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2	Network Working Group                                       O. Finkelman
3	Internet-Draft                                                     Qwilt
4	Updates: 8007 (if approved)                                    S. Mishra
5	Intended status: Standards Track                                 Verizon
6	Expires: March 28, 2021                                        N. Sopher
7	                                                                   Qwilt
8	                                                      September 24, 2020

10	               CDNI Control Triggers Interface Extensions
11	                 draft-ietf-cdni-triggers-extensions-06

13	Abstract

15	   This document updates RFC 8007 to include generic extensions and more
16	   granular content matching options, required by the Open Caching
17	   architecture.  The Open Caching architeccture is a use case of
18	   Content Delivery Network Interconnection (CDNI) in which the
19	   commercial Content Delivery Network (CDN) is the upstream CDN (uCDN)
20	   and the ISP caching layer serves as the downstream CDN (dCDN).  This
21	   document defines extensions to the Content Delivery Network
22	   Interconnection (CDNI) Control Interface/Triggers.  These extensions
23	   are derived from requirements raised by Open Caching architecture but
24	   are also applicable to CDNI use cases in general.

26	Requirements Language

28	   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
29	   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
30	   document are to be interpreted as described in RFC 2119 [RFC2119].

32	Status of This Memo

34	   This Internet-Draft is submitted in full conformance with the
35	   provisions of BCP 78 and BCP 79.

37	   Internet-Drafts are working documents of the Internet Engineering
38	   Task Force (IETF).  Note that other groups may also distribute
39	   working documents as Internet-Drafts.  The list of current Internet-
40	   Drafts is at https://datatracker.ietf.org/drafts/current/.

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

47	   This Internet-Draft will expire on March 28, 2021.

49	Copyright Notice

51	   Copyright (c) 2020 IETF Trust and the persons identified as the
52	   document authors.  All rights reserved.

54	   This document is subject to BCP 78 and the IETF Trust's Legal
55	   Provisions Relating to IETF Documents
56	   (https://trustee.ietf.org/license-info) in effect on the date of
57	   publication of this document.  Please review these documents
58	   carefully, as they describe your rights and restrictions with respect
59	   to this document.  Code Components extracted from this document must
60	   include Simplified BSD License text as described in Section 4.e of
61	   the Trust Legal Provisions and are provided without warranty as
62	   described in the Simplified BSD License.

64	Table of Contents

66	   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
67	     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
68	     1.2.  Structure of this document  . . . . . . . . . . . . . . .   4
69	   2.  Interfaces Extensions Overview  . . . . . . . . . . . . . . .   5
70	     2.1.  CDNI Control Interface / Triggers Extensions  . . . . . .   5
71	       2.1.1.  CI/T Objects  . . . . . . . . . . . . . . . . . . . .   5
72	       2.1.2.  Trigger Specification . . . . . . . . . . . . . . . .   5
73	       2.1.3.  Content Selection . . . . . . . . . . . . . . . . . .   5
74	       2.1.4.  Trigger Extensibility . . . . . . . . . . . . . . . .   6
75	       2.1.5.  Error Handling  . . . . . . . . . . . . . . . . . . .   6
76	     2.2.  CDNI Footprint and Capabilities Interface Extensions  . .   7
77	   3.  CI/T Version 2  . . . . . . . . . . . . . . . . . . . . . . .   7
78	     3.1.  CI/T Objects V2 . . . . . . . . . . . . . . . . . . . . .   7
79	     3.2.  Error Handling V2 . . . . . . . . . . . . . . . . . . . .  10
80	     3.3.  Properties of CI/T Version 2 objects  . . . . . . . . . .  11
81	       3.3.1.  Trigger Specification Version 2 . . . . . . . . . . .  11
82	       3.3.2.  RegexMatch  . . . . . . . . . . . . . . . . . . . . .  12
83	       3.3.3.  Playlist  . . . . . . . . . . . . . . . . . . . . . .  14
84	       3.3.4.  MediaProtocol . . . . . . . . . . . . . . . . . . . .  14
85	       3.3.5.  CI/T Trigger Extensions . . . . . . . . . . . . . . .  15
86	         3.3.5.1.  Enforcement Options . . . . . . . . . . . . . . .  15
87	         3.3.5.2.  GenericExtensionObject  . . . . . . . . . . . . .  18
88	       3.3.6.  Error Description Version 2 . . . . . . . . . . . . .  20
89	       3.3.7.  Error codes . . . . . . . . . . . . . . . . . . . . .  22
90	     3.4.  Examples  . . . . . . . . . . . . . . . . . . . . . . . .  22
91	       3.4.1.  Invalidation with Regex . . . . . . . . . . . . . . .  22
92	       3.4.2.  Preposition with Playlists  . . . . . . . . . . . . .  24
93	       3.4.3.  Extensions with Error Propagation . . . . . . . . . .  25
94	   4.  Trigger Extension Objects . . . . . . . . . . . . . . . . . .  27
95	     4.1.  LocationPolicy extension  . . . . . . . . . . . . . . . .  27
96	     4.2.  TimePolicy Extension  . . . . . . . . . . . . . . . . . .  29
97	       4.2.1.  UTCWindow . . . . . . . . . . . . . . . . . . . . . .  31
98	       4.2.2.  LocalTimeWindow . . . . . . . . . . . . . . . . . . .  32
99	       4.2.3.  DateLocalTime . . . . . . . . . . . . . . . . . . . .  33
100	         4.2.3.1.  Date and Local Time Format  . . . . . . . . . . .  33
101	         4.2.3.2.  Restrictions  . . . . . . . . . . . . . . . . . .  34
102	   5.  Footprint and Capabilities  . . . . . . . . . . . . . . . . .  34
103	     5.1.  CI/T Versions Capability Object . . . . . . . . . . . . .  34
104	       5.1.1.  CI/T Versions Capability Object Serialization . . . .  35
105	     5.2.  CI/T Playlist Protocol Capability Object  . . . . . . . .  35
106	       5.2.1.  CI/T Playlist Protocol Capability Object
107	               Serialization . . . . . . . . . . . . . . . . . . . .  35
108	     5.3.  CI/T Trigger Extension Capability Object  . . . . . . . .  36
109	       5.3.1.  CI/T Trigger Extension Capability Object
110	               Serialization . . . . . . . . . . . . . . . . . . . .  36
111	   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  37
112	     6.1.  CDNI Payload Types  . . . . . . . . . . . . . . . . . . .  37
113	       6.1.1.  CDNI ci-trigger-command.v2 Payload Type . . . . . . .  37
114	       6.1.2.  CDNI ci-trigger-status.v2 Payload Type  . . . . . . .  38
115	       6.1.3.  CDNI CI/T LocationPolicy Trigger Extension Type . . .  38
116	       6.1.4.  CDNI CI/T TimePolicy Trigger Extension Type . . . . .  38
117	       6.1.5.  CDNI FCI CI/T Versions Payload Type . . . . . . . . .  38
118	       6.1.6.  CDNI FCI CI/T Playlist Protocol Payload Type  . . . .  38
119	       6.1.7.  CDNI FCI CI/T Extension Objects Payload Type  . . . .  39
120	     6.2.  CDNI CI/T Trigger Error Codes types . . . . . . . . . . .  39
121	     6.3.  CDNI Media protocol types . . . . . . . . . . . . . . . .  39
122	   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  40
123	   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  40
124	   9.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  40
125	   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  41
126	     10.1.  Normative References . . . . . . . . . . . . . . . . . .  41
127	     10.2.  Informative References . . . . . . . . . . . . . . . . .  42
128	   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  43

130	1.  Introduction

132	   The Streaming Video Alliance [SVA] is a global association that works
133	   to solve streaming video challenges in an effort to improve end-user
134	   experience and adoption.  The Open Caching Working Group [OCWG] of
135	   the Streaming Video Alliance [SVA] is focused on the delegation of
136	   video delivery requests from commerical CDNs to a caching layer at
137	   the ISP's network.  Open Caching architecture is a specific use case
138	   of CDNI where the commercial CDN is the upstream CDN (uCDN) and the
139	   ISP caching layer is the downstream CDN (dCDN).  The Open Caching
140	   Content Management Operations Specification [OC-CM] defines objects
141	   and extensions required by Open Caching architecture for granular
142	   content management operations such as new content selection options.
143	   This document defines the objects and extensions required for
144	   granular content management operations.  For that purpose it extends
145	   CDNI Control Interface / Triggers [RFC8007] by adding new content
146	   selection options to the trigger specification and specifying a
147	   generic extension mechanism that enables adding future functions for
148	   controlling the trigger execution.  This document also defines and
149	   initial set of extension objects.  This document gives examples for
150	   the extensions specified herein, for complete examples of the trigger
151	   interface usage see Section 6 of [RFC8007].

153	   The CDNI Metadata Interface is described in [RFC8006].

155	   The CDNI Footprint and Capability Interface is described in
156	   [RFC8008].

158	   The CDNI Control Interface / Triggers is described in [RFC8007].

160	   For consistency with other CDNI documents, this document follows the
161	   CDNI convention of uCDN (upstream CDN) and dCDN downstream CDN) to
162	   represent the commercial CDN and ISP caching layer, respectively.

