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Barnes 3 Internet-Draft iconectiv 4 Intended status: Informational October 22, 2018 5 Expires: April 25, 2019 7 Session Initiation Protocol (SIP) Call Flow Examples with PASSporT 8 Diversion and History-Info 9 draft-barnes-stir-passport-div-hi-callflows-02 11 Abstract 13 This document focuses on use cases and call flows which include the 14 History-Info header field and a SIP Identity header field with a 15 PASSport with a "div" claim in cases of retargeting. These use cases 16 are derived from those provided in the SIP History-Info call flows 17 document. The objective is to describe the optimal way to correlate 18 the History-Info header fields with a PASSporT with diversion 19 information to increase the level of confidence in the History-Info 20 header field by the terminating entity making use of the information. 22 Status of This Memo 24 This Internet-Draft is submitted in full conformance with the 25 provisions of BCP 78 and BCP 79. 27 Internet-Drafts are working documents of the Internet Engineering 28 Task Force (IETF). Note that other groups may also distribute 29 working documents as Internet-Drafts. The list of current Internet- 30 Drafts is at https://datatracker.ietf.org/drafts/current/. 32 Internet-Drafts are draft documents valid for a maximum of six months 33 and may be updated, replaced, or obsoleted by other documents at any 34 time. It is inappropriate to use Internet-Drafts as reference 35 material or to cite them other than as "work in progress." 37 This Internet-Draft will expire on April 25, 2019. 39 Copyright Notice 41 Copyright (c) 2018 IETF Trust and the persons identified as the 42 document authors. All rights reserved. 44 This document is subject to BCP 78 and the IETF Trust's Legal 45 Provisions Relating to IETF Documents 46 (https://trustee.ietf.org/license-info) in effect on the date of 47 publication of this document. Please review these documents 48 carefully, as they describe your rights and restrictions with respect 49 to this document. Code Components extracted from this document must 50 include Simplified BSD License text as described in Section 4.e of 51 the Trust Legal Provisions and are provided without warranty as 52 described in the Simplified BSD License. 54 Table of Contents 56 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 2 57 2. Conventions and Terminology . . . . . . . . . . . . . . . . . 2 58 3. Detailed call flows . . . . . . . . . . . . . . . . . . . . . 3 59 3.1. PBX Voicemail Example . . . . . . . . . . . . . . . . . . 3 60 3.2. Consumer Voicemail Example . . . . . . . . . . . . . . . 10 61 4. Security Considerations . . . . . . . . . . . . . . . . . . . 15 62 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 63 5.1. Acknowledgements . . . . . . . . . . . . . . . . . . . . 16 64 6. Informative References . . . . . . . . . . . . . . . . . . . 16 65 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 17 67 1. Overview 69 Many services that use SIP require the ability to determine why and 70 how the call arrived at a specific application. The use cases 71 provided in [RFC7131] illustrate the use of the History-Info header 72 field [RFC7044] for example applications and common scenarios. The 73 document [I-D.ietf-stir-passport-divert] extends the PASSporT, 74 defined in [RFC8225] to cryptographically-sign the calling party 75 information, to include an indication that a call has been diverted 76 from its original destination to a new one. This document discusses 77 the applicability and use of this PASSporT extension for diverted 78 calls in the context of scenarios for which use of the History-Info 79 header field is essential for processing by the terminating entity. 