idnits 2.17.1 draft-ietf-mmusic-msrp-usage-data-channel-08.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 : ---------------------------------------------------------------------------- == There are 1 instance of lines with non-RFC2606-compliant FQDNs in the document. == There are 1 instance of lines with non-RFC6890-compliant IPv4 addresses in the document. If these are example addresses, they should be changed. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (March 18, 2018) is 2232 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-26) exists of draft-ietf-rtcweb-jsep-24 == Outdated reference: A later version (-28) exists of draft-ietf-mmusic-data-channel-sdpneg-16 ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) == Outdated reference: A later version (-37) exists of draft-ietf-mmusic-rfc4566bis-17 Summary: 1 error (**), 0 flaws (~~), 6 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 MMUSIC K. Drage, Ed. 3 Internet-Draft Unaffiliated 4 Intended status: Standards Track M. Makaraju 5 Expires: September 19, 2018 Nokia 6 J. Stoetzer-Bradler 7 R. Ejzak 8 J. Marcon 9 Unaffiliated 10 J. Recio, Ed. 11 CoSMo Software 12 March 18, 2018 14 MSRP over Data Channels 15 draft-ietf-mmusic-msrp-usage-data-channel-08 17 Abstract 19 This document specifies how the Message Session Relay Protocol (MSRP) 20 can be instantiated as a data channel sub-protocol, using the SDP 21 offer/answer exchange-based generic data channel negotiation 22 framework. Two network configurations are documented: a WebRTC end- 23 to-end configuration (connecting two MSRP over data channel 24 endpoints), and a gateway configuration (connecting an MSRP over data 25 channel endpoint with an MSRP over TCP or TLS endpoint). 27 Status of This Memo 29 This Internet-Draft is submitted in full conformance with the 30 provisions of BCP 78 and BCP 79. 32 Internet-Drafts are working documents of the Internet Engineering 33 Task Force (IETF). Note that other groups may also distribute 34 working documents as Internet-Drafts. The list of current Internet- 35 Drafts is at https://datatracker.ietf.org/drafts/current/. 37 Internet-Drafts are draft documents valid for a maximum of six months 38 and may be updated, replaced, or obsoleted by other documents at any 39 time. It is inappropriate to use Internet-Drafts as reference 40 material or to cite them other than as "work in progress." 42 This Internet-Draft will expire on September 19, 2018. 44 Copyright Notice 46 Copyright (c) 2018 IETF Trust and the persons identified as the 47 document authors. All rights reserved. 49 This document is subject to BCP 78 and the IETF Trust's Legal 50 Provisions Relating to IETF Documents 51 (https://trustee.ietf.org/license-info) in effect on the date of 52 publication of this document. Please review these documents 53 carefully, as they describe your rights and restrictions with respect 54 to this document. Code Components extracted from this document must 55 include Simplified BSD License text as described in Section 4.e of 56 the Trust Legal Provisions and are provided without warranty as 57 described in the Simplified BSD License. 59 Table of Contents 61 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 62 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 4 63 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 64 4. Principles . . . . . . . . . . . . . . . . . . . . . . . . . 4 65 4.1. MSRP Data Channel . . . . . . . . . . . . . . . . . . . . 4 66 4.2. Session Mapping . . . . . . . . . . . . . . . . . . . . . 5 67 4.3. MSRP URI . . . . . . . . . . . . . . . . . . . . . . . . 5 68 4.4. msrp-scheme . . . . . . . . . . . . . . . . . . . . . . . 5 69 5. End-to-End Configuration . . . . . . . . . . . . . . . . . . 5 70 5.1. Basic MSRP Support . . . . . . . . . . . . . . . . . . . 5 71 5.1.1. Session Negotiation . . . . . . . . . . . . . . . . . 5 72 5.1.1.1. Use of the dcmap Attribute . . . . . . . . . . . 5 73 5.1.1.2. Use of the dcsa Attribute . . . . . . . . . . . . 6 74 5.1.1.3. Use of the setup Attribute . . . . . . . . . . . 7 75 5.1.1.4. Example SDP Negotiation . . . . . . . . . . . . . 7 76 5.1.2. Session Opening . . . . . . . . . . . . . . . . . . . 8 77 5.1.3. Data Framing . . . . . . . . . . . . . . . . . . . . 8 78 5.1.4. Data Sending and Reporting . . . . . . . . . . . . . 9 79 5.1.5. Session Closing . . . . . . . . . . . . . . . . . . . 