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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reference: RFC 5226 (Obsoleted by RFC 8126) ** Downref: Normative reference to an Informational RFC: RFC 6443 == Outdated reference: draft-ietf-ecrit-car-crash has been published as RFC 8148 Summary: 3 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 ECRIT R. Gellens 3 Internet-Draft Core Technology Consulting 4 Intended status: Standards Track H. Tschofenig 5 Expires: April 15, 2017 Individual 6 October 12, 2016 8 Next-Generation Pan-European eCall 9 draft-ietf-ecrit-ecall-16.txt 11 Abstract 13 This document describes how to use IP-based emergency services 14 mechanisms to support the next generation of the pan European in- 15 vehicle emergency call service defined under the eSafety initiative 16 of the European Commission (generally referred to as "eCall"). eCall 17 is a standardized and mandated system for a special form of emergency 18 calls placed by vehicles, providing real-time communications and an 19 integrated set of related data. 21 This document also registers MIME Content Types and an Emergency Call 22 Additional Data Block for the eCall vehicle data and metadata/control 23 data, and an INFO package to enable carrying this data in INFO 24 requests. 26 Status of This Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at http://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on April 15, 2017. 43 Copyright Notice 45 Copyright (c) 2016 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (http://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 61 2. Document Scope . . . . . . . . . . . . . . . . . . . . . . . 4 62 3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5 63 4. eCall Requirements . . . . . . . . . . . . . . . . . . . . . 7 64 5. Vehicle Data . . . . . . . . . . . . . . . . . . . . . . . . 7 65 6. Data Transport . . . . . . . . . . . . . . . . . . . . . . . 7 66 7. Call Setup . . . . . . . . . . . . . . . . . . . . . . . . . 9 67 8. Test Calls . . . . . . . . . . . . . . . . . . . . . . . . . 10 68 9. The Metadata/Control Object . . . . . . . . . . . . . . . . . 11 69 9.1. The Control Block . . . . . . . . . . . . . . . . . . . . 12 70 9.1.1. The element . . . . . . . . . . . . . . . . . . 13 71 9.1.1.1. Attributes of the element . . . . . . . . . 13 72 9.1.1.2. Child Element of the element . . . . . . . 14 73 9.1.1.3. Ack Examples . . . . . . . . . . . . . . . . . . 15 74 9.1.2. The element . . . . . . . . . . . . . 15 75 9.1.2.1. Child Elements of the element . . 15 76 9.1.2.2. Capabilities Example . . . . . . . . . . . . . . 15 77 9.1.3. The element . . . . . . . . . . . . . . . . 16 78 9.1.3.1. Attributes of the element . . . . . . . 16 79 9.1.3.2. Request Example . . . . . . . . . . . . . . . . . 18 80 10. The emergencyCallData.eCall.MSD INFO package . . . . . . . . 18 81 10.1. Overall Description . . . . . . . . . . . . . . . . . . 18 82 10.2. Applicability . . . . . . . . . . . . . . . . . . . . . 19 83 10.3. Info Package Name . . . . . . . . . . . . . . . . . . . 19 84 10.4. Info Package Parameters . . . . . . . . . . . . . . . . 19 85 10.5. SIP Option-Tags . . . . . . . . . . . . . . . . . . . . 19 86 10.6. INFO Request Body Parts . . . . . . . . . . . . . . . . 20 87 10.7. Info Package Usage Restrictions . . . . . . . . . . . . 20 88 10.8. Rate of INFO Requests . . . . . . . . . . . . . . . . . 20 89 10.9. Info Package Security Considerations . . . . . . . . . . 20 90 10.10. Implementation Details . . . . . . . . . . . . . . . . . 20 91 10.11. Examples . . . . . . . . . . . . . . . . . . . . . . . . 21 92 11. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 21 93 12. Security Considerations . . . . . . . . . . . . . . . . . . . 26 94 13. Privacy Considerations . . . . . . . . . . . . . . . . . . . 27 95 14. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . 28 96 15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30 97 15.1. Service URN Registrations . . . . . . . . . . . . . . . 30 98 15.2. MIME Content-type Registration for 99 'application/emergencyCallData.eCall.MSD+per' . . . . . 31 100 15.3. MIME Content-type Registration for 101 'application/emergencyCallData.control+xml' . . . . . . 32 102 15.4. Registration of the 'eCall.MSD' entry in the Emergency 103 Call Additional Data Blocks registry . . . . . . . . . . 34 104 15.5. Registration of the 'control' entry in the Emergency 105 Call Additional Data Blocks registry . . . . . . . . . . 34 106 15.6. Registration of the emergencyCallData.eCall Info Package 34 107 15.7. URN Sub-Namespace Registration . . . . . . . . . . . . . 34 108 15.7.1. Registration for urn:ietf:params:xml:ns:eCall . . . 34 109 15.7.2. Registration for urn:ietf:params:xml:ns:control . . 35 110 15.8. Registry creation . . . . . . . . . . . . . . . . . . . 36 111 15.8.1. Action Registry . . . . . . . . . . . . . . . . . . 36 112 15.8.2. Reason Registry . . . . . . . . . . . . . . . . . . 37 113 16. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 38 114 17. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 38 115 18. Changes from Previous Versions . . . . . . . . . . . . . . . 38 116 18.1. Changes from draft-ietf-15 to draft-ietf-16 . . . . . . 38 117 18.2. Changes from draft-ietf-14 to draft-ietf-15 . . . . . . 38 118 18.3. Changes from draft-ietf-13 to draft-ietf-14 . . . . . . 38 119 18.4. Changes from draft-ietf-12 to draft-ietf-13 . . . . . . 38 120 18.5. Changes from draft-ietf-11 to draft-ietf-12 . . . . . . 39 121 18.6. Changes from draft-ietf-09 to draft-ietf-11 . . . . . . 39 122 18.7. Changes from draft-ietf-08 to draft-ietf-09 . . . . . . 