idnits 2.17.1 draft-ietf-siprec-metadata-10.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (November 19, 2012) is 4175 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) ** Obsolete normative reference: RFC 2141 (Obsoleted by RFC 8141) ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) == Outdated reference: A later version (-12) exists of draft-ietf-siprec-architecture-06 Summary: 2 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 SIPREC Ram Mohan. Ravindranath 2 Internet-Draft Cisco Systems, Inc. 3 Intended status: Standards Track Parthasarathi. Ravindran 4 Expires: May 23, 2013 Nokia Siemens Networks 5 Paul. Kyzivat 6 Huawei 7 November 19, 2012 9 Session Initiation Protocol (SIP) Recording Metadata 10 draft-ietf-siprec-metadata-10 12 Abstract 14 Session recording is a critical requirement in many communications 15 environments such as call centers and financial trading. In some of 16 these environments, all calls must be recorded for regulatory, 17 compliance, and consumer protection reasons. Recording of a session 18 is typically performed by sending a copy of a media stream to a 19 recording device. This document describes the metadata model as 20 viewed by Session Recording Server(SRS) and the Recording metadata 21 format. 23 Status of this Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at http://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on May 23, 2013. 40 Copyright Notice 42 Copyright (c) 2012 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (http://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 58 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 59 3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 4 60 4. Metadata Model . . . . . . . . . . . . . . . . . . . . . . . . 5 61 5. Recording Metadata Format . . . . . . . . . . . . . . . . . . 6 62 5.1. XML data format . . . . . . . . . . . . . . . . . . . . . 6 63 5.1.1. Namespace . . . . . . . . . . . . . . . . . . . . . . 7 64 5.1.2. recording . . . . . . . . . . . . . . . . . . . . . . 7 65 6. Recording Metadata classes . . . . . . . . . . . . . . . . . . 7 66 6.1. Recording Session . . . . . . . . . . . . . . . . . . . . 7 67 6.1.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 8 68 6.1.2. Linkages . . . . . . . . . . . . . . . . . . . . . . . 8 69 6.1.3. XML element . . . . . . . . . . . . . . . . . . . . . 8 70 6.2. Communication Session Group . . . . . . . . . . . . . . . 9 71 6.2.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 9 72 6.2.2. Linkages . . . . . . . . . . . . . . . . . . . . . . . 9 73 6.2.3. XML element . . . . . . . . . . . . . . . . . . . . . 10 74 6.3. Communication Session . . . . . . . . . . . . . . . . . . 10 75 6.3.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 11 76 6.3.2. Linkages . . . . . . . . . . . . . . . . . . . . . . . 11 77 6.3.3. XML element . . . . . . . . . . . . . . . . . . . . . 12 78 6.4. CSRSAssociation . . . . . . . . . . . . . . . . . . . . . 12 79 6.4.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 13 80 6.4.2. Linkages . . . . . . . . . . . . . . . . . . . . . . . 13 81 6.4.3. XML element . . . . . . . . . . . . . . . . . . . . . 13 82 6.5. Participant . . . . . . . . . . . . . . . . . . . . . . . 13 83 6.5.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 14 84 6.5.2. Linkages . . . . . . . . . . . . . . . . . . . . . . . 14 85 6.5.3. XML element . . . . . . . . . . . . . . . . . . . . . 14 86 6.6. ParticipantCSAssociation . . . . . . . . . . . . . . . . . 15 87 6.6.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 15 88 6.6.2. Linkages . . . . . . . . . . . . . . . . . . . . . . . 16 89 6.6.3. XML element . . . . . . . . . . . . . . . . . . . . . 16 90 6.7. Media Stream . . . . . . . . . . . . . . . . . . . . . . . 16 91 6.7.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 17 92 6.7.2. Linkages . . . . . . . . . . . . . . . . . . . . . . . 17 93 6.7.3. XML element . . . . . . . . . . . . . . . . . . . . . 17 94 6.8. ParticipantStream Association . . . . . . . . . . . . . . 17 95 6.8.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 18 96 6.8.2. Linkages . . . . . . . . . . . . . . . . . . . . . . . 18 97 6.8.3. XML element . . . . . . . . . . . . . . . . . . . . . 18 98 6.9. associate-time/disassociate-time . . . . . . . . . . . . . 18 99 6.10. Unique ID format . . . . . . . . . . . . . . . . . . . . . 19 100 7. SIP Recording Metadata Example . . . . . . . . . . . . . . . . 19 101 7.1. Complete SIP Recording Metadata Example . . . . . . . . . 19 102 7.2. Partial Update of Recording metadata XML body . . . . . . 21 103 8. XML Schema definition for Recording metadata . . . . . . . . . 21 104 9. Security Considerations . . . . . . . . . . . . . . . . . . . 