80 Descriptions of the example use cases, call flow diagrams and 81 messaging details including both History-Info header field and a SIP 82 Identity header field with a PASSport capturing the retargeted 83 identity are provided. 85 2. Conventions and Terminology 87 The term "retarget" is used as defined in [RFC7044]. The term 88 "divert" refers to a specific type of retargeting and is used per the 89 context in [I-D.ietf-stir-passport-divert]. The terms "location 90 service", "redirect" and "address-of-record (AOR)" are used 91 consistent with the terminology in [RFC3261]. 93 3. Detailed call flows 95 The scenarios in this section provide sample use cases for the 96 History-Info header along with a PASSporT(s) containing the 97 retargeted identity for informational purposes only. They are not 98 intended to be normative. In many cases, only the relevant messaging 99 details are included in the body of the call flow. 101 The current objective of these call flows is for discussion purposes 102 to determine if the current set of information proposed to be 103 captured in the PASSporT in cases of retargeting is sufficient. It 104 is anticipated that the cases where a "div" PASSporT is added would 105 be cases where the a History-Info header field has been added and 106 tagged "mp", indicating the hi-targeted-to-URI represents a user 107 other than the target user associated with the Request-URI in the 108 incoming request that was retargeted. 110 Given that the History-Info header field captures a full set of 111 information as to why a request is retargeted, it might seem 112 reasonable to just add the PASSporT to the History-Info header field 113 as opposed to adding a new Identity header field in cases of 114 retargeting. However, in that case, that would then require the 115 terminating user to search the History-Info entries to determine if 116 the request was "diverted" and whether the identity at the point of 117 retargeting was authenticated. An alternative is that rather than 118 just adding the retargeted destination, the complete History-Info 119 header field could be added to the PASSporT. This could increase the 120 confidence at the terminating user that all the information is valid. 121 At a minimum the "index" should be included as it's possible to have 122 entries containing the same target. For example, a proxy forwards a 123 request in the case of loose routing and then the request is 124 retargeted at the next hop. Also, there are cases whereby the first 125 entry with a specific tag is most relevant. Thus, being able to at 126 least correlate the contents of that entry with a PASSporT with 127 diverted information could be quite useful. 129 Editor's note: currently, there are only two examples - consumer and 130 PBX voicemail. It's probably quite useful to document more of the 131 flows once there is agreement on the best approach for correlating 132 the information. 134 3.1. PBX Voicemail Example 136 A typical use case for voicemail is one whereby the original called 137 party is not reachable and the call arrives at a voicemail system. 138 In some cases multiple alternate destinations may be tried without 139 success. The voicemail system typically requires the original called 140 party information to determine the appropriate mailbox so an 141 appropriate greeting can be provided and the appropriate party 142 notified of the message. 144 In this example, Alice calls Bob, whose SIP client is forwarded to 145 Carol. Carol does not answer the call, thus it is forwarded to a VM 146 (voicemail) server (VMS). In order to determine the appropriate 147 mailbox to use for this call, the VMS needs the original target for 148 the request. The original target is determined by finding the first 149 hi-entry tagged with "rc" or "mp" and using the hi-entry referenced 150 by the index of "rc" or "mp" header field parameter as the target for 151 determining the appropriate mailbox. This first hi-entry is used to 152 populate the "target" URI parameter as defined in [RFC4458]. 