9 80 5.2. Support for MSRP File Transfer Function . . . . . . . . . 9 81 6. Gateway Configuration . . . . . . . . . . . . . . . . . . . . 10 82 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 83 7.1. Subprotocol Identifier MSRP . . . . . . . . . . . . . . . 11 84 7.2. setup Attribute . . . . . . . . . . . . . . . . . . . . . 11 85 8. Security Considerations . . . . . . . . . . . . . . . . . . . 11 86 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 87 10. CHANGE LOG . . . . . . . . . . . . . . . . . . . . . . . . . 12 88 10.1. Changes against 'draft-ietf-mmusic-msrp-usage-data- 89 channel-07' . . . . . . . . . . . . . . . . . . . . . . 12 90 10.2. Changes against 'draft-ietf-mmusic-msrp-usage-data- 91 channel-06' . . . . . . . . . . . . . . . . . . . . . . 12 92 10.3. Changes against 'draft-ietf-mmusic-msrp-usage-data- 93 channel-05' . . . . . . . . . . . . . . . . . . . . . . 12 94 10.4. Changes against 'draft-ietf-mmusic-msrp-usage-data- 95 channel-04' . . . . . . . . . . . . . . . . . . . . . . 12 96 10.5. Changes against 'draft-ietf-mmusic-msrp-usage-data- 97 channel-03' . . . . . . . . . . . . . . . . . . . . . . 13 98 10.6. Changes against 'draft-ietf-mmusic-msrp-usage-data- 99 channel-02' . . . . . . . . . . . . . . . . . . . . . . 13 100 10.7. Changes against 'draft-ietf-mmusic-msrp-usage-data- 101 channel-01' . . . . . . . . . . . . . . . . . . . . . . 13 102 10.8. Changes against 'draft-ietf-mmusic-msrp-usage-data- 103 channel-00' . . . . . . . . . . . . . . . . . . . . . . 15 104 10.9. Changes against 'draft-ejzak-mmusic-msrp-usage-data- 105 channel-01' . . . . . . . . . . . . . . . . . . . . . . 15 106 10.10. Changes against '-00' . . . . . . . . . . . . . . . . . 16 107 11. Normative References . . . . . . . . . . . . . . . . . . . . 16 108 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 110 1. Introduction 112 The Message Session Relay Protocol (MSRP) [RFC4975] is a protocol for 113 transmitting a series of related instant messages in the context of a 114 session. In addition to instant messaging, MSRP can also be used for 115 image sharing or file transfer. MSRP is currently defined to work 116 over TCP and TLS connections. 118 This document defines the negotiation and transport of this MSRP 119 protocol over data channels, where a data channel is a bi-directional 120 communication channel running on top of SCTP/DTLS (as per 121 [I-D.ietf-rtcweb-data-channel]) and where MSRP is instantiated as a 122 sub-protocol of this data channel. The MSRP protocol negotiation 123 defined in this document is based on the generic SDP offer/answer 124 exchange based data channel negotiation as specified in 125 [I-D.ietf-mmusic-data-channel-sdpneg]. 127 Defining MSRP as a data channel sub-protocol has many benefits: 129 o provides to applications a proven protocol enabling instant 130 messaging, file transfer, image sharing 132 o integrates those features with other RTCWeb voice, video and data 133 features 135 o leverages the SDP-based negotiation already defined for MSRP 137 o allows the interworking with MSRP endpoints running on a TCP or 138 TLS connection 140 Considering an MSRP endpoint being an MSRP application that uses data 141 channel from WebRTC specifications [I-D.ietf-rtcweb-data-channel], 142 this document describes two configurations where the other endpoint 143 is respectively either another MSRP over data channel endpoint (e.g., 144 a WebRTC application) or an MSRP endpoint using either TCP or TLS 145 transport. 147 2. Conventions 149 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 150 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 151 document are to be interpreted as described in [RFC2119]. 153 3. Terminology 155 This document uses the following terms: 157 Data channel: A WebRTC data channel as specified in 158 [I-D.ietf-rtcweb-data-channel]. 160 MSRP data channel: A data channel specifically used to transport 161 the messages of one MSRP session. 163 External negotiation: Data channel negotiation based on out-of- 164 band or in-band mechanisms other than the Data Channel 165 Establishment Protocol specified in 166 [I-D.ietf-rtcweb-data-protocol]. 168 In-band: Transmission through the peer-to-peer SCTP association. 170 Out-of-band: Transmission through the call control signaling path, 171 e.g., using JSEP [I-D.ietf-rtcweb-jsep] and the SDP Offer/Answer 172 model [RFC3264]. 