25 105 9.1. Connection Security . . . . . . . . . . . . . . . . . . . 25 106 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 107 10.1. SIP recording metadata Schema Registration . . . . . . . . 26 108 11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 26 109 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 26 110 12.1. Normative References . . . . . . . . . . . . . . . . . . . 26 111 12.2. Informative References . . . . . . . . . . . . . . . . . . 27 112 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 28 114 1. Introduction 116 Session recording is a critical requirement in many communications 117 environments such as call centers and financial trading. In some of 118 these environments, all calls must be recorded for regulatory, 119 compliance, and consumer protection reasons. Recording of a session 120 is typically performed by sending a copy of a media stream to a 121 recording device. This document focuses on the Recording metadata 122 which describes the communication session. The document describes a 123 metadata model as viewed by Session Recording Server and the 124 Recording metadata format, the requirements for which are described 125 in [RFC6341] and the architecture for which is described in 126 [I-D.ietf-siprec-architecture]. 128 2. Terminology 130 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 131 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 132 document are to be interpreted as described in [RFC2119]. This 133 document only uses these key words when referencing normative 134 statements in existing RFCs." 136 3. Definitions 138 Metadata Model: An abstract representation of metadata using a 139 Unified Modelling Language(UML) class diagram. 141 Metadata classes: Each block in the model represents a class. A 142 class is a construct that is used as a blueprint to create 143 instances(called objects) of itself. The description of each class 144 also has representation of its attributes in a second compartment 145 below the class name. 147 Attributes: Attributes represents the attributes listed in each of 148 the classes. The attributes of a class are listed in the second 149 compartment below the class name. Each instance of class conveys 150 values for these attributes which adds to the recording's Metadata. 152 Linkages: Linkages represents the relationship between the classes in 153 the model. It represents the logical connections betweens classes(or 154 objects) in class diagrams/ object diagrams. The linkages used in 155 the Metadata model of this document are associations. 157 4. Metadata Model 159 Metadata is the information that describes recorded media and the CS 160 to which they relate. Below diagram shows a model for Metadata as 161 viewed by Session Recording Server (SRS). 163 +-------------------------------+ 164 | Recording Session (RS) | 165 +-------------------------------+ 166 |1..* | 1..* 167 | | 168 | | 0..* 169 | +-----------------+ 170 +------------+ | | Communication | 171 | CSRS | | | Session (CS) | 172 | Association|--+ | Group | 173 | | | +-----------------+ 174 +------------+ | | 0..1 175 | | 176 |0..* | 1..* 177 +-------------------------------+ 178 | Communication Session (CS) | 179 | | 180 +-------------------------------+ 181 | 1..* |0..1 182 +-----+ | 183 | | 0..* |0..* 184 | +-------------+ receives +----------------+ 185 | | Participant |----------| Media Streams | 186 | | |0..* 0..*| | 187 | | | | | 188 | | | | | 189 | | | sends | | 190 | | |----------| | 191 | | |1.* 0..*| | 192 | +-------------+ +----------------+ 193 | | | 194 | | | 195 | +------------------------+------------+ 196 | | 197 | | 198 | +------------------+ +----------------------+ 199 | |ParticipantCS | | ParticipantStream | 200 +-----------| Association | | Association | 201 | | | | 202 +------------------+ +----------------------+ 204 The Metadata model is a class diagram in Unified Modelling 205 Language(UML). The model describes the structure of a metadata in 206 general by showing the classes, their attributes, and the 207 relationships among the classes. Each block in the model above 208 represents a class. The linkages between the classes represents the 209 relationships which can be associations or Composition. The metadata 210 is conveyed from SRC to SRS. 212 The model allows the capture of a snapshot of a recording's Metadata 213 at a given instant in time. Metadata changes to reflect changes in 214 what is being recorded. For example, if in a conference a 215 participant joins SRC sends a snapshot of metadata having that 216 participant information (with attributes like name/AoR pair and 217 associate-time) to the SRS. 219 Some of the metadata is not required to be conveyed explicitly from 220 the SRC to the SRS, if it can be obtained contextually by the 221 SRS(e.g., from SIP or SDP signalling). 