164	1.1.  Terminology

166	   This document reuses the terminology defined in [RFC6707], [RFC8006],
167	   [RFC8007], and [RFC8008].

169	   Additionally, the following terms are used throughout this document
170	   and are defined as follows:

172	   o  HLS - HTTP Live Streaming

174	   o  DASH - Dynamic Adaptive Streaming Over HTTP

176	   o  MSS - Microsoft Smooth Streaming

178	1.2.  Structure of this document

180	   The remainder of this document is organized as follows:

182	   o  Section 2 gives an overview of the extensions specified in this
183	      document.

185	   o  Section 3 specifies version 2 of the CDNI Control Interface /
186	      Triggers.

188	   o  Section 4 specifies an initial set of trigger extension objects.

190	   o  Section 5 specifies Footprint and Capability objects for CI/T
191	      version and extensions.

193	   o  Section 6 list the IANA considerations of this document.

195	   o  Section 7 describes the security considerations for the specified
196	      properties and extensions.

198	2.  Interfaces Extensions Overview

200	   This document defines extensions for the CDNI Control Interface /
201	   Triggers (CI/T) [RFC8007] and defines FCI objects as per the CDNI
202	   Footprint and Capabilities Interface [RFC8008].

204	2.1.  CDNI Control Interface / Triggers Extensions

206	2.1.1.  CI/T Objects

208	   This document specifies version 2 of the CI/T commands and objects.
209	   In this context the CI/T commands and objects as were specified in
210	   [RFC8007] are considered to be version 1.

212	2.1.2.  Trigger Specification

214	   This document specifies version 2 of the Trigger Specification which
215	   is an enhancement of the Trigger Specification that includes all
216	   properties as defined in Section 5.2.1 of [RFC8007] as well as the
217	   additional properties required by the use cases listed below in
218	   Section 2.1.3 and Section 2.1.4.

220	2.1.3.  Content Selection

222	   The trigger specification as defined in Section 5.2.1 of [RFC8007]
223	   provides means to select content objects by matching a full content
224	   URL or patterns with wildcards.  This document specifies two
225	   additional selection options:

227	   o  Regular Expression - Using regex a uCDN can create more complex
228	      rules to select the content objects for the cases of
229	      "invalidation" and "purge".  For example, purging specific content
230	      within a specific directory path.

232	   o  Content Playlist - Using video playlist files, a uCDN can trigger
233	      an operation that will be applied to a collection of distinct
234	      media files in a format that is natural for a streaming video
235	      content provider.  A playlist may have several formats,
236	      specifically HTTP Live Streaming (HLS) *.m3u8 manifest [RFC8216],
237	      Microsoft Smooth Streaming (MSS) *.ismc client manifest [MSS], and
238	      Dynamic Adaptive Streaming over HTTP (DASH) *.mpd file [ISO/IEC
239	      23009-1:2014] [MPEG-DASH].

241	2.1.4.  Trigger Extensibility

243	   The CDNI Control Interface / Triggers [RFC8007] defines a set of
244	   properties and objects used by the trigger commands.  In this
245	   document we define an extension mechanism to the triggers interface
246	   that enables the application to add various functions that allow
247	   finer control over the trigger execution.  This document specifies a
248	   generic trigger extension object wrapper for managing individual CDNI
249	   trigger extensions in an opaque manner.

251	   This document also registers CDNI Payload Types [RFC7736] under the
252	   namespace CIT for the initial set of trigger extension types:

254	   o  CIT.LocationPolicy (for controlling the locations in which the
255	      trigger is executed)

257	   o  CIT.TimePolicy (for scheduling a trigger to run in a specific time
258	      window)

260	   Example use cases

262	   o  Pre-position with cache location policy

264	   o  Purge content with cache location policy

266	   o  Pre-position at a specific time

268	   o  Purge by content acquisition time (e.g. purge all content acquired
269	      in the past X hours)

271	2.1.5.  Error Handling

273	   This document extends the CI/T Error Handling (see Section 4.7 of
274	   [RFC8007]) to support the following:

276	   o  Playlists and Regexs - report errors that happened due to specific
277	      playlists and/or regexs.

279	   o  Extension errors - report an error that happened due to an
280	      extension object.

282	   o  Error propagation - enable the uCDN to traceback an error to the
283	      dCDN in which it occurred.

285	2.2.  CDNI Footprint and Capabilities Interface Extensions

287	   Extending the trigger mechanism with optional properties requires the
288	   ability for the dCDN to advertise which optional properties it
289	   supports.

291	   The CDNI Footprint and Capabilities Interface [RFC8008] enables the
292	   dCDN to advertise the capabilities it supports across different
293	   footprints.  This document introduces FCI objects to support the
294	   advertisement of these optional properties.

296	   Example use cases

298	   o  Trigger types: Advertise which trigger types are supported by the
299	      dCDN.  CDNI defines three trigger types (purge, invalidate, pre-
300	      position), but it does not necessarily mean that all dCDNs support
301	      all of them.  The uCDN may prefer to work only with dCDN that
302	      support what the uCDN needs.

304	   o  Content selection rule types: Advertise which selection types are
305	      supported.  For example, if adding content regex as a means to
306	      match on content URLs, not all dCDN would support it.  For
307	      playlist mapping, advertise which types and versions of protocols
308	      are supported, e.g.  HLS.vX/DASH.vY/MSS.vX, DASH templates.  Note
309	      that the version string or schema are protocol specific.

311	   o  Trigger extensions: Advertise which trigger extensions object
312	      types are supported by the dCDN.

314	3.  CI/T Version 2

316	   [RFC8007] does not define a version number and versioning scheme.
317	   We, therefore, designate the interface and objects as defined in
318	   Section 5 of [RFC8007] as version 1.  The following sections define
319	   version 2 of the CI/T objects and their properties as extensions of
320	   version 1.

322	3.1.  CI/T Objects V2

324	   Version 2 of the CI/T interface requires the support of the following
325	   objects:

327	   o  CI/T Commands v2: A trigger command request using the payload type
328	      ci-trigger-command.v2.  Version 2 MUST only use "trigger.v2"
329	      objects as defined in Section 3.3.1, instead of "trigger" objects.
330	      All other properties of the trigger command v2 are as defined in
331	      Section 5.1.1 of [RFC8007].

333	   o  Trigger Status Resource v2: A trigger status resource response
334	      using the payload type ci-trigger-status.v2.  Version 2 MUST only
335	      use "trigger.v2" objects as defined in Section 3.3.1, instead of a
336	      "trigger" object, as well as "errors.v2" array as defined in
337	      Section 3.3.6, instead of a "errors" array.  All other properties
338	      of the trigger status v2 are as defined in Section 5.1.2 of
339	      [RFC8007].  The errors array "errors.v2" is a list of all errors
340	      that occurred in any of the downstream CDNs along the execution
341	      path.  When a downstream CDN, dCDN-A, propagates a trigger to
342	      another downstream CDN, dCDN-B, it MUST also propagated back all
343	      errors reported by dCDN-B in the trigger status resource and add
344	      them to its own trigger status resource.

346	   o  Trigger Collections: The payload type ci-trigger-collection is
347	      used with no changes and as defined in 5.1.3 of [RFC8007].

349	   Usage example of version 2 of trigger command
350	   REQUEST:

352	       POST /triggers HTTP/1.1
353	       User-Agent: example-user-agent/0.1
354	       Host: triggers.dcdn.example.com
355	       Accept: */*
356	       Content-Type: application/cdni; ptype=ci-trigger-command.v2
357	       {
358	         "trigger.v2": { <properties of a trigger.v2 object> },
359	         "cdn-path": [ "AS64496:0" ]
360	       }

362	   RESPONSE:

364	       HTTP/1.1 201 Created
365	       Date: Wed, 04 May 2016 08:48:10 GMT
366	       Content-Length: 467
367	       Content-Type: application/cdni; ptype=ci-trigger-status.v2
368	       Location: https://triggers.dcdn.example.com/triggers/0
369	       Server: example-server/0.1

371	       {
372	          "errors.v2": [ { <properties of 1st error.v2 object> },
373	                           ...,
374	                         { <properties of Nth error.v2 object> }
375	          ],
376	          "ctime": 1462351690,
377	          "etime": 1462351698,
378	          "mtime": 1462351690,
379	          "status": "pending",
380	          "trigger.v2": { <properties of a trigger.v2 object> }
381	       }

383	   Usage example of version 2 of trigger status for the trigger created
384	   in the above trigger command example:

386	   REQUEST:

388	       GET /triggers/0 HTTP/1.1
389	       User-Agent: example-user-agent/0.1
390	       Host: triggers.dcdn.example.com
391	       Accept: */*

393	   RESPONSE:

395	       HTTP/1.1 200 OK
396	       Content-Length: 467
397	       Expires: Wed, 04 May 2016 08:49:10 GMT
398	       Server: example-server/0.1
399	       ETag: "6990548174277557683"
400	       Cache-Control: max-age=60
401	       Date: Wed, 04 May 2016 08:48:10 GMT
402	       Content-Type: application/cdni; ptype=ci-trigger-status.v2

404	       {
405	          "errors.v2": [ { <properties of 1st error.v2 object> },
406	                           ...,
407	                         { <properties of Nth error.v2 object> }
408	          ],
409	          "ctime": 1462351690,
410	          "etime": 1462351698,
411	          "mtime": 1462351690,
412	          "status": "pending",
413	          "trigger.v2": { <properties of a trigger.v2 object> }
414	       }

416	3.2.  Error Handling V2

418	   The CDNI CI/T interface defines a mechanism for error reporting (see
419	   Section 4.7 of [RFC8007]) and an Error Description object for
420	   reporting errors (see Section 5.2.6 of [RFC8007]).  This document
421	   specifies version 2 of CI/T error handling in order to support the
422	   following:

424	   o  Extension errors - report an error that happened due to an
425	      extension object.  As extension objects are expected to be added
426	      to the interface as new requirements comes along, it is expected
427	      that in some cases a dCDN may receive a trigger that it cannot
428	      process or does not understand.  It is essential for the trigger
429	      caller to be able to understand when such errors occur so they can
430	      take actions to fix them.  This document adds a mechanism to
431	      report extension errors.

