTMF without the use of
2833	   <group> and event exchange mechanism. When using the <play> element
2834	   within the group framework and barge is specified, detection of barge
2835	   condition generates an implicit terminate event to the play
2836	   primitive.

2838	   Following sections describe the child elements of <play>.

2840	10.7.1.1 <audio>

2842	   Identifies pre-recorded audio to play. Local URI references may
2843	   resolve to a single physical audio clip, a logical clip, or a
2844	   provisioned sequence of clips (physical or logical). A logical clip
2845	   is one which can be rendered differently based on the language
2846	   attribute. Logical clips are provisioned for each of the languages
2847	   that a media server supports. Remote URI references are resolved
2848	   according to the capabilities of the remote server.

2850	      Attributes:

2852	         uri: Identifies the location of the audio to be played. The
2853	         file and http schemes are supported.

2855	         format: defines the encoding and file type of the audio
2856	         resource. The format attribute is defined as a string type of
2857	         form �audio/<filetype>;codecs=<codec>�. The keyword �audio�
2858	         identifies an audio content. The codecs field identifies the
2859	         audio file�s codec to be used for decoding the audio content.
2860	         If format attribute is not specified, the filetype MUST be
2861	         determined from the URI and the codec information MUST be
2862	         determined from the media resource.

2864	         audiosamplerate: Identifies audio sample rate in kHz. If not
2865	         specified, the sample rate SHOULD be determined from the media
2866	         resource.

2868	         audiosamplesize: Identifies audio sample size in bits. If not
2869	         specified, the sample size SHOULD be determined from the media
2870	         resource.

2872	         iterate: specifies the number of times the audio is to be
2873	         played. Defaults to once '1'.

2875	                                 (MSML)

2877	         xml:lang: specifies the language to use when the URI identifies
2878	         a logical clip, either directly, or as part of a sequence.

2880	10.7.1.2 <video>

2882	   Identifies pre-recorded multimedia to play. Contents identified by
2883	   the URI attribute may contain audio only, video only, or both audio
2884	   and video. Media Server SHOULD attempt to play both audio and video
2885	   from the identified URI, if both are available in the content.

2887	      Attributes:

2889	         uri: Identifies the location of the video or multimedia to be
2890	         played. The file and http schemes are supported.

2892	         format: defines the encoding and file type of the video or
2893	         multimedia resource. The format attribute is defined as a
2894	         string type of form
2895	         �video/<filetype>;codecs=<codecx>,<codecy>�. The keyword
2896	         �video� identifies video only media or media containing audio
2897	         and video. The �codecs� field identifies the audio and/or video
2898	         codecs to be used for decoding the file content, where the
2899	         order of the codec values is not significant. In the event of
2900	         audio and video content, using �video� keyword, the
2901	         codecs=<codecx>,<codecy> field MAY be used to identify the
2902	         audio codec and the video codec. If not specified, the codec
2903	         information SHOULD be determined from the media file.

2905	         audiosamplerate: Identifies audio sample rate in kHz. If not
2906	         specified, the sample rate SHOULD be determined from the media
2907	         file.

2909	         audiosamplesize: Identifies audio sample size in bits. If not
2910	         specified, the sample size SHOULD be determined from the media
2911	         file.

2913	         codecconfig: Identifies an optional special instruction string
2914	         for codec configuration. Default is to send no special
2915	         configuration string to the codec.

2917	         profile: Identifies a video profile name specific to the codec.
2918	         If not specified, default video profile of the codec SHOULD be
2919	         selected.

2921	         level: Identifies a video profile level to the codec. Default
2922	         is to send no profile information to the codec and allow the
2923	         codec to select an internal default.

2925	                                 (MSML)

2927	         imagewidth: Identifies the width of video image in pixels.
2928	         Default is to use image width information from media file.

2930	         imageheight: Identifies the height of video image in pixels.
2931	         Default is to use image height information from media file.

2933	         maxbitrate: Identifies the bitrate of the video signal in kbps.
2934	         Default is to use maximum bitrate information from the media
2935	         file.

2937	         framerate: Identifies the video frame rate in frames per
2938	         second. Default is to use frame rate information from the media
2939	         file.

2941	         iterate: specifies the number of times the audio is to be
2942	         played. Defaults to once '1'.

2944	10.7.1.3 <media>

2946	   Identifies multimedia content for play. All content of <media>
2947	   element MUST start to play concurrently. This element may be used to
2948	   generate a multi-media stream from two independent media resources,
2949	   one identifying audio and the other identifying video.

2951	   The <media> element MUST contain at least one child element. Valid
2952	   child elements of <media> are <audio> and <video>, as described
2953	   earlier. <media> element MUST contain at most one <audio> element or
2954	   at most one <video> element.

2956	10.7.1.4 <var>

2958	   Specifies the generation of audio from a variable using prerecorded
2959	   audio segments. A variable represents a semantic concept (such as
2960	   date or number) and dynamically produces the appropriate speech.

2962	   Prerecorded audio allows an application vendor or service provider to
2963	   choose the exact voice for their audio and therefore completely
2964	   control the "sound and feel" of the service provided to end users. It
2965	   provides very high audio quality and allows the variables to blend
2966	   seamlessly into the surrounding audio segments.

2968	   Text to speech (TTS) using SSML may also be used to render variables,
2969	   but may not provide as good quality, or allow as complete control of
2970	   the "sound and feel" or user experience. TTS is normally used for
2971	   reading text such as emails and for very large vocabularies such as
2972	   stock names. TTS results in a very clear difference between the
2973	   variables and the surrounding audio segments. (See MSML Dialog Speech
2974	   package).

2976	                                 (MSML)

2978	      Attributes:

2980	         type: specifies the type of variable. Mandatory. Variable type
2981	         must be one of "date", "digits", "duration", "month", "money",
2982	         "number", "silence", "time", or "weekday".

2984	         subtype: specifies an optional clarification of type. Specific
2985	         values depend upon the type.

2987	         value: text which should be rendered appropriate to the type
2988	         and subtype attributes.

2990	         xml:lang: specifies the language to use when rendering the
2991	         variable.

2993	10.7.1.5 <playexit>

2995	   The <playexit> element MUST be invoked when generation of all content
2996	   of the <play> has come to completion. The contents of this element
2997	   MAY be used to send events.

2999	      Attributes:

3001	         none

3003	10.7.2 <dtmfgen>

3005	   DTMF generator originates one or more DTMF digits in sequence.

3007	      Attributes:

3009	         id: an optional identifier which may be referenced elsewhere
3010	         for sending events to the dtmfgen primitive.

3012	         digits: A string of characters from the alphabet "0-9a-d#*"
3013	         which correspond to a sequence of DTMF tones. Mandatory.

3015	         level: used to define the power level for which the tones will
3016	         be generated. Expressed in dBm0 in a range of 0 to -96 dBm0.
3017	         Larger negative values express lower power levels. Note that
3018	         values lower than -55 dBm0 will be rejected by most receivers
3019	         (TR-TSY-000181, ITU-T Q.24A). Default is -6 dBm0.

3021	         dur: the duration in milliseconds for which each tone should be
3022	         generated. Implementations may round the value if they only
3023	         support discrete durations. Default 100 ms.

3025	                                 (MSML)

3027	         interval: the duration in milliseconds of a silence interval
3028	         following each generated tone. Implementations may round the
3029	         value if they only support discrete durations. Default 100 ms.

3031	      Events:

3033	         terminate: terminates DTMF generation and assigns values to the
3034	         shadow variables.

3036	      Shadow Variables:

3038	         dtmfgen.end: contains the event which caused DTMF generation to
3039	         stop.

3041	   The following sections describe the child elements of <dtmfgen>.

3043	10.7.2.1 <dtmfgenexit>

3045	   The <dtmfgenexit> element MUST be invoked when the DTMF generation
3046	   operation completes or is terminated as a result of receiving the
3047	   terminate event. The <dtmfgenexit> element MAY be used to send events
3048	   when the recording has completed.

3050	      Attributes:

3052	         none

3054	10.7.3 <record>

3056	   Record creates a recording. Similar to play, <record> supports two
3057	   states; create and suspend. Received media becomes part of the
3058	   recording when <record> is in the create state and is discarded when
3059	   it is in the suspend state.

3061	   Recording MUST be terminated when a terminate event is received or
3062	   when a nospeech event is received and no audio has yet been recorded.
3063	   <record> differentiates different types of terminate events.

3065	   An optional <play> element MAY be specified as a child element of
3066	   <record>. This mechanism provides a complete play-record operation,
3067	   where the prompt(s) specified within the <play> element are played in
3068	   advance of start of recording.

3070	   Note: Attributes prespeech, postspeech, and termkey provide a
3071	   simplified mechanism for controlling record operations using implicit
3072	   DTMF and VAD, without the use of <group> and event exchange
3073	   mechanism.

3075	                                 (MSML)

3077	      Attributes:

3079	         id: an optional identifier which may be referenced elsewhere
3080	         for sending events to the record primitive.

3082	         append: a boolean which defines whether the recording is
3083	         allowed to be appended to an existing file if dest already
3084	         exists. Default is "false". The attribute is ignored if the
3085	         scheme is http.

3087	         dest: the destination for the recording, which will contain
3088	         either audio only, video only, or both audio and video
3089	         depending on the stream(s) being recorded. Recording MAY be
3090	         either local or external based upon the attribute value. File
3091	         and http schemes are supported.

3093	         audiodest: the destination for the audio only recording.
3094	         Recording MAY be either local or external based upon the
3095	         attribute value. All combinations of dest, audiodest, and
3096	         videodest are valid. File and http schemes are supported.

3098	         videodest: the destination for the video only recording.
3099	         Recording MAY be either local or external based upon the
3100	         attribute value. All combinations of dest, audiodest, and
3101	         videodest are valid. File and http schemes are supported.

3103	         format: defines the encoding and file type of the recording.
3104	         The format attribute is defined as a string type of form
3105	         �audio|video/filetype;codecs=x,y�. The keyword �audio�
3106	         identifies an audio only recording, while the keyword �video�
3107	         identifies video only recording or an audio plus video
3108	         recording. The codecs field identifies the audio and/or video
3109	         codecs to be used for the recording, where the order of the
3110	         codec values is not significant. In the event of audio and
3111	         video recording, using �video� keyword, the codecs=x,y field
3112	         MAY be used to identify the audio codec and the video codec.

3114	         codecconfig: Identifies an optional special instruction string
3115	         for codec configuration. Default is to send no special
3116	         configuration string to the codec.

3118	         audiosamplerate: Identifies audio sample rate in kHz. If not
3119	         specified, the sample rate SHOULD be determined from the media
3120	         source.

3122	         audiosamplesize: Identifies audio sample size in bits. If not
3123	         specified, the sample size SHOULD be determined from the media
3124	         source.

3126	                                 (MSML)

3128	         profile: Identifies a video profile name specific to the codec.
3129	         If not specified, default video profile of the codec SHOULD be
3130	         selected for the recording.

3132	         level: Identifies a video profile level to the codec. Default
3133	         is to send no profile information to the codec and allow the
3134	         codec to select an internal default.

3136	         imagewidth: Identifies the width of video image in pixels.
3137	         Default is to use image width information from the media
3138	         source.

3140	         imageheight: Identifies the height of video image in pixels.
3141	         Default is to use image height information from the media
3142	         source.

3144	         maxbitrate: Identifies the bitrate of the video signal in kbps.
3145	         Default is to use maximum bitrate information from the media
3146	         source.

3148	         framerate: Identifies the video frame rate in frames per
3149	         second. Default is to use frame rate information from the media
3150	         source.

3152	         initial: defines the initial state for the record element.
3153	         Default is "create", which starts the recording as soon as the
3154	         <record> element is executed. The �initial� attribute is
3155	         applicable only when <record> is used within the <group>
3156	         structure.

3158	         maxtime: defines the maximum length of the recording in units
3159	         of time.

3161	         prespeech: defines a timer value, in seconds, for detection of
3162	         absence of audio energy at the start of the record operation.
3163	         If no audio energy is detection for the amount of time
3164	         specified by prespeech, the recording is terminated. Default is
3165	         �0s�, which does not activate the prespeech timer.

3167	         postspeech: defines a timer value, in seconds, for detection of
3168	         absence of audio energy while the recoding is in progress.
3169	         During an in progress recording, if absence of audio energy is
3170	         detected as specified by the postspeech timer, the recording is
3171	         terminated. Default is �0s�, which disables the ability to
3172	         terminate a recording due to postspeech silence.

3174	         termkey: defines a single DTMF key which when detection
3175	         terminates the recording. Absence of this attribute prevents
3176	                                 (MSML)

3178	         the recording from being terminated due to detection of DTMF
3179	         digits. When termkey is specified, the detected DTMF digit
3180	         terminates the recording and the DTMF digit is not entered in
3181	         the digit buffer.

3183	      Events:

3185	         Following describes input events to the media primitive object.
3186	         The MSML Dialog Group package allows an event exchange
3187	         mechanism between primitives.

3189	         pause: causes the record to enter the suspend state. Received
3190	         media is discarded.

3192	         resume: causes record to resume if it was suspended. It has no
3193	         effect otherwise.

3195	         toggle-state: causes the suspend / create state to toggle.

3197	         terminate: terminates the recording and assigns values to the
3198	         shadow variables.

3200	         terminate.cancelled: terminates the recording and assigns
3201	         values to the shadow variables. If the dest attribute used the
3202	         file scheme, the local recording is deleted. Applications are
3203	         responsible for removing external files created using the http
3204	         scheme.

3206	         terminate.finalsilence: terminates the recording and assigns
3207	         values to the shadow variables. If the dest attribute used the
3208	         file scheme, the final silence is removed from the recording.

3210	         nospeech: terminates the recording and assigns values to the
3211	         shadow variables if it is received and no recording has yet
3212	         been created. The "nospeech" event is ignored if audio has
3213	         already been recorded.

3215	      Shadow Variables:

3217	         record.len: the actual length of the recording measured in
3218	         units of time. This does not include time which may have
3219	         elapsed while the record was in the suspend state.

3221	         record.end: contains the event which caused the record to
3222	         terminate. When the record terminates because maxtime is
3223	         exceeded, end is assigned the value
3224	         "record.complete.maxlength".

3226	                                 (MSML)

3228	         Record termination due to prespeech silence, results in
3229	         assigned value of �record.failed.prespeech�

3231	         Record termination due to postspeech silence, results in
3232	         assigned value of �record.complete.postspeech�

3234	         Record termination due to DTMF detection, results in assigned
3235	         value of �record.complete.termkey�

3237	   The following sections describe the child elements of <record>.

3239	10.7.3.1 <play>

3241	   The optional <play> element as a child element of <record> allows a
3242	   prompt to be played prior to start of recording. The record operation
3243	   starts at the end of the play sequence or if the play is barged by
3244	   DTMF, assuming that barge=true is specified for <play>. For a
3245	   complete description, refer to <play> element.

3247	10.7.3.2 <recordexit>

3249	   The <recordexit> element MUST be invoked when the record operation
3250	   completes or when the recording is terminated as a result of
3251	   receiving the terminate event. The <recordexit> element MAY be used
3252	   to send events when the recording has completed.

3254	      Attributes:

3256	         none

3258	10.7.4 <dtmf> or <collect>

3260	   DTMF input fulfils several roles within MSML Dialogs. It is used to
3261	   trigger events which will affect the media processing operation of
3262	   other primitives. It is also used to collect DTMF digits from a media
3263	   stream which are to be reported back to the user of MSML Dialog.
3264	   Often DTMF detection is used for both purposes. Barge is the most
3265	   common example, where a prompt is stopped based upon DTMF input but
3266	   more digits may remain to be collected.

3268	   DTMF detection supports multiple simultaneous recognition patterns.
3269	   Different patterns can be used to trigger sending different events in
3270	   order to implement DTMF controls. Alternatively one pattern may be
3271	   used to represent a collection and another pattern, a substring of
3272	   the first, used as a barge indication.

3274	   An optional <play> element MAY be specified as a child element of
3275	   <dtmf> or <collect>. This mechanism provides a complete play-collect
3276	                                 (MSML)

3278	   operation, where the prompt(s) specified within the <play> element
3279	   are played in advance of DTMF digit collection.

3281	   Note that all patterns share the same digit collection buffer, inter-
3282	   digit timing, a single <nomatch> element, and a single <noinput>
3283	   element. As such, multiple patterns may not be suitable to support
3284	   simultaneous collections for different purposes. When this is
3285	   required, separate <dtmf> elements should be used instead.

3287	   <dtmf> terminates if any of the <pattern>, <noinput>, or <nomatch>
3288	   elements are matched the maximum number of times that they are
3289	   allowed. The number of times they may match may be specified as an
3290	   attribute of <dtmf> or of the individual child elements.

3292	   Element identifier <dtmf> is equivalent to <collect>. However,
3293	   <collect> is the preferred name. MSML clients SHOULD use <collect>,
3294	   while MSML servers SHOULD support both.

3296	      Attributes:

3298	         id: an optional identifier which may be referenced elsewhere
3299	         for sending events to this primitive.

3301	         cleardb: a boolean indication of whether the buffer for digit
3302	         collection should be cleared of any collected digits when the
3303	         element is instantiated. If set to false, any digits currently
3304	         in the buffer MUST be immediately compared against the pattern
3305	         elements.

3307	         fdt: defines the first-digit timer value. The first-digit timer
3308	         is started when DTMF detection is initially invoked. If no DTMF
3309	         digits are detected during this initial interval, the <noinput>
3310	         element MUST be invoked.

3312	         idt: defines the inter-digit timer to be used when digits are
3313	         being collected. When specified, the timers is started when the
3314	         first digit is detected and restarted on each subsequent digit.
3315	         Timer expiration is applied to all patterns. After that, if any
3316	         patterns remain active and a nomatch element is specified, the
3317	         nomatch is executed and DTMF input MUST terminate. The idt
3318	         attribute should only be used when digit collection is being
3319	         performed. No default.

3321	         starttimer: boolean value which defines whether the first digit
3322	         timer (fdt) is started initially. When set to false, the
3323	         starttimer event must be received for it to start. Default
3324	         false.

3326	                                 (MSML)

3328	         iterate: specifies the number of times the <pattern>,
3329	         <noinput>, and <nomatch> elements may be executed unless those
3330	         elements specify differently. The value "forever" MAY be used
3331	         to indicate that these may be executed any number of times.
3332	         Default is once '1'.

3334	      Events:

3336	         Following describes input events to the media primitive object.
3337	         The MSML Dialog Group package allows an event exchange
3338	         mechanism between primitives.

3340	         starttimer: starts the first digit timer (fdt) if it has not
3341	         already been started. Has no effect otherwise.

3343	         terminate: terminates the DTMF input and assigns values to the
3344	         shadow variables.

3346	      Shadow Variables:

3348	         dtmf.digits: the string of DTMF digits which have been received
3349	         (the contents of the digit buffer).

3351	         dtmf.len: the number of digits in the digit buffer.

3353	         dtmf.last: the last digit in the digit buffer.

3355	         dtmf.end: contains the event which caused the <dtmf> to
3356	         terminate or is assigned one of "dtmf.match", "dtmf.noinput",
3357	         or "dtmf.nomatch" depending upon which of the corresponding
3358	         elements reached its maximum.

3360	   The following sections describe the child elements of <dtmf> or
3361	   <collect>.

3363	10.7.4.1 <play>

3365	   The optional <play> element as a child element of <dtmf> or <collect>
3366	   allows a prompt to be played prior to DTMF digit collection. DTMF
3367	   digit collection starts at the end of the play sequence or if the
3368	   play is barged by DTMF, assuming that barge=true is specified for
3369	   <play>. For a complete description, refer to <play> element.