174 Peer: From the perspective of one of the agents in a session, its 175 peer is the other agent. Specifically, from the perspective of 176 the SDP offerer, the peer is the SDP answerer. From the 177 perspective of the SDP answerer, the peer is the SDP offerer. 179 4. Principles 181 4.1. MSRP Data Channel 183 In this document, an MSRP data channel is a data channel for which 184 the instantiated sub-protocol is "MSRP", and where the MSRP-related 185 negotiation is done as part of the SDP-based external negotiation 186 method defined in [I-D.ietf-mmusic-data-channel-sdpneg]. 188 4.2. Session Mapping 190 In this design, the MSRP session maps to the SCTP association and the 191 "SCTP stream pair" assigned to the data channel, and each MSRP 192 session maps to one data channel exactly. 194 4.3. MSRP URI 196 This document extends the MSRP URI syntax [RFC4975] by defining the 197 new transport parameter value "dc": 199 transport /= "dc" / 1*ALPHANUM 200 ; Add "dc" to existing transports per [RFC4975] 202 MSRP design provides for new transport bindings, see Section 6 of 203 [RFC4975], MSRP implementations are expected to allow unrecognized 204 transports for which there is no need to establish a connection to 205 the resource described by the URI, as it's the case of data channels 206 (Section 5.1.2). 208 4.4. msrp-scheme 210 The msrp-scheme portion of the MSRP-URI that represents an MSRP data 211 channel endpoint (used in the SDP path attribute and in the MSRP 212 message headers) is always "msrps", which indicates that the MSRP 213 data channel is always secured using DTLS as described in 214 [I-D.ietf-rtcweb-data-channel]. 216 5. End-to-End Configuration 218 This section describes the network configuration where each MSRP 219 endpoint is running MSRP over a data channel. 221 5.1. Basic MSRP Support 223 5.1.1. Session Negotiation 225 5.1.1.1. Use of the dcmap Attribute 227 The SDP offer SHALL include a dcmap attribute line (defined in 228 [I-D.ietf-mmusic-data-channel-sdpneg]) within the media description 229 of the SCTP association for each MSRP data channel session to be 230 negotiated. 232 The attribute includes the following data channel parameters: 234 o "label=" labelstring 235 o "subprotocol=" "MSRP" 237 The labelstring is set by the MSRP application according to 238 [I-D.ietf-mmusic-data-channel-sdpneg]. Ordered and reliable data 239 channels MUST always be used, so that the "max-retr" and "max-time" 240 parameters SHALL NOT be used. If the "ordered" parameter is used, 241 then its value MUST be equal to "true". 243 Rest of the SDP offer/answer procedures are per 244 [I-D.ietf-mmusic-data-channel-sdpneg]. 246 The following is an example of the dcmap attribute for an MSRP 247 session to be negotiated with stream-id=2 and label="chat": 249 a=dcmap:2 label="chat";subprotocol="MSRP" 251 5.1.1.2. Use of the dcsa Attribute 253 The SDP offer SHALL also include within the media description for the 254 SCTP association, a dcsa attribute line (defined in 255 [I-D.ietf-mmusic-data-channel-sdpneg]) for each MSRP-specific SDP 256 attribute to be negotiated for each MSRP data channel being 257 negotiated. 259 The MSRP-specific items that can be negotiated include at least all 260 of the following well-known attributes: 262 o defined in [RFC4975]: "path", "accept-types", "accept-wrapped- 263 types", "max-size" 265 o defined in [RFC4566]: "sendonly", "recvonly", "inactive", and 266 "sendrecv" 268 o defined in [RFC6135]: "setup" 270 o defined in [RFC6714]: "msrp-cema" 272 o defined in [RFC5547]: all the parameters related to MSRP file 273 transfer. See Section 5.2. 275 The msrp-cema attribute SHALL be assumed to be present for every MSRP 276 session using data channel transport, so the inclusion of the msrp- 277 cema attribute is OPTIONAL. This ensures that the data channel 278 transport for the MSRP session is established without using the path 279 attribute. 281 The SDP answer SHALL include zero or more corresponding dcsa 282 attribute lines for each negotiated MSRP session, according to the 283 MSRP-specific attribute negotiation rules in the corresponding 284 specifications. 286 A new SDP offer/answer MAY update the MSRP subprotocol attributes 287 while keeping the same subprotocol a=dcmap description. The 288 semantics for newly negotiated MSRP subprotocol attributes are per 289 [RFC4975]. 