433	   o  Error propagation - enable the uCDN to traceback an error to the
434	      dCDN in which it occurred.  CDNI triggers may be propagated over a
435	      chain of downstream CDNs.  Let us take for example an upstream
436	      (uCDN-A) CDN A that is delegating to a downstream CDN B (dCDN-B)
437	      and dCDN-B is delegating to a downstream CDN C (dCDN-C).  Triggers
438	      sent from uCDN-A to dCDN-B may be redistributed from dCDN-B to
439	      dCDN-C and errors can happen anywhere along the path.  Therefore,
440	      it might be essential for uCDN-A that sets the trigger, to be able
441	      to trace back an error to the downstream CDN where it occurred.
442	      This document adds a mechanism to propagate the ID of the faulty
443	      dCDN back to the uCDN by adding the CDN ID to the error
444	      description.  When a downstream dCDN-B propagates a trigger to
445	      another downstream dCDN-C, it MUST also propagate back the errors
446	      received in the trigger status resource from dCDN-C by adding them
447	      to the errors array in its own status resource to be sent back to
448	      the originating uCDN-A.  While propagating back the errors, and
449	      depending on the implementation, downstream dCDN-B MAY also
450	      specify the dCDN-C CDN identifier, indicating that the error
451	      relates spefically to this CDN.  The trigger originating upstream
452	      CDN will receive an array of errors that occurred in all the CDNs
453	      along the execution path, where each error MAY carrying its own
454	      CDN identifier.

456	3.3.  Properties of CI/T Version 2 objects

458	   This section defines the values that can appear in the top-level
459	   objects described in Section 3.1, and their encodings.

461	3.3.1.  Trigger Specification Version 2

463	   Version 2 of the Trigger Specification adds the following properties
464	   on top of the existing properties of the trigger specification
465	   defined in Section 5.2.1 of [RFC8007].

467	      Property: content.regexs

469	         Description: Regexs of content URLs to which the CI/T trigger
470	         command applies.

472	         Type: A JSON array of RegexMatch objects (see Section 3.3.2).

474	         Mandatory: No, but at least one of "metadata.*" or "content.*"
475	         MUST be present and non-empty.

477	      Property: content.playlists

479	         Description: Playlists of content the CI/T trigger command
480	         applies to.

482	         Type: A JSON array of Playlist objects (see Section 3.3.3).

484	         Mandatory: No, but at least one of "metadata.*" or "content.*"
485	         MUST be present and non-empty.

487	      Property: extensions

489	         Description: Array of trigger extension data.

491	         Type: Array of GenericTriggerExtension objects (see
492	         Section 3.3.5.2).

494	         Mandatory: No.  The default is no extensions.

496	   Example of an invalidation trigger.v2 with a list of regex objects, a
497	   list of playlist objects, and extensions:

499	   {
500	     "trigger.v2": {
501	       "type": "invalidate",
502	       "content.regexs": [ <list of RegexMatch objects> ],
503	       "content.playlists": [ <list of Playlist objects> ],
504	       "extensions": [ <list of GenericTriggerExtension objects ]
505	     },
506	     "cdn-path": [ "AS64496:0" ]
507	   }

509	3.3.2.  RegexMatch

511	   A RegexMatch consists of a regular expression string a URI is matched
512	   against, and flags describing the type of match.  It is encoded as a
513	   JSON object with following properties:

515	      Property: regex

517	         Description: A regular expression for URI matching.

519	         Type: A regular expression to match against the URI, i.e
520	         against the path-absolute and the query string parameters
521	         [RFC3986].  The regular expression string MUST be compatible
522	         with PCRE [PCRE841].

524	         Note: Because '\' has special meaning in JSON [RFC8259] as the
525	         escape character within JSON strings, the regular expression
526	         character '\' MUST be escaped as '\\'.

528	         Mandatory: Yes.

530	      Property: case-sensitive

532	         Description: Flag indicating whether or not case-sensitive
533	         matching should be used.

535	         Type: JSON boolean.  Either "true" (the matching is case
536	         sensitive) or "false" (the matching is case insensitive).

538	         Mandatory: No; default is case-insensitive match (i.e., a value
539	         of "false").

541	      Property: match-query-string

543	         Description: Flag indicating whether to include the query part
544	         of the URI when comparing against the regex.

546	         Type: JSON boolean.  Either "true" (the full URI, including the
547	         query part, should be compared against the regex) or "false"
548	         (the query part of the URI should be dropped before comparison
549	         with the given regex).

551	         Mandatory: No; default is "false".  The query part of the URI
552	         MUST be dropped before comparison with the given regex.  This
553	         makes the regular expression simpler and safer for cases in
554	         which the query parameters are not relevant for the match.

556	   Example of a case sensitive, no query parameters, regex match
557	   against:

559	   "^(https:\/\/video\.example\.com)\/([a-z])\/
560	    movie1\/([1-7])\/*(index.m3u8|\d{3}.ts)$"

562	   {
563	     "regex": "^(https:\\/\\/video\\.example\\.com)\\/([a-z])\\/movie1\
564	              \/([1-7])\\/*(index.m3u8|\\d{3}.ts)$",
565	     "case-sensitive": true,
566	     "match-query-string": false
567	   }

569	   This regex matches URLs of domain video.example.com where the path
570	   structure is /(single lower case letter)/(name-of-title)/(single
571	   digit between 1 to 7)/(index.m3u8 or a 3 digit number with ts
572	   extension).  For example:

574	   https://video.example.com/d/movie1/5/index.m3u8
575	   or
576	   https://video.example.com/k/movie1/4/013.ts

578	3.3.3.  Playlist

580	   A Playlist consists of a full URL and a media protocol identifier.
581	   An implementation that supports a specific playlist media protocol
582	   MUST be able to parse playlist files of that protocol type and
583	   extract, possibly recursively, the URLs to all media objects and/or
584	   sub playlist files, and apply the trigger to each one of them
585	   separately.

587	   Playlist is encoded as a JSON object with following properties:

589	      Property: playlist

591	         Description: A URL to the playlist file.

593	         Type: A URL represented as a JSON string.

595	         Mandatory: Yes.

597	      Property: media-protocol

599	         Description: Media protocol to be when parsing and interpreting
600	         this playlist.

602	         Type: MediaProtocol (see Section 3.3.4).

604	         Mandatory: Yes.

606	   Example of a HLS playlist:

608	   {
609	     "playlist": "https://www.example.com/hls/title/index.m3u8",
610	     "media-protocol": "hls"
611	   }

613	3.3.4.  MediaProtocol

615	   Media Protocol objects are used to specify registered type of media
616	   protocol (see Section 6.3) used for protocol related operations like
617	   pre-position according to playlist.

619	   Type: JSON string

621	   Example:

623	   "dash"

625	3.3.5.  CI/T Trigger Extensions

627	   A "trigger.v2" object, as defined in Section 3.3.1 includes an
628	   optional array of trigger extension objects.  A trigger extension
629	   contain properties that are used as directives for dCDN when
630	   executing the trigger command -- for example, location policies, time
631	   policies and so on.  Each such CDNI Trigger extension is a
632	   specialization of a CDNI GenericTriggerExtension object.  The
633	   GenericTriggerExtension object abstracts the basic information
634	   required for trigger distribution from the specifics of any given
635	   property (i.e., property semantics, enforcement options, etc.).  All
636	   trigger extensions are optional, and it is thus the responsibility of
637	   the extension specification to define a consistent default behavior
638	   for the case the extension is not present.

640	3.3.5.1.  Enforcement Options

642	   The trigger enforcement options concept is in accordance with the
643	   metadata enforcement options as defined in Section 3.2 of [RFC8006].

645	   The GenericTriggerExtension object defines the properties contained
646	   within it as well as whether or not the properties are "mandatory-to-
647	   enforce".  If the dCDN does not understand or support a mandatory-to-
648	   enforce property, the dCDN MUST NOT execute the trigger command.  If
649	   the extension is not mandatory-to-enforce, then that
650	   GenericTriggerExtension object can be safely ignored and the trigger
651	   command can be processed in accordance with the rest of the CDNI
652	   Trigger spec.

654	   Although a CDN MUST NOT execute a trigger command if a mandatory-to-
655	   enforce extension cannot be enforced, it could still be safe to
656	   redistribute that trigger (the "safe-to-redistribute" property) to
657	   another CDN without modification.  For example, in the cascaded CDN
658	   case, a transit CDN (tCDN) could convey mandatory-to-enforce trigger
659	   extension to a dCDN.  For a trigger extension that does not require
660	   customization or translation (i.e., trigger extension that is safe-
661	   to-redistribute), the data representation received off the wire MAY
662	   be stored and redistributed without being understood or supported by
663	   the tCDN.  However, for trigger extension that requires translation,
664	   transparent redistribution of the uCDN trigger values might not be
665	   appropriate.  Certain triggers extensions can be safely, though
666	   perhaps not optimally, redistributed unmodified.  For example, pre-
667	   position command might be executed in suboptimal times for some
668	   geographies if transparently redistributed, but it might still work.