3371	10.7.4.2 <pattern>

3373	   The pattern element describes one or more DTMF digits that are to be
3374	   recognized. When the pattern is matched, the child elements MUST be
3375	   executed.

3377	                                 (MSML)

3379	      Attributes:

3381	         digits: The digit pattern which should be matched.

3383	         format: an enumerated value which defines the format used to
3384	         express the digit pattern. The format may be "mgcp" or "megaco"
3385	         for patterns expressed as digit map from those specifications,
3386	         or as one of the simple built-in formats defined within this
3387	         specification. Currently, a single built-in format
3388	         "moml+digits" is defined which allows a match based on either
3389	         one or more specific digits, or based upon a specific length
3390	         specification with an optional return key. "moml+digits" is the
3391	         default.

3393	         iterate: specifies the number of times the <pattern> may be
3394	         matched. The value "forever" may be used to indicate that
3395	         <pattern> may be matched any number of times. This value
3396	         overrides any specified in <dtmf>. Default is once '1'.

3398	10.7.4.3 <detect>

3400	   The contents of the <detect> element MUST be executed whenever any
3401	   DTMF is first detected. It MUST be matched at most once.

3403	      Attributes:

3405	         none

3407	10.7.4.4 <noinput>

3409	   The <noinput> element is used when DTMF is being collected. Children
3410	   of the <noinput> element MUST be executed when DTMF has not been
3411	   detected and the first digit timeout occurs.

3413	      Attributes:

3415	         iterate: specifies the number of times the <noinput> may be
3416	         triggered. The value "forever" may be used to indicate that
3417	         <noinput> may be triggered any number of times. This value
3418	         overrides any specified in <dtmf>. Default is once '1'.

3420	10.7.4.5 <nomatch>

3422	   The <nomatch> element is used when DTMF is being collected. Children
3423	   of the <nomatch> element MUST be executed when it is determined that
3424	   none of the individual patterns can be matched.

3426	      Attributes:

3428	                                 (MSML)

3430	         iterate: specifies the number of times the <nomatch> may be
3431	         triggered. The value "forever" may be used to indicate that
3432	         <nomatch> may be triggered any number of times. This value
3433	         overrides any specified in <dtmf>. Default is once '1'.

3435	10.7.4.6 <dtmfexit>

3437	   The <dtmfexit> element MUST be invoked when the dtmf input completes
3438	   because one of <pattern>, <noinput>, or <nomatch> occurred its
3439	   maximum number of times.

3441	      Attributes:

3443	         None

3445	10.7.5 <moml>

3447	   The root element <moml> MUST be used when the document is a stand-
3448	   alone MSML Dialog, where the invoking application media type
3449	   indicates �application/moml+xml�. Additionally, for backwards
3450	   compatibility, the <moml> element MUST be used within <dialogstart>
3451	   which contains an in-line embedded MSML dialog.

3453	   Valid contents of <moml> are all elements described within this MSML
3454	   Dialog Base package.

3456	      Attributes:

3458	         version: "1.0" Mandatory.

3460	         id: an identifier unique to this object. Events returned from
3461	         MSML dialog (the "target" attribute of a <send> is equal to
3462	         "source") will be correlated with this identifier. Mandatory.

3464	      Events:

3466	         terminate: terminates the MOML context. A terminate event gets
3467	         sent to the currently executing <group> or primitive.

3469	10.8 MSML Dialog Group Package

3471	   The group package defines a single control flow construct that
3472	   specifies concurrent execution. Primitives are composed for
3473	   concurrent execution by placing them within a <group> element. Groups
3474	   define how media flows between multiple concurrently executing
3475	   primitives. They have one or more inputs and one or more outputs. A
3476	                                 (MSML)

3478	   <group> represents the declaration of a complex media processing
3479	   operation. The event interaction between primitives (see the
3480	   following sub-section) is defined within the context of one or more
3481	   groups. However groups themselves do not scope events, they simply
3482	   define that primitives are concurrently executing and a primitive
3483	   must be executing in order to receive an event.

3485	   Placing primitives within a group structure is an optional feature of
3486	   this specification. It allows for complex services to created using
3487	   the event exchange mechanism between the primitives. For simpler
3488	   services, such as play/collect or play/record, the use of group
3489	   mechanism is not necessary. MSML Dialog Group package is dependent on
3490	   the MSML Dialog Base package.

3492	   Groups may also be used to describe media objects which transform a
3493	   media stream while optionally allowing application or user control of
3494	   the transformation. For example a gain control could be defined which
3495	   responds to user speech or DTMF input. In this case a recognition
3496	   primitive would send events to a gain control primitive.

3498	   Groups have one attribute which defines the media flow within them.
3499	   They also have a dimension which defines how many media inputs and
3500	   outputs they have. Currently dimensions of 1 and 2 are supported
3501	   based upon the group topology. These correspond to a group with one
3502	   input and one output and a group with two inputs and two outputs.

3504	   Media flow to and from the primitives within the group is based upon
3505	   a topology attribute of the <group> element. This differs from a
3506	   similar mechanism in Media Policy Manipulation in the Conference
3507	   Policy Control Protocol [3] which explicitly defined connections. The
3508	   topology attribute defines a topology schema and implies the group
3509	   dimension.

3511	   There are several common ways in which primitives are often connected
3512	   together. A schema provides a convenient template which can be
3513	   applied to multiple primitives without having to define all of the
3514	   individual media relationships. The following two schemas are
3515	   initially defined for 1 dimensional groups:

3517	   o  parallel: specifies that media sent to the group is sent to every
3518	   primitive which has an input. The group bridges the output from every
3519	   primitive which has an output into a single common group output;

3521	   o  serial: specifies that the first primitive listed in the group
3522	   receives the media sent to the group. Its output is to be connected
3523	   to the input of the next primitive defined within the group and so on
3524	   until the last primitive within the group which becomes the group
3525	   output.

3527	                                 (MSML)

3529	   Groups with these topologies are shown in the two diagrams below. The
3530	   group on the left has a parallel topology and that on the right has a
3531	   serial topology.

3533	           /-> P1 --\
3534	          /          \
3535	   G(in) +---> P2 ----> G(out)     G(in) --> P1 --> P2 --> P3 --> G(out)
3536	          \          /
3537	           \-> P3 --/

3539	   More complex media flows MAY be created by nesting groups of serial
3540	   and parallel topologies within each other. For example, the diagram
3541	   below has a group with a serial topology nested within a star
3542	   topology.

3544	                  /-----> P1 ------------------------\
3545	                 /                                    \
3546	         Gs(in) +-> Gp(in) --> P2 --> P3 --> Gp(out) -+> Gs(out)

3548	   This combination could be used to create record operation where DTMF
3549	   was to be clamped from the recording itself, but a DTMF key press is
3550	   still used to stop the recording. In this case, P1 would be a DTMF
3551	   recognizer, P2 would be a clamp primitive, and P3 a recorder as shown
3552	   by the following example. This example omits child elements and
3553	   attributes not concerned with the core concept. The following section
3554	   discusses sending events and the details of each of the primitives is
3555	   defined in section 4.

3557	         <group topology="parallel">
3558	            <dtmf/>
3559	            <group topology="serial">
3560	               <clamp/>
3561	               <record/>
3562	            </group>
3563	         </group>

3565	   A single schema, "fullduplex" is defined for a two dimensional group.
3566	   A full-duplex two dimensional group is has exactly two immediate
3567	                                 (MSML)

3569	   children. Those children may be primitives or other one dimensional
3570	   groups. A "fullduplex" group must only be used as the top most group
3571	   and must not be nested. Each primitive (P1) and group (G2) becomes
3572	   half of the full-duplex group as shown in the diagram below.

3574	                 G-A(in1)  +-> G2 --> G-B(out1)

3576	                 G-A(out2) <-- P1 <-+ G-B(in2)

3578	   Full duplex groups are symmetrical when both halves are the same.
3579	   They are asymmetrical when they differ. Asymmetric groups need to
3580	   have a name associated with each side. The left side is defined as
3581	   the input of the first child of the full-duplex group combined with
3582	   the output of the second child. The right side is reverse. These
3583	   sides were labeled A and B respectively in the preceding diagram.

3585	   An example of a full-duplex group is the user operated gain control
3586	   mentioned at the beginning of this sub-section. The gain should
3587	   operate on the audio which a user hears, but the gain is controlled
3588	   by recognizing things such as DTMF or spoken commands in media which
3589	   the user originates. The following shows the XML tag grouping which
3590	   would accomplish this and corresponds to the media flow shown in the
3591	   diagram above. If the user's audio is not required for anything other
3592	   than control of the gain, then the <relay> is not required and the
3593	   internal group could be omitted. A complete XML description for this
3594	   is included in the examples section.

3596	         <group topology="fullduplex">
3597	            <group topology="parallel">
3598	               <dtmf/>
3599	               <relay/>
3600	            </group>
3601	            <gain/>
3602	         </group>

3604	   Primitives within a group MUST begin concurrently but MAY finish
3605	   asynchronously based upon events which they receive or their task
3606	   completes. A group MUST terminate when all of the primitives within
3607	   it have completed. If the group contains a <groupexit> element, then
3608	   the contents of that element MUST be executed as part of group
3609	   termination.

3611	                                 (MSML)

3613	   A group itself MAY receive a terminate event requesting termination.
3614	   A terminate event sent to the group causes a terminate event to be
3615	   sent to each of its currently active primitives. The <groupexit>
3616	   element is not executed until all primitives have processed their
3617	   respective terminate events.

3619	10.8.1 <group>

3621	   The <group> element allows the contained primitives to be executed
3622	   concurrently.

3624	   Attributes:

3626	   topology: specifies a schema which defines the flow of media within
3627	   the group. Three schemas are initially defined. "fullduplex" is
3628	   specified for use with two dimensional groups. "parallel" and
3629	   "serial" are for use with one dimensional groups. The definition of
3630	   these topologies is defined in section 2. Mandatory.

3632	   id: identifies name of the group. Mandatory when groups are nested.

3634	   Events:

3636	   terminate: causes a terminate event to be sent to each element
3637	   contained within the group.

3639	10.8.2 <groupexit>

3641	   The <groupexit> element allows events to be sent when group
3642	   processing completes. Group processing completes when all contained
3643	   primitives terminate.

3645	   Attributes:

3647	   none

3649	   Events:

3651	   none

3653	10.9 MSML Dialog Transform Package

3655	   The MSML Dialog Transform package gathers together the simple
3656	   primitives which work as filters on half duplex media streams.

3658	                                 (MSML)

3660	10.9.1 <vad>

3662	   Voice activity detection (VAD) is used to detect voice and silence
3663	   when speech recognition is not required. Similar to both speech and
3664	   DTMF, a VAD has different media conditions which it can match. Those
3665	   conditions can be qualified by a minimum length of time which is
3666	   required for them to be considered recognized.

3668	      Attributes:

3670	         starttimer: boolean value which defines whether the timer is
3671	         started to allow recognition of the initial condition (voice,
3672	         silence). When set to false, the starttimer event must be
3673	         received in order for the initial condition to be recognized.
3674	         The timer does not affect recognition of the transition
3675	         conditions. Default false.

3677	      Events:

3679	         starttimer: starts the timer to allow recognition of the
3680	         initial condition if it has not already been started. Has no
3681	         effect otherwise.

3683	         terminate: terminates voice activity detection.

3685	      Shadow Variables:

3687	         none

3689	   The following sections describe the child elements of <vad>.

3691	10.9.1.1 <voice>, <silence>, <tvoice>, <tsilence>

3693	   Each child element corresponds to a condition which a VAD can detect.
3694	   The first two detect when voice or silence has been initially present
3695	   for a minimum length of time since the VAD was started. The second
3696	   two require that a transition to the voice or silence condition first
3697	   occur.

3699	      Attributes:

3701	         len: the length of time the condition must persist in order to
3702	         be recognized. In the case of <tvoice> and <tsilence>, the
3703	         length of time applies only to the final recognized condition.

3705	         sen: the maximum length of time the condition not being
3706	         detected may occur without causing the detector to begin
3707	         measuring that condition.

3709	                                 (MSML)

3711	10.9.2 <gain>

3713	   Gain MAY be used to adjust of the gain of a media stream by a
3714	   specific amount.

3716	      attributes:

3718	         incr: an increment, expressed in dB, which will be used to
3719	         adjust the gain when "louder" and "softer" events are received.
3720	         Default is 3 dB.

3722	         amt: a specific gain to apply specified in dB.

3724	      events:

3726	         mute: self explanatory.

3728	         unmute: self explanatory.

3730	         reset: sets the gain to zero dB.

3732	         louder: makes the audio on a stream louder.

3734	         softer: makes the audio on a stream quieter.

3736	         amt: sets the gain to the specified value between -96 dB and 9
3737	         dB.

3739	10.9.3 <agc>

3741	   Automatic gain control MAY be used to have a media server
3742	   automatically adjust the gain of a media stream.

3744	      attributes:

3746	         tgtlvl: the desired target level for AGC specified in dBm0.

3748	         maxgain: the maximum gain that AGC will apply specified in dB.

3750	      events:

3752	         mute: self explanatory.

3754	         unmute: self explanatory.

3756	                                 (MSML)

3758	10.9.4 <gate>

3760	   A simple filter which will pass or halt media, regardless of the
3761	   format of the media stream, based on the events it receives. <gate>
3762	   shares the same mute and unmute events for compatibility with the
3763	   gain primitives <gain> and <agc>.

3765	      attributes:

3767	         initial: the values "pass" and "halt" define whether media is
3768	         initially allowed to pass. Default is to pass.

3770	      events:

3772	         mute: halts media flow through the primitive.

3774	         unmute: allows media to pass through the primitive.

3776	10.9.5 <clamp>

3778	   This element MAY be used to filter DTMF tones from a media stream.
3779	   Media other than DTMF tones is passed unchanged.

3781	      attributes:

3783	         none.

3785	      events:

3787	         none.

3789	10.9.6 <relay>

3791	   This element is a simple primitive which copies its input to its
3792	   output.

3794	      attributes:

3796	         none.

3798	      events:

3800	         none.

3802	10.10 MSML Dialog Speech Package

3804	   The MSML speech package defines functionality which MAY be used for
3805	   automatic speech recognition <speech> and extends the <play>
3806	                                 (MSML)

3808	   primitive defined in the MSML Dialog Base package to include speech
3809	   synthesis. As such, this package depends on the MSML Dialog Base
3810	   package.

3812	10.10.1 <speech>

3814	   Activates grammars or user input rules associated with speech
3815	   recognition. If multiple grammars are specified, all are activated.
3816	   All active grammars share the same timers, recognition attributes,
3817	   and <noinput> and <nomatch> elements. Each grammar may have its own
3818	   <match> element.

3820	   <speech> terminates if any of the <grammar>, <noinput>, or <nomatch>
3821	   elements are matched the maximum number of times that they are
3822	   allowed. The number of times they may match may be specified as an
3823	   attribute of <speech> or of the individual child elements.

3825	      Attributes:

3827	         noint: specifies a time period during which speech input must
3828	         be started, otherwise the associated <noinput> element is
3829	         invoked.

3831	         norect: specifies a maximum time period during in which speech
3832	         must begin to be matched, otherwise the associated <nomatch>
3833	         element is invoked.

3835	         spcmplt: specifies the length of silence necessary after speech
3836	         before a result will be finalized in the case where there is a
3837	         complete match of an active grammar. Following the silence, the
3838	         appropriate <match> element will be triggered if the result is
3839	         above the confidence level. Otherwise a <nomatch> element will
3840	         be triggered.

3842	         spincmplt: specifies the length of silence necessary after
3843	         speech before a result will be finalized in the case where
3844	         there is a incomplete match of all active grammars. Following
3845	         the silence, the <nomatch> element will be triggered.

3847	         confidence: the minimum confidence level which the recognizer
3848	         must have to consider a recognition result as matching a
3849	         grammar. Expressed as an integer between 1-100.

3851	         sens: specifies the sensitivity of the recognizer to determine
3852	         whether speech is present. Lower sensitivity may be required
3853	         for the recognizer to work well in the presence of high
3854	         background noise or line echo.

3856	                                 (MSML)

3858	         starttimer: boolean value which defines whether the no input
3859	         (noint) and no recognition (norect) are started initially. When
3860	         set to false, the starttimer event must be received in order to
3861	         start them. Default false.

3863	         iterate: specifies the number of times the <grammar>,
3864	         <noinput>, and <nomatch> elements may be executed unless those
3865	         elements specify differently. The value "forever" may be used
3866	         to indicate that these may be executed any number of times.
3867	         Default is once '1'.

3869	      Events:

3871	         sens: sets the sensitivity of the recognizer as described
3872	         above.

3874	         starttimer: starts the no input (noint) and no recognition
3875	         (norect) timers if they have not already been started. Has no
3876	         effect otherwise.

3878	         terminate: terminates the speech input and assigns values to
3879	         the shadow variables.

3881	      Shadow Variables:

3883	         speech.end: contains the event which caused the <speech> to
3884	         terminate or is assigned one of "speech.match",
3885	         "speech.noinput", or "speech.nomatch" depending upon which of
3886	         the corresponding elements reached its maximum.

3888	         speech.results: contains the results of a matched grammar. The
3889	         results are formatted using the Natural Language Semantics
3890	         Markup Language (NLSML) [6]. When this variable is referenced
3891	         to return results, the results are returned as a separate MIME
3892	         entity.

3894	   The following sections describe the child elements of <speech>.

3896	10.10.1.1 <grammar>

3898	   Specifies and activates a speech grammar based on Speech Recognition
3899	   Grammar Specification (SRGS) [5] XML notation. Grammars may be
3900	   referenced by a URI or defined inline. Child elements of <match> MUST
3901	   be executed when the specified speech grammar is matched.

3903	      Attributes:

3905	                                 (MSML)

3907	         uri: specifies the location of an SRGS grammar when the grammar
3908	         is not defined inline.

3910	         iterate: specifies the number of times the <grammar> may be
3911	         matched. The value "forever" MAY be used to indicate that
3912	         <grammar> may be matched any number of times. This value
3913	         overrides any specified in <speech>. Default is once '1'.

3915	10.10.1.2 <match>

3917	   <match> is a child of <grammar> and specifies the actions to take
3918	   when the corresponding grammar is matched.

3920	10.10.1.3 <noinput>

3922	   The <noinput> element is used when speech is being recognized.
3923	   Children of the <noinput> element MUST be executed when speech has
3924	   not been detected and the no input timeout (noint) occurs.

3926	      Attributes:

3928	         iterate: specifies the number of times the <noinput> may be
3929	         triggered. The value "forever" may be used to indicate that
3930	         <noinput> may be triggered any number of times. This value
3931	         overrides any specified in <speech>. Default is once '1'.

3933	10.10.1.4 <nomatch>

3935	   The <nomatch> element is used when speech is being recognized.
3936	   Children of the <nomatch> element MUST be executed when it is
3937	   determined that none of the active grammars will match.

3939	      Attributes:

3941	         iterate: specifies the maximum number of times the <nomatch>
3942	         may be triggered. The value "forever" MAY be used to indicate
3943	         that <nomatch> may be triggered any number of times. This value
3944	         overrides any specified in <speech>. Default is once '1'.

3946	10.10.1.5 <speechexit>

3948	   The <speechexit> element MUST be invoked when the speech input
3949	   completes because one of <grammar>, <noinput>, or <nomatch> occurred
3950	   its maximum number of times.