291 5.1.1.3. Use of the setup Attribute 293 A dsca embedded setup attribute, as defined in [RFC4145], MUST be 294 used for MSRP sessions over data channels. It is used to negotiate 295 which MSRP session endpoint assumes the active role as per 296 Section 4.2.2 of [RFC6135] and Section 5.4 of [RFC4975]. It has no 297 relationship with the DTLS connection establishment roles. 299 The dcsa embedded setup attribute is of the form "a=dcsa:x 300 setup:", with x being the data channel's SCTP stream 301 identifier, so that such attribute is explicitly associated with an 302 MSRP session over a specific data channel. 304 It is considered an error if an MSRP over data channel description 305 does not contain a dcsa embedded setup attribute. 307 The SDP setup attribute can also be used in WebRTC data channel 308 related SDP media descriptions as a media level attribute, which is 309 associated with the corresponding UDP/DTLS/SCTP or TCP/DTLS/SCTP "m" 310 line. Such an "a=setup" attribute is used as specified in 311 [I-D.ietf-mmusic-sctp-sdp] in order to negotiate the establishment 312 roles of the DTLS connection and has no relationship with the MSRP 313 session. 315 5.1.1.4. Example SDP Negotiation 317 The following is an example of an "m" line for data channels in an 318 SDP offer that includes the attributes needed to establish two MSRP 319 sessions: one for chat and one for file transfer. The example is 320 derived from a combination of examples in [RFC4975] and [RFC5547]. 322 m=application 54111 UDP/DTLS/SCTP webrtc-datachannel 323 c=IN IP4 79.97.215.79 324 a=max-message-size:100000 325 a=sctp-port:5000 326 a=setup:actpass 327 a=fingerprint:SHA-1 \ 328 4A:AD:B9:B1:3F:82:18:3B:54:02:12:DF:3E:5D:49:6B:19:E5:7C:AB 329 a=tls-id:4a756565cddef001be82 330 a=dcmap:0 label="chat";subprotocol="MSRP" 331 a=dcsa:0 setup:active 332 a=dcsa:0 accept-types:message/cpim text/plain 333 a=dcsa:0 path:msrps://bob.example.com:54111/si438dsaodes;dc 334 a=dcmap:2 label="file transfer";subprotocol="MSRP" 335 a=dcsa:2 sendonly 336 a=dcsa:2 setup:active 337 a=dcsa:2 accept-types:message/cpim 338 a=dcsa:2 accept-wrapped-types:* 339 a=dcsa:2 path:msrps://bob.example.com:54111/jshA7we;dc 340 a=dcsa:2 file-selector:name:"picture1.jpg" \ 341 type:image/jpeg size:1463440 hash:sha-1:\ 342 FF:27:0D:81:14:F1:8A:C3:35:3B:36:64:2A:62:C9:3E:D3:6B:51:B4 343 a=dcsa:2 file-transfer-id:rjEtHAcYVZ7xKwGYpGGwyn5gqsSaU7Ep 344 a=dcsa:2 file-disposition:attachment 345 a=dcsa:2 file-date:creation:"Mon, 12 Jan 2018 15:01:31 +0800" 346 a=dcsa:2 file-icon:cid:id2@bob.example.com 347 a=dcsa:2 file-range:1-1463440 349 5.1.2. Session Opening 351 Section 5.1.1.3 describes how the active MSRP session endpoint role 352 is negotiated. The active MSRP session endpoint does not use the 353 path attribute to open a transport connection to its peer. Instead, 354 it uses the data channel established for this MSRP session by the 355 generic data channel opening procedure defined in 356 [I-D.ietf-mmusic-data-channel-sdpneg]. 358 As soon as this data channel is opened, the MSRP session is actually 359 opened by the active MSRP session endpoint. In order to do this the 360 active MSRP endpoint sends an MSRP SEND message (empty or not) to the 361 other MSRP endpoint. The msrp-cema attribute is implicitly 362 associated with every MSRP session using data channel transport. 364 5.1.3. Data Framing 366 Each text-based MSRP message is sent on the corresponding SCTP stream 367 using standard MSRP framing and chunking procedures, as defined in 368 [RFC4975], with each MSRP chunk delivered in a single SCTP user 369 message. Therefore all sent MSRP chunks including the MSRP chunk 370 header MUST have lengths of less than or equal to the value of the 371 peer's "a=max-message-size" attribute, which is associated with the 372 data channel's SCTP association. 374 5.1.4. Data Sending and Reporting 376 Data sending and reporting procedures SHALL conform to RFC 4975. 378 5.1.5. Session Closing 380 The closure of an MSRP session MUST be signaled via an SDP offer/ 381 answer exchange which removes the "a=dcmap:" and "a=dcsa:" attribute 382 lines associated with the MSRP session from the associated DTLS/SCTP 383 based media description. This results in the associated data channel 384 being closed as well as per [I-D.ietf-mmusic-data-channel-sdpneg], 385 where the actual data channel closure procedure is typically 386 initiated by the SDP answerer right after having accepted the SDP 387 offer. 