670	   Redistribution safety MUST be specified for each
671	   GenericTriggerExtension property.  If a CDN does not understand or
672	   support a given GenericTriggerExtension property that is not safe-to-
673	   redistribute, the CDN MUST set the "incomprehensible" flag to true
674	   for that GenericTriggerExtension object before redistributing it.
675	   The "incomprehensible" flag signals to a dCDN that trigger metadata
676	   was not properly transformed by the tCDN.  A CDN MUST NOT attempt to
677	   execute a trigger with an extension that has been marked as
678	   "incomprehensible" by a uCDN.

680	   tCDNs MUST NOT change the value of mandatory-to-enforce or safe-to-
681	   redistribute when propagating a trigger to a dCDN.  Although a tCDN
682	   can set the value of "incomprehensible" to true, a tCDN MUST NOT
683	   change the value of "incomprehensible" from true to false.

685	   Table 1 describes the action to be taken by a tCDN for the different
686	   combinations of mandatory-to-enforce ("MtE") and safe-to-redistribute
687	   ("StR") properties when the tCDN either does or does not understand
688	   the trigger extension object in question:

690	   +-------+-------+------------+--------------------------------------+
691	   | MtE   | StR   | Extension  | Trigger action                       |
692	   |       |       | object     |                                      |
693	   |       |       | understood |                                      |
694	   |       |       | by tCDN    |                                      |
695	   +-------+-------+------------+--------------------------------------+
696	   | False | True  | True       | Can execute and redistribute.        |
697	   | False | True  | False      | Can execute and redistribute.        |
698	   | False | False | False      | Can execute. MUST set                |
699	   |       |       |            | "incomprehensible" to true when      |
700	   |       |       |            | redistributing.                      |
701	   | False | False | True       | Can execute. Can redistribute after  |
702	   |       |       |            | transforming the trigger extension   |
703	   |       |       |            | (if the CDN knows how to do so       |
704	   |       |       |            | safely); otherwise, MUST set         |
705	   |       |       |            | "incomprehensible" to true when      |
706	   |       |       |            | redistributing.                      |
707	   | True  | True  | True       | Can execute and redistribute.        |
708	   | True  | True  | False      | MUST NOT execute but can             |
709	   |       |       |            | redistribute..                       |
710	   | True  | False | True       | Can execute. Can redistribute after  |
711	   |       |       |            | transforming the trigger extension   |
712	   |       |       |            | (if the CDN knows how to do so       |
713	   |       |       |            | safely); otherwise, MUST set         |
714	   |       |       |            | "incomprehensible" to true when      |
715	   |       |       |            | redistributing.                      |
716	   | True  | False | False      | MUST NOT serve.  MUST set            |
717	   |       |       |            | "incomprehensible" to true when      |
718	   |       |       |            | redistributing.                      |
719	   +-------+-------+------------+--------------------------------------+

721	   Table 1: Action to be taken by a tCDN for the different combinations
722	                         of MtE and StR properties

724	   Table 2 describes the action to be taken by a dCDN for the different
725	   combinations of mandatory-to-enforce and "incomprehensible"
726	   ("Incomp") properties, when the dCDN either does or does not
727	   understand the trigger extension object in question:

729	   +-------+--------+---------------+----------------------------------+
730	   | MtE   | Incomp | Extension     | Trigger action                   |
731	   |       |        | object        |                                  |
732	   |       |        | understood by |                                  |
733	   |       |        | dCDN          |                                  |
734	   +-------+--------+---------------+----------------------------------+
735	   | False | False  | True          | Can execute.                     |
736	   | False | True   | True          | Can execute but MUST NOT         |
737	   |       |        |               | interpret/apply any trigger      |
738	   |       |        |               | extension marked as              |
739	   |       |        |               | "incomprehensible".              |
740	   | False | False  | False         | Can execute.                     |
741	   | False | True   | False         | Can execute but MUST NOT         |
742	   |       |        |               | interpret/apply any trigger      |
743	   |       |        |               | extension marked as              |
744	   |       |        |               | "incomprehensible".              |
745	   | True  | False  | True          | Can execute.                     |
746	   | True  | True   | True          | MUST NOT execute.                |
747	   | True  | False  | False         | MUST NOT execute.                |
748	   | True  | True   | False         | MUST NOT execute.                |
749	   +-------+--------+---------------+----------------------------------+

751	   Table 2: Action to be taken by a dCDN for the different combinations
752	                       of MtE and Incomp properties

754	3.3.5.2.  GenericExtensionObject

756	   A GenericTriggerExtension object is a wrapper for managing individual
757	   CDNI Trigger extensions in an opaque manner.

759	      Property: generic-trigger-extension-type

761	         Description: Case-insensitive CDNI Trigger extension object
762	         type.

764	         Type: String containing the CDNI Payload Type [RFC7736] of the
765	         object contained in the generic-trigger-extension-value
766	         property (see table in Section 6.1).

768	         Mandatory: Yes.

770	      Property: generic-trigger-extension-value

772	         Description: CDNI Trigger extension object.

774	         Type: Format/Type is defined by the value of the generic-
775	         trigger-extension-type property above.

777	         Mandatory: Yes.

779	      Property: mandatory-to-enforce

781	         Description: Flag identifying whether or not the enforcement of
782	         this trigger extension is mandatory.

784	         Type: Boolean

786	         Mandatory: No.  Default is to treat the trigger extension as
787	         mandatory-to-enforce (i.e., a value of True).

789	      Property: safe-to-redistribute

791	         Description: Flag identifying whether or not this trigger
792	         extension can be safely redistributed without modification,
793	         even if the CDN fails to understand the extension.

795	         Type: Boolean

797	         Mandatory: No.  Default is to allow transparent redistribution
798	         (i.e., a value of True).

800	      Property: incomprehensible

802	         Description: Flag identifying whether or not any CDN in the
803	         chain of delegation has failed to understand and/or failed to
804	         properly transform this trigger extension object.  Note: This
805	         flag only applies to trigger extension objects whose safe-to-
806	         redistribute property has a value of False.

808	         Type: Boolean

810	         Mandatory: No.  Default is comprehensible (i.e., a value of
811	         False).

813	   Example of a GenericTriggerExtension containing a specific trigger
814	   extension object:

816	   {
817	     "generic-trigger-extension-type":
818	        <Type of this trigger extension object>,
819	     "generic-trigger-extension-value":
820	         {
821	           <properties of this trigger extension object>
822	         },
823	     "mandatory-to-enforce": true,
824	     "safe-to-redistribute": true,
825	     "incomprehensible": false
826	   }

828	3.3.6.  Error Description Version 2

830	   Version 2 of the Error Description adds the "content.playlists",
831	   "content.regexs", "extensions" and "cdn" properties on top of the
832	   existing properties of version 1 of the trigger Error Description as
833	   defined in Section 5.2.6 of [RFC8007].

835	      Properties: content.regexs, content.playlists

837	         Description: Content Regex and Playlist references copied from
838	         the Trigger Specification.  Only those regexs and playlists to
839	         which the error applies are included in each property, but
840	         those references MUST be exactly as they appear in the request;
841	         the dCDN MUST NOT change or generalize the URLs or Regexs.
842	         Note that these properties are added on top of the already
843	         existing properties: "metadata.urls", "content.urls",
844	         "metadata.patterns" and "content.patterns".

846	         Type: A JSON array of JSON strings, where each string is copied
847	         from a "content.regexs" or "content.playlists" value in the
848	         corresponding Trigger Specification.

850	         Mandatory: At least one of "content.regexs",
851	         "content.playlists", "metadata.urls", "content.urls",
852	         "metadata.patterns" or "content.patterns" is mandatory in each
853	         Error Description object.

855	      Property: extensions

857	         Description: Array of trigger extension objects copied from the
858	         corresponding "extensions" array from the Trigger
859	         Specification.  Only those extensions to which the error
860	         applies are included, but those extensions MUST be exactly as
861	         they appear in the request.

863	         Type: Array of GenericTriggerExtension objects, where each
864	         extension object is copied from the "extensions" array values
865	         in the Trigger Specification.

867	         Mandatory: No.  The "extensions" array SHOULD be used only if
868	         the error relates to extension objects.

870	      Property: cdn

872	         Description: The CDN PID of the CDN where the error occurred.
873	         The "cdn" property is used by the originating uCDN or by
874	         propagating dCDN in order to distinguish in which CDN the error
875	         occured.

877	         Type: A non-empty JSON string, where the string is a CDN PID as
878	         defined in Section 4.6 of [RFC8007].

880	         Mandatory: Yes. In the case the dCDN does not like to expose
881	         this information, it should provide its own CDN PID.