223 5. Recording Metadata Format 225 This section gives an overview of Recording Metadata Format. Some 226 data from the metadata model is assumed to be made available to the 227 SRS through Session Description Protocol (SDP)[RFC4566], and 228 therefore this data is not represented in the XML document format 229 specified in this document. SDP attributes describes about different 230 media formats like audio, video. The other metadata attributes like 231 participant details are represented in a new Recording specific XML 232 document namely application/rs-metadata+xml. The SDP label attribute 233 [RFC4574] provides an identifier by which a metadata XML document can 234 refer to a specific media description in the SDP sent from the SRC to 235 the SRS. 237 The XML document format can be used to represent either the complete 238 metadata or a partial update to the metadata. The latter includes 239 only elements that have changed compared to the previously reported 240 metadata. 242 5.1. XML data format 244 Recording Metadata document is an XML document. recording element 245 MUST be present in all recording metadata XML document. recording 246 acts as container for all other elements in this XML document. 248 Recording object is a XML document. It MUST have the XML declaration 249 and it SHOULD contain an encoding declaration in the XML declaration, 250 e.g., "". If the charset 251 parameter of the MIME content type declaration is present and it is 252 different from the encoding declaration, the charset parameter takes 253 precedence. 255 Every application conforming to this specification MUST accept the 256 UTF-8 character encoding to ensure the minimal interoperability. 258 Syntax and semantics error in recording XML document has to be 259 informed to the originator using application specific mechanism. 261 5.1.1. Namespace 263 The namespace URI for elements defined by this specification is a 264 Uniform Resource Namespace (URN) [RFC2141], using the namespace 265 identifier 'ietf' defined by [RFC2648] and extended by [RFC3688]. 267 The URN is as follows: urn:ietf:params:xml:ns:recording 269 5.1.2. recording 271 recording element MUST contain an xmlns namespace attribute with 272 value as urn:ietf:params:xml:ns:recording. One recording element 273 MUST be present in the all recording metadata XML document. 275 dataMode element shows whether the XML document is complete document 276 or partial update. The default value is complete. 278 6. Recording Metadata classes 280 This section describes each class of the metadata model, and the 281 attributes of each class. This section also describes how different 282 classes are linked and the XML element for each of them. 284 6.1. Recording Session 285 +-------------------------------+ 286 | Recording Session (RS) | 287 +-------------------------------+ 288 | | 289 | Start/End Time | 290 | | 291 | | 292 | | 293 +-------------------------------+ 294 |1..* | 1..* 295 | | 296 |0..* | 0..* 297 Communication Communication 298 Session Session Group(CS Group) 300 Each instance of a Recording Session class (namely the Recording 301 Session Object) represents a SIP session created between an SRC and 302 SRS for the purpose of recording a Communication Session. 304 6.1.1. Attributes 306 A Recording Session class has the following attributes: 307 o Start/End Time - Represents the Start/End time of a Recording 308 Session object. 310 6.1.2. Linkages 312 Each instance of Recording Session has: 314 o Zero or more instances of Communication Session Group. CSG may be 315 zero because it is optional metadata object. Also the allowance 316 of zero instances is to accommodate persistent recording, where 317 there may be none. 318 o Zero or more instances of Communication Session objects. 320 6.1.3. XML element 322 Recording Session object is represented by recording XML element. 323 That in turn relies on the SIP/SDP session with which the XML 324 document is associated to provide some of the attributes of the 325 Recording Session element. 327 Start and End time value are derivable from Date header(if present in 328 SIP message) in RS. In cases where Date header is not present, 329 Start/End time are derivable from the time at which SRS receives the 330 notification of SIP message to setup RS / disconnect RS. 332 6.2. Communication Session Group 334 Recording Session (RS) 335 | 1..* 336 | 337 | 0..* 338 +-------------------------------+ 339 | Communication Session | 340 | Group | 341 +-------------------------------+ 342 | Unique-ID | 343 | associate-time | 344 | disassociate-time | 345 | | 346 +-------------------------------+ 347 | 0..1 348 | 349 | 1..