389 The port value for the "m" line SHOULD NOT be changed (e.g. to zero) 390 when closing an MSRP session (unless all data channels are being 391 closed and the SCTP association is no longer needed), since this 392 would close the SCTP association and impact all of the data channels. 393 In all cases in [RFC4975] where the procedure calls for setting the 394 port to zero for the MSRP "m" line in an SDP offer for TCP transport, 395 the SDP offerer of an MSRP session with data channel transport SHALL 396 remove the corresponding dcmap and dcsa attributes. 398 The SDP answerer must ensure that no dcmap or dcsa attributes are 399 present in the SDP answer if no corresponding attributes are present 400 in the received SDP offer. 402 5.2. Support for MSRP File Transfer Function 404 [RFC5547] defines an end-to-end file transfer method based on MSRP 405 and the SDP offer/answer mechanism. This file transfer method is 406 also usable by MSRP endpoints using data channels, with the following 407 considerations: 409 o As an MSRP session maps to one data channel, a file transfer 410 session maps also to one data channel. 412 o SDP attributes specified in [RFC5547] for a file transfer "m" line 413 are embedded as subprotocol-specific attributes using the syntax 414 defined in [I-D.ietf-mmusic-data-channel-sdpneg]. 416 o Once the file transfer is complete, the same data channel MAY be 417 reused for another file transfer. 419 6. Gateway Configuration 421 This section describes the network configuration where one MSRP 422 endpoint uses data channels as MSRP transport, the other MSRP 423 endpoint uses TLS/TCP connections as MSRP transport, and the two MSRP 424 endpoints interwork via an MSRP gateway. 426 Specifically, a gateway can be configured to interwork an MSRP 427 session over a data channel with a peer that does not support data 428 channel transport in one of two ways. 430 In one model, the gateway performs as a MSRP B2BUA to interwork all 431 the procedures as necessary between the endpoints. No further 432 specification is needed for this model. 434 Alternately, the gateway can use CEMA procedures to provide transport 435 level interworking between MSRP endpoints using different transport 436 protocols as follows. 438 When the gateway performs transport level interworking between MSRP 439 endpoints, all of the procedures in Section 5 apply to each peer, 440 with the following additions: 442 o The endpoint establishing an MSRP session using data channel 443 transport SHALL NOT request inclusion of any relays, although it 444 MAY interoperate with a peer that signals the use of relays. 446 o The gateway receiving an SDP offer that includes a request to 447 negotiate an MSRP session on a data channel can provide transport 448 level interworking by forwarding TCP or TLS transport parameters 449 in a new "m" line with the appropriate attributes within the 450 forwarded SDP offer. 452 * Especially, the gateway interworks the received MSRP over data 453 channel associated dcsa embedded setup attribute with the media 454 description level "a=setup" attribute of the MSRP over TCP or 455 TLS "m" line within its forwarded SDP offer. 457 o Similarly, a gateway receiving an SDP offer to negotiate an MSRP 458 session using TCP or TLS transport with an endpoint that only 459 supports data channel transport for MSRP can provide transport 460 level interworking by establishing a new data channel for the MSRP 461 session with the target endpoint. 463 * In this case the gateway interworks the received MSRP over TCP 464 or TLS associated "a=setup" attribute with the dcsa embedded 465 setup attribute of the generated MSRP over data channel 466 description. 468 7. IANA Considerations 470 7.1. Subprotocol Identifier MSRP 472 NOTE to RFC Editor: Please replace "XXXX" with the number of this 473 RFC. 475 This document adds the subprotocol identifier "MSRP" to the 476 "WebSocket Subprotocol Name Registry" as follows: 478 +--------------------------+---------+ 479 | Subprotocol Identifier: | MSRP | 480 | Subprotocol Common Name: | MSRP | 481 | Subprotocol Definition: | RFCXXXX | 482 | Reference: | RFCXXXX | 483 +--------------------------+---------+ 485 7.2. setup Attribute 487 NOTE to RFC Editor: Please replace "XXXX" with the number of this 488 RFC. 490 This document modifies the usage of the SDP setup attribute, if this 491 attribute is embedded in a dcsa attribute and associated with an MSRP 492 session over a data channel. The modified usage is described in 493 Section 5.1.1.3. 