883	   Example of an Error Description object reporting a malformed
884	   Playlist:

886	   {
887	      "content.playlists": [
888	         {
889	           "playlist": "https://www.example.com/hls/title/index.m3u8",
890	           "media-protocol": "hls"
891	         }
892	       ],
893	      "description": "Failed to parse HLS playlist",
894	      "error": "econtent",
895	      "cdn": "AS64500:0"
896	   },

898	   Example of an Error Description object reporting an unsupported
899	   extension object:

901	 {
902	   "errors.v2": [
903	    {
904	      "extensions": [
905	         {
906	           "generic-trigger-extension-type":
907	              <Type of this erroneous trigger extension object>,
908	           "generic-trigger-extension-value":
909	               {
910	                 <properties of this erroneous trigger extension object>
911	               },
912	         }
913	       ],
914	      "description": "unrecognized extension <type>",
915	      "error": "eextension",
916	      "cdn": "AS64500:0"
917	    },
918	   ]
919	 }

921	3.3.7.  Error codes

923	   This document adds the error code "eextension" to the error codes
924	   table defined in Section 5.2.6 of [RFC8007].  This error code
925	   designates that an error occurred while parsing a generic trigger
926	   extension, or that the specific extension is not supported by the
927	   CDN.  A CDN that fails to execute a trigger due a generic extension
928	   object which is "mandatory-to-enforce" MUST report it using the
929	   "errors.v2" array within the trigger status resource, while setting
930	   the error code to "eextension" and providing an appropriate
931	   description.  The "eextension" error code is a registered type of
932	   "CDNI CI/T Trigger Error Codes" (see Section 6.2).

934	3.4.  Examples

936	   The following subsections provides usage examples of the specified
937	   interface extensions being used by the trigger command and status
938	   resource.

940	3.4.1.  Invalidation with Regex

942	   In the following example a CI/T "invalidate" command uses the Regex
943	   property to specify the range of content objects for invalidation,
944	   the command is rejected by the dCDN due to regex complexity, and an
945	   appropriate error is reflected in the status response.

947	REQUEST:

949	    POST /triggers HTTP/1.1
950	    User-Agent: example-user-agent/0.1
951	    Host: triggers.dcdn.example.com
952	    Accept: */*
953	    Content-Type: application/cdni; ptype=ci-trigger-command.v2
954	    {
955	      "trigger.v2": {
956	        "type": "invalidate",
957	        "content.regexs": [
958	          {
959	            "regex": "^(https:\\/\\/video\\.example\\.com)\\/
960	            ([a-z])\\/movie1\\/([1-7])\\/*(index.m3u8|\\d{3}.ts)$",
961	            "case-sensitive": true,
962	            "match-query-string": false
963	          },
964	          { <RegexMatch #2> },
965	          ...
966	          { <RegexMatch #N> },
967	        ],
968	      },
969	      "cdn-path": [ "AS64496:0" ]
970	    }

972	RESPONSE:

974	    HTTP/1.1 201 Created
975	    Date: Wed, 04 May 2016 08:48:10 GMT
976	    Content-Length: 467
977	    Content-Type: application/cdni; ptype=ci-trigger-status.v2
978	    Location: https://triggers.dcdn.example.com/triggers/0
979	    Server: example-server/0.1

981	    {
982	       "errors.v2": [
983	         {
984	           "content.regexs": [
985	              {
986	                "regex": "^(https:\\/\\/video\\.example\\.com)\\/
987	                ([a-z])\\/movie1\\/([1-7])\\/*(index.m3u8|\\d{3}.ts)$",
988	                "case-sensitive": true,
989	                "match-query-string": false
990	              },
991	            ],
992	           "description": "The dCDN rejected a regex due to complexity",
993	           "error": "ereject",
994	           "cdn": "AS64500:0"
995	         },
996	       ],
997	       "ctime": 1462351690,
998	       "etime": 1462351698,
999	       "mtime": 1462351690,
1000	       "status": "failed",
1001	       "trigger.v2": { <content of trigger object from the command> }
1002	    }

1004	3.4.2.  Preposition with Playlists

1006	   In the following example a CI/T "preposition" command uses the
1007	   Playlist property to specify the full media library of a specific
1008	   content.  The command fails due to playlist parse error and an
1009	   appropriate error is reflected in the status response.

1011	REQUEST:

1013	    POST /triggers HTTP/1.1
1014	    User-Agent: example-user-agent/0.1
1015	    Host: triggers.dcdn.example.com
1016	    Accept: */*
1017	    Content-Type: application/cdni; ptype=ci-trigger-command.v2
1018	    {
1019	      "trigger.v2": {
1020	        "type": "preposition",
1021	        "content.playlists": [
1022	         {
1023	          "playlist": "https://www.example.com/hls/title/index.m3u8",
1024	          "media-protocol": "hls"
1025	         },
1026	         { <Playlist #2> },
1027	         ...
1028	         { <Playlist #N> },
1029	        ],
1030	      },
1031	      "cdn-path": [ "AS64496:0" ]
1032	    }

1034	RESPONSE:

1036	    HTTP/1.1 201 Created
1037	    Date: Wed, 04 May 2016 08:48:10 GMT
1038	    Content-Length: 467
1039	    Content-Type: application/cdni; ptype=ci-trigger-status.v2
1040	    Location: https://triggers.dcdn.example.com/triggers/0
1041	    Server: example-server/0.1

1043	    {
1044	       "errors.v2": [
1045	         {
1046	           "content.playlists": [
1047	              {
1048	                "playlist": "https://www.example.com/hls/title/index.m3u8",
1049	                "media-protocol": "hls"
1050	              },
1051	            ],
1052	           "description": "The dCDN was not able to parse the playlist",
1053	           "error": "econtent",
1054	           "cdn": "AS64500:0"
1055	         },
1056	       ],
1057	       "ctime": 1462351690,
1058	       "etime": 1462351698,
1059	       "mtime": 1462351690,
1060	       "status": "failed",
1061	       "trigger.v2": { <content of trigger object from the command> }
1062	    }

1064	3.4.3.  Extensions with Error Propagation

1066	   In the following example a CI/T "preposition" command is using two
1067	   extensions to control the way the trigger is executed.  In this
1068	   example the receiving dCDN identified as "AS64500:0" does not support
1069	   the first extension in the extensions array. dCDN "AS64500:0" further
1070	   distributes this trigger to another downstream CDN that is identified
1071	   as "AS64501:0", which does not support the second extension in the
1072	   extensions array.  The error is propagate from "AS64501:0" to
1073	   "AS64500:0" and the errors.v2 array reflects both errors.

1075	  REQUEST:

1077	      POST /triggers HTTP/1.1
1078	      User-Agent: example-user-agent/0.1
1079	      Host: triggers.dcdn.example.com
1080	      Accept: */*
1081	      Content-Type: application/cdni; ptype=ci-trigger-command.v2
1082	      {
1083	        "trigger.v2": {
1084	          "type": "preposition",
1085	          "content.playlists": [
1086	           {
1087	             "playlist": "https://www.example.com/hls/title/index.m3u8",
1088	             "media-protocol": "hls"
1089	           },
1090	          ],
1091	          "extensions": [
1092	              {
1093	                "generic-trigger-extension-type":
1094	                   <Type of trigger extension object #1>,
1095	                "generic-trigger-extension-value":
1096	                    {
1097	                      <properties of trigger extension object #1>
1098	                    },
1099	                "mandatory-to-enforce": true,
1100	                "safe-to-redistribute": true,
1101	              },
1102	              {
1103	                "generic-trigger-extension-type":
1104	                   <Type of trigger extension object #2>,
1105	                "generic-trigger-extension-value":
1106	                    {
1107	                      <properties of trigger extension object #2>
1108	                    },
1109	                "mandatory-to-enforce": true,
1110	                "safe-to-redistribute": true,
1111	              },
1112	          ],
1113	        },
1114	        "cdn-path": [ "AS64496:0" ]
1115	      }

1117	  RESPONSE:

1119	      HTTP/1.1 201 Created
1120	      Date: Wed, 04 May 2016 08:48:10 GMT
1121	      Content-Length: 467
1122	      Content-Type: application/cdni; ptype=ci-trigger-status.v2
1123	      Location: https://triggers.dcdn.example.com/triggers/0
1124	      Server: example-server/0.1

1126	      {
1127	         "errors.v2": [
1128	           {
1129	             "extensions": [
1130	                {
1131	                  "generic-trigger-extension-type":
1132	                     <Type of trigger extension object #1>,
1133	                  "generic-trigger-extension-value":
1134	                      {
1135	                        <properties of trigger extension object #1>
1136	                      },
1137	                  "mandatory-to-enforce": true,
1138	                  "safe-to-redistribute": true,
1139	                },
1140	              ],

1142	             "description": "unrecognized extension <type>",
1143	             "error": "eextension",
1144	             "cdn": "AS64500:0"
1145	           },
1146	           {
1147	             "extensions": [
1148	                {
1149	                  "generic-trigger-extension-type":
1150	                     <Type of trigger extension object #2>,
1151	                  "generic-trigger-extension-value":
1152	                      {
1153	                        <properties of trigger extension object #2>
1154	                      },
1155	                  "mandatory-to-enforce": true,
1156	                  "safe-to-redistribute": true,
1157	                },
1158	              ],
1159	             "description": "unrecognized extension <type>",
1160	             "error": "eextension",
1161	             "cdn": "AS64501:0"
1162	           },
1163	         ],
1164	         "ctime": 1462351690,
1165	         "etime": 1462351698,
1166	         "mtime": 1462351690,
1167	         "status": "failed",
1168	         "trigger.v2": { <content of trigger object from the command> }
1169	      }

1171	4.  Trigger Extension Objects

1173	   The objects defined below are intended to be used in the
1174	   GenericTriggerExtension object's generic-trigger-extension-value
1175	   field as defined in Section Section 3.3.5.2, and their generic-
1176	   trigger-extension-type property MUST be set to the appropriate CDNI
1177	   Payload Type as defined in Section 6.1 .