154 If the SIP Identity header field with "div" claims has been added by 155 the entities retargeting, it can be ascertained that the call should 156 be forwarded to Bob's voicemail prior to forwarding the call to 157 voicemail. The value of the "tn" in the "div" field of the claim 158 should match the hi-targeted-to URI in the hi-entry with the hi-index 159 matching the "hi" value in the "div" claim. 161 The reason associated with the first hi-entry tagged with "rc" or 162 "mp" (i.e., 302) could be used to provide a customized voicemail 163 greeting and is used to populate the "cause" URI parameter as defined 164 in [RFC4458]. Note that some VMSs may also (or instead) use the 165 information available in the History-Info headers for custom handling 166 of the VM based on how and why the call arrived at the VMS. 168 Furthermore it is the proxy forwarding the call to VMS that 169 determines the target of the voicemail, it is the proxy that sets the 170 target of voicemail which is also the entity that utilizes [RFC7044] 171 to find the target which is usually based on local policy installed 172 by the user or an administrator. 174 Alice example.com Bob Carol VM 175 12155551211 12155551212 12155551213 177 | INVITE F1 | | | | 178 |------------->| | | | 179 | | INVITE F2 | | | 180 | |------------->| | | 181 | | | | | 182 | 100 Trying | | | | 183 |<-------------| 302 Moved Temporarily F3 | | 184 | |<-------------| | | 185 | | | | | 186 | | ACK | | | 187 | |------------->| | | 188 | | | | | 189 | | INVITE F4 | | | 190 | |--------------------------->| | 191 | | | | | 192 | | 180 Ringing F5 | | 193 | |<---------------------------| | 194 | | | | | 195 | 180 Ringing | | | | 196 |<-------------| | | | 197 | | | | | 198 | | (timeout) | | 199 | | | | | 200 | | INVITE F6 | | | 201 | |-------------------------------------->| 202 | | | | | 203 | | 200 OK F7 | 204 | |<--------------------------------------| 205 | 200 OK | | | | 206 |<-------------| | | | 207 | | | | | 208 | ACK | 209 |----------------------------------------------------->| 211 F1 INVITE Alice -> Example.com 213 INVITE sip:bob@example.com SIP/2.0 214 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 215 Max-Forward: 70 216 From: Alice ;tag=kkaz- 217 To: Bob 218 Supported: histinfo 219 Call-Id: 12345600@example.com 220 CSeq: 1 INVITE 221 History-Info: ;index=1 222 Contact: Alice 223 Content-Length: 225 [SDP Not Shown] 227 F2 INVITE Example.com -> Bob 229 INVITE sip:12155551212@example.com;user=phone SIP/2.0 230 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK12s4 231 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 232 Max-Forward: 69 233 From: Alice ;tag=kkaz- 234 To: Bob ;tag=1928301774> 235 Supported: histinfo 236 Call-Id: 12345600@example.com 237 CSeq: 1 INVITE 238 History-Info: ;index=1 239 History-Info: ;\ 240 index=1.1;rc=1 241 Identity: eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1I \ 242 joiaHR0cHM6Ly9jZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9.eyJ \ 243 kZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhdC \ 244 I6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0.r \ 245 q3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYs \ 246 ojNCpTzO3QfPOlckGaS6hEck7w;info=;alg=ES256 248 Contact: Alice 249 Content-Type: application/sdp 250 Content-Length: 252 [SDP Not Shown] 254 F3 302 Moved Temporarily Bob -> Example.com 256 SIP/2.0 302 Moved Temporarily 257 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK12s4;\ 