495 Usage level "dcsa(MSRP)" should be added to the IANA registration of 496 the SDP setup attribute as follows: 498 +-----------------------+-------------------------------------------+ 499 | Contact name: | MMUSIC Chairs | 500 | Contact email: | mmusic-chairs@ietf.org | 501 | Attribute name: | setup | 502 | Usage level: | dcsa(MSRP) | 503 | Purpose: | Negotiate the active role of an MSRP | 504 | | session over a data channel as per | 505 | | Section 5.1.1.3 | 506 | Reference: | RFCXXXX | 507 +-----------------------+-------------------------------------------+ 509 8. Security Considerations 511 MSRP traffic over data channels is secured, including 512 confidentiality, integrity and source authentication, as specified by 513 [I-D.ietf-rtcweb-data-channel] 514 Note that discussion in [RFC4975] on MSRP message attribution to 515 remote identities applies to data channel transport. 517 9. Acknowledgments 519 The authors wish to acknowledge the borrowing of ideas from another 520 internet draft by Peter Dunkley and Gavin Llewellyn, and to thank 521 Flemming Andreasen, Christian Groves, Christer Holmberg, Paul 522 Kyzivat, Jonathan Lennox, Uwe Rauschenbach, Albrecht Schwarz and 523 Keith Drage for their invaluable comments. 525 10. CHANGE LOG 527 10.1. Changes against 'draft-ietf-mmusic-msrp-usage-data-channel-07' 529 o Move security considerations after IANA considerations, following 530 RFC7322 suggested order. 532 o Update references to use xml.resource.org citation database. 534 o Reformat of the section discussing setup parameter 536 o Align examples with latest [I-D.ietf-mmusic-data-channel-sdpneg] 537 draft. 539 o Edit section 6 for clarity. 541 o Security requirements. 543 o Clarify comment on unrecognized transports and session opening. 545 o Update year, add editor. 547 10.2. Changes against 'draft-ietf-mmusic-msrp-usage-data-channel-06' 549 o Modification of Keith's address information. 551 10.3. Changes against 'draft-ietf-mmusic-msrp-usage-data-channel-05' 553 o Modification of Juergen's address information. 555 10.4. Changes against 'draft-ietf-mmusic-msrp-usage-data-channel-04' 557 o Addition of [I-D.ietf-mmusic-rfc4566bis] to list of normative 558 references. 560 o Addition of Section 7.2 as per section 8.2.4 of 561 [I-D.ietf-mmusic-rfc4566bis]. 563 10.5. Changes against 'draft-ietf-mmusic-msrp-usage-data-channel-03' 565 o Addition of IANA registration related Section 7.1. 567 10.6. Changes against 'draft-ietf-mmusic-msrp-usage-data-channel-02' 569 o Addition of "a=setup:actpass", "a=connection:new", 570 "a=fingerprint:..." and "a=dcsa:x setup=active" SDP attributes to 571 the SDP example in Section 5.1.1.4. 573 o Addition of [RFC4145] and [I-D.ietf-mmusic-sctp-sdp] to list of 574 normative references. 576 o Addition of new Section 5.1.1.3 describing how the active MSRP 577 session endpoint role is negotiated. 579 o Extension of first paragraph of Section 5.1.2 with new first 580 sentence "Section 5.1.1.3 describes how the active MSRP session 581 endpoint role is negotiated.". 583 o First sentence of second paragraph in Section 5.1.2 was "As soon 584 as this data channel is opened, the MSRP session is actually 585 opened by the active MSRP endpoint which sends an MSRP SEND 586 message (empty or not) to the other MSRP endpoint." Replacement 587 of this sentence with "As soon as this data channel is opened, the 588 MSRP session is actually opened by the active MSRP endpoint. In 589 order to do this the active MSRP endpoint sends an MSRP SEND 590 message (empty or not) to the other MSRP endpoint." 592 o Addition of setup attribute specific behavior descriptions of data 593 channel to TCP or TLS interworking gateways in Section 6. 