1179	4.1.  LocationPolicy extension

1181	   A content operation may be relevant for a specific geographical
1182	   region, or need to be excluded from a specific region.  In this case,
1183	   the trigger should be applied only to parts of the network that are
1184	   either "included" or "not excluded" by the location policy.  Note
1185	   that the restrictions here are on the cache location rather than the
1186	   client location.

1188	   The LocationPolicy object defines which CDN or cache locations for
1189	   which the trigger command is relevant.

1191	   Example use cases:

1193	   o  Pre-position: Certain contracts allow for pre-positioning or
1194	      availability of contract in all regions except for certain
1195	      excluded regions in the world, including caches.  For example,
1196	      some content cannot ever knowingly touch servers in a specific
1197	      country, including cached content.  Therefore, these regions MUST
1198	      be excluded from a pre-positioning operation.

1200	   o  Purge: In certain cases, content may have been located on servers
1201	      in regions where the content must not reside.  In such cases a
1202	      purge operation to remove content specifically from that region,
1203	      is required.

1205	   Object specification

1207	      Property: locations

1209	         Description: An Access List that allows or denies (blocks) the
1210	         trigger execution per cache location.

1212	         Type: Array of LocationRule objects (see Section 4.2.2.1 of
1213	         [RFC8006])

1215	         Mandatory: Yes.

1217	   If a location policy object is not listed within the trigger command,
1218	   the default behavior is to execute the trigger in all available
1219	   caches and locations of the dCDN.

1221	   The trigger command is allowed, or denied, for a specific cache
1222	   location according to the action of the first location whose
1223	   footprint matches against that cache's location.  If two or more
1224	   footprints overlap, the first footprint that matches against the
1225	   cache's location determines the action a CDN MUST take.  If the
1226	   "locations" property is an empty list or if none of the listed
1227	   footprints match the location of a specific cache location, then the
1228	   result is equivalent to a "deny" action.

1230	   The following is an example of generic trigger extension object
1231	   containing a location policy object that allows the trigger execution
1232	   in the US but blocks its execution in Canada:

1234	   {
1235	      "generic-trigger-extension-type": "CIT.LocationPolicy",
1236	      "generic-trigger-extension-value":
1237	       {
1238	          "locations": [
1239	            {
1240	              "action": "allow",
1241	              "footprints": [
1242	                {
1243	                  "footprint-type": "countrycode",
1244	                  "footprint-value": ["us"]
1245	                }
1246	              ]
1247	            },
1248	            {
1249	              "action": "deny",
1250	              "footprints": [
1251	                {
1252	                  "footprint-type": "countrycode",
1253	                  "footprint-value": ["ca"]
1254	                }
1255	              ]
1256	            }
1257	          ]
1258	       },
1259	      "mandatory-to-enforce": true,
1260	      "safe-to-redistribute": true,
1261	      "incomprehensible": false
1262	   }

1264	4.2.  TimePolicy Extension

1266	   A uCDN may wish to perform content management operations on the dCDN
1267	   in a specific schedule.  The TimePolicy extensions allows the uCDN to
1268	   instruct the dCDN to execute the trigger command in a desired time
1269	   window.  For example, a content provider that wishes to pre-populate
1270	   a new episode at off-peak time so that it would be ready on caches at
1271	   prime time when the episode is released for viewing.  A scheduled
1272	   operation enables the uCDN to direct the dCDN in what time frame to
1273	   execute the trigger.

1275	   A uCDN may wish to to schedule a trigger such that the dCDN will
1276	   execute it in local time, as it is measured in each region.  For
1277	   example, a uCDN may wish the dCDN to pull the content at off-peak
1278	   hours, between 2AM-4AM, however, as a CDN is distributed across
1279	   multiple time zones, the UTC definition of 2AM depends on the actual
1280	   location.

1282	   We define two alternatives for localized scheduling:

1284	   o  Regional schedule: When used in conjunction with the Location
1285	      Policy defined in Section 4.1, the uCDN can trigger separate
1286	      commands for different geographical regions, for each region using
1287	      a different schedule.  This allows the uCDN to control the
1288	      execution time per region.

1290	   o  Local Time schedule: We introduce a "local time" version for
1291	      Internet timestamps that follows the notation for local time as
1292	      defined in Section 4.2.2 of [ISO8601].  When local time is used,
1293	      that dCDN SHOULD execute the triggers at different absolute times,
1294	      according the local time of each execution location.

1296	   Object specification

1298	      Property: unix-time-window

1300	         Description: A UNIX epoch time window in which the trigger
1301	         SHOULD be executed.

1303	         Type: TimeWindow object using UNIX epoch timestamps (see
1304	         Section 4.2.3.2 of [RFC8006])

1306	         Mandatory: No, but exactly one of "unixEpochWindow",
1307	         "utcWindow" or "localTimeWindow" MUST be present.

1309	      Property: utc-window

1311	         Description: A UTC time window in which the trigger SHOULD be
1312	         executed.

1314	         Type: UTCWindow object as defined in Section 4.2.1.

1316	         Mandatory: No, but exactly one of "unixEpochWindow",
1317	         "utcWindow" or "localTimeWindow" MUST be present.

1319	      Property: local-time-window

1321	         Description: A local time window.  The dCDN SHOULD execute the
1322	         trigger at the defined time frame, interpreted as the the local
1323	         time per location.

1325	         Type: LocalTimeWindow object as defined in Section 4.2.2.

1327	         Mandatory: No, but exactly one of "unixEpochWindow",
1328	         "utcWindow" or "localTimeWindow" MUST be present.

1330	   If a time policy object is not listed within the trigger command, the
1331	   default behavior is to execute the trigger in a time frame most
1332	   suitable to the dCDN taking under consideration other constrains and
1333	   / or obligations.

1335	   Example of a generic trigger extension object containing a time
1336	   policy object that schedules the trigger execution to a window
1337	   between 09:00 01/01/2000 UTC and 17:00 01/01/2000 UTC, using the
1338	   "unix-time-window" property:

1340	   {
1341	      "generic-trigger-extension-type": "CIT.TimePolicy",
1342	      "generic-trigger-extension-value":
1343	       {
1344	         "unix-time-window": {
1345	            "start": 946717200,
1346	            "end": 946746000
1347	         }
1348	       }
1349	      "mandatory-to-enforce": true,
1350	      "safe-to-redistribute": true,
1351	      "incomprehensible": false
1352	   }

1354	4.2.1.  UTCWindow

1356	   A UTCWindow object describes a time range in UTC or UTC and a zone
1357	   offset that can be applied by a TimePolicy.

1359	      Property: start

1361	         Description: The start time of the window.

1363	         Type: Internet date and time as defined in [RFC3339].

1365	         Mandatory: No, but at least one of "start" or "end" MUST be
1366	         present and non-empty.

1368	      Property: end

1370	         Description: The end time of the window.

1372	         Type: Internet date and time as defined in [RFC3339].

1374	         Mandatory: No, but at least one of "start" or "end" MUST be
1375	         present and non-empty.

1377	   Example UTCWindow object that describes a time window from 02:30
1378	   01/01/2000 UTC to 04:30 01/01/2000 UTC:

1380	   {
1381	     "start": 2000-01-01T02:30:00.00Z,
1382	     "end": 2000-01-01T04:30:00.00Z,
1383	   }

1385	   Example UTCWindow object that describes a time window in New York
1386	   time zone offset UTC-05:00 from 02:30 01/01/2000 to 04:30 01/01/2000:

1388	   {
1389	     "start": 2000-01-01T02:30:00.00-05:00,
1390	     "end": 2000-01-01T04:30:00.00-05:00,
1391	   }

1393	4.2.2.  LocalTimeWindow

1395	   A LocalTimeWindow object describes a time range in local time.  The
1396	   reader of this object MUST interpret it as "the local time at the
1397	   location of execution".  For example, if the time window states 2AM
1398	   to 4AM local time then a dCDN that has presence in both London (UTC)
1399	   and New York (UTC-05:00) will execute the trigger at 2AM-4AM UTC in
1400	   London and at 2AM-4AM UTC-05:00 in New York.

1402	      Property: start

1404	         Description: The start time of the window.

1406	         Type: JSON string formatted as DateLocalTime as defined in
1407	         Section 4.2.3.

1409	         Mandatory: No, but at least one of "start" or "end" MUST be
1410	         present and non-empty.

1412	      Property: end

1414	         Description: The end time of the window.

1416	         Type: JSON string formatted as DateLocalTime as defined in
1417	         Section 4.2.3.

1419	         Mandatory: No, but at least one of "start" or "end" MUST be
1420	         present and non-empty.

1422	   Example LocalTimeWindow object that describes a local time window
1423	   from 02:30 01/01/2000 to 04:30 01/01/2000.