3952	      Attributes:

3954	         none
3955	                                 (MSML)

3957	10.10.2 <play>

3959	   The <play> element, as defined in the MSML Dialog Base package, is
3960	   extended with a new child element for synthesizing speech. From an
3961	   XML perspective, <tts> is a member of a media substitution group. See
3962	   the schema at the end of this document for details.

3964	   The following sections describe the child elements of <play>.

3966	10.10.2.1 <tts>

3968	   Contents of the <tts> element are rendered using Text To Speech
3969	   services and must be compliant to the SSML specification. Element
3970	   content MAY be plain text, contain the SSML <speak> element, or the
3971	   uri attribute should identify the location of text to be rendered.

3973	      Attributes:

3975	         uri: Identifies the location of the text to be rendered. The
3976	         file and http schemes are supported.

3978	         iterate: specifies the number of times the text to speech block
3979	         is to be rendered. Defaults to once '1'.

3981	         xml:lang: specifies the language to use when it is not
3982	         explicitly specified as an attribute for <speak>.

3984	10.11 MSML Dialog Fax Detection Package

3986	   The fax detection package defines primitives which allow a media
3987	   server to provide facsimile detection services.

3989	10.11.1 <faxdetect>

3991	   Fax tone detection is used to detect the presence of the T.30 CNG
3992	   tone in a media stream. Child elements of <faxtone> are executed when
3993	   the CNG tone is detected.

3995	      Attributes:

3997	         None
3998	                                 (MSML)

4000	10.12 MSML Dialog Fax Send/Receive Package

4002	10.12.1 <faxsend>

4004	   The <faxsend> primitive provides the functionality of a calling fax
4005	   terminal. This typically means sending a set of pages. However, it
4006	   can also mean requesting the called terminal to send pages instead
4007	   of, or in addition to, sending pages. The fax images to send are
4008	   defined by the <sendobj> elements, described below.

4010	   Requesting the called terminal to send pages happens when the
4011	   <rxpoll> element is included as part of <faxsend>. This element may
4012	   be included in addition to, or instead of, the <sendobj> element. One
4013	   <sendobj> (at a minimum) or <rxpoll> element must be present. When
4014	   both are present, a media server will first send pages and will then
4015	   poll the other terminal, requesting pages.

4017	   Because fax is a distinct media type, the <faxsend> primitive is not
4018	   expected to interact with other primitives. Rather, it will interact
4019	   using fax protocols with a remote fax terminal (or gateway) and will
4020	   send requested status events to its invoking environment. During fax
4021	   operation, shadow variables are used to record the progress and
4022	   parameters of the varying stages of fax operation.

4024	   Status events are requested by including one or more status request
4025	   elements. These elements correspond to different stages or events in
4026	   fax operation and cause pre-defined events to be sent to the invoking
4027	   environment when they occur. Since the only recipient of these events
4028	   is expected to be a fax Control Agent, requests are simplified by
4029	   associating a pre-defined namelist of shadow variables with each
4030	   event. This decision may be revisited to allowed tailored namelists
4031	   based on further implementation experience. Status requests apply
4032	   both to sending and polling operation.

4034	      Attributes:

4036	         lclid: the identifier that a media server uses to identify
4037	         itself.

4039	         minspeed: the minimum acceptable speed to negotiate for the
4040	         operation.

4042	         maxspeed: the maximum speed to negotiate for the operation.
4043	         This attribute is primarily for testing purposes.

4045	         ecm: specifies whether Error Correction Mode (ECM) is allowed
4046	         to be used if supported by the remote terminal. Defaults to
4047	         "true".

4049	                                 (MSML)

4051	      Events:

4053	         terminate: terminates the fax send operation.

4055	      Shadow Variables:

4057	         fax.rmtid: the identifier of the remote fax terminal.

4059	         fax.rate: the negotiated speed for the operation.

4061	         fax.resolution: identifies the resolution of the image. Both
4062	         metric and inch based resolutions are defined. Metric based
4063	         resolutions are: 75x75, 150x150, 204x98, 204x196, 204x391,
4064	         408x391. Inch based resolutions are: 200x200, 300x300, 400x400,
4065	         600x600.

4067	         fax.pagesize: identifies the negotiated page size. Metric sizes
4068	         are "A3", "A4", "A5", "A6", and "B4". Inch based page sizes are
4069	         "Letter" and "Legal".

4071	         fax.encoding: identifies the image encoding utilized. Valid
4072	         values are "MH", "R", "MMR", and "JPEG".

4074	         fax.ecm: identifies whether ECM operation was used.

4076	         fax.pagebadlines: the number of bad lines in a page.

4078	         fax.objbadlines: the number of bad lines in an object.

4080	         fax.opbadlines: the number of bad lines in an operation.

4082	         fax.objuri: the objuri of the current object.

4084	         fax.resendcount: the number of pages resent due to errors.

4086	         fax.totalpages: the number of pages processed or stored.

4088	         fax.totalobjects: the count of the objects used in the
4089	         operation.

4091	         fax.duration: the duration of the operation expressed as a
4092	         duration in seconds and milliseconds (e.g. "23s250ms").

4094	         fax.result: contains the reason which caused the fax operation
4095	         to complete. When the operation completes successfully, the
4096	         value will be assigned "fax.success". Other values include:
4097	         "fax.partial", "fax.nofax", "fax.remotedisconnect",
4098	         "fax.uri.access.error", and "fax.invalid.startpage".

4100	                                 (MSML)

4102	   The following sections describe the child elements of <faxsend>.

4104	10.12.1.1 <sendobj>

4106	   <sendobj> is used to define a fax transmission. There MAY be multiple
4107	   instances of the element which will be transmitted in order.

4109	      Attributes:

4111	         objuri: a URI that points to the fax image that will be
4112	         transmitted. Mandatory.

4114	         startpage: the first page of a multi-page objuri to send.

4116	         pagecount: page count.

4118	10.12.1.2 <hdrfooter>

4120	   <hdrfooter> describes the header/footer that a media server MAY put
4121	   on pages. The header or footer may be defined as the content of the
4122	   <format> child element. The <format> element is only allowed if the
4123	   type attribute has a value of "header" or "footer".

4125	      Attributes:

4127	         type: specifies whether a header or a footer should be put on
4128	         pages and identifies the source of the header or footer. The
4129	         following enumerated values may be used:

4131	            "header" indicates that the media server should put a header
4132	                     on pages using the contents of the <format>
4133	                     element.

4135	            "nohdr"  indicates that there should be no header or footer.

4137	            "footer" indicates that the media server should put a footer
4138	                     on pages using the contents of the <format>
4139	                     element.

4141	         style: defines the style of insertion onto a fax page that a
4142	         media server should use for the header or footer. Valid styles
4143	         are "append", "overlay", or "replace".

4145	   <format> is a child of the <hdrfooter> element that defines the style
4146	   format to be used for the header or footer. It uses a "C" language
4147	   style format statement (as shown below) to define the contents and
4148	   layout of the header or footer.

4150	                                 (MSML)

4152	           code    length   name              format
4153	            %a       3     day of week       3-character abbreviation
4154	            %d       2     date              01-31
4155	            %m       2     month             01-12
4156	            %y       2     year              00-99
4157	            %Y       4     year              0000-9999
4158	            %I       2     12 hour           01-12
4159	            %H       2     24 hour           00-23
4160	            %M       2     minute            00-59
4161	            %S       2     seconds           00-59
4162	            %p       2     AM/PM             AM or PM
4163	            %P       2     page number       01-99
4164	            %T       2     total pages       01-99
4165	            %l       20    local ID (sender) 0-9, + or spaces
4166	            %r       20    remote ID (rcvr)  0-9, + or spaces
4167	            %%       1     percent           display % in header/ftr
4168	10.12.1.3 <rxpoll>

4170	   <rxpoll> provides the information necessary for a receive polling
4171	   operation to occur. The object(s) to be received are defined by one
4172	   or more <rcvobj> elements. The <rcvobj> is defined further under the
4173	   child elements of <faxrcv>. The <rxpoll> element MAY also include a
4174	   description of the header/footer that a media server SHOULD put on
4175	   received pages. The <hdrfooter> element and it's usage is described
4176	   above.

4178	      Attributes:

4180	         rmtid: specifies the identifier of the remote fax terminal that
4181	         to be associated with a polling operation. A media server MUST
4182	         NOT execute a polling operation unless the value of rmtid
4183	         matches that of the connected remote machine.

4185	10.12.1.4 <faxstart>

4187	   Requests that an event be sent when fax operation has begun. When
4188	   triggered, the following will be executed:

4190	   <send target="source" event="fax.start"/>
4191	                                 (MSML)

4193	10.12.1.5 <faxnegotiate>

4195	   Requests that an event be sent when a negotiation has been completed.
4196	   Multiple events MAY be sent each time a DCS frame is sent or
4197	   received. When triggered, the following will be executed:

4199	   <send target="source" event="fax.negotiate"
4200	      namelist="fax.rmtid
4201	         fax.rate
4202	         fax.resolution
4203	         fax.pagesize
4204	         fax.encoding
4205	         fax.ecm"/>

4207	10.12.1.6 <faxpagedone>

4209	   Requests that an event be sent when a page has been sent or received.
4210	   When triggered, the following will be executed:

4212	   <send target="source" event="fax.pagedone"
4213	         namelist="fax.resolution
4214	         fax.pagesize
4215	         fax.encoding
4216	         fax.pagebadlines
4217	         fax.resendcount"/>

4219	10.12.1.7 <faxobjectdone>

4221	   Requests that an event be sent when an objuri has been completed.
4222	   When triggered, the following will be executed:

4224	   <send target="source" event="fax.objectdone"
4225	         namelist="fax.objuri
4226	         fax.objbadlines
4227	         fax.resendcount
4228	         fax.totalpages
4229	         fax.result"/>

4231	10.12.1.8 <faxopcomplete>

4233	   Requests that an event be sent when an operation has been completed.
4234	   When triggered, the following will be executed:

4236	                                 (MSML)

4238	   <send target="source" event="fax.opcomplete"
4239	         namelist="fax.totalpages
4240	         fax.opbadlines
4241	         fax.resendcount
4242	         fax.totalobjects
4243	         fax.duration
4244	         fax.result"/>

4246	10.12.1.9 <faxpollstarted>

4248	   Requests that an event be sent when a polling operation has started.
4249	   When triggered, the following will be executed:

4251	   <send target="source" event="fax.opcomplete"
4252	         namelist="fax.rmtid
4253	         fax.rate
4254	         fax.resolution
4255	         fax.pagesize
4256	         fax.encoding
4257	         fax.ecm"/>

4259	10.12.2 <faxrcv>

4261	   The <faxrcv> primitive provides the functionality of a called fax
4262	   terminal. Typically this type of operation is to receive pages.
4263	   However, it can include sending pages instead of, or in addition to,
4264	   receiving them. The fax objects to receive are defined by the
4265	   <rcvobj> elements, described below.

4267	   A media server SHOULD send pages as a polled terminal when the
4268	   <txpoll> element is included as part of <faxrcv>. This element may be
4269	   included in addition to, or instead of, the <rcvobj> element. One
4270	   <rcvobj> or <txpoll> element must be present. When both are present,
4271	   a media server SHOULD first receive pages and will then allow the
4272	   other terminal to poll the media server, requesting pages.

4274	   Because fax is a distinct media type, the <faxrcv> primitive is not
4275	   expected to interact with other primitives. Rather, it will interact
4276	   using fax protocols with a remote fax terminal and will send
4277	   requested status events to its invoking environment. During fax
4278	   operation, shadow variables are used to record the progress and
4279	   parameters of the varying stages of fax operation.

4281	   Status events are requested by including one or more status request
4282	   elements. These elements correspond to different stages or events in
4283	   fax operation and cause pre-defined events to be sent to the invoking
4284	   environment when they occur. Since the only recipient of these events
4285	   is expected to be a fax Control Agent, requests are simplified by
4286	                                 (MSML)

4288	   associating a pre-defined namelist of shadow variables with each
4289	   event. This decision may be revisited to allowed tailored namelists
4290	   based on further implementation experience. Status requests apply
4291	   both to receiving and polling operation.

4293	      Attributes:

4295	         lclid: the identifier that a media server uses to identify
4296	         itself.

4298	         ecm: specifies whether ECM mode is allowed to be used if
4299	         supported by the remote terminal. Defaults to "true".

4301	      Events:

4303	         terminate: terminates the fax reception operation.

4305	      Shadow Variables:

4307	         <faxrcv> supports the same set of shadow variables as <faxsend>

4309	   The following sections describe the child elements of <faxrcv>.

4311	   In addition to the elements defined below, <faxrcv> MAY also have the
4312	   following child elements which were defined under <faxsend>:

4314	      o  <hdrfooter>
4315	      o  <faxstart>
4316	      o  <faxnegotiate>
4317	      o  <faxpagedone>
4318	      o  <faxobjectdone>
4319	      o  <faxopcomplete>
4320	      o  <faxpollstarted>

4322	   Their meaning and usage is the same as previously defined.

4324	10.12.2.1 <rcvobj>

4326	   <rcvobj> is used to define fax objects that a media server will
4327	   receive. There may be multiple instances of the element which will be
4328	   used in order.

4330	      Attributes:

4332	         objuri: a URI that points to the location that a received image
4333	         is to be stored. Mandatory.

4335	                                 (MSML)

4337	         maxpages: the maximum number of pages that will be stored in
4338	         objuri.

4340	10.12.2.2 <txpoll>

4342	   <txpoll> provides the information for a polling operation to occur as
4343	   part of a fax receive operation. Multiple object(s) to be send may be
4344	   supplied by one or more <sendobj> elements. In the event of multiple
4345	   occurrences, a media server MUST select the <sendobj> element whose
4346	   rmtid attribute matches that of the remote terminal.

4348	   The <sendobj> element was defined previously as a child element of
4349	   <faxsend>. For <txpoll> is extended with an rmtid attribute that
4350	   specifies the identifier of the remote fax terminal and is used to
4351	   select the specific <sendobj> to send.

4353	   A media server SHOULD put a header/footer on transmitted pages based
4354	   on any <hdrfooter> element included as part of <txpoll>.

4356	      Attributes:

4358	         none

4360	11. Response Codes

4362	   Response codes are used to indicate reasons for failures as well as
4363	   completion status. The appropriate code and description must be
4364	   passed to the invoking environment on failure.

4366	   The response codes defined in this section are returned as the value
4367	   of the response attribute to the <result> element. Some values may
4368	   also be returned as part of a namelist to an "msml.dialog.exit" event
4369	   generated when an executing MSML dialog fails.

4371	      Informational (1xx)

4373	         Reserved for future use

4375	      Success (200)

4377	         200 OK

4379	      Request Error (4xx)

4381	         400  Bad Request
4382	         401  Unknown Element
4383	         402  Unsupported Element
4384	                                 (MSML)

4386	         403  Missing mandatory element content
4387	         404  Forbidden element content
4388	         405  Invalid element content
4389	         406  Unknown attribute
4390	         407  Attribute not supported
4391	         408  Missing mandatory attribute
4392	         409  Forbidden attribute is present

4394	         410  Invalid attribute value

4396	         420 Unsupported media description language
4397	         421 Unknown media description language
4398	         422 Ambiguous request (both URI and inline description)
4399	         423 External document fetch error
4400	         424 Syntax error in foreign language
4401	         425 Semantic error in foreign language
4402	         426 Unknown error executing foreign language

4404	         430 Object does not exist
4405	         431 Object instance name already used
4406	         432 Conference name already in use
4407	         433 reserved
4408	         434 External document fetch error

4410	         440 Cannot join objects of the specified class
4411	         441 Objects have incompatible media types
4412	         442 reserved
4413	         443 reserved
4414	         444 Number of media inputs exceeded

4416	         450 Objects have incompatible media formats
4417	         451 Incompatible media stream format
4418	                                 (MSML)

4420	      Server Error (5xx)

4422	         500  Internal media server error
4423	         503  Service Unavailable
4424	         510  Not in service
4425	         511  Service Unavailable
4426	         520  No resource to fulfill request
4427	         521  Internal limit exceeded

4429	12. MSML Conference Examples

4431	   These examples focus on MSML Conference Core package used by an
4432	   Control Agent (CA) to control services on a Media Server (MS). They
4433	   show the relationship between SIP signaling to establish media
4434	   sessions and MSML service control commands. For brevity, only the
4435	   content of MSML messages is shown. The examples assumes that the CA
4436	   and MS use the IPv4 address and UDP port number of the audio stream
4437	   (on the MS) to identify the MSML connection.

4439	12.1 Establishing a Dial-in Conference

4441	           UA                   Control Agent             Media Server
4442	           |                         |                           |
4443	           |                         |        INVITE F1          |
4444	           |                         |-------------------------->|
4445	           |                         |           200 F2          |
4446	           |                         |<--------------------------|
4447	           |                         |           ACK F3          |
4448	           |                         |-------------------------->|
4449	           |                         |                           |
4450	           |                         |     createconference> F4  |
4451	           |                         |-------------------------->|
4452	           |                         |           200 F5          |
4453	           |                         |<--------------------------|
4454	           |    INVITE (SDP UA) F6   |                           |
4455	           |------------------------>|                           |
4456	           |                         |      INVITE (SDP UA) F7   |
4457	           |                         |-------------------------->|
4458	           |                         |        200 (SDP MS) F8    |
4459	           |                         |<--------------------------|
4460	           |                         |           ACK F9          |
4461	                                 (MSML)

4463	           |                         |-------------------------->|
4464	           |     200 (SDP MS) F10    |                           |
4465	           |<------------------------|                           |
4466	           |        ACK F11          |                           |
4467	           |------------------------>|                           |
4468	           |                         |     <dialogstart> F12     |
4469	           |                         |-------------------------->|
4470	           |                         |           200 F13         |
4471	           |                         |<--------------------------|
4472	           |                         |    HTTP interactions F14  |
4473	           |                         |<------------------------->|
4474	           |                         |  <event>(dialog.exit) F15 |
4475	           |                         |<--------------------------|
4476	           |                         |         <join> F16        |
4477	           |                         |-------------------------->|
4478	           |                         |           200 F17         |
4479	           |                         |<--------------------------|
4480	           |         ...             |            ...            |
4481	           |                         |                           |
4482	           |                         |     <dialogstart> F18     |
4483	           |                         |-------------------------->|
4484	           |                         |           200 F19         |
4485	           |                         |-------------------------->|
4486	           |                         |    HTTP interactions F20  |
4487	           |                         |<--------------------------|
4488	           |                         |  <event>(dialog.exit) F21 |
4489	           |                         |-------------------------->|
4490	           |         ...             |            ...            |
4491	           |                         |                           |

4493	   Steps 1-3: establish an MSML control channel for the conference.
4494	   Alternatively, a control channel could already have been established
4495	   which was used for all CA/MS interactions. A control channel per
4496	   conference is only one possible model. Currently MSML uses SIP INFO
4497	   requests and responses on this SIP dialog. There is a proposal to use
4498	   this message exchange to establish a TCP channel for MSML similar to
4499	   the approach used for MRCPv2. This approach would require that a
4500	   request identifier be added to the <msml> element to correlate
4501	   requests and responses. This currently relies on the SIP INFO request
4502	   and response for this property. MSML messages are shown without
4503	   specifying the transport in this example but it assumes a
4504	   request/response correlation based on transport messages.

4506	   Step 4: create a conference that will mix the loudest two speakers
4507	   and report those speakers to the Control Agent every ten seconds. The
4508	                                 (MSML)

4510	   media server will automatically terminate remaining media sessions
4511	   and delete the conference and associated resources and when the
4512	   control channel is terminated.