* 350 Communication Session (CS) 352 One instance of a Communication Session Group class (namely the 353 Communication Session Group object) provides association or linking 354 of Communication Sessions. 356 6.2.1. Attributes 358 A CS Group has the following attributes: 359 o Unique-ID - This Unique-ID is to group different CSs that are 360 related. SRC (or SRS) is responsible for ensuring the uniqueness 361 of Unique-ID in case multiple SRC interacts with the same SRS. 362 The mechanism by which SRC groups the CS is outside the scope of 363 SIPREC. 364 o Associate-time - Associate-time for CS-Group shall be calculated 365 by SRC as the time when a grouping is formed. The rules that 366 determine how a grouping of different Communication Session 367 objects is done by SRC is outside the scope of SIPREC. 368 o Disassociate-time - Disassociate-time for CS-Group shall be 369 calculated by SRC as the time when the grouping ends 371 6.2.2. Linkages 373 The linkages between Communication Session Group class and other 374 classes is association. A communication Session Group is associated 375 with RS and CS in the following manner: 377 o There is one or more Recording Session objects per Communication 378 Session Group. 379 o Each Communication Session Group object has to be associated with 380 one or more RS [Here each RS can be setup by the potentially 381 different SRCs] 382 o There is one or more Communication Sessions per CS Group [e.g. 383 Consult Transfer] 385 6.2.3. XML element 387 Group element is an optional element provides the information about 388 the communication session group 390 Each communication session group (CSG)object is represented using one 391 group element. Each group element has unique Base 64 URN UUID 392 attribute which helps to uniquely identify CSG. 394 6.3. Communication Session 396 Recording Communication 397 Session Session Group(CS Group) 398 |1..* | 0..1 399 | | 400 |0..* | 1..* 401 +-------------------------------+ 402 | Communication Session (CS) | 403 | | 404 +-------------------------------+ 405 | CS Identifier | 406 | Termination Reason | 407 | Start-time | 408 | Stop-time | 409 +-------------------------------+ 410 | | 411 | 0..* |0..1 412 | | 413 | 0..* |0..* 414 Participant Media Stream 416 A Communication Session class and its object in the metadata model 417 represents Communication Session and its properties needed as seen by 418 SRC. 420 6.3.1. Attributes 422 A communication Session class has the following attributes: 424 o Termination Reason - This represents the reason why a CS was 425 terminated. The communication session MAY contain a Call 426 Termination Reason. This MAY be derived from SIP Reason header 427 [RFC3326] of CS. 428 o CS Identifier - This attribute is used to uniquely identify a CS. 429 o Start-time - This optional attribute represents start time of CS 430 as seen by SRC 431 o Stop-time - This optional attribute represents stop time of CS as 432 seen by SRC 434 This document does not specify attributes relating to what should 435 happen to a recording of a CS after it has been delivered to the SRS, 436 e.g., how long to retain the recording, what access controls to 437 apply. The SRS is assumed to behave in accordance with policy. The 438 ability for the SRC to influence this policy is outside the scope of 439 this document. However if there are implementations where SRC has 440 enough information, this could be sent as Extension Data attached to 441 CS 443 6.3.2. Linkages 445 A Communication Session is linked to CS-Group, Participant, Media 446 Stream and Recording Session classes using the association 447 relationship. Association between CS and Participant allows: 449 o CS to have atleast zero or more participants 450 o Participant is associated with zero or more CSs. This includes 451 participants who are not directly part of any CS. An example of 452 such a case is participants in a premixed media stream. The SRC 453 may have knowledge of such Participants, yet not have any 454 signaling relationship with them. This might arise if one 455 participant in CS is a conf focus. To summarize even if SRC does 456 not have direct signalling relationships with all participants in 457 a CS, it should nevertheless create a Participant object for each 458 participant that it knows about. 459 o The model also allows participants in CS that are not participants 460 in the media. An example is the identity of a 3pcc controller 461 that has initiated a CS to two or more participants of the CS. 462 Another example is the identity of a conference focus. Of course 463 a focus is probably in the media, but since it may only be there 464 as a mixer, it may not report itself as a participant in any of 465 the media streams. 