595 10.7. Changes against 'draft-ietf-mmusic-msrp-usage-data-channel-01' 597 o In the abstract replacement of the first sentence "This document 598 specifies how the Message Session Relay Protocol (MSRP) can be 599 instantiated as a data channel sub-protocol, using the SDP offer/ 600 answer exchange-based external negotiation defined in 601 [I-D.ietf-mmusic-data-channel-sdpneg]" with "This document 602 specifies how the Message Session Relay Protocol (MSRP) can be 603 instantiated as a data channel sub-protocol, using the SDP offer/ 604 answer exchange-based generic data channel negotiation framework" 605 in order to remove the reference from the abstract text. 607 o Addition of following sentence to the second paragraph in 608 Section 1: "The MSRP protocol negotiation defined in this document 609 is based on the generic SDP offer/answer exchange based data 610 channel negotiation as specified in 611 [I-D.ietf-mmusic-data-channel-sdpneg]". 613 o In Section 4.1 replacement of sub-protocol identifier "msrp" with 614 "MSRP" in order to make this consistent with the formal 615 specification in Section 5.1.1.1. 617 o Throughout the text replacement of "shall" with "SHALL" etc where 618 appropriate as per [RFC2119]. 620 o In Section 5.1.1.1 replacement of sentence 'The max-retr, max-time 621 and ordered parameters shall not be used.' with 'Ordered and 622 reliable data channels MUST always be used, such that the "max- 623 retr" and "max-time" parameters SHALL NOT be used. If the 624 "ordered" parameter is used, then its value MUST be equal to 625 "true".'. 627 o In Section 5.1.1.1 removal of "(on default SCTP port 5000)" from 628 the sentence preceding the example "a=dcmap" attribute line. 630 o In Section 5.1.1.2 first paragraph was "The SDP offer shall also 631 include a dcsa attribute line (defined in 632 [I-D.ietf-mmusic-data-channel-sdpneg]) within the media 633 description for the SCTP association for each MSRP-specific SDP 634 attribute to be negotiated for each MSRP data channel being 635 negotiated.". Replacement of this paragraph with "The SDP offer 636 SHALL also include within the media description for the SCTP 637 association a dcsa attribute line (defined in 638 [I-D.ietf-mmusic-data-channel-sdpneg]) for each MSRP-specific SDP 639 attribute to be negotiated for each MSRP data channel being 640 negotiated.". 642 o Appended following sentence at the end of the first paragraph of 643 Section 5.1.3: "Therefore all sent MSRP chunks MUST have lengths 644 of less than or equal to the value of the peer's "a=max-message- 645 size" attribute, which is associated with the data channel's SCTP 646 association.". 648 o Addition of the previously missing colon to the "a=sctp-port" 649 attribute line in Section 5.1.1.4. 651 o In Section 5.1.5 replacement of the first paragraph "Closing of an 652 MSRP session is done using the generic data channel closing 653 procedure defined in [I-D.ietf-mmusic-data-channel-sdpneg]." with 654 'The closure of an MSRP session MUST be signaled via an SDP offer/ 655 answer exchange which removes the "a=dcmap:" and "a=dcsa:" 656 attribute lines associated with the MSRP session from the 657 associated DTLS/SCTP based media description. This results in the 658 associated data channel being closed as well as per 659 [I-D.ietf-mmusic-data-channel-sdpneg], where the actual data 660 channel closure procedure is typically initiated by the SDP 661 answerer right after having accepted the SDP offer.'. 663 10.8. Changes against 'draft-ietf-mmusic-msrp-usage-data-channel-00' 665 o Additional reference to [I-D.ietf-mmusic-data-channel-sdpneg] in 666 list of normative references. 668 o Replacement of previous document title "MSRP over SCTP/DTLS data 669 channels" with "MSRP over Data Channels" in order to align with 670 the terminology used in [I-D.ietf-mmusic-data-channel-sdpneg]. 672 o In Section 3 "WebRTC data channel" was defined as "A bidirectional 673 channel consisting of paired SCTP outbound and inbound streams." 674 Replacement of this definition with "Data channel: A WebRTC data 675 channel as specified in [I-D.ietf-rtcweb-data-channel]", and 676 consistent usage of either "data channel" or "MSRP data channel" 677 in the remainder of the document." 679 o In the introduction replacement of references to 680 [I-D.ietf-rtcweb-data-protocol] with a reference to 681 [I-D.ietf-rtcweb-data-channel]. 683 o Consistent usage of '"m" line' in whole document as per [RFC4566]. 