4514	      <msml version="1.1">
4515	         <createconference name="exampleConf" deletewhen="nocontrol">
4516	             <audiomix>
4517	                <n-loudest n="3"/>
4518	                <asn ri="10s"/>
4519	             </audiomix>
4520	         </createconference>
4521	      </msml>

4523	   Step 5: conference created successfully

4525	      <msml version="1.1">
4526	         <result response="200"/>
4527	      </msml>

4529	   Steps 6-11: standard 3PCC establishment of a user initiated media
4530	   session to a media server. This is the equivalent of a dial-in
4531	   conference participant. The "To:" header returned by the MS in the
4532	   200 response of Step F8 was:

4534	   To: <sip:msml@ms.example.com>;tag=jd87dfg4h

4536	   Step 12: request an initial dialog with the participant to prompt for
4537	   their name, desired conference, etc. The dialog completes by
4538	   informing the participant they are joining the conference. If this
4539	   was not the first participant, the dialog could also announce the
4540	   other participants.

4542	      <msml version="1.1">
4543	         <dialogstart target="conn:jd87dfg4h" name=�12345�
4544	             type="application/vxml+xml"
4545	             src="http://server.example.com/scripts/initial.vxml"/>
4546	      </msml>

4548	   Step 13: dialog started successfully. The dialog identifier is
4549	   returned.

4551	                                 (MSML)

4553	      <msml version="1.1">
4554	         <result response="200"/>
4555	         <dialogid>conn:jd87dfg4h/dialog:12345</dialogid>
4556	      </msml>

4558	   Step 14: sequence of HTTP VoiceXML dialog interactions.

4560	   Step 15: the VoiceXML browser exits (but does not disconnect). If a
4561	   namelist had been specified within the VoiceXML <exit> element, it
4562	   would have been included in the <event> sent to the CA.

4564	      <msml version="1.1">
4565	         <event name="msml.dialog.exit"
4566	                id="conn:jd87dfg4h/dialog:12345"/>
4567	      </msml>

4569	   Step 16: join the participant to the conference and have the volume
4570	   of their contributing audio automatically adjusted to a target level
4571	   of -20 dBm0.

4573	      <msml version="1.1">
4574	         <join id1="conn:jd87dfg4h" id2="conf:exampleConf">
4575	            <stream media="audio" dir="from-id1">
4576	                <gain agc="true" tgtlvl="-20"/>
4577	            </stream>
4578	            <stream media="audio" dir="to-id1"/>
4579	      </msml>

4581	   Step 17: successfully joined to conference

4583	      <msml version="1.1">
4584	         <result response="200"/>
4585	      </msml>

4587	   Steps 6 through 17 are repeated for the second participant.

4589	                                 (MSML)

4591	   Step 18: play a join tone or message announcing the new participant
4592	   to the conference.

4594	      <msml version="1.1">

4596	         <dialogstart target="conf:exampleConf"

4598	             type="application/vxml+xml"

4600	             src="http://server.example.com/scripts/joinmsg.vxml"/>

4602	      </msml>

4604	   Step 19: dialog started successfully. The dialog identifier is
4605	   returned. Media Server assigned a unique identifier since name
4606	   attribute was not specified in <dialogstart>.

4608	      <msml version="1.1">
4609	         <result response="200"/>
4610	         <dialogid>conf:ExampleConf/dialog:j6fs8745</dialogid>
4611	      </msml>

4613	   Step 20: HTTP VoiceXML dialog interaction(s).

4615	   Step 21: the VoiceXML browser exits.

4617	      <msml version="1.1">
4618	         <event name="msml.dialog.exit"
4619	                id="conf:ExampleConf/dialog:j6fs8745"/>
4620	      </msml>

4622	   Steps 6 through 21 are repeated for the third and subsequent
4623	   participants.

4625	12.2 Example of a Sidebar Audio Conference

4627	   This example assumes that a conference has already been established
4628	   as in the previous example. It creates a sidebar conference that
4629	   hears the main conference as a whisper. Three participants are moved
4630	                                 (MSML)

4632	   to the sidebar. After some period of time, the sidebar participants
4633	   are returned to the main conference and the sidebar is deleted.

4635	   Step1: the sidebar conference is created. It is joined half-duplex to
4636	   the main conference and a manual gain object is inserted in the media
4637	   stream. Three participants are then moved from the main conference to
4638	   the sidebar. Although not shown, an CA could include the "mark"
4639	   attribute in each element to allow recovery in the event of a mid-
4640	   transaction error.

4642	      <msml version="1.1">
4643	         <createconference name="sidebarConf"
4644	                           deletewhen="nomedia">
4645	             <audiomix/>
4646	         </createconference>
4647	         <join id1="conf:sidebarConf" id2="conf:exampleConf">
4648	             <stream media="audio" dir="to-id1">
4649	                 <gain amt="-20"/>
4650	             </stream>
4651	         </join>
4652	         <unjoin id1="conn:gs5s4-1" id2="conf:exampleConf"/>
4653	         <join id1="conn:gs5s4-1" id2="conf:sidebarConf"/>
4654	         <unjoin id1="conn:hd764gr9-2" id2="conf:exampleConf"/>
4655	         <join id1="conn:hd764gr9-2" id2="conf:sidebarConf"/>
4656	         <unjoin id1="conn:h37frdvgs65-3" id2="conf:exampleConf"/>
4657	         <join id1="conn:h37frdvgs65-3" id2="conf:sidebarConf"/>
4658	      </msml>

4660	   Step 2: sidebar conference created successfully and participants
4661	   joined.

4663	      <msml version="1.1">
4664	         <result response="200"/>
4665	      </msml>

4667	   Step 3: once the sidebar conference has completed, the participants
4668	   are rejoined to the main conference. The sidebar is destroyed
4669	   automatically by the MS when the last media stream is removed as
4670	   specified when the sidebar conference was created.

4672	      <msml version="1.1">
4673	         <unjoin id1="conn:gs5s4-1" id2="conf:sidebarConf"/>
4674	         <join id1="conn:gs5s4-1" id2="conf:exampleConf"/>
4675	         <unjoin id1="conn:hd764gr9-2" id2="conf:sidebarConf"/>
4676	         <join id1="conn:hd764gr9-2" id2="conf:exampleConf"/>
4677	         <unjoin id1="conn:h37frdvgs65-3" id2="conf:sidebarConf"/>
4678	         <join id1="conn:h37frdvgs65-3" id2="conf:exampleConf"/>
4679	      </msml>
4680	                                 (MSML)

4682	   Step 4: participants successfully moved to main conference and
4683	   sidebar destroyed.

4685	      <msml version="1.1">
4686	         <result response="200"/>
4687	      </msml>

4689	12.3 Example of Removing a Conference

4691	   This example assumes a conference created similar to the first
4692	   example where there is an MSML control channel specific to the
4693	   conference and the conference has been configured to be deleted when
4694	   that channel is removed (using SIP).

4696	   Steps 1-2: the CA signals BYE for the SIP dialog used to establish
4697	   the conference control channel.

4699	   Steps 3-6: the MS initiates terminating the media sessions for each
4700	   participant remaining in the conference.

4702	   The MS deletes the conference and removes all resources when the last
4703	   participant has been removed.

4705	12.4 Example of Modifying Video Layout

4707	   Assume that a conference named "example" is created using the
4708	   following mixer descriptions.

4710	             +---+---+
4711	             | 1 | 2 |
4712	             +---+---+
4713	             | 3 | 4 |
4714	             +---+---+

4716	         <createconference name="quad-split">
4717	            <audiomix>
4718	               <n-loudest n="3"/>
4719	               <asn ri="10s"/>
4720	            </audiomix>
4721	            <videolayout>
4722	                                 (MSML)

4724	               <root size="CIF" background="white" />
4725	               <selector id="default" method="vas" si="500ms">
4726	                  <region id="1" left="0" top="0" size="1/4"/>
4727	               </selector>
4728	               <region id="2" left="50%" top="0" size="1/4"/>
4729	               <region id="3" left="0%" top="50%" size="1/4">
4730	               <region id="4" left="50%" top="50%" size="1/4"/>
4731	            </videolayout>
4732	         </createconference>

4734	   The following would change the size of the video window to QCIF and
4735	   the background color to the default "black".

4737	         <modifyconference id="conf:example">
4738	            <videolayout>
4739	               <root size="4CIF"/>
4740	            </videolayout>
4741	         </modifyconference>

4743	   The relative location of the regions does not change. However the
4744	   sizes of the regions do change because they are relative to the size
4745	   of the root window. The result is a layout that looks identical but
4746	   half the size.

4748	   The following would freeze the video displayed in region "2" without
4749	   affecting any other attributes of that region.

4751	         <modifyconference id="conf:example">
4752	            <videolayout>
4753	               <region id="2" left="50%" top="0" size="1/4"
4754	                              freeze="true"/>
4755	            </videolayout>
4756	         </modifyconference>

4758	13. MSML Dialog Examples

4760	   These examples focus on the MSML Dialog Base package and the MSML
4761	   Dialog Group package.

4763	13.1 Announcement

4765	   The following is a simple announcement scenario. Two recorded audio
4766	   files are played in sequence followed by generated speech followed by
4767	   a variable. The results are reported once media generation completes.

4769	   <?xml version="1.0" encoding="UTF-8"?>
4770	                                 (MSML)

4772	   <msml version="1.1">
4773	      <dialogstart target=�conn:12345� name=�12345�>
4774	         <play>
4775	            <audio uri="file://clip1.wav"/>
4776	            <audio uri="http://host1/clip2.wav"/>
4777	            <tts uri="http://host2/text.ssml"/>
4778	            <var type="date" subtype="mdy" value="20030601"/>
4779	         </play>
4780	         <send target="source" event="done" namelist="play.amt
4781	                                            play.end"/>
4782	      </dialogstart>
4783	   </msml>

4785	13.2 Voice Mail Retrieval

4787	   Below is an example which shows a simple voice mail retrieval
4788	   operation consisting of playing a message and allowing the user to
4789	   pause and resume play using '5' to toggle the state. The operation
4790	   would terminate when the play completed or the user entered '#'.
4791	   During the play, the user can advance forward and backward through
4792	   the message as well as rewinding to the beginning.

4794	   <?xml version="1.0" encoding="UTF-8"?>
4795	   <msml version="1.1">
4796	     <dialogstart target=�conn:12345� name=�12345�>
4797	      <group topology="parallel">
4798	         <play>
4799	            <audio uri="file://message.wav"/>
4800	            <playexit>
4801	               <send target="group" event="terminate"/>
4802	            </playexit>
4803	         </play>
4804	         <dtmf iterate="forever">
4805	            <pattern digits="5">
4806	               <send target="play" event="toggle-state"/>
4807	            </pattern>
4808	            <pattern digits="6">
4809	               <send target="play" event="forward"/>
4810	            </pattern>
4811	            <pattern digits="7">
4812	               <send target="play" event="backward"/>
4813	            </pattern>
4814	            <pattern digits="8">
4815	               <send target="play" event="restart"/>
4816	            </pattern>
4817	            <pattern digits="#">
4818	               <send target="play" event="terminate"/>
4819	            </pattern>
4820	                                 (MSML)

4822	         </dtmf>
4823	      </group>
4824	    </dialogsgtart>
4825	   </msml>

4827	13.3 Play and Record

4829	   A more complex example is a play and record operation. This sources
4830	   and sinks media and uses voice activity DTMF detection and
4831	   recognition to influence behavior. Any DTMF input or voice activity
4832	   will barge the play and cause the record to begin. However, if the
4833	   prompt was barged with a DTMF digit of '#', the record terminates
4834	   without starting. When the play terminates, it send a starttimer
4835	   event to the VAD to allow it to recognize an initial silence
4836	   condition. The recording will be terminated (without starting) when
4837	   the VAD detects an initial 3 seconds of silence.

4839	   Once resumed (based upon voice detection) the recording may be
4840	   terminated under several conditions. It will terminate after 5
4841	   seconds of silence or after 60 seconds elapses. It will also
4842	   terminate if a '#' key is recognized. Every aspect of this behavior
4843	   can be modified by changing what is recognized and the events which
4844	   are sent. The following example uses the MSML Dialog Group package.

4846	   <?xml version="1.0" encoding="UTF-8"?>
4847	   <msml  version="1.1">
4848	    <dialogstart target=�conn:12345� name=�12345�>
4849	      <group topology="parallel">
4850	         <play>
4851	            <audio uri="file://prompt.wav"/>
4852	            <playexit>
4853	               <send target="vad" event="starttimer"/>
4854	            </playexit>
4855	         </play>
4856	         <dtmf>
4857	            <pattern digits="#">
4858	               <send target="record" event="terminate.termkey"/>
4859	            </pattern>
4860	            <detect>
4861	               <send target="play" event="terminate"/>
4862	            </detect>
4863	         </dtmf>
4864	         <vad>
4865	            <voice len="10ms">
4866	               <send target="play" event="terminate"/>
4867	               <send target="record" event="resume"/>
4868	            </voice>
4869	            <silence len="3s">
4870	                                 (MSML)

4872	               <send target="record" event="nospeech"/>
4873	            </silence>
4874	            <tsilence len="5s">
4875	               <send target="record" event="terminate.finalsilence"/>
4876	            </tsilence>
4877	         </vad>
4878	         <record initial="suspend" maxtime="60s"
4879	                 dest="file://record.wav" format="g729">
4880	            <recordexit>
4881	               <send target="group" event="terminate"/>
4882	            </recordexit>
4883	         </record>
4884	         <groupexit>
4885	            <send target="source" event="done"
4886	                  namelist="record.len record.end"/>
4887	         </groupexit>
4888	      </group>
4889	    </dialogstart>
4890	   </msml>

4892	   The following implements the same functionality, as described above,
4893	   in using the MSML Dialog Base package, using the <record> composite
4894	   mechanism for the play and record operation.

4896	   <?xml version="1.0" encoding="UTF-8"?>
4897	   <msml  version="1.1">
4898	    <dialogstart target=�conn:12345� name=�12345�>
4899	      <record prespeech=�3s� postspeech=�5s� maxtime="60s" termkey=�#�
4900	                 dest="file://record.wav" format="g729">
4901	         <play barge=�true�>
4902	            <audio uri="file://prompt.wav"/>
4903	         </play>
4904	         <recordexit>
4905	            <send target="source" event="done"
4906	                  namelist="record.len record.end"/>
4907	         </recordexit>
4908	      </record>
4909	    </dialogstart>
4910	   </msml>

4912	13.4 Speech Recognition

4914	   The following simple example requests that a user speak the name of a
4915	   city and returns the result.

4917	   <?xml version="1.0" encoding="UTF-8"?>
4918	   <msml version="1.1">
4919	    <dialogstart target=�conn:12345� name=�12345�>
4920	                                 (MSML)

4922	      <group topology="parallel">
4923	         <play>
4924	            <audio uri="file://prompt.wav"/>
4925	         </play>
4926	         <speech>
4927	            <grammar version="1.0">
4928	               <rule id="city" scope="public">
4929	                  <item>
4930	                     <one-of>
4931	                        <item>vancouver</item>
4932	                        <item>new york</item>
4933	                        <item>london</item>
4934	                     </one-of>
4935	                  </item>
4936	               </rule>
4937	               <match>
4938	                  <send target="group" event="terminate"/>
4939	               </match>
4940	            </grammar>
4941	            <noinput>
4942	               <send target="group" event="terminate"/>
4943	            </noinput>
4944	            <nomatch>
4945	               <send target="group" event="terminate"/>
4946	            </nomatch>
4947	         </speech>
4948	         <groupexit>
4949	            <send target="source" event="done"
4950	                          namelist="speech.end speech.results"/>
4951	         </groupexit>
4952	      </group>
4953	    </dialogstart>
4954	   </msml>

4956	13.5 Play and Collect

4958	   This example prompts a user to enter 4 DTMF digits terminated by the
4959	   '#' key. The prompt will be barged and the user has 10 seconds to
4960	   begin entering input or no input will be indicated.

4962	   <?xml version="1.0" encoding="UTF-8"?>
4963	   <msml version="1.1">
4964	    <dialogstart target=�conn:12345� name=�12345�>
4965	      <group topology="parallel">
4966	         <play>
4967	            <audio uri="file://prompt.wav"/>
4968	            <playexit>
4969	               <send target="dtmf" event="starttimer"/>
4970	                                 (MSML)

4972	            </playexit>
4973	         </play>
4974	         <dtmf fdt="10s" idt="16s">
4975	            <pattern digits="xxxx#">
4976	               <send target="group" event="terminate"/>
4977	            </pattern>
4978	            <detect>
4979	               <send target="play" event="terminate"/>
4980	            </detect>
4981	            <noinput>
4982	               <send target="group" event="terminate"/>
4983	            </noinput>
4984	            <nomatch>
4985	               <send target="group" event="terminate"/>
4986	            </nomatch>
4987	         </dtmf>
4988	         <groupexit>
4989	            <send target="source" event="done"
4990	                  namelist="dtmf.digits dtmf.end"/>
4991	         </groupexit>
4992	      </group>
4993	    </dialogstart>
4994	   </msml>

4996	   The following implements the same functionality, as described above,
4997	   using the MSML Dialog Base package, using the <collect> composite
4998	   mechanism for the play and collect operation.

5000	   <?xml version="1.0" encoding="UTF-8"?>
5001	   <msml version="1.1">
5002	    <dialogstart target=�conn:12345� name=�12345�>

5004	      <collect fdt="10s" idt="16s">
5005	         <play barge=�true�>
5006	            <audio uri="file://prompt.wav"/>
5007	         </play>
5008	         <pattern digits="xxxx#">
5009	            <send target="source" event="done"
5010	                  namelist="dtmf.digits dtmf.end"/>
5011	         </pattern>
5012	         <noinput>
5013	            <send target="source" event="done"
5014	                  namelist="dtmf.end"/>
5015	         </noinput>
5016	         <nomatch>
5017	            <send target="source" event="done"
5018	                  namelist="dtmf.end"/>
5019	         </nomatch>
5020	                                 (MSML)

5022	      </dtmf>
5023	    </dialogstart>
5024	   </msml>

5026	13.6 User Controlled Gain

5028	   This shows an example of nesting groups to create an arbitrary full
5029	   duplex media control. DTMF is detected on media flowing in one
5030	   direction and used to adjust the gain applied to media flowing in the
5031	   opposite direction. Additionally, the stream which is used to detect
5032	   DTMF has DTMF removed and its gain automatically adjusted before
5033	   leaving the group. This widget could be used between a conference
5034	   participant and a conference mixer.

5036	   <?xml version="1.0" encoding="UTF-8"?>
5037	   <msml  version="1.0">
5038	    <dialogstart target=�conn:12345� name=�12345�>
5039	      <group topology="fullduplex">
5040	         <group topology="parallel">
5041	            <dtmf>
5042	               <pattern digits="1" iterate="forever">
5043	                  <send target="gain" event="louder"/>
5044	               </pattern>
5045	               <pattern digits="2" iterate="forever">
5046	                  <send target="gain" event="softer"/>
5047	               </pattern>
5048	            </dtmf>
5049	            <group topology="serial">
5050	               <clamp/>
5051	               <agc tgtlvl="0"/>
5052	            </group>
5053	         </group>
5054	         <gain amt="0" incr="5"/>
5055	      </group>
5056	    </dialogstart>
5057	   </msml>

5059	14. Change Summary

5061	   MSML-00 is an initial draft, however it is derived from draft-
5062	   melanchuk-sipping-msml-06 [22] and draft-melanchuk-sipping-moml-06
5063	   [23]. Earlier versions of these specifications were co-authored by
5064	   Tim Melanchuk (while he was an employee of Convedia) and Garland
5065	   Sharratt. All functionality supported in [22] and [23] is supported
5066	   within this MSML specification, no new functionality is introduced in
5067	   this initial version, and there are no XML or SIP interface changes
5068	   introduced, allowing MSML-00 client/server implementations to be
5069	   fully compatible with implementations based on [22] and [23]. This
5070	                                 (MSML)

5072	   specification completely replaces earlier internet drafts MSML [22]
5073	   and MOML [23].