467 Association between CS and Media Stream allows: 469 o A CS to have zero or more Streams 470 o A stream can be associated with at most one CS. Stream in 471 persistent RS is not required to be associated with any CS before 472 CS is created and hence the zero association is allowed. 474 Association between CS and RS allows: 476 o Each instance of RS has Zero or more instances of Communication 477 Session objects. 478 o Each CS has to be associated with one more RS [ Here each RS can 479 be potentially setup by different SRCs] 481 6.3.3. XML element 483 Session element provides the information about the communication 484 session 486 Each communication session(CS) object is represented by one session 487 element. Each session element has unique Base 64 URN UUID attribute 488 which helps to uniquely identify CS. 490 Reason element MAY be included to represent the Termination Reason 491 attribute. group-ref element MAY exist to indicate the group where 492 the mentioned session belongs. 494 6.4. CSRSAssociation 496 1..* 0..* 497 Recording Communication 498 Session ----------+---------- Session 499 | 500 | 501 | 502 +-------------------+ 503 | CSRSAssociation | 504 +-------------------+ 505 | Association-Time | 506 | Disassociaton-Time| 507 +-------------------+ 509 A CSRS Association class and its objects has attributes of CS object 510 which are attributes of association of a session to a RS. 512 6.4.1. Attributes 514 CSRS association class has the following attributes: 516 o Associate-time - associate-time is calculated by SRC as the time 517 it sees a CS is associated to a RS 518 o Disassociate-time- Disassociate-time is calculated by SRC as the 519 time it see a CS disassociate from a RS. 520 It is possible that a given CS can have multiple associate/ 521 disassociate times within given RS. 523 6.4.2. Linkages 525 CSRS association class is linked to CS and RS classes. There are no 526 cardinalties for this linkage. 528 6.4.3. XML element 530 sessionrecordingassoc is the XML element to represent CSRS 531 association object. session URN UUID is used to uniquely identify 532 this element and link with the specific session. 534 6.5. Participant 536 Communication Session (CS) 537 | 0..* 538 | 539 | 0..* 540 +-------------------------------+ 541 | Participant | 542 | | 543 +-------------------------------+ 544 | AoR / Name Pair list | 545 | | 546 | | 547 +-------------------------------+ 548 | 0..* 1..*| 549 receives| |sends 550 | 0..* 0..*| 551 Media Stream 553 A Participant class and its objects has information about a device 554 that is part of a CS and/or contributes/consumes media stream(s) 555 belonging to a CS. 557 6.5.1. Attributes 559 Participant has attributes like: 561 o AoR / Name pair list - This attribute is a list of Name/AoR tuple. 562 An AoR MAY be SIP/SIPS/TEL URI. Name represents Participant 563 name(SIP display name) or DN number ( in case it is known). There 564 are cases where a participant can have more than one AoR [e.g. 565 P-Asserted-identity header [RFC3325] which can have both SIP and 566 TEL URIs] 568 This document does not specify other attributes relating to 569 participant e.g. Participant Role, Participant type. An SRC which 570 has information of these attributes can indicate the same as part of 571 extension data to Participant from SRC to SRS. 573 6.5.2. Linkages 575 The participant class is linked to MS and CS class using association 576 relationship. The association between participant and Media Stream 577 allows: 579 o Participant to receives zero or more media streams 580 o Participant to send zero or more media streams. (Same participant 581 provides multiple streams e.g. audio and video) 582 o Media stream to be received by zero or more participants. Its 583 possible, though perhaps unlikely, that a stream is generated but 584 sent only to the SRC and SRS, not to any participant. E.g. In 585 conferencing where all participants are on hold and the SRC is 586 collocated with the focus. Also a media stream may be received by 587 multiple participants (e.g. Whisper calls, side conversations). 588 o Media stream to be sent by one or more participants (pre-mixed 589 streams). 591 Example of a case where a participant receives Zero or more streams - 592 a Supervisor may have side conversation with Agent, while Agent 593 converses with customer. 595 6.5.3. XML element 597 A participant element represents a Participant object. 