258 received=192.0.2.101 259 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 260 From: Alice ;tag=kkaz- 261 To: Bob ;tag=2g22d-lnf 262 Supported: histinfo 263 Call-Id: 12345600@example.com 264 CSeq: 1 INVITE 265 History-Info: ;index=1 266 History-Info: ;\ 267 index=1.1;rc=1 268 Identity: eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1I \ 269 joiaHR0cHM6Ly9jZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9.eyJ \ 270 kZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhdC \ 271 I6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0.r \ 272 q3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYs \ 273 ojNCpTzO3QfPOlckGaS6hEck7w;info=;alg=ES256 275 Contact: ;mp=1 276 Content-Type: application/sdp 277 Content-Length: 279 [SDP Not Shown] 280 F4 INVITE Example.com -> Carol 282 INVITE sip:12155551213@example.com;user=phone SIP/2.0 283 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK4522 284 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 285 Max-Forward: 69 286 From: Alice ;tag=kkaz- 287 To: Bob 288 Supported: histinfo 289 Call-Id: 12345600@example.com 290 CSeq: 1 INVITE 291 History-Info: ;index=1 292 History-Info: ;\ 294 index=1.1;rc=1 295 History-Info: ;index=1.2;mp=1 296 History-Info: ;\ 297 index=1.2.1;rc=1.2 298 Identity: eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1I \ 299 joiaHR0cHM6Ly9jZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9.eyJ \ 300 kZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhdC \ 301 I6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0.r \ 302 q3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYs \ 303 ojNCpTzO3QfPOlckGaS6hEck7w;info=;alg=ES256 305 Identity:..sv5CTo05KqpSmtHt3dcEiO/1CWTSZtnG3iV+1nmurLXV/HmtyNS7L 306 eU7d7OV8HweTTDobV3itTmgPwCFjaEmMyEI3d7SyN21yNDo2ER/Ovgtw0Lu5csIp 307 pPqOg1uXndzHbG7mR6Rl9BnUhHufVRbp51Mn3w0gfUs=; \ 308 info=;alg=ES256; 309 ppt=div 310 Contact: Alice 311 Content-Type: application/sdp 312 Content-Length: 314 [SDP Not Shown] 316 F5 180 Ringing Carol -> Example.com 318 SIP/2.0 180 Ringing 319 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK4522;\ 320 received=192.0.2.101 321 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 322 From: Alice ;tag=kkaz- 323 To: Bob ;tag=setss3x 324 Supported: histinfo 325 Call-Id: 12345600@example.com 326 CSeq: 1 INVITE 327 History-Info: ;index=1 328 History-Info: ;\ 330 index=1.1;rc=1 331 History-Info: ;index=1.2;mp=1 332 History-Info: ;index=1.2.1;rc=1.2 334 Contact: Carol 335 Content-Type: application/sdp 336 Content-Length: 338 [SDP Not Shown] 340 F6 INVITE Example.com -> VM 342 INVITE sip:vm@192.0.2.6;target=sip:bob%40example.com;cause=480\ 343 SIP/2.0 344 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK4523 345 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 346 Max-Forward: 69 347 From: Alice ;tag=kkaz- 348 To: Bob 349 Supported: histinfo 350 Call-Id: 12345600@example.com 351 CSeq: 1 INVITE 352 History-Info: ;index=1 353 History-Info: ;\ 355 index=1.1;rc=1 356 History-Info: ;\ 358 index=1.2;mp=1 359 History-Info: ;\ 361 index=1.2.1;rc=1.2 362 History-Info: ;\ 364 index=1.3;mp=1 365 History-Info: ;\ 367 index=1.3.1;rc=1.3 368 Identity: eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1I \ 369 joiaHR0cHM6Ly9jZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9.eyJ \ 370 kZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhdC \ 371 I6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0.r \ 372 q3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYs \ 373 ojNCpTzO3QfPOlckGaS6hEck7w;info=;alg=ES256 375 Identity: ..sv5CTo05KqpSmtHt3dcEiO/1CWTSZtnG3iV+1nmurLXV/HmtyNS7L 376 eU7d7OV8HweTTDobV3itTmgPwCFjaEmMyEI3d7SyN21yNDo2ER/Ovgtw0Lu5csIp 377 pPqOg1uXndzHbG7mR6Rl9BnUhHufVRbp51Mn3w0gfUs=; \ 378 info=;alg=ES256;ppt=div 