5075	   Additional sample scripts added and includes minor wording
5076	   corrections.

5078	   Previous versions of MSML specification are defined in this internet
5079	   draft as MSML Core and MSML Conference Core packages.

5081	   Previous versions of MOML specification are defined in this internet
5082	   draft as MSML Dialog Core, MSML Dialog Base, and all other MSML
5083	   Dialog packages.

5085	15. Future Work

5087	   The following capabilities may be added in future versions of this
5088	   draft:

5090	      o Ability for MSML clients to audit or query the Media Server for
5091	         supported set of MSML packages and profiles.

5093	      O Ability for MSML clients to perform state auditing of current
5094	         resources allocated and in use by the Media Server.

5096	      o Ability to version MSML packages and profiles and naming scheme
5097	         for MSML extension packages.

5099	16. XML Schema - MSML Core and MSML Conference Core Packages

5101	   The MSML schema uses one core schema which defines the MSML
5102	   Conference Core package and which includes two other schemas; one
5103	   defines the MSML datatypes, the other defines the MSML Dialog
5104	   packages.

5106	   The schema including MSML Core package and MSML Conference Core
5107	   package is:

5109	   <?xml version="1.0" encoding="UTF-8"?>
5110	   <xs:schema elementFormDefault="qualified"
5111	              attributeFormDefault="unqualified"
5112	              xmlns:xs="http://www.w3.org/2001/XMLSchema">
5113	    <xs:include schemaLocation="moml.xsd"/>
5114	    <xs:include schemaLocation="msml-datatypes.xsd"/>
5115	    <xs:element name="msml">
5116	                                 (MSML)

5118	     <xs:complexType>
5119	      <xs:choice>
5120	       <xs:group ref="msmlRequest" maxOccurs="unbounded"/>
5121	       <xs:element name="event">
5122	        <xs:complexType>
5123	         <xs:choice maxOccurs="unbounded">
5124	          <xs:sequence>
5125	           <xs:element name="name" type="msmlEventNameValue.datatype"/>
5126	           <xs:element name="value">
5127	            <xs:simpleType>
5128	             <xs:restriction base="xs:string">
5129	              <xs:pattern value="[a-zA-Z0-9.]+"/>
5130	             </xs:restriction>
5131	            </xs:simpleType>
5132	           </xs:element>
5133	          </xs:sequence>
5134	         </xs:choice>
5135	         <xs:attribute name="name" type="msmlEventName.datatype"
5136	                       use="required"/>
5137	         <xs:attribute name="id" type="msmlEventSource.datatype"
5138	                       use="required"/>
5139	        </xs:complexType>
5140	       </xs:element>
5141	       <xs:element name="result">
5142	        <xs:complexType>
5143	         <xs:sequence>
5144	          <xs:element name="description" minOccurs="0">
5145	           <xs:simpleType>
5146	            <xs:restriction base="xs:string">
5147	             <xs:pattern value="[a-zA-Z0-9.-_]+"/>
5148	            </xs:restriction>
5149	           </xs:simpleType>
5150	          </xs:element>
5151	          <xs:choice minOccurs="0" maxOccurs="unbounded">
5152	           <xs:element name="confid" type="confID.datatype"/>
5153	           <xs:element name="dialogid" type="dialogID.datatype"/>
5154	          </xs:choice>
5155	         </xs:sequence>
5156	         <xs:attribute name="response">
5157	          <xs:simpleType>
5158	           <xs:restriction base="xs:string">
5159	            <xs:pattern value="\d{3}"/>
5160	           </xs:restriction>
5161	          </xs:simpleType>
5162	         </xs:attribute>
5163	         <xs:attribute name="mark" type="mark.datatype"/>
5164	        </xs:complexType>
5165	       </xs:element>
5166	                                 (MSML)

5168	      </xs:choice>
5169	      <xs:attribute name="version" type="xs:string"
5170	                    use="required" fixed="1.1"/>
5171	     </xs:complexType>
5172	    </xs:element>
5173	    <xs:group name="msmlRequest">
5174	     <xs:choice>
5175	      <xs:element name="createconference">
5176	       <xs:complexType>
5177	        <xs:all>
5178	         <xs:element name="audioMix" type="audioMixType"/>
5179	         <xs:element name="videoLayout" type="videoLayoutType"/>
5180	         <xs:element name="reserve">
5181	          <xs:complexType>
5182	           <xs:sequence>
5183	            <xs:element name="resource" maxOccurs="unbounded">
5184	             <xs:complexType>
5185	              <xs:sequence>
5186	               <xs:any namespace="##other" processContents="lax"
5187	                       minOccurs="0" maxOccurs="unbounded"/>
5188	              </xs:sequence>
5189	              <xs:attribute name="n" type="xs:positiveInteger"
5190	                            default="1"/>
5191	              <xs:anyAttribute namespace="##any"/>
5192	             </xs:complexType>
5193	            </xs:element>
5194	           </xs:sequence>
5195	           <xs:attribute name="required"
5196	                         type="boolean.datatype" default="true"/>
5197	          </xs:complexType>
5198	         </xs:element>
5199	        </xs:all>
5200	        <xs:attribute name="name" type="msmlInstanceID.datatype"/>
5201	        <xs:attribute name="deletewhen" default="never">
5202	         <xs:simpleType>
5203	          <xs:restriction base="xs:string">
5204	           <xs:enumeration value="nomedia"/>
5205	           <xs:enumeration value="nocontrol"/>
5206	           <xs:enumeration value="never"/>
5207	          </xs:restriction>
5208	         </xs:simpleType>
5209	        </xs:attribute>
5210	        <xs:attribute name="term" type="boolean.datatype"
5211	                      default="true"/>
5212	        <xs:attribute ref="mark"/>
5213	       </xs:complexType>
5214	      </xs:element>
5215	      <xs:element name="modifyconference">
5216	                                 (MSML)

5218	       <xs:complexType>
5219	        <xs:all>
5220	         <xs:element name="audioMix" type="audioMixType" minOccurs="0"/>
5221	         <xs:element name="videoLayout" type="videoLayoutType"
5222	                     minOccurs="0"/>
5223	        </xs:all>
5224	        <xs:attribute name="id" type="confID.datatype" use="required"/>
5225	        <xs:attribute ref="mark"/>
5226	       </xs:complexType>
5227	      </xs:element>
5228	      <xs:element name="destroyconference">
5229	       <xs:complexType>
5230	        <xs:all>
5231	         <xs:element name="audioMix" type="basicAudioMixType"
5232	                     minOccurs="0"/>
5233	         <xs:element name="videoLayout"
5234	                     type="basicVideoLayoutType" minOccurs="0"/>
5235	        </xs:all>
5236	        <xs:attribute name="id" type="confID.datatype" use="required"/>
5237	        <xs:attribute ref="mark"/>
5238	       </xs:complexType>
5239	      </xs:element>
5240	      <xs:element name="dialogstart">
5241	       <xs:complexType>
5242	        <xs:sequence>
5243	         <xs:group ref="momlRequest"/>
5244	         <xs:group ref="sendType" minOccurs="0"/>
5245	        </xs:sequence>
5246	        <xs:attribute name="target"
5247	                      type="independentID.datatype" use="required"/>
5248	        <xs:attribute name="type"
5249	                      type="dialogLanguage.datatype" use="required"/>
5250	        <xs:attribute name="name" type="msmlInstanceID.datatype"/>
5251	        <xs:attribute name="src" type="xs:anyURI" use="optional"/>
5252	        <xs:attribute ref="mark"/>
5253	       </xs:complexType>
5254	      </xs:element>
5255	      <xs:element name="dialogend">
5256	       <xs:complexType>
5257	        <xs:attribute name="id" type="dialogID.datatype"
5258	                      use="required"/>
5259	        <xs:attribute ref="mark"/>
5260	       </xs:complexType>
5261	      </xs:element>
5262	      <xs:element name="join">
5263	       <xs:complexType>
5264	        <xs:sequence>
5265	         <xs:element name="stream" type="streamType"
5266	                                 (MSML)

5268	                     minOccurs="0" maxOccurs="4"/>
5269	        </xs:sequence>
5270	        <xs:attribute name="id1" type="independentID.datatype"
5271	                      use="required"/>
5272	        <xs:attribute name="id2" type="independentID.datatype"
5273	                      use="required"/>
5274	        <xs:attribute ref="mark"/>
5275	       </xs:complexType>
5276	      </xs:element>
5277	      <xs:element name="modifystream">
5278	       <xs:complexType>
5279	        <xs:sequence>
5280	         <xs:element name="stream" type="streamType" maxOccurs="4"/>
5281	        </xs:sequence>
5282	        <xs:attribute name="mark" type="mark.datatype"/>
5283	       </xs:complexType>
5284	      </xs:element>
5285	      <xs:element name="unjoin">
5286	       <xs:complexType>
5287	        <xs:sequence>
5288	         <xs:element name="stream" type="basicStreamType"
5289	                     minOccurs="0" maxOccurs="4"/>
5290	        </xs:sequence>
5291	        <xs:attribute name="id1" type="independentID.datatype"
5292	                      use="required"/>
5293	        <xs:attribute name="id2" type="independentID.datatype"
5294	                      use="required"/>
5295	        <xs:attribute ref="mark"/>
5296	       </xs:complexType>
5297	      </xs:element>
5298	      <xs:element name="monitor">
5299	       <xs:complexType>
5300	        <xs:attribute name="id1" type="connID.datatype" use="required"/>
5301	        <xs:attribute name="id2" type="independentID.datatype"
5302	                      use="required"/>
5303	        <xs:attribute name="compressed"
5304	                      type="boolean.datatype" default="false"/>
5305	        <xs:attribute ref="mark"/>
5306	       </xs:complexType>
5307	      </xs:element>
5308	      <xs:element name="send">
5309	       <xs:complexType>
5310	        <xs:attribute name="event" type="msmlEvent.datatype"
5311	                      use="required"/>
5312	        <xs:attribute name="target" type="msmlTarget.datatype"
5313	                      use="required"/>
5314	        <xs:attribute name="valuelist" type="xs:string"/>
5315	        <xs:attribute ref="mark"/>
5316	                                 (MSML)

5318	       </xs:complexType>
5319	      </xs:element>
5320	     </xs:choice>
5321	    </xs:group>
5322	    <xs:complexType name="basicStreamType">
5323	     <xs:attribute name="dir">
5324	      <xs:simpleType>
5325	       <xs:restriction base="xs:string">
5326	        <xs:enumeration value="to-id1"/>
5327	        <xs:enumeration value="from-id1"/>
5328	       </xs:restriction>
5329	      </xs:simpleType>
5330	     </xs:attribute>
5331	     <xs:attribute name="media">
5332	      <xs:simpleType>
5333	       <xs:restriction base="xs:string">
5334	        <xs:enumeration value="audio"/>
5335	        <xs:enumeration value="video"/>
5336	       </xs:restriction>
5337	      </xs:simpleType>
5338	     </xs:attribute>
5339	    </xs:complexType>
5340	    <xs:complexType name="streamType">
5341	     <xs:complexContent>
5342	      <xs:extension base="basicStreamType">
5343	       <xs:choice minOccurs="0" maxOccurs="unbounded">
5344	        <xs:element name="gain">
5345	         <xs:complexType>
5346	          <xs:attribute name="amt" use="optional">
5347	           <xs:simpleType>
5348	            <xs:restriction base="xs:integer">
5349	             <xs:minInclusive value="-96"/>
5350	             <xs:maxInclusive value="96"/>
5351	            </xs:restriction>
5352	           </xs:simpleType>
5353	          </xs:attribute>
5354	          <xs:attribute name="agc" type="boolean.datatype"/>
5355	          <xs:attribute name="tgtlvl" use="optional">
5356	           <xs:simpleType>
5357	            <xs:restriction base="xs:nonPositiveInteger">
5358	             <xs:minInclusive value="-40"/>
5359	             <xs:maxInclusive value="0"/>
5360	            </xs:restriction>
5361	           </xs:simpleType>
5362	          </xs:attribute>
5363	          <xs:attribute name="maxgain" default="10">
5364	           <xs:simpleType>
5365	            <xs:restriction base="xs:nonNegativeInteger">
5366	                                 (MSML)

5368	             <xs:minInclusive value="0"/>
5369	             <xs:maxInclusive value="40"/>
5370	            </xs:restriction>
5371	           </xs:simpleType>
5372	          </xs:attribute>
5373	         </xs:complexType>
5374	        </xs:element>
5375	        <xs:element name="clamp">
5376	         <xs:complexType>
5377	          <xs:attribute name="dtmf" type="boolean.datatype"/>
5378	          <xs:attribute name="tones" type="boolean.datatype"/>
5379	         </xs:complexType>
5380	        </xs:element>
5381	        <xs:element name="visual"/>
5382	       </xs:choice>
5383	       <xs:attribute name="preferred" type="boolean.datatype"/>
5384	       <xs:attribute name="display" type="xs:string"/>
5385	      </xs:extension>
5386	     </xs:complexContent>
5387	    </xs:complexType>
5388	    <xs:complexType name="basicAudioMixType">
5389	     <xs:attribute name="id" type="xs:string" use="required"/>
5390	    </xs:complexType>
5391	    <xs:complexType name="audioMixType">
5392	     <xs:complexContent>
5393	      <xs:extension base="basicAudioMixType">
5394	       <xs:all>
5395	        <xs:element name="asn" minOccurs="0">
5396	         <xs:complexType>
5397	          <xs:attribute name="ri" type="posDuration.datatype"/>
5398	         </xs:complexType>
5399	        </xs:element>
5400	        <xs:element name="n-loudest" minOccurs="0">
5401	         <xs:complexType>
5402	          <xs:attribute name="n" type="xs:positiveInteger"
5403	                        use="required"/>
5404	         </xs:complexType>
5405	        </xs:element>
5406	       </xs:all>
5407	      </xs:extension>
5408	     </xs:complexContent>
5409	    </xs:complexType>
5410	    <xs:complexType name="basicVideoLayoutType">
5411	     <xs:attribute name="id" type="xs:string" use="required"/>
5412	     <xs:attribute name="type" type="xs:string"
5413	                   use="required" fixed="text/msml-basic-layout"/>
5414	    </xs:complexType>
5415	    <xs:complexType name="videoLayoutType">
5416	                                 (MSML)

5418	     <xs:complexContent>
5419	      <xs:extension base="basicVideoLayoutType">
5420	       <xs:choice>
5421	        <xs:element name="selector">
5422	         <xs:complexType>
5423	          <xs:complexContent>
5424	           <xs:extension base="selectorType">
5425	            <xs:sequence>
5426	             <xs:element name="root" type="rootType"/>
5427	            </xs:sequence>
5428	           </xs:extension>
5429	          </xs:complexContent>
5430	         </xs:complexType>
5431	        </xs:element>
5432	        <xs:sequence>
5433	         <xs:element name="root" type="rootType"/>
5434	         <xs:choice maxOccurs="unbounded">
5435	          <xs:element name="selector" minOccurs="0"
5436	                      maxOccurs="unbounded">
5437	           <xs:complexType>
5438	            <xs:complexContent>
5439	             <xs:extension base="selectorType">
5440	              <xs:sequence>
5441	               <xs:element name="region"/>
5442	              </xs:sequence>
5443	             </xs:extension>
5444	            </xs:complexContent>
5445	           </xs:complexType>
5446	          </xs:element>
5447	          <xs:element name="region" minOccurs="0" maxOccurs="unbounded">
5448	           <xs:complexType>
5449	            <xs:complexContent>
5450	             <xs:extension base="regionType"/>
5451	            </xs:complexContent>
5452	           </xs:complexType>
5453	          </xs:element>
5454	         </xs:choice>
5455	        </xs:sequence>
5456	       </xs:choice>
5457	      </xs:extension>
5458	     </xs:complexContent>
5459	    </xs:complexType>
5460	    <xs:complexType name="regionType">
5461	     <xs:attribute name="id" type="xs:string" use="required"/>
5462	     <xs:attribute name="left" type="xs:positiveInteger"/>
5463	     <xs:attribute name="top" type="xs:positiveInteger"/>
5464	     <xs:attribute name="relativeSize">
5465	      <xs:simpleType>
5466	                                 (MSML)

5468	       <xs:restriction base="xs:string">
5469	        <xs:enumeration value="1/4"/>
5470	        <xs:enumeration value="1/3"/>
5471	        <xs:enumeration value="2/3"/>
5472	        <xs:enumeration value="3/4"/>
5473	        <xs:enumeration value="1"/>
5474	       </xs:restriction>
5475	      </xs:simpleType>
5476	     </xs:attribute>
5477	     <xs:attribute name="priority">
5478	      <xs:simpleType>
5479	       <xs:restriction base="xs:float">
5480	        <xs:minInclusive value="0"/>
5481	        <xs:maxExclusive value="1"/>
5482	       </xs:restriction>
5483	      </xs:simpleType>
5484	     </xs:attribute>
5485	     <xs:attribute name="title" type="xs:string"/>
5486	     <xs:attribute name="titleTextColor" type="xs:string"/>
5487	     <xs:attribute name="titleBackgroundColor" type="xs:string"/>
5488	     <xs:attribute name="borderColor" type="xs:string"/>
5489	     <xs:attribute name="borderWidth" type="xs:positiveInteger"/>
5490	     <xs:attribute name="logo" type="xs:anyURI"/>
5491	    </xs:complexType>
5492	    <xs:complexType name="selectorType">
5493	     <xs:attribute name="id" type="xs:string" use="required"/>
5494	     <xs:attribute name="method" use="required">
5495	      <xs:simpleType>
5496	       <xs:restriction base="xs:string">
5497	        <xs:enumeration value="vas"/>
5498	        <xs:enumeration value="sequence"/>
5499	       </xs:restriction>
5500	      </xs:simpleType>
5501	     </xs:attribute>
5502	     <xs:attribute name="status" default="active">
5503	      <xs:simpleType>
5504	       <xs:restriction base="xs:string">
5505	        <xs:enumeration value="active"/>
5506	        <xs:enumeration value="disabled"/>
5507	       </xs:restriction>
5508	      </xs:simpleType>
5509	     </xs:attribute>
5510	     <xs:attribute name="si" type="posDuration.datatype" default="1s"/>
5511	     <xs:attribute name="blankothers" type="xs:boolean"
5512	                   default="false"/>
5513	     <xs:attribute name="speakersees" default="current">
5514	      <xs:simpleType>
5515	       <xs:restriction base="xs:string">
5516	                                 (MSML)

5518	        <xs:enumeration value="current"/>
5519	        <xs:enumeration value="previous"/>
5520	       </xs:restriction>
5521	      </xs:simpleType>
5522	     </xs:attribute>
5523	    </xs:complexType>
5524	    <xs:complexType name="rootType">
5525	     <xs:attribute name="size" default="CIF">
5526	      <xs:simpleType>
5527	       <xs:restriction base="xs:string">
5528	        <xs:enumeration value="16CIF"/>
5529	        <xs:enumeration value="4CIF"/>
5530	        <xs:enumeration value="CIF"/>
5531	        <xs:enumeration value="QCIF"/>
5532	       </xs:restriction>
5533	      </xs:simpleType>
5534	     </xs:attribute>
5535	     <xs:attribute name="backgroundcolor" type="xs:string"
5536	                   default="black"/>
5537	     <xs:attribute name="backgroundimage" type="xs:anyURI"/>
5538	    </xs:complexType>
5539	    <xs:attribute name="mark" type="mark.datatype"/>
5540	   </xs:schema>

5542	   Following schema defines the basic MSML datatypes used by the schema
5543	   defined above. Note that several regular expressions required them to
5544	   be split across two lines for formatting reasons.