1425	   {
1426	     "start": 2000-01-01T02:30:00.00,
1427	     "end": 2000-01-01T04:30:00.00,
1428	   }

1430	4.2.3.  DateLocalTime

1432	   DateLocalTime is a timestamp that follows the date and local time
1433	   notation in Section 4.3.2 of [ISO8601] as a complete date and time
1434	   extended representation, where the time zone designator is omitted.
1435	   In addition, for simplicity and as exact accuracy is not an objective
1436	   in this case, this specification does not support the decimal
1437	   fractions of seconds, and does not take leap second into
1438	   consideration.

1440	   Type: JSON string using the format "date-local-time" as defined in
1441	   Section 4.2.3.1.

1443	4.2.3.1.  Date and Local Time Format

1445	   The Date and Local Time format is specified here using the syntax
1446	   description notation defined in [ABNF].

1448	   date-fullyear   = 4DIGIT
1449	   date-month      = 2DIGIT  ; 01-12
1450	   date-mday       = 2DIGIT  ; 01-28, 01-29, 01-30, 01-31 based on
1451	                             ; month/year
1452	   time-hour       = 2DIGIT  ; 00-23
1453	   time-minute     = 2DIGIT  ; 00-59
1454	   time-second     = 2DIGIT  ; 00-59 leap seconds are not supported

1456	   local-time      = time-hour ":" time-minute ":" time-second
1457	   full-date       = date-fullyear "-" date-month "-" date-mday
1458	   date-local-time = full-date "T" local-time

1460	   Example time representing 09:00AM on 01/01/2000 local time:

1462	   2000-01-01T09:00:00.00

1464	      NOTE: Per [ABNF] and [ISO8601], the "T" character in this syntax
1465	      may alternatively be lower case "t".  For simplicity, Applications
1466	      that generate the "date-local-time" format defined here, SHOULD
1467	      only use the upper case letter "T".

1469	4.2.3.2.  Restrictions

1471	   The grammar element date-mday represents the day number within the
1472	   current month.  The maximum value varies based on the month and year
1473	   as follows:

1475	   Month Number  Month/Year           Maximum value of date-mday
1476	   ------------  ----------           --------------------------
1477	   01            January              31
1478	   02            February, normal     28
1479	   02            February, leap year  29
1480	   03            March                31
1481	   04            April                30
1482	   05            May                  31
1483	   06            June                 30
1484	   07            July                 31
1485	   08            August               31
1486	   09            September            30
1487	   10            October              31
1488	   11            November             30
1489	   12            December             31

1491	   See Appendix C of [RFC3339] for a sample C code that determines if a
1492	   year is a leap year.

1494	   The grammar element time-second may have the values 0-59.  The value
1495	   of 60 that is used in [ISO8601] to represent a leap second MUST NOT
1496	   be used.

1498	   Although [ISO8601] permits the hour to be "24", this profile of
1499	   [ISO8601] only allows values between "00" and "23" for the hour in
1500	   order to reduce confusion.

1502	5.  Footprint and Capabilities

1504	   This section covers the FCI objects required for advertisement of the
1505	   extensions and properties introduced in this document.

1507	5.1.  CI/T Versions Capability Object

1509	   The CI/T versions capability object is used to indicate support for
1510	   one or more CI/T objects versions.  Note that the default version as
1511	   originally defined in [RFC8007] MUST be implicitly supported
1512	   regardless of the versions listed in this capability object.

1514	      Property: versions

1516	         Description: A list of version numbers.

1518	         Type: An array of JSON strings

1520	         Mandatory: No.  The default is version 1.  A missing or an
1521	         empty versions list means that only version 1 of the interface
1522	         and objects is supported.

1524	5.1.1.  CI/T Versions Capability Object Serialization

1526	   The following shows an example of CI/T Versions Capability object
1527	   serialization for a dCDN that supports versions 2 and 2.1 of the CI/T
1528	   interface.

1530	   {
1531	    "capabilities": [
1532	      {
1533	        "capability-type": "FCI.TriggerVersion",
1534	        "capability-value": {
1535	          "versions": [ "1", "2", "2.1" ]
1536	        },
1537	        "footprints": [
1538	          <Footprint objects>
1539	        ]
1540	      }
1541	    ]
1542	   }

1544	5.2.  CI/T Playlist Protocol Capability Object

1546	   The CI/T Playlist Protocol capability object is used to indicate
1547	   support for one or more MediaProtocol types listed in Section 6.3 by
1548	   the playlists property of the "trigger.v2" object.

1550	      Property: media-protocols

1552	         Description: A list of media protocols.

1554	         Type: A list of MediaProtocol (from the CDNI Triggers media
1555	         protocol types Section 6.3)

1557	         Mandatory: No.  The default, in case of a missing or an empty
1558	         list, is none supported.

1560	5.2.1.  CI/T Playlist Protocol Capability Object Serialization

1562	   The following shows an example of CI/T Playlist Protocol Capability
1563	   object serialization for a dCDN that supports "hls" and "dash".

1565	   {
1566	    "capabilities": [
1567	      {
1568	        "capability-type": "FCI.TriggerPlaylistProtocol",
1569	        "capability-value": {
1570	          "media-protocols": ["hls", "dash"]
1571	        },
1572	        "footprints": [
1573	          <Footprint objects>
1574	        ]
1575	      }
1576	    ]
1577	   }

1579	5.3.  CI/T Trigger Extension Capability Object

1581	   The CI/T Generic Extension capability object is used to indicate
1582	   support for one or more GenericExtensionObject types.

1584	      Property: trigger-extension

1586	         Description: A list of supported CDNI CI/T
1587	         GenericExtensionObject types.

1589	         Type: List of strings corresponding to entries from the "CDNI
1590	         Payload Types" registry [RFC7736] that are under the CIT
1591	         namespace, and that correspond to CDNI CI/T
1592	         GenericExtensionObject objects.

1594	         Mandatory: No.  The default, in case of a missing or an empty
1595	         list, MUST be interpreted as "no GenericExtensionObject types
1596	         are supported".  A non-empty list MUST be interpreted as
1597	         containing "the only GenericExtensionObject types that are
1598	         supported".

1600	5.3.1.  CI/T Trigger Extension Capability Object Serialization

1602	   The following shows an example of CI/T Trigger Extension Capability
1603	   object serialization for a dCDN that supports the
1604	   "CIT.LocationPolicy" and the "CIT.TimePolicy" objects.

1606	   {
1607	    "capabilities": [
1608	      {
1609	        "capability-type": "FCI.TriggerGenericExtension",
1610	        "capability-value": {
1611	          "trigger-extension": ["CIT.LocationPolicy", "CIT.TimePolicy"]
1612	        },
1613	        "footprints": [
1614	          <Footprint objects>
1615	        ]
1616	      }
1617	    ]
1618	   }

1620	6.  IANA Considerations

1622	6.1.  CDNI Payload Types

1624	   This document requests the registration of the following CDNI Payload
1625	   Types under the IANA "CDNI Payload Types" registry defined in
1626	   [RFC7736]:

1628	              +-----------------------------+---------------+
1629	              | Payload Type                | Specification |
1630	              +-----------------------------+---------------+
1631	              | ci-trigger-command.v2       | RFCthis       |
1632	              | ci-trigger-status.v2        | RFCthis       |
1633	              | CIT.LocationPolicy          | RFCthis       |
1634	              | CIT.TimePolicy              | RFCthis       |
1635	              | FCI.TriggerVersion          | RFCthis       |
1636	              | FCI.TriggerPlaylistProtocol | RFCthis       |
1637	              | FCI.TriggerGenericExtension | RFCthis       |
1638	              +-----------------------------+---------------+

1640	   [RFC Editor: Please replace RFCthis with the published RFC number for
1641	   this document.]

1643	6.1.1.  CDNI ci-trigger-command.v2 Payload Type

1645	   Purpose: The purpose of this payload type is to distinguish version 2
1646	   of the CI/T command (and any associated capability advertisement)

1648	   Interface: CI/T

1650	   Encoding: see Section 3.1

1652	6.1.2.  CDNI ci-trigger-status.v2 Payload Type

1654	   Purpose: The purpose of this payload type is to distinguish version 2
1655	   of the CI/T status resource response (and any associated capability
1656	   advertisement)

1658	   Interface: CI/T

1660	   Encoding: see Section 3.1

1662	6.1.3.  CDNI CI/T LocationPolicy Trigger Extension Type

1664	   Purpose: The purpose of this Trigger Extension type is to distinguish
1665	   LocationPolicy CIT Trigger Extension objects.

1667	   Interface: CI/T

1669	   Encoding: see Section 4.1

1671	6.1.4.  CDNI CI/T TimePolicy Trigger Extension Type

1673	   Purpose: The purpose of this Trigger Extension type is to distinguish
1674	   TimePolicy CI/T Trigger Extension objects.