379 Identity: ... L2V4YW1wbGUuY2VydCJ9eyJhdHRlc3QiOiJBIiwiZGVzdCI6 \ 380 eyJ0biI6IisxMjE1NTU1MTIxMyJ9LCJpYXQiOiIxNDcxMzc1NDE4Iiwib3JpZyI \ 381 6eyJ0biI64oCdKzEyMTU1 NTUxMjEyIn0sIm9yaWdpZCI6IjEyM2U0NTY3LWU4O \ 382 ;info =;alg=ES256; ppt=div 383 Contact: Alice 384 Content-Type: application/sdp 385 Content-Length: 387 [SDP Not Shown] 389 F7 200 OK VM -> Example.com 391 SIP/2.0 200 OK 392 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK4523;\ 393 received=192.0.2.101 394 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 395 From: Alice ;tag=kkaz- 396 To: Bob ;tag=3dweggs 397 Supported: histinfo 398 Call-Id: 12345600@example.com 399 CSeq: 1 INVITE 400 History-Info: ;index=1 401 History-Info: ;\ 403 index=1.1;rc=1 404 History-Info: ;index=1.2;mp=1 406 History-Info: ;index=1.2.1;rc=1.2 409 History-Info: ;\ 411 index=1.3;mp=1 412 History-Info: ;\ 414 index=1.3.1;rc=1.3 415 Contact: 416 Content-Type: application/sdp 417 Content-Length: 419 [SDP Not Shown] 421 Figure 1: Enterprise Voicemail Example 423 The VMS can look at the last hi-entry and finds the target of the 424 mailbox by looking at the URI entry in the "target" URI parameter in 425 the hi-entry. 427 3.2. Consumer Voicemail Example 429 In the case of a consumer, when the call is retargeted, it is usually 430 to another administrative domain. The voicemail system in these 431 environment typically requires the last called party information to 432 determine the appropriate mailbox so an appropriate greeting can be 433 provided and the appropriate party notified of the message. 435 In this example, Alice calls Bob but Bob has temporarily forwarded 436 his phone to his wife Carol. Carol does not answer the call, thus it 437 is forwarded to a VM (voicemail) server (VMS). In order to determine 438 the appropriate mailbox to use for this call, the VMS needs the 439 appropriate target for the request. The last target is determined by 440 finding the hi-entry referenced by the index of last hi-entry tagged 441 with "mp" for determining the appropriate mailbox. 443 If the SIP Identity header field with "div" claims has been added by 444 the entities retargeting, it can be ascertained that the call should 445 be forwarded to Carol's voicemail prior to forwarding the call to 446 voicemail. The value of the "tn" in the "div" field of the claim 447 should match the hi-targeted-to URI in the hi-entry with the hi-index 448 matching the "hi" value in the "div" field. 450 This hi-entry is used to populate the "target" URI parameter as 451 defined in [RFC4458]. Note that some VMSs may also (or instead) use 452 the information available in the History-Info headers for custom 453 handling of the VM in terms of how and why the called arrived at the 454 VMS. 456 Alice example.com Bob Carol VM 457 12155551211 12155551212 12155551213 459 | INVITE F1 | | | | 460 |------------->| | | | 461 | | INVITE F2 | | | 462 | |------------->| | | 463 | | | | | 464 | 100 Trying | | | | 465 |<-------------| 302 Moved Temporarily F3 | | 466 | |<-------------| | | 467 | | | | | 468 | | ACK | | | 469 | |------------->| | | 470 | | | | | 471 | | INVITE F4 | | | 472 | |--------------------------->| | 473 | | | | | 474 | | 180 Ringing F5 | | 475 | |<---------------------------| | 476 | | | | | 477 | 180 Ringing | | | | 478 |<-------------| | | | 479 | | | | | 480 | | (timeout) | | 481 | | | | | 482 | | INVITE F6 | | | 483 | |-------------------------------------->| 484 | | | | | 485 | | 200 OK F7 | 486 | |<--------------------------------------| 487 | 200 OK | | | | 488 |<-------------| | | | 489 | | | | | 490 | ACK | 491 |----------------------------------------------------->| 493 F1 INVITE Alice -> Example.com 495 INVITE sip:12155551212@example.com;user=phone SIP/2.0 496 