5546	   <?xml version="1.0" encoding="UTF-8"?>
5547	   <xs:schema elementFormDefault="qualified"
5548	              attributeFormDefault="unqualified"
5549	              xmlns:xs="http://www.w3.org/2001/XMLSchema">
5550	    <xs:simpleType name="conferenceType.datatype">
5551	     <xs:restriction base="xs:string">
5552	      <xs:enumeration value="audio.basic"/>
5553	      <xs:enumeration value="audio.advanced"/>
5554	     </xs:restriction>
5555	    </xs:simpleType>
5556	    <xs:simpleType name="msmlInstanceID.datatype">
5557	     <xs:restriction base="xs:string">
5558	      <xs:pattern value="[a-zA-Z0-9.:-_]+"/>
5559	     </xs:restriction>
5560	    </xs:simpleType>
5561	    <xs:simpleType name="connID.datatype">
5562	     <xs:restriction base="xs:string">
5563	                                 (MSML)

5565	      <xs:pattern value="conn:[a-zA-Z0-9.:-_]+"/>
5566	     </xs:restriction>
5567	    </xs:simpleType>
5568	    <xs:simpleType name="confID.datatype">
5569	     <xs:restriction base="xs:string">
5570	      <xs:pattern value="conf:[a-zA-Z0-9.:-_]+"/>
5571	     </xs:restriction>
5572	    </xs:simpleType>
5573	    <xs:simpleType name="operatorID.datatype">
5574	     <xs:restriction base="xs:string">
5575	      <xs:pattern value="conf:[a-zA-Z0-9.:-_]+"/>
5576	      <xs:pattern value="conn:[a-zA-Z0-9.:-_]+"/>
5577	     </xs:restriction>
5578	    </xs:simpleType>
5579	    <xs:simpleType name="dialogID.datatype">
5580	     <xs:restriction base="xs:string">
5581	      <xs:pattern value="conf:[a-zA-Z0-9.:-_]+/dialog:[a-zA-Z0-9.:-
5582	   _]+"/>
5583	      <xs:pattern value="conn:[a-zA-Z0-9.:-_]+/dialog:[a-zA-Z0-9.:-
5584	   _]+"/>
5585	     </xs:restriction>
5586	    </xs:simpleType>
5587	    <xs:simpleType name="independentID.datatype">
5588	     <xs:restriction base="xs:string">
5589	      <xs:pattern value="conf:[a-zA-Z0-9.:-_]+"/>
5590	      <xs:pattern value="conn:[a-zA-Z0-9.:-_]+"/>
5591	     </xs:restriction>
5592	    </xs:simpleType>
5593	    <xs:simpleType name="duplex.datatype">
5594	     <xs:restriction base="xs:string">
5595	      <xs:enumeration value="half"/>
5596	      <xs:enumeration value="full"/>
5597	     </xs:restriction>
5598	    </xs:simpleType>
5599	    <xs:simpleType name="confclass.datatype">
5600	     <xs:restriction base="xs:string">
5601	      <xs:enumeration value="standard"/>
5602	      <xs:enumeration value="preferred"/>
5603	     </xs:restriction>
5604	    </xs:simpleType>
5605	    <xs:simpleType name="dialogLanguage.datatype">
5606	     <xs:restriction base="xs:string">
5607	      <xs:enumeration value="application/moml+xml"/>
5608	      <xs:enumeration value="application/voicexml+xml"/>
5609	     </xs:restriction>
5610	    </xs:simpleType>
5611	    <xs:simpleType name="msmlEvent.datatype">
5612	     <xs:restriction base="xs:string"/>
5613	                                 (MSML)

5615	    </xs:simpleType>
5616	    <xs:simpleType name="msmlEventName.datatype">
5617	     <xs:restriction base="xs:string">
5618	      <xs:pattern value="msml.dialog.exit"/>
5619	      <xs:pattern value="msml.conf.asn"/>
5620	      <xs:pattern value="msml.conf.nomedia"/>
5621	      <xs:pattern value="msml.dialog.exit"/>
5622	      <xs:pattern value="[a-zA-Z0-9.:_-]+"/>
5623	     </xs:restriction>
5624	    </xs:simpleType>
5625	    <xs:simpleType name="msmlTarget.datatype">
5626	     <xs:restriction base="xs:string">
5627	      <xs:pattern value="conf:[a-zA-Z0-9.:_-]+(/oper:[a-zA-Z0-9.:_-
5628	   ]+|\*)*"/>
5629	      <xs:pattern value="conn:[a-zA-Z0-9.:_-]+(/oper:[a-zA-Z0-9.:_-
5630	   ]+|\*)+"/>
5631	     </xs:restriction>
5632	    </xs:simpleType>
5633	    <xs:simpleType name="msmlEventSource.datatype">
5634	     <xs:restriction base="xs:string">
5635	      <xs:pattern value="conf:[a-zA-Z0-9.:_-]+"/>
5636	      <xs:pattern
5637	       value="(conf:[a-zA-Z0-9.:_-]+|conn:[a-zA-Z0-9.:_-]+)
5638	             /dialog:[a-zA-Z0-9.:_-]+"/>
5639	     </xs:restriction>
5640	    </xs:simpleType>
5641	    <xs:simpleType name="msmlEventNameValue.datatype">
5642	     <xs:restriction base="xs:string"/>
5643	    </xs:simpleType>
5644	    <xs:simpleType name="mark.datatype">
5645	     <xs:restriction base="xs:string">
5646	      <xs:pattern value="[a-zA-Z0-9.:-_]+"/>
5647	     </xs:restriction>
5648	    </xs:simpleType>
5649	   </xs:schema>

5651	17. XML Schema � MSML Dialog/Transform/Speech/Fax Packages

5653	   The following set of schemas collectively define the MSML Dialog
5654	   packages.

5656	   Note: the following schema is only needed when use of root element
5657	   <moml> is required.

5659	   <?xml version="1.0" encoding="UTF-8"?>
5660	   <xs:schema elementFormDefault="unqualified"
5661	                                 (MSML)

5663	      attributeFormDefault="unqualified"
5664	      xmlns:xs="http://www.w3.org/2001/XMLSchema">
5665	     <xs:include schemaLocation="moml-group-module.xsd"/>
5666	     <xs:include schemaLocation="moml-basic-primitives-module.xsd"/>
5667	     <xs:include schemaLocation="moml-transform-primitives-module.xsd"/>
5668	     <xs:include schemaLocation="moml-speech-module.xsd"/>
5669	     <xs:element name="moml">
5670	      <xs:complexType>
5671	         <xs:choice>
5672	            <xs:group ref="momlRequest"/>
5673	            <xs:element ref="event"/>
5674	         </xs:choice>
5675	         <xs:attribute name="version" type="xs:string"
5676	             use="required" fixed="1.0"/>
5677	         <xs:attribute name="id" type="momlID.datatype" use="required"/>
5678	      </xs:complexType>
5679	   </xs:element>
5680	   </xs:schema>

5682	   Following is the schema which defines the MSML Dialog datatypes
5683	   (moml-datatypes.xsd). It is included by each of the other MSML Dialog
5684	   packages.

5686	   <?xml version="1.0" encoding="UTF-8"?>
5687	   <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
5688	              elementFormDefault="qualified"
5689	              attributeFormDefault="unqualified">
5690	    <xs:simpleType name="momlID.datatype">
5691	     <xs:restriction base="xs:string">
5692	      <xs:pattern value="[a-zA-Z0-9][a-zA-Z0-9._\-]*"/>
5693	     </xs:restriction>
5694	    </xs:simpleType>
5695	    <xs:simpleType name="momlEvent.datatype">
5696	     <xs:restriction base="xs:string">
5697	      <xs:pattern value="[a-zA-Z0-9][a-zA-Z0-9._\-]*"/>
5698	     </xs:restriction>
5699	    </xs:simpleType>
5700	    <xs:simpleType name="momlNamelist.datatype">
5701	     <xs:restriction base="xs:string"/>
5702	    </xs:simpleType>
5703	    <xs:simpleType name="dtmfDigits.datatype">
5704	     <xs:restriction base="xs:string">
5705	      <xs:pattern value="[0-9#*]+"/>
5706	     </xs:restriction>
5707	    </xs:simpleType>
5708	    <xs:simpleType name="iterate.datatype">
5709	     <xs:union memberTypes="xs:positiveInteger">
5710	                                 (MSML)

5712	      <xs:simpleType>
5713	       <xs:restriction base="xs:negativeInteger">
5714	        <xs:minInclusive value="-1"/>
5715	       </xs:restriction>
5716	      </xs:simpleType>
5717	      <xs:simpleType>
5718	       <xs:restriction base="xs:string">
5719	        <xs:enumeration value="forever"/>
5720	       </xs:restriction>
5721	      </xs:simpleType>
5722	     </xs:union>
5723	    </xs:simpleType>
5724	    <xs:simpleType name="momlTarget.datatype">
5725	     <xs:restriction base="xs:string">
5726	      <xs:pattern value="[a-zA-Z0-9][a-zA-Z0-9._\-]*"/>
5727	     </xs:restriction>
5728	    </xs:simpleType>
5729	    <xs:simpleType name="boolean.datatype">
5730	     <xs:restriction base="xs:string">
5731	      <xs:enumeration value="true"/>
5732	      <xs:enumeration value="false"/>
5733	     </xs:restriction>
5734	    </xs:simpleType>
5735	    <xs:simpleType name="duration.datatype">
5736	     <xs:restriction base="xs:string">
5737	      <xs:pattern value="(\+|\-)?([0-9]*\.)?[0-9]+(ms|s)"/>
5738	     </xs:restriction>
5739	    </xs:simpleType>
5740	    <xs:simpleType name="posDuration.datatype">
5741	     <xs:restriction base="xs:string">
5742	      <xs:pattern value="(\+)?([0-9]*\.)?[0-9]+(ms|s)"/>
5743	     </xs:restriction>
5744	    </xs:simpleType>
5745	   </xs:schema>

5747	   Following is the schema which defines the Dialog core package (moml-
5748	   core-module.xsd). It is included by each of the other MSML Dialog
5749	   packages.

5751	   <?xml version="1.0" encoding="UTF-8"?>
5752	   <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
5753	      elementFormDefault="unqualified"
5754	      attributeFormDefault="unqualified">
5755	    <xs:include schemaLocation="moml-datatypes.xsd"/>
5756	    <xs:group name="momlRequest">
5757	     <xs:choice maxOccurs="unbounded">
5758	      <xs:group ref="executeType"/>
5759	                                 (MSML)

5761	      <xs:element ref="send" maxOccurs="unbounded"/>
5762	     </xs:choice>
5763	    </xs:group>
5764	    <xs:element name="primitive" type="primitiveType" abstract="true"/>
5765	    <xs:complexType name="primitiveType">
5766	     <xs:attribute name="id" type="momlID.datatype"/>
5767	    </xs:complexType>
5768	    <xs:element name="control" abstract="true"/>
5769	    <xs:group name="executeType">
5770	     <xs:choice maxOccurs="unbounded">
5771	      <xs:element ref="primitive"/>
5772	      <xs:element ref="control"/>
5773	     </xs:choice>
5774	    </xs:group>
5775	    <xs:group name="sendType">
5776	     <xs:choice>
5777	      <xs:choice>
5778	       <xs:element name="exit" type="exitType"/>
5779	       <xs:element name="disconnect" type="exitType"/>
5780	      </xs:choice>
5781	      <xs:sequence>
5782	       <xs:element ref="send" maxOccurs="unbounded"/>
5783	       <xs:choice minOccurs="0">
5784	        <xs:element name="exit" type="exitType"/>
5785	        <xs:element name="disconnect" type="exitType"/>
5786	       </xs:choice>
5787	      </xs:sequence>
5788	     </xs:choice>
5789	    </xs:group>
5790	    <xs:element name="send">
5791	     <xs:complexType>
5792	      <xs:attribute name="event" type="momlEvent.datatype"
5793	          use="required"/>
5794	      <xs:attribute name="target" type="momlTarget.datatype"
5795	          use="required"/>
5796	      <xs:attribute name="namelist" type="momlNamelist.datatype"/>
5797	     </xs:complexType>
5798	    </xs:element>
5799	    <xs:complexType name="exitType">
5800	     <xs:attribute name="namelist" type="momlNamelist.datatype"/>
5801	    </xs:complexType>
5802	    <xs:element name="event">
5803	     <xs:complexType>
5804	      <xs:sequence maxOccurs="unbounded">
5805	       <xs:element name="name" type="xs:string"/>
5806	       <xs:element name="value" type="xs:string"/>
5807	      </xs:sequence>
5808	      <xs:attribute name="name" type="xs:string" use="required"/>
5809	                                 (MSML)

5811	      <xs:attribute name="id" type="xs:string" use="required"/>
5812	     </xs:complexType>
5813	    </xs:element>
5814	   </xs:schema>

5816	   The schema for the MSML Dialog Base package (moml-basic-primitives-
5817	   module.xsd) is:

5819	   <?xml version="1.0" encoding="UTF-8"?>
5820	   <xs:schema elementFormDefault="unqualified"
5821	              attributeFormDefault="unqualified"
5822	              xmlns:xs="http://www.w3.org/2001/XMLSchema">

5824	     <xs:include schemaLocation="moml-datatypes.xsd"/>
5825	     <xs:include schemaLocation="moml-core-module.xsd"/>
5826	     <xs:import namespace="http://www.w3.org/XML/1998/namespace"
5827	                schemaLocation="http://www.w3.org/2001/xml.xsd"/>
5828	     <xs:element name="play" substitutionGroup="primitive">
5829	       <xs:complexType>
5830	         <xs:complexContent>
5831	           <xs:extension base="primitiveType">
5832	             <xs:sequence>
5833	               <xs:choice maxOccurs="unbounded">
5834	                 <xs:element name="audio" minOccurs="0"
5835	                             maxOccurs="unbounded">
5836	                   <xs:complexType>
5837	                     <xs:attribute name="uri" type="xs:anyURI"
5838	                                   use="required"/>
5839	                     <xs:attribute name="iterate"
5840	                                   type="iterate.datatype" default="1"/>
5841	                     <xs:attribute name="format" type="xs:string"
5842	                                   use="optional"/>
5843	                     <xs:attribute name="audiosamplerate"
5844	                                   type="xs:positiveInteger"
5845	                                   use="optional"/>
5846	                     <xs:attribute name="audiosamplesize"
5847	                                   type="xs:positiveInteger"
5848	                                   use="optional"/>
5849	                     <xs:attribute ref="xml:lang"/>
5850	                   </xs:complexType>
5851	                 </xs:element>
5852	                 <xs:element name="video" minOccurs="0"
5853	                             maxOccurs="unbounded">
5854	                   <xs:complexType>
5855	                     <xs:attribute name="uri" type="xs:anyURI"
5856	                                   use="required"/>
5857	                     <xs:attribute name="iterate"
5858	                                 (MSML)

5860	                                   type="iterate.datatype"
5861	                                   use="optional" default="1"/>
5862	                     <xs:attribute name="format" type="xs:string"
5863	                                   use="optional"/>
5864	                     <xs:attribute name="audiosamplerate"
5865	                                   type="xs:positiveInteger"
5866	                                   use="optional"/>
5867	                     <xs:attribute name="audiosamplesize"
5868	                                   type="xs:positiveInteger"
5869	                                   use="optional"/>
5870	                     <xs:attribute name="codecconfig" type="xs:string"
5871	                                   use="optional"/>
5872	                     <xs:attribute name="profile" type="xs:string"
5873	                                   use="optional"/>
5874	                     <xs:attribute name="level" type="xs:string"
5875	                                   use="optional"/>
5876	                     <xs:attribute name="imagewidth"
5877	                                   type="xs:positiveInteger"
5878	                                   use="optional"/>
5879	                     <xs:attribute name="imageheight"
5880	                                   type="xs:positiveInteger"
5881	                                   use="optional"/>
5882	                     <xs:attribute name="maxbitrate"
5883	                                   type="xs:positiveInteger"
5884	                                   use="optional"/>
5885	                     <xs:attribute name="framerate"
5886	                                   type="xs:positiveInteger"
5887	                                   use="optional"/>
5888	                   </xs:complexType>
5889	                 </xs:element>
5890	                 <xs:element name="media" minOccurs="0"
5891	                             maxOccurs="unbounded">
5892	                   <xs:complexType>
5893	                     <xs:choice>
5894	                       <xs:element name="audio" minOccurs="0">
5895	                         <xs:complexType>
5896	                           <xs:attribute name="uri" type="xs:anyURI"
5897	                                         use="required"/>
5898	                           <xs:attribute name="iterate"
5899	                                         type="iterate.datatype"
5900	                                         default="1"/>
5901	                           <xs:attribute name="format" type="xs:string"
5902	                                         use="optional"/>
5903	                           <xs:attribute name="audiosamplerate"
5904	                                         type="xs:positiveInteger"
5905	                                         use="optional"/>
5906	                           <xs:attribute name="audiosamplesize"
5907	                                         type="xs:positiveInteger"

5909	                                 (MSML)

5911	                                         use="optional"/>
5912	                           <xs:attribute ref="xml:lang"/>
5913	                         </xs:complexType>
5914	                       </xs:element>
5915	                       <xs:element name="video" minOccurs="0">
5916	                         <xs:complexType>
5917	                           <xs:attribute name="uri" type="xs:anyURI"
5918	                                         use="required"/>
5919	                           <xs:attribute name="iterate"
5920	                                         type="iterate.datatype"
5921	                                         use="optional" default="1"/>
5922	                           <xs:attribute name="format" type="xs:string"
5923	                                         use="optional"/>
5924	                           <xs:attribute name="audiosamplerate"
5925	                                         type="xs:positiveInteger"
5926	                                         use="optional"/>
5927	                           <xs:attribute name="audiosamplesize"
5928	                                         type="xs:positiveInteger"
5929	                                         use="optional"/>
5930	                           <xs:attribute name="codecconfig"
5931	                                         type="xs:string"
5932	                                         use="optional"/>
5933	                           <xs:attribute name="profile" type="xs:string"
5934	                                         use="optional"/>
5935	                           <xs:attribute name="level" type="xs:string"
5936	                                         use="optional"/>
5937	                           <xs:attribute name="imagewidth"
5938	                                         type="xs:positiveInteger"
5939	                                         use="optional"/>
5940	                           <xs:attribute name="imageheight"
5941	                                         type="xs:positiveInteger"
5942	                                         use="optional"/>
5943	                           <xs:attribute name="maxbitrate"
5944	                                         type="xs:positiveInteger"
5945	                                         use="optional"/>
5946	                           <xs:attribute name="framerate"
5947	                                         type="xs:positiveInteger"
5948	                                         use="optional"/>
5949	                         </xs:complexType>
5950	                       </xs:element>
5951	                     </xs:choice>
5952	                   </xs:complexType>
5953	                 </xs:element>
5954	                 <xs:element ref="smedia" minOccurs="0"
5955	                             maxOccurs="unbounded"/>
5956	               </xs:choice>
5957	               <xs:choice minOccurs="0">
5958	                 <xs:element name="playexit">
5959	                                 (MSML)