685 o In the gateway configuration section (Section 6) replacement of 686 the first sentence "This section describes the network 687 configuration where one endpoint runs MSRP over a WebRTC SCTP/DTLS 688 connection, the other MSRP endpoint runs MSRP over one or more 689 TLS/TCP connections, and the two endpoints interwork via an MSRP 690 gateway" with "This section describes the network configuration 691 where one MSRP endpoint uses data channels as MSRP transport, the 692 other MSRP endpoint uses TLS/TCP connections as MSRP transport, 693 and the two MSRP endpoints interwork via an MSRP gateway". 695 10.9. Changes against 'draft-ejzak-mmusic-msrp-usage-data-channel-01' 697 o Removed empty spaces after ";" in the examples' "a=dcmap" 698 attribute lines. 700 o In all examples, the "m" line proto value "DTLS/SCTP" was replaced 701 with "UDP/DTLS/SCTP" and the "a=fmtp" attribute lines were 702 replaced with "a=max-message-size" attribute lines, as per draft- 703 ietf-mmusic-sctp-sdp-12. 705 10.10. Changes against '-00' 707 o Transport parameter change for MSRP to allow MSRP RFC transports. 709 o Clarification on SDP offer/answer and removing duplicated 710 procedures and refer them to draft-ejzak-mmusic-data-channel- 711 sdpneg-02. 713 11. Normative References 715 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 716 Requirement Levels", BCP 14, RFC 2119, 717 DOI 10.17487/RFC2119, March 1997, 718 . 720 [I-D.ietf-rtcweb-jsep] 721 Uberti, J., Jennings, C., and E. Rescorla, "JavaScript 722 Session Establishment Protocol", draft-ietf-rtcweb-jsep-24 723 (work in progress), October 2017. 725 [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model 726 with Session Description Protocol (SDP)", RFC 3264, 727 DOI 10.17487/RFC3264, June 2002, 728 . 730 [I-D.ietf-rtcweb-data-protocol] 731 Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data Channel 732 Establishment Protocol", draft-ietf-rtcweb-data- 733 protocol-09 (work in progress), January 2015. 735 [I-D.ietf-rtcweb-data-channel] 736 Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data 737 Channels", draft-ietf-rtcweb-data-channel-13 (work in 738 progress), January 2015. 740 [I-D.ietf-mmusic-data-channel-sdpneg] 741 Drage, K., Makaraju, M., Stoetzer-Bradler, J., Ejzak, R., 742 Marcon, J., and R. Even, "SDP-based Data Channel 743 Negotiation", draft-ietf-mmusic-data-channel-sdpneg-16 744 (work in progress), December 2017. 746 [I-D.ietf-mmusic-sctp-sdp] 747 Holmberg, C., Shpount, R., Loreto, S., and G. Camarillo, 748 "Session Description Protocol (SDP) Offer/Answer 749 Procedures For Stream Control Transmission Protocol (SCTP) 750 over Datagram Transport Layer Security (DTLS) Transport.", 751 draft-ietf-mmusic-sctp-sdp-26 (work in progress), April 752 2017. 754 [RFC4145] Yon, D. and G. Camarillo, "TCP-Based Media Transport in 755 the Session Description Protocol (SDP)", RFC 4145, 756 DOI 10.17487/RFC4145, September 2005, 757 . 759 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 760 Description Protocol", RFC 4566, DOI 10.17487/RFC4566, 761 July 2006, . 763 [I-D.ietf-mmusic-rfc4566bis] 764 Handley, M., Jacobson, V., Perkins, C., and A. Begen, 765 "SDP: Session Description Protocol", draft-ietf-mmusic- 766 rfc4566bis-17 (work in progress), June 2016. 768 [RFC4975] Campbell, B., Ed., Mahy, R., Ed., and C. Jennings, Ed., 769 "The Message Session Relay Protocol (MSRP)", RFC 4975, 770 DOI 10.17487/RFC4975, September 2007, 771 . 773 [RFC5547] Garcia-Martin, M., Isomaki, M., Camarillo, G., Loreto, S., 774 and P. Kyzivat, "A Session Description Protocol (SDP) 775 Offer/Answer Mechanism to Enable File Transfer", RFC 5547, 776 DOI 10.17487/RFC5547, May 2009, 777 . 779 [RFC6135] Holmberg, C. and S. Blau, "An Alternative Connection Model 780 for the Message Session Relay Protocol (MSRP)", RFC 6135, 781 DOI 10.17487/RFC6135, February 2011, 782 . 784 [RFC6714] Holmberg, C., Blau, S., and E. Burger, "Connection 785 Establishment for Media Anchoring (CEMA) for the Message 786 Session Relay Protocol (MSRP)", RFC 6714, 787 DOI 10.17487/RFC6714, August 2012, 788 . 790 Authors' Addresses 792 Keith Drage (editor) 793 Unaffiliated 795 Email: drageke@ntlworld.com 796 Maridi R. Makaraju (Raju) 797 Nokia 798 2000 Lucent Lane 799 Naperville, Illinois 800 US 802 Email: Raju.Makaraju@nokia.com 804 Juergen Stoetzer-Bradler 805 Unaffiliated 807 Email: Juergen.S-B.ietf@email.de 809 Richard Ejzak 810 Unaffiliated 812 Email: richard.ejzak@gmail.com 814 Jerome Marcon 815 Unaffiliated 817 Jose M. Recio (editor) 818 CoSMo Software 820 Email: jose@ch3m4.com