599 Participant MUST have a NameID complex element which contains AoR as 600 attribute and Name as element. AOR element is SIP/SIPS URI FQDN or 601 IP address which represents the user. name is an optional element to 602 represent display name. 604 Each participant element has unique ID (Base 64 URN UUID) attribute 605 which helps to uniquely identify participant and session Base 64 URN 606 UUID to associate participant with specific session element. Base 64 607 URN UUID of participant MUST used in the scope of CSG and no new Base 608 64 URN UUID has to be created for the same element (participant, 609 stream) between different CS in the same CSG. In case Base 64 URN 610 UUID has to be used permanent, careful usage of Base 64 URN UUID to 611 original AoR has to be decided by the implementers and it is 612 implementer's choice. 614 6.6. ParticipantCSAssociation 616 1..* 0..* 617 Communication 618 Session ----------+---------- Participant 619 | 620 | 621 | 622 +-------------------+ 623 | ParticipantCS | 624 | Association | 625 +-------------------+ 626 | Capabilities | 627 | Association-Time | 628 | Disassociaton-Time| 629 +-------------------+ 631 A participantCS Association class and its objects has attributes of 632 participant object which are attributes of association of a 633 participant to a Session. 635 6.6.1. Attributes 637 ParticipantCS association class has the following attributes: 639 o Associate-time - associate-time is calculated by SRC as the time 640 it sees a participant is associated to CS 641 o Disassociate-time- Disassociate-time is calculated by SRC as the 642 time it see a participant disassociate from a CS. It is possible 643 that a given participant can have multiple associate/disassociate 644 times within given communication session. 645 o Capabilities - A participant capabilities as defined in [RFC3840] 646 which is an optional attribute that includes the capabilities of a 647 participant in a CS. Each participant shall have Zero or more 648 capabilities. A participant may use different capabilities 649 depending on the role it plays at a particular instance. IOW if a 650 participants moves across different CSs ( due to transfer e.t.c) 651 OR is simultaneously present in different CSs its role may be 652 different and hence the capability used. 653 o "send" or "recv" element in each participant is associating SDP 654 m-lines with the participant. send element indicates that 655 participant is sending the stream of media with the mentioned 656 media description. recv element indicates that participant is 657 receiving the stream and by default all participant will receive 658 the stream. recv element has relevance in case whisper call 659 scenario wherein few of the participant in the session receives 660 the stream and not others. 662 6.6.2. Linkages 664 The participantCS association class is linked to participant and CS 665 classes. There are no cardinalties for this linkage. 667 6.6.3. XML element 669 participantsessionassoc XML element represent participantCS 670 association object. participant and session id is used to uniquely 671 identify this element 673 NOTE: RFC 4235 encoding shall be used to represent capabilities 674 attribute in XML. 676 6.7. Media Stream 678 Participant 679 | 0..* 1..*| 680 receives| |sends 681 | 0..* 0..*| 682 +-------------------------+ 683 | Media Stream | 684 | | 685 Communication 0..1 0..* +-------------------------+ 686 Session ------------| | 687 | Media Stream Reference | 688 | Content-type | 689 | | 690 +-------------------------+ 692 A Media Stream class (and its objects) has the properties of media as 693 seen by SRC and sent to SRS. Different snapshots of media stream 694 object may be sent whenever there is a change in media (e.g. dir 695 change like pause/resume and/or codec change and/or participant 696 change.). 698 6.7.1. Attributes 700 A Media Stream class has the the following attributes: 702 o Media Stream Reference - In implementations this can reference to 703 m-line 704 o Content - The content of an MS element will be described in terms 705 of value from the [RFC4796] registry. 707 The metadata model should include media streams that are not being 708 delivered to the SRS. Examples include cases where SRC offered 709 certain media types but SRS chooses to accept only a subset of them 710 OR an SRC may not even offer a certain media type due it its 711 restrictions to record 713 6.7.2. Linkages 715 A Media Stream is linked to participant and CS classes using the 716 association relationship. The details of association with the 717 Participant are described in the Participant class section. The 718 details of association with CS is mentioned in the CS section. 720 6.7.3. XML element 722 stream element represents a Media Stream object. Stream element 723 indicates SDP media lines associated with the session and 724 participants. 