5961	                   <xs:complexType>
5962	                     <xs:group ref="sendType"/>
5963	                   </xs:complexType>
5964	                 </xs:element>
5965	               </xs:choice>
5966	             </xs:sequence>
5967	             <xs:attribute name="interval" type="posDuration.datatype"
5968	                           use="optional"/>
5969	             <xs:attribute name="iterate" type="iterate.datatype"
5970	                           use="optional" default="1"/>
5971	             <xs:attribute name="offset" type="duration.datatype"
5972	                           use="optional"/>
5973	             <xs:attribute name="initial" use="optional"
5974	                           default="generate">
5975	               <xs:simpleType>
5976	                 <xs:restriction base="xs:string">
5977	                   <xs:enumeration value="generate"/>
5978	                   <xs:enumeration value="suspend"/>
5979	                 </xs:restriction>
5980	               </xs:simpleType>
5981	             </xs:attribute>
5982	             <xs:attribute name="maxtime" type="posDuration.datatype"
5983	                           use="optional"/>
5984	             <xs:attribute name="skip" type="duration.datatype"
5985	                           use="optional" default="3s"/>
5986	             <xs:attribute name="barge" type="boolean.datatype"
5987	                           use="optional" default="false"/>
5988	             <xs:attribute name="cleardb" type="boolean.datatype"
5989	                           use="optional" default="false"/>
5990	             <xs:attribute ref="xml:lang"/>
5991	           </xs:extension>
5992	         </xs:complexContent>
5993	       </xs:complexType>
5994	     </xs:element>
5995	     <xs:element name="record" substitutionGroup="primitive">
5996	       <xs:complexType>
5997	         <xs:complexContent>
5998	           <xs:extension base="primitiveType">
5999	             <xs:choice minOccurs="0">
6000	               <xs:element ref="play" minOccurs="0"/>
6001	               <xs:element name="recordexit">
6002	                 <xs:complexType>
6003	                   <xs:group ref="sendType"/>
6004	                 </xs:complexType>
6005	               </xs:element>
6006	             </xs:choice>
6007	             <xs:attribute name="append" type="boolean.datatype"
6008	                           use="optional" default="false"/>
6009	                                 (MSML)

6011	             <xs:attribute name="dest" type="xs:anyURI" use="optional"/>
6012	             <xs:attribute name="audiodest" type="xs:anyURI"
6013	                           use="optional"/>
6014	             <xs:attribute name="videodest" type="xs:anyURI"
6015	                           use="optional"/>
6016	             <xs:attribute name="format" use="required">
6017	               <xs:simpleType>
6018	                 <xs:restriction base="xs:string"/>
6019	               </xs:simpleType>
6020	             </xs:attribute>
6021	             <xs:attribute name="codecconfig" use="optional">
6022	               <xs:simpleType>
6023	                 <xs:restriction base="xs:string"/>
6024	               </xs:simpleType>
6025	             </xs:attribute>
6026	             <xs:attribute name="audiosamplerate"
6027	                           type="xs:positiveInteger" use="optional"/>
6028	             <xs:attribute name="audiosamplesize"
6029	                           type="xs:positiveInteger" use="optional"/>
6030	             <xs:attribute name="profile" use="optional">
6031	               <xs:simpleType>
6032	                 <xs:restriction base="xs:string"/>
6033	               </xs:simpleType>
6034	             </xs:attribute>
6035	             <xs:attribute name="level" use="optional">
6036	               <xs:simpleType>
6037	                 <xs:restriction base="xs:string"/>
6038	               </xs:simpleType>
6039	             </xs:attribute>
6040	             <xs:attribute name="imagewidth" type="xs:positiveInteger"
6041	                           use="optional"/>
6042	             <xs:attribute name="imageheight" type="xs:positiveInteger"
6043	                           use="optional"/>
6044	             <xs:attribute name="maxbitrate" type="xs:positiveInteger"
6045	                           use="optional"/>
6046	             <xs:attribute name="framerate" type="xs:positiveInteger"
6047	                           use="optional"/>
6048	             <xs:attribute name="maxtime" type="posDuration.datatype"
6049	                           use="required"/>
6050	             <xs:attribute name="initial" use="optional"
6051	                           default="create">
6052	               <xs:simpleType>
6053	                 <xs:restriction base="xs:string">
6054	                   <xs:enumeration value="create"/>
6055	                   <xs:enumeration value="suspend"/>
6056	                 </xs:restriction>
6057	               </xs:simpleType>
6058	             </xs:attribute>
6059	                                 (MSML)

6061	             <xs:attribute name="prespeech" type="posDuration.datatype"
6062	                           use="optional" default="0s"/>
6063	             <xs:attribute name="postspeech" type="posDuration.datatype"
6064	                           use="optional" default="0s"/>
6065	             <xs:attribute name="termkey" use="optional">
6066	               <xs:simpleType>
6067	                 <xs:restriction base="xs:string">
6068	                   <xs:pattern value="[0-9#*ABCD]"/>
6069	                   <xs:enumeration value="create"/>
6070	                   <xs:enumeration value="suspend"/>
6071	                 </xs:restriction>
6072	               </xs:simpleType>
6073	             </xs:attribute>
6074	           </xs:extension>
6075	         </xs:complexContent>
6076	       </xs:complexType>
6077	     </xs:element>
6078	     <xs:element name="dtmf" substitutionGroup="primitive">
6079	       <xs:complexType>
6080	         <xs:complexContent>
6081	           <xs:extension base="primitiveType">
6082	             <xs:sequence>
6083	               <xs:element name="pattern" maxOccurs="unbounded">
6084	                 <xs:complexType>
6085	                   <xs:group ref="sendType"/>
6086	                   <xs:attribute name="digits" type="xs:string"
6087	                                 use="required"/>
6088	                   <xs:attribute name="format">
6089	                     <xs:simpleType>
6090	                       <xs:restriction base="xs:string">
6091	                         <xs:enumeration value="mgcp"/>
6092	                         <xs:enumeration value="megaco"/>
6093	                         <xs:enumeration value="moml+digits"/>
6094	                       </xs:restriction>
6095	                     </xs:simpleType>
6096	                   </xs:attribute>
6097	                   <xs:attribute name="iterate" type="iterate.datatype"
6098	                                 default="1"/>
6099	                 </xs:complexType>
6100	               </xs:element>
6101	               <xs:element name="detect" minOccurs="0">
6102	                 <xs:complexType>
6103	                   <xs:group ref="sendType"/>
6104	                 </xs:complexType>
6105	               </xs:element>
6106	               <xs:element name="noinput" type="iterateSendType"
6107	                           minOccurs="0"/>
6108	               <xs:element name="nomatch" type="iterateSendType"
6109	                                 (MSML)

6111	                           minOccurs="0"/>
6112	               <xs:element name="dtmfexit" minOccurs="0">
6113	                 <xs:complexType>
6114	                   <xs:group ref="sendType"/>
6115	                 </xs:complexType>
6116	               </xs:element>
6117	               <xs:element ref="play" minOccurs="0"/>
6118	             </xs:sequence>
6119	             <xs:attribute name="cleardb" type="boolean.datatype"
6120	                           default="true"/>
6121	             <xs:attribute name="fdt" type="posDuration.datatype"
6122	                           default="0s"/>
6123	             <xs:attribute name="idt" type="posDuration.datatype"
6124	                           default="4s"/>
6125	             <xs:attribute name="edt" type="posDuration.datatype"
6126	                           default="4s"/>
6127	             <xs:attribute name="starttimer" type="boolean.datatype"
6128	                           default="false"/>
6129	             <xs:attribute name="iterate" type="iterate.datatype"
6130	                           default="1"/>
6131	           </xs:extension>
6132	         </xs:complexContent>
6133	       </xs:complexType>
6134	     </xs:element>
6135	     <xs:element name="collect" substitutionGroup="primitive">
6136	       <xs:complexType>
6137	         <xs:complexContent>
6138	           <xs:extension base="primitiveType">
6139	             <xs:sequence>
6140	               <xs:element name="pattern" maxOccurs="unbounded">
6141	                 <xs:complexType>
6142	                   <xs:group ref="sendType"/>
6143	                   <xs:attribute name="digits" type="xs:string"
6144	                                 use="required"/>
6145	                   <xs:attribute name="format">
6146	                     <xs:simpleType>
6147	                       <xs:restriction base="xs:string">
6148	                         <xs:enumeration value="mgcp"/>
6149	                         <xs:enumeration value="megaco"/>
6150	                         <xs:enumeration value="moml+digits"/>
6151	                       </xs:restriction>
6152	                     </xs:simpleType>
6153	                   </xs:attribute>
6154	                   <xs:attribute name="iterate" type="iterate.datatype"
6155	                                 default="1"/>
6156	                 </xs:complexType>
6157	               </xs:element>
6158	               <xs:element name="detect" minOccurs="0">
6159	                                 (MSML)

6161	                 <xs:complexType>
6162	                   <xs:group ref="sendType"/>
6163	                 </xs:complexType>
6164	               </xs:element>
6165	               <xs:element name="noinput" type="iterateSendType"
6166	                           minOccurs="0"/>
6167	               <xs:element name="nomatch" type="iterateSendType"
6168	                           minOccurs="0"/>
6169	               <xs:element name="dtmfexit" minOccurs="0">
6170	                 <xs:complexType>
6171	                   <xs:group ref="sendType"/>
6172	                 </xs:complexType>
6173	               </xs:element>
6174	               <xs:element ref="play" minOccurs="0"/>
6175	             </xs:sequence>
6176	             <xs:attribute name="cleardb" type="boolean.datatype"
6177	                           default="true"/>
6178	             <xs:attribute name="fdt" type="posDuration.datatype"
6179	                           default="0s"/>
6180	             <xs:attribute name="idt" type="posDuration.datatype"
6181	                           default="4s"/>
6182	             <xs:attribute name="edt" type="posDuration.datatype"
6183	                           default="4s"/>
6184	             <xs:attribute name="starttimer" type="boolean.datatype"
6185	                           default="false"/>
6186	             <xs:attribute name="iterate" type="iterate.datatype"
6187	                           default="1"/>
6188	           </xs:extension>
6189	         </xs:complexContent>
6190	       </xs:complexType>
6191	     </xs:element>
6192	     <xs:element name="dtmfgen" substitutionGroup="primitive">
6193	       <xs:complexType>
6194	         <xs:complexContent>
6195	           <xs:extension base="primitiveType">
6196	             <xs:choice minOccurs="0">
6197	               <xs:element name="dtmfgenexit">
6198	                 <xs:complexType>
6199	                   <xs:group ref="sendType"/>
6200	                 </xs:complexType>
6201	               </xs:element>
6202	             </xs:choice>
6203	             <xs:attribute name="level" use="optional" default="-6">
6204	               <xs:simpleType>
6205	                 <xs:restriction base="xs:nonPositiveInteger">
6206	                   <xs:maxInclusive value="0"/>
6207	                   <xs:minInclusive value="-96"/>
6208	                 </xs:restriction>
6209	                                 (MSML)

6211	               </xs:simpleType>
6212	             </xs:attribute>
6213	             <xs:attribute name="digits" type="dtmfDigits.datatype"
6214	                           use="required"/>
6215	             <xs:attribute name="dur" type="posDuration.datatype"
6216	                           use="optional" default="100ms"/>
6217	             <xs:attribute name="interval" type="posDuration.datatype"
6218	                           use="optional" default="100ms"/>
6219	           </xs:extension>
6220	         </xs:complexContent>
6221	       </xs:complexType>
6222	     </xs:element>
6223	     <xs:complexType name="iterateSendType">
6224	       <xs:group ref="sendType"/>
6225	       <xs:attribute name="iterate" type="iterate.datatype"
6226	                     default="1"/>
6227	     </xs:complexType>
6228	     <xs:element name="smedia" type="smediaType" abstract="true"/>
6229	     <xs:complexType name="smediaType">
6230	       <xs:attribute ref="xml:lang"/>
6231	       <xs:attribute name="iterate" type="iterate.datatype"/>
6232	     </xs:complexType>
6233	     <xs:element name="var" substitutionGroup="smedia">
6234	       <xs:complexType>
6235	         <xs:complexContent>
6236	           <xs:extension base="smediaType">
6237	             <xs:attribute name="type" use="required">
6238	               <xs:simpleType>
6239	                 <xs:restriction base="xs:string">
6240	                   <xs:enumeration value="date"/>
6241	                   <xs:enumeration value="digits"/>
6242	                   <xs:enumeration value="duration"/>
6243	                   <xs:enumeration value="month"/>
6244	                   <xs:enumeration value="money"/>
6245	                   <xs:enumeration value="number"/>
6246	                   <xs:enumeration value="silence"/>
6247	                   <xs:enumeration value="time"/>
6248	                   <xs:enumeration value="weekday"/>
6249	                 </xs:restriction>
6250	               </xs:simpleType>
6251	             </xs:attribute>
6252	             <xs:attribute name="subtype" type="xs:string"
6253	                           use="optional"/>
6254	             <xs:attribute name="value" type="xs:string"
6255	                           use="required"/>
6256	           </xs:extension>
6257	         </xs:complexContent>
6258	       </xs:complexType>
6259	                                 (MSML)

6261	     </xs:element>
6262	   </xs:schema>

6264	   The schema for the MSML Dialog Group package (moml-group-module.xsd)
6265	   is:

6267	   <?xml version="1.0" encoding="UTF-8"?>
6268	   <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
6269	      elementFormDefault="unqualified"
6270	      attributeFormDefault="unqualified">
6271	    <xs:include schemaLocation="moml-datatypes.xsd"/>
6272	    <xs:include schemaLocation="moml-core-module.xsd"/>
6273	    <xs:element name="group" substitutionGroup="control">
6274	     <xs:complexType>
6275	      <xs:sequence>
6276	       <xs:group ref="executeType"/>
6277	       <xs:element name="groupexit" minOccurs="0">
6278	        <xs:complexType>
6279	         <xs:group ref="sendType"/>
6280	        </xs:complexType>
6281	       </xs:element>
6282	      </xs:sequence>
6283	      <xs:attribute name="id" type="momlID.datatype"/>
6284	      <xs:attribute name="topology" use="required">
6285	       <xs:simpleType>
6286	        <xs:restriction base="xs:string">
6287	         <xs:enumeration value="serial"/>
6288	         <xs:enumeration value="parallel"/>
6289	         <xs:enumeration value="fullduplex"/>
6290	        </xs:restriction>
6291	       </xs:simpleType>
6292	      </xs:attribute>
6293	     </xs:complexType>
6294	    </xs:element>
6295	   </xs:schema>

6297	   The schema for the MSML Dialog Transform package (moml-transform-
6298	   primitives-module.xsd) is:

6300	   <?xml version="1.0" encoding="UTF-8"?>
6301	   <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
6302	              elementFormDefault="unqualified"
6303	              attributeFormDefault="unqualified">
6304	                                 (MSML)

6306	    <xs:include schemaLocation="moml-datatypes.xsd"/>
6307	    <xs:include schemaLocation="moml-core-module.xsd"/>
6308	    <xs:import namespace="http://www.w3.org/XML/1998/namespace"
6309	               schemaLocation="http://www.w3.org/2001/xml.xsd"/>
6310	    <xs:element name="vad" substitutionGroup="primitive">
6311	     <xs:complexType>
6312	      <xs:complexContent>
6313	      <xs:extension base="primitiveType">
6314	      <xs:all>
6315	       <xs:element name="voice" type="vadPatternType" minOccurs="0"/>
6316	       <xs:element name="silence" type="vadPatternType" minOccurs="0"/>
6317	       <xs:element name="tvoice" type="vadPatternType" minOccurs="0"/>
6318	       <xs:element name="tsilence" type="vadPatternType" minOccurs="0"/>
6319	      </xs:all>
6320	      <xs:attribute name="starttimer" type="boolean.datatype"
6321	                    default="false"/>
6322	      </xs:extension>
6323	      </xs:complexContent>
6324	     </xs:complexType>
6325	    </xs:element>
6326	    <xs:element name="gain" substitutionGroup="primitive">
6327	     <xs:complexType>
6328	      <xs:complexContent>
6329	      <xs:extension base="primitiveType">
6330	      <xs:attribute name="incr" default="3">
6331	       <xs:simpleType>
6332	        <xs:restriction base="xs:positiveInteger">
6333	         <xs:maxInclusive value="96"/>
6334	        </xs:restriction>
6335	       </xs:simpleType>
6336	      </xs:attribute>
6337	      <xs:attribute name="amt" use="required">
6338	       <xs:simpleType>
6339	        <xs:restriction base="xs:integer">
6340	         <xs:minInclusive value="-96"/>
6341	         <xs:maxInclusive value="96"/>
6342	        </xs:restriction>
6343	       </xs:simpleType>
6344	      </xs:attribute>
6345	      </xs:extension>
6346	      </xs:complexContent>
6347	     </xs:complexType>
6348	    </xs:element>
6349	    <xs:element name="agc" substitutionGroup="primitive">
6350	     <xs:complexType>
6351	      <xs:complexContent>
6352	      <xs:extension base="primitiveType">
6353	      <xs:attribute name="tgtlvl" use="required">
6354	                                 (MSML)

6356	       <xs:simpleType>
6357	        <xs:restriction base="xs:nonPositiveInteger">
6358	         <xs:minInclusive value="-40"/>
6359	         <xs:maxInclusive value="0"/>
6360	        </xs:restriction>
6361	       </xs:simpleType>
6362	      </xs:attribute>
6363	      <xs:attribute name="maxgain" default="10">
6364	       <xs:simpleType>
6365	        <xs:restriction base="xs:nonNegativeInteger">
6366	         <xs:minInclusive value="0"/>
6367	         <xs:maxInclusive value="40"/>
6368	        </xs:restriction>
6369	       </xs:simpleType>
6370	      </xs:attribute>
6371	      </xs:extension>
6372	      </xs:complexContent>
6373	     </xs:complexType>
6374	    </xs:element>
6375	    <xs:element name="gate" substitutionGroup="primitive">
6376	     <xs:complexType>
6377	      <xs:complexContent>
6378	      <xs:extension base="primitiveType">
6379	      <xs:attribute name="initial" default="pass">
6380	       <xs:simpleType>
6381	        <xs:restriction base="xs:string">
6382	         <xs:enumeration value="pass"/>
6383	         <xs:enumeration value="halt"/>
6384	        </xs:restriction>
6385	       </xs:simpleType>
6386	      </xs:attribute>
6387	      </xs:extension>
6388	      </xs:complexContent>
6389	     </xs:complexType>
6390	    </xs:element>
6391	    <xs:element name="clamp" substitutionGroup="primitive">
6392	     <xs:complexType>
6393	      <xs:complexContent>
6394	       <xs:extension base="primitiveType"/>
6395	      </xs:complexContent>
6396	     </xs:complexType>
6397	    </xs:element>
6398	    <xs:element name="relay" substitutionGroup="primitive">
6399	     <xs:complexType>
6400	      <xs:complexContent>
6401	       <xs:extension base="primitiveType"/>
6402	      </xs:complexContent>
6403	     </xs:complexType>
6404	                                 (MSML)

6406	    </xs:element>
6407	    <xs:complexType name="vadPatternType">
6408	     <xs:group ref="sendType"/>
6409	     <xs:attribute name="iterate" type="iterate.datatype" default="1"/>
6410	     <xs:attribute name="len" type="posDuration.datatype"
6411	                   use="required"/>
6412	     <xs:attribute name="sen" type="posDuration.datatype"
6413	                   use="optional"/>
6414	    </xs:complexType>
6415	   </xs:schema>

6417	   Following is the schema for the MSML Speech package (moml-speech-
6418	   module.xsd). Note that several URL were split across several lines
6419	   for formatting reasons.