1676	   Interface: CI/T

1678	   Encoding: see Section 4.2

1680	6.1.5.  CDNI FCI CI/T Versions Payload Type

1682	   Purpose: The purpose of this payload type is to distinguish FCI
1683	   advertisement objects for CI/T Triggers Versions objects

1685	   Interface: FCI

1687	   Encoding: see Section 5.1.1

1689	6.1.6.  CDNI FCI CI/T Playlist Protocol Payload Type

1691	   Purpose: The purpose of this payload type is to distinguish FCI
1692	   advertisement objects for CI/T Playlist Protocol objects

1694	   Interface: FCI

1696	   Encoding: see Section 5.2.1

1698	6.1.7.  CDNI FCI CI/T Extension Objects Payload Type

1700	   Purpose: The purpose of this payload type is to distinguish FCI
1701	   advertisement objects for CI/T Extension objects

1703	   Interface: FCI

1705	   Encoding: see Section 5.3.1

1707	6.2.  CDNI CI/T Trigger Error Codes types

1709	   The IANA is requested to update the "CDNI CI/T Error Codes"
1710	   subregistry (defined in Section 7.3 of [RFC8007] and located at
1711	   <https://www.iana.org/assignments/cdni-parameters>) with the
1712	   following registration:

1714	   +------------+--------------------------------------+---------------+
1715	   | Error Code | Description                          | Specification |
1716	   +------------+--------------------------------------+---------------+
1717	   | eextension | The dCDN failed to parse a generic   | Section       |
1718	   |            | "mandatory-to-enforce" extension     | Section 3.3.7 |
1719	   |            | object, or does not support this     | of this       |
1720	   |            | extension.                           | document.     |
1721	   +------------+--------------------------------------+---------------+

1723	6.3.  CDNI Media protocol types

1725	   The IANA is requested to create a new "CDNI MediaProtocol Types"
1726	   subregistry in the "Content Delivery Networks Interconnection (CDNI)
1727	   Parameters" registry.  The "CDNI MediaProtocol Types" namespace
1728	   defines the valid MediaProtocol object values in
1729	   Section Section 3.3.4, used by the Playlist object.  Additions to the
1730	   MediaProtocol namespace conform to the "Specification Required"
1731	   policy as defined in Section 4.6 of [RFC8126], where the
1732	   specification defines the MediaProtocol Type and the protocol to
1733	   which it is associated.  The designated expert will verify that new
1734	   protocol definitions do not duplicate existing protocol definitions
1735	   and prevent gratuitous additions to the namespace.

1737	   The following table defines the initial MediaProtocol values
1738	   corresponding to the HLS, MSS, and DASH protocols:

1740	   +---------------+-------------------+---------------+---------------+
1741	   | MediaProtocol | Description       | Specification | Protocol      |
1742	   | Type          |                   |               | Specification |
1743	   +---------------+-------------------+---------------+---------------+
1744	   | hls           | HTTP Live         | RFCthis       | RFC 8216      |
1745	   |               | Streaming         |               | [RFC8216]     |
1746	   | mss           | Microsoft Smooth  | RFCthis       | MSS [MSS]     |
1747	   |               | Streaming         |               |               |
1748	   | dash          | Dynamic Adaptive  | RFCthis       | MPEG-DASH     |
1749	   |               | Streaming over    |               | [MPEG-DASH]   |
1750	   |               | HTTP (MPEG-DASH)  |               |               |
1751	   +---------------+-------------------+---------------+---------------+

1753	   [RFC Editor: Please replace RFCthis with the published RFC number for
1754	   this document.]

1756	7.  Security Considerations

1758	   All security considerations listed in Section 8 of [RFC8007] and
1759	   Section 7 of [RFC8008] apply to this document as well.

1761	   This document defines the capability to use regular expression within
1762	   the trigger spec for more granular content selection.  The usage of
1763	   regex introduced the risk of regex complexity attacks, a.k.a ReDos
1764	   attacks.  An attacker may be able to craft a regular expression that
1765	   can exhaust server resources and may take exponential time in the
1766	   worst case.  An implementation MUST protect itself by at least accept
1767	   triggers only from an authenticated party over a secured connection.
1768	   An implementation SHOULD also protect itself by using secure
1769	   programing techniques and decline trigger commands that use
1770	   potentially risky regex, such techniques are readily available in
1771	   secure programming literature and are beyond the scope of this
1772	   document.

1774	8.  Acknowledgments

1776	   TBD

1778	9.  Contributors

1780	   The authors would like to thank all members of the "Streaming Video
1781	   Alliance" (SVA) Open Caching Working Group for their contribution in
1782	   support of this document.

1784	10.  References

1786	10.1.  Normative References

1788	   [ABNF]     Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
1789	              Specifications: ABNF", STD 68, RFC 5234,
1790	              DOI 10.17487/RFC5234, January 2008,
1791	              <https://www.rfc-editor.org/info/rfc5234>.

1793	   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
1794	              Requirement Levels", BCP 14, RFC 2119,
1795	              DOI 10.17487/RFC2119, March 1997,
1796	              <https://www.rfc-editor.org/info/rfc2119>.

1798	   [RFC3339]  Klyne, G. and C. Newman, "Date and Time on the Internet:
1799	              Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
1800	              <https://www.rfc-editor.org/info/rfc3339>.

1802	   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
1803	              Resource Identifier (URI): Generic Syntax", STD 66,
1804	              RFC 3986, DOI 10.17487/RFC3986, January 2005,
1805	              <https://www.rfc-editor.org/info/rfc3986>.

1807	   [RFC8006]  Niven-Jenkins, B., Murray, R., Caulfield, M., and K. Ma,
1808	              "Content Delivery Network Interconnection (CDNI)
1809	              Metadata", RFC 8006, DOI 10.17487/RFC8006, December 2016,
1810	              <https://www.rfc-editor.org/info/rfc8006>.

1812	   [RFC8007]  Murray, R. and B. Niven-Jenkins, "Content Delivery Network
1813	              Interconnection (CDNI) Control Interface / Triggers",
1814	              RFC 8007, DOI 10.17487/RFC8007, December 2016,
1815	              <https://www.rfc-editor.org/info/rfc8007>.

1817	   [RFC8008]  Seedorf, J., Peterson, J., Previdi, S., van Brandenburg,
1818	              R., and K. Ma, "Content Delivery Network Interconnection
1819	              (CDNI) Request Routing: Footprint and Capabilities
1820	              Semantics", RFC 8008, DOI 10.17487/RFC8008, December 2016,
1821	              <https://www.rfc-editor.org/info/rfc8008>.

1823	   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
1824	              Writing an IANA Considerations Section in RFCs", BCP 26,
1825	              RFC 8126, DOI 10.17487/RFC8126, June 2017,
1826	              <https://www.rfc-editor.org/info/rfc8126>.

1828	   [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
1829	              Interchange Format", STD 90, RFC 8259,
1830	              DOI 10.17487/RFC8259, December 2017,
1831	              <https://www.rfc-editor.org/info/rfc8259>.

1833	10.2.  Informative References

1835	   [ISO8601]  ISO, "Data elements and interchange formats -- Information
1836	              interchange -- Representation of dates and times",
1837	              ISO 8601:2004, Edition 3, 12 2004,
1838	              <https://www.iso.org/standard/40874.html>.

1840	   [MPEG-DASH]
1841	              ISO, "Information technology -- Dynamic adaptive streaming
1842	              over HTTP (DASH) -- Part 1: Media presentation description
1843	              and segment format", ISO/IEC 23009-1:2014, Edition 2, 05
1844	              2014, <https://www.iso.org/standard/65274.html>.

1846	   [MSS]      Microsoft, "[MS-SSTR]: Smooth Streaming Protocol",
1847	              Protocol Revision 8.0, September 2017,
1848	              <https://msdn.microsoft.com/en-us/library/ff469518.aspx>.

1850	   [OC-CM]    Finkelman, O., Ed., Devabhaktuni, J., and M. Stock, "Open
1851	              Caching Content Management Operations Specification",
1852	              November 2017,
1853	              <https://www.streamingvideoalliance.org/document/open-
1854	              caching-content-management-operations-specification/>.

1856	   [OCWG]     Streaming Video Alliance, "Open Caching",
1857	              <https://www.streamingvideoalliance.org/technical-groups/
1858	              open-caching/>.

1860	   [PCRE841]  Hazel, P., "Perl Compatible Regular Expressions",
1861	              Version 8.41, July 2017, <http://www.pcre.org/>.

1863	   [RFC6707]  Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content
1864	              Distribution Network Interconnection (CDNI) Problem
1865	              Statement", RFC 6707, DOI 10.17487/RFC6707, September
1866	              2012, <https://www.rfc-editor.org/info/rfc6707>.

1868	   [RFC7736]  Ma, K., "Content Delivery Network Interconnection (CDNI)
1869	              Media Type Registration", RFC 7736, DOI 10.17487/RFC7736,
1870	              December 2015, <https://www.rfc-editor.org/info/rfc7736>.

1872	   [RFC8216]  Pantos, R., Ed. and W. May, "HTTP Live Streaming",
1873	              RFC 8216, DOI 10.17487/RFC8216, August 2017,
1874	              <https://www.rfc-editor.org/info/rfc8216>.

1876	   [SVA]      "Streaming Video Alliance",
1877	              <https://www.streamingvideoalliance.org>.

1879	Authors' Addresses

1881	   Ori Finkelman
1882	   Qwilt
1883	   6, Ha'harash
1884	   Hod HaSharon  4524079
1885	   Israel

1887	   Email: ori.finkelman.ietf@gmail.com

1889	   Sanjay Mishra
1890	   Verizon
1891	   13100 Columbia Pike
1892	   Silver Spring, MD  20904
1893	   USA

1895	   Email: sanjay.mishra@verizon.com

1897	   Nir B. Sopher
1898	   Qwilt
1899	   6, Ha'harash
1900	   Hod HaSharon  4524079
1901	   Israel

1903	   Email: nir@apache.org