726 This element indicates the SDP m-line properties like label 727 attributes. Label attribute is used to link m-line SDP body using 728 label attribute in SDP m-line. 730 Each stream element has unique Base 64 URN UUID attribute which helps 731 to uniquely identify stream and session Base 64 URN UUID to associate 732 stream with specific session element. 734 The content attribute if an SRC wishes to send is conveyed in RS SDP. 736 6.8. ParticipantStream Association 737 +-------------------+ 738 | ParticipantSteam | 739 | Association | 740 +-------------------+ +----------Participant 741 | Association-Time | | 0..*| 1..*| 742 | Disassociaton-Time|---+ recv| |sends 743 | Recv | | 0..*| 0..*| 744 | Send | | | | 745 +-------------------+ | | | 746 +----------Media Stream 748 A ParticipantStream association class and its object has attributes 749 that are attributes of association of a Participant to a Stream. 751 6.8.1. Attributes 753 A participantStream association class has the following attributes: 755 o Associate-Time: This attributes indicates the time a Participant 756 started contributing to a Media Stream 757 o Disassociate-Time: This attribute indicates the time a Participant 758 stopped contributing to a Media Stream 760 6.8.2. Linkages 762 The participantStream association class is linked to participant and 763 Stream classes. There are no cardinalties for this linkage. 765 6.8.3. XML element 767 ParticipantStreamAssoc XML element represents participant to stream 768 association object. participant element is used to uniquely identify 769 this element and related with stream using stream unique URN id.. 771 6.9. associate-time/disassociate-time 773 associate-time/disassociate-time contains a string indicating the 774 date and time of the status change of this tuple. The value of this 775 element MUST follow the IMPP datetime format [RFC3339]. Timestamps 776 that contain 'T' or 'Z' MUST use the capitalized forms. At a time, 777 any of the time tuple associate-time or disassociate-time MAY exist 778 in the element namely group, session, participant and not both 779 timestamp at the same time. 781 As a security measure, the timestamp element SHOULD be included in 782 all tuples unless the exact time of the status change cannot be 783 determined. 785 6.10. Unique ID format 787 Unique id is generated in two steps: 788 o UUID is created using [RFC4122]) 789 o UUID is encoded using base64 as defined in [RFC4648] 791 The above mentioned unique-id mechanism SHOULD be used for each 792 metadata element. 794 7. SIP Recording Metadata Example 796 7.1. Complete SIP Recording Metadata Example 798 The following example provides all the tuples involved in Recording 799 Metadata XML body. 801 802 803 complete 804 805 2010-12-16T23:41:07Z 806 807 808 sip:alice@atlanta.com 809 810 811 FOO! 812 bar 813 814 815 816 7+OTCyoxTmqmqyA/1weDAg== 817 818 819 FaXHlc+3WruaroDaNE87am== 820 FOO! 821 bar 822 823 824 2010-12-16T23:41:07Z 825 826 828 829 Bob B 830 831 832 FOO! 833 bar 834 835 838 2010-12-16T23:41:07Z 839 840 842 i1Pz3to5hGk8fuXl+PbwCw== 843 UAAMm5GRQKSCMVvLyl4rFw== 844 8zc6e0lYTlWIINA6GR+3ag== 845 EiXGlc+4TruqqoDaNE76ag== 846 847 849 850 Paul 851 852 853 FOO! 854 bar 855 856 859 2010-12-16T23:41:07Z 860 861 863 8zc6e0lYTlWIINA6GR+3ag== 864 EiXGlc+4TruqqoDaNE76ag== 865 UAAMm5GRQKSCMVvLyl4rFw== 866 i1Pz3to5hGk8fuXl+PbwCw== 867 868 870 871 872 874 875 876 878 879 880 882 883 884 886 SIP Recording Metadata Example XML body 888 7.2. Partial Update of Recording metadata XML body 890 The following example provides partial update in Recording Metadata 891 XML body for the above example. The example has a snapshot that 892 carries the disassociate-time for a participant from a session. 894 895 896 partial 897 899 900 Bob R 901 902 FOO! 903 bar 904 905 908 2010-12-16T23:41:07Z 909 910 912 Partial update of SIP Recording Example XML body 914 8. XML Schema definition for Recording metadata 916 This section defines XML schema for Recording metadata document 918 919 924 925 926 927 928 929 931 933 935 937 939 942 945 948 952 953 954 955 956 958 960 964 965 967 968 969 970 972 974 976 978 982 983 985 986 987 988 990 992 996 997 999 1000 1001 1002 1004 1008 1009 1011 1012 1013 1014 1017 1019 1023 1024 1026 1028 1029 1030 1031 1033 1035 1037 1039 1043 1044 1046 1047 1048 1049 1051 1055 1056 1058 1059 1060 1061 1062 1063 1064 1066 1068 1069 1070 1071 1072 1073 1075 1076 1077 1078 1079 1080 1081 1083 1085 9. Security Considerations 1087 The metadata information sent from SRC to SRS MAY reveal sensitive 1088 information about different participants in a session. For this 1089 reason, it is RECOMMENDED that a SRC use a strong means for 1090 authentication and metadata information protection and that it apply 1091 comprehensive authorization rules when using the metadata format 1092 defined in this document. The following sections will discuss each 1093 of these aspects in more detail. 