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 497 Max-Forward: 70 498 From: Alice ;tag=kkaz- 499 To: Bob 500 Supported: histinfo 501 Call-Id: 12345600@example.com 502 CSeq: 1 INVITE 503 History-Info: ;index=1 504 Contact: Alice 505 Content-Length: 507 [SDP Not Shown] 509 F2 INVITE Example.com -> Bob 511 INVITE sip:12155551212@192.0.2.5;user=phone SIP/2.0 512 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK12s4 513 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 514 Max-Forward: 69 515 From: Alice ;tag=kkaz- 516 To: Bob 517 Supported: histinfo 518 Call-Id: 12345600@example.com 519 CSeq: 1 INVITE 520 History-Info: ;index=1 521 History-Info: ;index=1.1;rc=1 522 Identity: eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1I \ 523 joiaHR0cHM6Ly9jZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9.eyJ \ 524 kZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhdC \ 525 I6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0.r \ 526 q3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYs \ 527 ojNCpTzO3QfPOlckGaS6hEck7w;info=;alg=ES256 529 Contact: Alice 530 Content-Type: application/sdp 531 Content-Length: 533 [SDP Not Shown] 535 F3 302 Moved Temporarily Bob -> Example.com 537 SIP/2.0 302 Moved Temporarily 538 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK12s4;\ 539 received=192.0.2.101 540 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 541 From: Alice ;tag=kkaz- 542 To: Bob ;tag=2241s3s-t 543 Supported: histinfo 544 Call-Id: 12345600@example.com 545 CSeq: 1 INVITE 546 History-Info: ;index=1 547 History-Info: ;index=1.1;rc=1 548 Contact: ;mp=1 549 Content-Type: application/sdp 550 Content-Length: 552 [SDP Not Shown] 554 F4 INVITE Example.com -> Carol 556 INVITE sip:12155551213@example.com;user=phone SIP/2.0 557 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK24s5 558 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 559 Max-Forward: 69 560 From: Alice ;tag=kkaz- 561 To: Carol 562 Supported: histinfo 563 Call-Id: 12345600@example.com 564 CSeq: 1 INVITE 565 History-Info: ;index=1 566 History-Info: \ 569 ;index=1.1;rc=1 570 History-Info: ;\ 571 index=1.2;mp=1 572 History-Info: ;index=1.2.1;rc=1.2 573 Identity: eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1I \ 574 joiaHR0cHM6Ly9jZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9.eyJ \ 575 kZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhdC \ 576 I6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0.r \ 577 q3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYs \ 578 ojNCpTzO3QfPOlckGaS6hEck7w;info=;alg=ES256 580 Identity:..sv5CTo05KqpSmtHt3dcEiO/1CWTSZtnG3iV+1nmurLXV/HmtyNS \ 581 7Ltrg9dlxkWzoeU7d7OV8HweTTDobV3itTmgPwCFjaEmMyEI3d7SyN21yNDo2\ 582 EROvgtw0Lu5csIppPqOg1uXndzHbG7mR6Rl9BnUhHufVRbp51Mn3w0gfUs=; \ 583 info=;alg=ES256;ppt=div 584 Contact: Alice 585 Content-Type: application/sdp 586 Content-Length: 588 [SDP Not Shown] 590 F5 180 Ringing Carol -> Example.com 592 SIP/2.0 180 Ringing 593 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bK24s5;\ 594 received=192.0.2.101 595 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 596 From: Alice ;tag=kkaz- 597 To: Carol 598 Supported: histinfo 599 Call-Id: 12345600@example.com 600 CSeq: 1 INVITE 601 History-Info: ;index=1 602 History-Info: \ 605 ;index=1.1;rc=1 606 History-Info: ;\ 607 index=1.2;mp=1 608 History-Info: ;index=1.2.1;rc=1.2 609 Contact: 610 Content-Type: application/sdp 611 Content-Length: 613 [SDP Not Shown] 615 F6 INVITE Example.com -> VM 617 INVITE sip:vm@192.0.2.6;target=sip:sip:12155551213%40home.example.com\ 618 SIP/2.0 619 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bKbbg4 620 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 621 Max-Forward: 69 622 From: Alice ;tag=kkaz- 623 To: Carol 624 Supported: histinfo 625 Call-Id: 12345600@example.com 626 CSeq: 1 INVITE 627 History-Info: ;index=1 628 History-Info: \ 631 ;index=1.1;rc=1 632 History-Info: ;\ 633 index=1.2;mp=1 634 History-Info: ;index=1.2.1;rc=1.2 635 History-Info: ;index=1.2.2;mp=1.2 638 History-Info: ;index=1.2.2.1;rc=1.2.2 641 Identity: eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1I \ 642 joiaHR0cHM6Ly9jZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9.eyJ \ 643 kZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhdC \ 644 I6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0.r \ 645 q3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYs \ 646 ojNCpTzO3QfPOlckGaS6hEck7w;info=;alg=ES256 648 Identity:..sv5CTo05KqpSmtHt3dcEiO/1CWTSZtnG3iV+1nmurLXV/HmtyNS \ 649 7Ltrg9dlxkWzoeU7d7OV8HweTTDobV3itTmgPwCFjaEmMyEI3d7SyN21yNDo2\ 650 EROvgtw0Lu5csIppPqOg1uXndzHbG7mR6Rl9BnUhHufVRbp51Mn3w0gfUs=; \ 651 info=;alg=ES256;ppt=div 652 Contact: Alice 653 Content-Type: application/sdp 654 Content-Length: 656 [SDP Not Shown] 657 F7 200 OK VM -> Example.com 659 SIP/2.0 200 OK 660 Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bKbbg4 661 Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK42t2 662 From: Alice ;tag=kkaz- 663 To: Bob ;tag=3dweggs 664 Supported: histinfo 665 Call-Id: 12345600@example.com 666 CSeq: 1 INVITE 667 History-Info: ;index=1 668 History-Info: ;\ 671 index=1.1;rc=1 672 History-Info: ;\ 673 index=1.2;mp=1 674 History-Info: ;index=1.2.1;rc=1.2 675 History-Info: ;index=1.2.2;mp=1.2 678 History-Info: ;index=1.2.2.1;rc=1.2.2 682 Contact: 683 Content-Type: application/sdp 684 Content-Length: 686 [SDP Not Shown] 688 Figure 2: Consumer Voicemail Example 690 The VMS can look at the last hi-entry and find the target of the 691 mailbox by looking for the "target" URI parameter in the hi-entry and 692 the reason by the "cause" URI parameter in the same hi-entry. 694 4. Security Considerations 696 This document adds no new security considerations beyond those 697 specified in [RFC7044] for the History-Info header field and 698 [RFC8224] for the Identity header field. 700 5. IANA Considerations 702 This document has no IANA considerations. 704 5.1. Acknowledgements 706 6. Informative References 708 [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, 709 A., Peterson, J., Sparks, R., Handley, M., and E. 710 Schooler, "SIP: Session Initiation Protocol", RFC 3261, 711 DOI 10.17487/RFC3261, June 2002, 712 . 714 [RFC4458] Jennings, C., Audet, F., and J. Elwell, "Session 715 Initiation Protocol (SIP) URIs for Applications such as 716 Voicemail and Interactive Voice Response (IVR)", RFC 4458, 717 DOI 10.17487/RFC4458, April 2006, 718 . 720 [RFC7044] Barnes, M., Audet, F., Schubert, S., van Elburg, J., and 721 C. Holmberg, "An Extension to the Session Initiation 722 Protocol (SIP) for Request History Information", RFC 7044, 723 DOI 10.17487/RFC7044, February 2014, 724 . 726 [RFC7131] Barnes, M., Audet, F., Schubert, S., van Elburg, H., and 727 C. Holmberg, "Session Initiation Protocol (SIP) History- 728 Info Header Call Flow Examples", RFC 7131, 729 DOI 10.17487/RFC7131, March 2014, 730 . 732 [RFC8224] Peterson, J., Jennings, C., Rescorla, E., and C. Wendt, 733 "Authenticated Identity Management in the Session 734 Initiation Protocol (SIP)", RFC 8224, 735 DOI 10.17487/RFC8224, February 2018, 736 . 738 [RFC8225] Wendt, C. and J. Peterson, "PASSporT: Personal Assertion 739 Token", RFC 8225, DOI 10.17487/RFC8225, February 2018, 740 . 742 [I-D.ietf-stir-passport-divert] 743 Peterson, J., "PASSporT Extension for Diverted Calls", 744 draft-ietf-stir-passport-divert-04 (work in progress), 745 October 2018. 747 Author's Address 749 Mary Barnes 750 iconectiv 751 TX 752 US 754 Email: mary.ietf.barnes@gmail.com