6421	   <?xml version="1.0" encoding="UTF-8"?>
6422	   <xs:schema elementFormDefault="qualified"
6423	              attributeFormDefault="unqualified"
6424	              xmlns:xs="http://www.w3.org/2001/XMLSchema">
6425	    <xs:include schemaLocation="moml-datatypes.xsd"/>
6426	    <xs:include schemaLocation="moml-core-module.xsd"/>
6427	    <xs:include schemaLocation="moml-basic-primitives-module.xsd"/>
6428	    <xs:include schemaLocation="http://www.w3.org/TR/2002/WD-speech-
6429	                synthesis-20020405/synthesis-core.xsd"/>
6430	    <xs:include schemaLocation="http://www.w3.org/TR/speech-
6431	                grammar/grammar-core.xsd"/>
6432	    <xs:element name="speech" substitutionGroup="primitive">
6433	     <xs:complexType>
6434	      <xs:complexContent>
6435	       <xs:extension base="primitiveType">
6436	        <xs:sequence>
6437	         <xs:element name="grammar" maxOccurs="unbounded">
6438	          <xs:complexType>
6439	           <xs:complexContent>
6440	            <xs:extension base="grammar">
6441	             <xs:choice>
6442	              <xs:element name="match" type="iterateSendType"
6443	                          minOccurs="0"/>
6444	             </xs:choice>
6445	             <xs:attribute name="uri" type="xs:anyURI"/>
6446	             <xs:attribute name="iterate" type="iterate.datatype"
6447	                           default="1"/>
6448	            </xs:extension>
6449	           </xs:complexContent>
6450	          </xs:complexType>
6451	         </xs:element>
6452	         <xs:element name="noinput" type="iterateSendType"
6453	                                 (MSML)

6455	                     minOccurs="0"/>
6456	         <xs:element name="nomatch" type="iterateSendType"
6457	                     minOccurs="0"/>
6458	         <xs:element name="speechexit" minOccurs="0">
6459	          <xs:complexType>
6460	           <xs:group ref="sendType"/>
6461	          </xs:complexType>
6462	         </xs:element>
6463	        </xs:sequence>
6464	        <xs:attribute name="noint" type="posDuration.datatype"/>
6465	        <xs:attribute name="norect" type="posDuration.datatype"/>
6466	        <xs:attribute name="spcmplt" type="posDuration.datatype"/>
6467	        <xs:attribute name="confidence">
6468	         <xs:simpleType>
6469	          <xs:restriction base="xs:positiveInteger">
6470	           <xs:maxInclusive value="100"/>
6471	          </xs:restriction>
6472	         </xs:simpleType>
6473	        </xs:attribute>
6474	        <xs:attribute name="sens" type="xs:positiveInteger"/>
6475	        <xs:attribute name="starttimer" type="boolean.datatype"
6476	                      default="false"/>
6477	        <xs:attribute name="iterate" type="iterate.datatype"
6478	                      default="1"/>
6479	       </xs:extension>
6480	      </xs:complexContent>
6481	     </xs:complexType>
6482	    </xs:element>
6483	    <xs:element name="tts" type="smediaType"
6484	                substitutionGroup="smedia"/>
6485	   </xs:schema>

6487	   Following is the schema for the MSML Fax packages (moml-fax-
6488	   module.xsd).

6490	   <?xml version="1.0" encoding="UTF-8"?>
6491	   <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
6492	              elementFormDefault="qualified"
6493	              attributeFormDefault="unqualified">
6494	    <xs:include schemaLocation="moml-datatypes.xsd"/>
6495	    <xs:include schemaLocation="moml-core-module.xsd"/>
6496	    <xs:element name="faxdetect" substitutionGroup="primitive">
6497	     <xs:complexType>
6498	      <xs:choice>
6499	       <xs:group ref="sendType"/>
6500	      </xs:choice>
6501	     </xs:complexType>
6502	                                 (MSML)

6504	    </xs:element>
6505	    <xs:element name="faxsend" substitutionGroup="primitive">
6506	     <xs:complexType>
6507	      <xs:sequence>
6508	       <xs:element name="sendobj" type="sendobjType" minOccurs="0"
6509	                   maxOccurs="unbounded"/>
6510	       <xs:element name="hdrfooter" type="hdrfooterType" minOccurs="0"/>
6511	       <xs:element name="rxpoll" minOccurs="0">
6512	        <xs:complexType>
6513	         <xs:sequence>
6514	          <xs:element name="rcvobj" type="rcvobjType"
6515	                      maxOccurs="unbounded"/>
6516	          <xs:element name="hdrfooter" type="hdrfooterType"
6517	                      minOccurs="0"/>
6518	         </xs:sequence>
6519	         <xs:attribute name="rmtid" type="faxid.datatype"
6520	                       use="required"/>
6521	        </xs:complexType>
6522	       </xs:element>
6523	       <xs:group ref="faxstatusrequest"/>
6524	      </xs:sequence>
6525	      <xs:attribute name="lclid" type="faxid.datatype" use="optional"/>
6526	      <xs:attribute name="minspeed" type="faxspeed.datatype"
6527	                    use="optional"/>
6528	      <xs:attribute name="maxspeed" type="faxspeed.datatype"
6529	                    use="optional"/>
6530	      <xs:attribute name="ecm" type="boolean.datatype" use="optional"/>
6531	     </xs:complexType>
6532	    </xs:element>
6533	    <xs:element name="faxrecv" substitutionGroup="primitive">
6534	     <xs:complexType>
6535	      <xs:sequence>
6536	       <xs:element name="rcvobj" type="rcvobjType" minOccurs="0"
6537	                   maxOccurs="unbounded"/>
6538	       <xs:element name="hdrfooter" type="hdrfooterType" minOccurs="0"/>
6539	       <xs:element name="txpoll" minOccurs="0">
6540	        <xs:complexType>
6541	         <xs:sequence>
6542	          <xs:element name="sendobj" type="sendobjType"
6543	                      maxOccurs="unbounded"/>
6544	          <xs:element name="hdrfooter" type="hdrfooterType"
6545	                      minOccurs="0"/>
6546	         </xs:sequence>
6547	         <xs:attribute name="rmtid" type="faxid.datatype"/>
6548	        </xs:complexType>
6549	       </xs:element>
6550	       <xs:group ref="faxstatusrequest"/>
6551	      </xs:sequence>
6552	                                 (MSML)

6554	      <xs:attribute name="lclid" type="faxid.datatype" use="optional"/>
6555	      <xs:attribute name="ecm" type="boolean.datatype" default="true"/>
6556	     </xs:complexType>
6557	    </xs:element>
6558	    <xs:group name="faxstatusrequest">
6559	     <xs:all>
6560	      <xs:element name="faxstart" minOccurs="0"/>
6561	      <xs:element name="faxnegotiate" minOccurs="0"/>
6562	      <xs:element name="faxpagedone" minOccurs="0"/>
6563	      <xs:element name="faxobjectdone" minOccurs="0"/>
6564	      <xs:element name="faxopcomplete" minOccurs="0"/>
6565	      <xs:element name="faxpollstart" minOccurs="0"/>
6566	     </xs:all>
6567	    </xs:group>
6568	    <xs:complexType name="hdrfooterType">
6569	     <xs:choice>
6570	      <xs:element name="format" type="xs:string" minOccurs="0"
6571	                  maxOccurs="unbounded"/>
6572	     </xs:choice>
6573	     <xs:attribute name="type" type="hdrfooter.datatype"/>
6574	     <xs:attribute name="style" type="hdrfooterstyle.datatype"/>
6575	    </xs:complexType>
6576	    <xs:complexType name="formatType">
6577	     <xs:simpleContent>
6578	      <xs:extension base="xs:string">
6579	       <xs:attribute name="style">
6580	        <xs:simpleType>
6581	         <xs:restriction base="xs:string">
6582	          <xs:enumeration value="append"/>
6583	          <xs:enumeration value="overlay"/>
6584	          <xs:enumeration value="replace"/>
6585	         </xs:restriction>
6586	        </xs:simpleType>
6587	       </xs:attribute>
6588	      </xs:extension>
6589	     </xs:simpleContent>
6590	    </xs:complexType>
6591	    <xs:complexType name="rcvobjType">
6592	     <xs:attribute name="objuri" type="xs:anyURI" use="required"/>
6593	     <xs:attribute name="maxpages" type="xs:positiveInteger"/>
6594	    </xs:complexType>
6595	    <xs:complexType name="sendobjType">
6596	     <xs:attribute name="objuri" type="xs:anyURI" use="required"/>
6597	     <xs:attribute name="startpage" type="xs:positiveInteger"/>
6598	     <xs:attribute name="pagecount" type="xs:positiveInteger"/>
6599	    </xs:complexType>
6600	    <xs:simpleType name="faxid.datatype">
6601	     <xs:restriction base="xs:string">
6602	                                 (MSML)

6604	      <xs:pattern value="[0-9+*- ]{20}"/>
6605	     </xs:restriction>
6606	    </xs:simpleType>
6607	    <xs:simpleType name="faxspeed.datatype">
6608	     <xs:restriction base="xs:string">
6609	      <xs:enumeration value="2400"/>
6610	      <xs:enumeration value="4800"/>
6611	      <xs:enumeration value="7200"/>
6612	      <xs:enumeration value="9600"/>
6613	      <xs:enumeration value="12000"/>
6614	      <xs:enumeration value="14400"/>
6615	     </xs:restriction>
6616	    </xs:simpleType>
6617	    <xs:simpleType name="hdrfooter.datatype">
6618	     <xs:restriction base="xs:string">
6619	      <xs:enumeration value="header"/>
6620	      <xs:enumeration value="footer"/>
6621	      <xs:enumeration value="autohdr"/>
6622	      <xs:enumeration value="nohdr"/>
6623	     </xs:restriction>
6624	    </xs:simpleType>
6625	    <xs:simpleType name="hdrfooterstyle.datatype">
6626	     <xs:restriction base="xs:string">
6627	      <xs:enumeration value="append"/>
6628	      <xs:enumeration value="overlay"/>
6629	      <xs:enumeration value="replace"/>
6630	     </xs:restriction>
6631	    </xs:simpleType>
6632	   </xs:schema>

6634	18. Security Considerations

6636	   MSML is invoked through other languages and protocols and as such
6637	   security considerations depend on those environments.

6639	   MSML being an XML based language, security considerations as defined
6640	   by RFC 3023 [14] are applicable.

6642	19. IANA Considerations

6644	   IANA registrations for �application/msml+xml�, �text/msml-basic-
6645	   layout�, and �application/moml+xml� media types are planned.

6647	   MGCP and Megaco/H.248 packages are registered with IANA so that there
6648	   is no conflict between packages developed by different authors. The
6649	   package scheme planned for future extensibility of MSML will also
6650	   require IANA registry of packages.

6652	                                 (MSML)

6654	20. URN Sub-Namespace Registration

6656	   The namespace URI for elements defined within this specification is a
6657	   URN [24]. It uses the namespace identifier 'ietf' defined by [25] and
6658	   extended by RFC 3688 [26]. The regisgtration of URN
6659	   (urn:ietf:params:xml:ns:msml) is planned.

6661	21. XML Schema Registration

6663	   The XML schema associated with the MSML specification, is planned for
6664	   registration as per the guidelines in RFC 3688 [26].

6666	22. References

6668	   [1] J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J.
6669	   Peterson, R. Sparks, M. Handley, and E. Schooler, "SIP: Session
6670	   Initiation Protocol", RFC3261, Internet Engineering Taskforce, June
6671	   2002.

6673	   [2] J. Rosenberg, H. Schulzrinne, and P. Kyzivat, "Indicating User
6674	   Agent Capabilities in the Session Initiation Protocol (SIP)",
6675	   Internet Engineering Taskforce, December 2003. Work in progress.

6677	   [3] R. Mahy and N. Ismail, "Media Policy Manipulation in the
6678	   Conference Policy Control Protocol", Internet Draft, Internet
6679	   Engineering Taskforce, Feb. 2003. Work in progress.

6681	   [4] Bray, T., Paoli, J., Sperberg-McQueen, C., and E. Maler,
6682	   �Extensible Markup Language (XML) 1.0 (Second Edition),� W3C
6683	   FirstEdition REC-xml-20001006, October 2000.

6685	   [5] World Wide Web Consortium, "Speech Recognition Grammar
6686	   Specification Version 1.0" (SRGS), W3C Candidate Recommendation, June
6687	   26, 2002

6689	   [6] World Wide Web Consortium, "Natural Language Semantics Markup
6690	   Language (NLSML) for the Speech Interface Framework", W3C Working
6691	   Draft, May 2001.

6693	   [7] World Wide Web Consortium, "Voice Extensible Markup Language
6694	   (VoiceXML) Version 2.0, W3C Candidate Recommendation, February 20,
6695	   2003

6697	   [8] Berners-Lee, T., Fielding, R., and L. Masinter, �Uniform Resource
6698	   Identifiers (URI): Generic Syntax,� RFC 2396, August 1998.

6700	                                 (MSML)

6702	   [9] J. Van Dyke, E. Burger, A. Spitzer, "Basic Network Media Services
6703	   with SIP", Internet Draft, Internet Engineering Task Force, February
6704	   2005. Work in progress.

6706	   [10] C. Jennings, SIP Support for Application Initiation, Internet
6707	   Draft, Internet Engineering Taskforce, Oct. 2002. Work in progress.

6709	   [11] A. B. Roach, Session Initiation Protocol (SIP)-Specific Event
6710	   Notification, RFC 3265, Internet Engineering Taskforce, June 2002.

6712	   [12] E. Levinson, "Content-ID and Message-ID Uniform Resource
6713	   Locators", RFC 2392, Internet Engineering Taskforce, August 1998.

6715	   [13] S. Bradner, �Key words for use in RFCs to Indicate Requirement
6716	   Levels,� RFC 2119, Internet Engineering Taskforce, March 1997.

6718	   [14] M. Murata, S. St.Laurent, and D. Kohn, �XML Media Types,� RFC
6719	   3023, Internet Engineering Taskforce, January 2001.

6721	   [15] Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson,
6722	   �RTP Profile for Audio and Video Conferences with Minimal Control,�
6723	   RFC 3550, July 2003.

6725	   [16] Rosenberg, J., Peterson, J., Schulzrinne, H., and G. Camarillo,
6726	   �Best Current Practices for Third Party Call Control (3pcc) in the
6727	   Session Initiation Protocol (SIP),� RFC 3725, April 2004.

6729	   [17] Donovan, S., �The SIP INFO Method,� RFC 2976, October 2000.

6731	   [18] Handley, M. and V. Jacobson, �SDP: Session Description
6732	   Protocol,� RFC 2327, April 1998.

6734	   [19] Ossenbruggen, J., Rutledge, L., Saccocio, B., Schmitz, P., Kate,
6735	   W., Ayars, J., Bulterman, D., Cohen, A., Day, K., Hodge, E., Hoschka,
6736	   P., Hyche, E., Jourdan, M., Kubota, K., Lanphier, R., Laya�da, N.,
6737	   Michel, T., and D. Newman, �Synchronized Multimedia Integration
6738	   Language (SMIL 2.0) Specification,� W3C REC REC-smil20-20010807,
6739	   August 2001.

6741	   [20] Bos, B., Lie, H., Lilley, C., and I. Jacobs, �Cascading Style
6742	   Sheets, level 2 (CSS2) Specification,� W3C REC REC-CSS2-19980512, May
6743	   1998.

6745	   [21] Freed, N. and N. Borenstein, �Multipurpose Internet Mail
6746	   Extensions (MIME) Part Two: Media Types,� RFC 2046, November 1996.

6748	   [22] Saleem, A. and Sharratt, G., �Media Sessions Markup Language�
6749	   Internet Draft (draft-melanchuk-sipping-msml-06), October 21, 2005.

6751	                                 (MSML)

6753	   [23] Saleem, A. and Sharratt, G., �Media Objects Markup Language�
6754	   Internet Draft (draft-melanchuk-sipping-moml-06), October 21, 2005.

6756	   [24] Moats, R., "URN Syntax", RFC 2141, May 1997.

6758	   [25] Moats, R., "A URN Namespace for IETF Documents", RFC 2648,
6759	   August 1999.

6761	   [26] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January
6762	   2004.

6764	Acknowledgments

6766	   Yong Xin and Sergiu Stambolian of Convedia provided key insights,
6767	   both theoretic and through development experience, on several
6768	   versions of the drafts.

6770	   Stephen Buko and George Raskulinec of Intel made numerous valuable
6771	   contributions towards enhancements of multimedia playback and record
6772	   operations.

6774	   David Asher of NMS Communications provided valuable insights towards
6775	   creation of standard profiles and a modularization scheme based on
6776	   packages for better interoperability.

6778	   Gilles Compienne of Ubiquity Software has provided feedback on
6779	   several earlier versions of this draft.

6781	   Chris Boulton and Ben Smith, both of Ubiquity, and Michael Rice of
6782	   VocalData helped clarify several issues, while Bruce Walsh and Kevin
6783	   Fitzgerald, both of Spectel/Avaya, provided important feedback. Cliff
6784	   Schornak of Commetrex significantly contributed to the facsimile
6785	   work. Peter Danielsen of Lucent has contributed thoughtful and
6786	   detailed reviews for several earlier versions of the draft.

6788	Authors' Addresses

6790	   Adnan Saleem
6791	   Convedia
6792	   4190 Still Creek Drive, Suite 300
6793	   Vancouver, BC, V5C 6C6
6794	   Canada

6796	   Phone: +1 604 918 6376
6797	   Email: asaleem@convedia.com
6798	                                 (MSML)

6800	   Garland Sharratt
6801	   Convedia
6802	   4190 Still Creek Drive, Suite 300
6803	   Vancouver, BC, V5C 6C6
6804	   Canada

6806	   Phone: +1 604 918 6393
6807	   Email: gsharratt@convedia.com

6809	Intellectual Property Statement

6811	   The IETF takes no position regarding the validity or scope of any
6812	   Intellectual Property Rights or other rights that might be claimed to
6813	   pertain to the implementation or use of the technology described in
6814	   this document or the extent to which any license under such rights
6815	   might or might not be available; nor does it represent that it has
6816	   made any independent effort to identify any such rights. Information
6817	   on the procedures with respect to rights in RFC documents can be
6818	   found in BCP 78 and BCP 79.

6820	   Copies of IPR disclosures made to the IETF Secretariat and any
6821	   assurances of licenses to be made available, or the result of an
6822	   attempt made to obtain a general license or permission for the use of
6823	   such proprietary rights by implementers or users of this
6824	   specification can be obtained from the IETF on-line IPR repository at
6825	   http://www.ietf.org/ipr.

6827	   The IETF invites any interested party to bring to its attention any
6828	   copyrights, patents or patent applications, or other proprietary
6829	   rights that may cover technology that may be required to implement
6830	   this standard. Please address the information to the IETF at ietf-
6831	   ipr@ietf.org.

6833	Copyright Statement

6835	   Copyright (C) The Internet Society (2005). This document is subject
6836	   to the rights, licenses and restrictions contained in BCP 78, and
6837	   except as set forth therein, the authors retain all their rights
6838	                                 (MSML)

6840	Disclaimer of Validity

6842	   This document and the information contained herein are provided on an
6843	   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
6844	   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
6845	   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
6846	   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
6847	   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
6848	   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

6850	Acknowledgement

6852	   Funding for the RFC Editor function is currently provided by the
6853	   Internet Society.