1095 9.1. Connection Security 1097 It is RECOMMENDED that a SRC authenticate SRS using the normal SIP 1098 authentication mechanisms, such as Digest as defined in Section 22 of 1099 [RFC3261]. The mechanism used for conveying the metadata information 1100 MUST ensure integrity and SHOULD ensure confidentially of the 1101 information. In order to achieve these, an end-to-end SIP encryption 1102 mechanism, such as S/MIME described in [RFC3261], SHOULD be used. 1104 If a strong end-to-end security means (such as above) is not 1105 available, it is RECOMMENDED that a SRC use mutual hop-by-hop 1106 Transport Layer Security (TLS) authentication and encryption 1107 mechanisms described in "SIPS URI Scheme" and "Interdomain Requests" 1108 of [RFC3261]. 1110 10. IANA Considerations 1112 This specification registers a new XML namespace, and a new XML 1113 schema. 1115 10.1. SIP recording metadata Schema Registration 1117 URI: urn:ietf:params:xml:ns:recording 1119 Registrant Contact: IETF SIPREC working group, Ram mohan 1120 R(rmohanr@cisco.com) 1122 XML: the XML schema to be registered is contained in Section 6. 1124 Its first line is and its last 1125 line is 1127 11. Acknowledgement 1129 We wish to thank John Elwell, Henry Lum, Leon Portman, De Villers, 1130 Andrew Hutton(Siemens-Enterprise), Deepanshu Gautam(Huawei),Charles 1131 Eckel(Cisco), Muthu Arul Mozhi (Cisco), Michael Benenson(Cisco), 1132 Hadriel Kaplan (ACME), Brian Rosen, Scott Orton(Broadsoft), Ofir Roth 1133 (NICE), Mary Barnes(Polycom), Ken Rehor(Cisco) for their valuable 1134 comments and inputs. 1136 We wish to thank Joe Hildebrand(Cisco), Peter Saint-Andre(Cisco), 1137 Matt Miller(Cisco) for the valuable XML related guidance and Martin 1138 Thompson for validating the XML schema and providing comments on the 1139 same. 1141 12. References 1143 12.1. Normative References 1145 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1146 Requirement Levels", BCP 14, RFC 2119, March 1997. 1148 [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997. 1150 [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, 1151 A., Peterson, J., Sparks, R., Handley, M., and E. 1152 Schooler, "SIP: Session Initiation Protocol", RFC 3261, 1153 June 2002. 1155 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 1156 January 2004. 1158 [RFC3339] Klyne, G., Ed. and C. Newman, "Date and Time on the 1159 Internet: Timestamps", RFC 3339, July 2002. 1161 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 1162 Description Protocol", RFC 4566, July 2006. 1164 [RFC4574] Levin, O. and G. Camarillo, "The Session Description 1165 Protocol (SDP) Label Attribute", RFC 4574, August 2006. 1167 [RFC4796] Hautakorpi, J. and G. Camarillo, "The Session Description 1168 Protocol (SDP) Content Attribute", RFC 4796, 1169 February 2007. 1171 [RFC3840] Rosenberg, J., Schulzrinne, H., and P. Kyzivat, 1172 "Indicating User Agent Capabilities in the Session 1173 Initiation Protocol (SIP)", RFC 3840, August 2004. 1175 [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally 1176 Unique IDentifier (UUID) URN Namespace", RFC 4122, 1177 July 2005. 1179 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data 1180 Encodings", RFC 4648, October 2006. 1182 12.2. Informative References 1184 [RFC6341] Rehor, K., Portman, L., Hutton, A., and R. Jain, "Use 1185 Cases and Requirements for SIP-Based Media Recording 1186 (SIPREC)", RFC 6341, August 2011. 1188 [I-D.ietf-siprec-architecture] 1189 Hutton, A., Portman, L., Jain, R., and K. Rehor, "An 1190 Architecture for Media Recording using the Session 1191 Initiation Protocol", draft-ietf-siprec-architecture-06 1192 (work in progress), September 2012. 1194 [RFC2648] Moats, R., "A URN Namespace for IETF Documents", RFC 2648, 1195 August 1999. 1197 [RFC3326] Schulzrinne, H., Oran, D., and G. Camarillo, "The Reason 1198 Header Field for the Session Initiation Protocol (SIP)", 1199 RFC 3326, December 2002. 1201 [RFC3325] Jennings, C., Peterson, J., and M. Watson, "Private 1202 Extensions to the Session Initiation Protocol (SIP) for 1203 Asserted Identity within Trusted Networks", RFC 3325, 1204 November 2002. 1206 Authors' Addresses 1208 Ram Mohan Ravindranath 1209 Cisco Systems, Inc. 1210 Cessna Business Park, 1211 Kadabeesanahalli Village, Varthur Hobli, 1212 Sarjapur-Marathahalli Outer Ring Road 1213 Bangalore, Karnataka 560103 1214 India 1216 Email: rmohanr@cisco.com 1218 Parthasarathi Ravindran 1219 Nokia Siemens Networks 1220 Bangalore, Karnataka 1221 India 1223 Email: partha@parthasarathi.co.in 1225 Paul Kyzivat 1226 Huawei 1227 Hudson, MA 1228 USA 1230 Email: pkyzivat@alum.mit.edu