39 123 18.8. Changes from draft-ietf-07 to draft-ietf-08 . . . . . . 39 124 18.9. Changes from draft-ietf-06 to draft-ietf-07 . . . . . . 40 125 18.10. Changes from draft-ietf-05 to draft-ietf-06 . . . . . . 40 126 18.11. Changes from draft-ietf-04 to draft-ietf-05 . . . . . . 40 127 18.12. Changes from draft-ietf-03 to draft-ietf-04 . . . . . . 40 128 18.13. Changes from draft-ietf-02 to draft-ietf-03 . . . . . . 40 129 18.14. Changes from draft-ietf-01 to draft-ietf-02 . . . . . . 41 130 18.15. Changes from draft-ietf-00 to draft-ietf-01 . . . . . . 41 131 18.16. Changes from draft-gellens-03 to draft-ietf-00 . . . . . 41 132 18.17. Changes from draft-gellens-02 to -03 . . . . . . . . . . 41 133 18.18. Changes from draft-gellens-01 to -02 . . . . . . . . . . 42 134 18.19. Changes from draft-gellens-00 to -01 . . . . . . . . . . 42 135 19. References . . . . . . . . . . . . . . . . . . . . . . . . . 42 136 19.1. Normative References . . . . . . . . . . . . . . . . . . 42 137 19.2. Informative references . . . . . . . . . . . . . . . . . 43 138 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 44 140 1. Terminology 142 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 143 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 144 document are to be interpreted as described in [RFC2119]. 146 This document re-uses terminology defined in Section 3 of [RFC5012]. 148 Additionally, we use the following abbreviations: 150 +--------+----------------------------------------+ 151 | Term | Expansion | 152 +--------+----------------------------------------+ 153 | 3GPP | 3rd Generation Partnership Project | 154 | | | 155 | CEN | European Committee for Standardization | 156 | | | 157 | EENA | European Emergency Number Association | 158 | | | 159 | ESInet | Emergency Services IP network | 160 | | | 161 | IMS | IP Multimedia Subsystem | 162 | | | 163 | IVS | In-Vehicle System | 164 | | | 165 | MNO | Mobile Network Operator | 166 | | | 167 | MSD | Minimum Set of Data | 168 | | | 169 | PSAP | Public Safety Answering Point | 170 +--------+----------------------------------------+ 172 2. Document Scope 174 This document is focused on the signaling, data exchange, and 175 protocol needs of next-generation eCall (NG-eCall, also referred to 176 as packet-switched eCall or all-IP eCall) within the SIP framework 177 for emergency calls, as described in [RFC6443] and [RFC6881]. eCall 178 itself is specified by 3GPP (3rd Generation Partnership Project) and 179 CEN (European Committee for Standardization) and these specifications 180 include far greater scope than is covered here. 182 The eCall service operates over cellular wireless communication, but 183 this document does not address cellular-specific details, nor client 184 domain selection (e.g., circuit-switched versus packet-switched). 185 All such aspects are the purview of their respective standards 186 bodies. The scope of this document is limited to eCall operating 187 within a SIP-based environment (e.g., 3GPP IMS Emergency Calling 188 [TS23.167]). 190 The technical contents of this document also provide a basis for 191 reuse and extension for related emergency call systems (which is why 192 there are extension points), but such reuse is a topic for other 193 documents. 195 Note that vehicles designed for multiple regions might need to 196 support eCall and other Advanced Automatic Crash Notification (AACN) 197 systems (such as described in [I-D.ietf-ecrit-car-crash]), but this 198 is out of scope of this document. 200 3. Introduction 202 Emergency calls made from vehicles (e.g., in the event of a crash) 203 assist in significantly reducing road deaths and injuries by allowing 204 emergency services to be aware of the incident, the state of the 205 vehicle, the location of the vehicle, and to have a voice channel 206 with the vehicle occupants. This enables a quick and appropriate 207 response. 209 The European Commission initiative of eCall was conceived in the late 210 1990s, and has evolved to a European Parliament decision requiring 211 the implementation of a compliant in-vehicle system (IVS) in new 212 vehicles and the deployment of eCall in the European Member States in 213 the very near future. Other regions are developing eCall-compatible 214 systems. 216 The pan-European eCall system provides a standardized and mandated 217 mechanism for emergency calls by vehicles. eCall establishes 218 procedures for such calls to be placed by in-vehicle systems, 219 recognized and processed by the mobile network, and routed to a 220 specialized PSAP where the vehicle data is available to assist the 221 call taker in assessing and responding to the situation. eCall 222 provides a standard set of vehicle, sensor (e.g., crash related), and 223 location data. 225 An eCall can be either user-initiated or automatically triggered. 226 Automatically triggered eCalls indicate a car crash or some other 227 serious incident. Manually triggered eCalls might be reports of 228 witnessed crashes or serious hazards. PSAPs might apply specific 229 operational handling to manual and automatic eCalls. 231 Legacy eCall is standardized (by 3GPP [SDO-3GPP] and CEN [CEN]) as a 232 3GPP circuit-switched call over GSM (2G) or UMTS (3G). Flags in the 233 call setup mark the call as an eCall, and further indicate if the 234 call was automatically or manually triggered. The call is routed to 235 an eCall-capable PSAP, a voice channel is established between the 236 vehicle and the PSAP, and an eCall in-band modem is used to carry a 237 defined set of vehicle, sensor (e.g., crash related), and location 238 data (the Minimum Set of Data or MSD) within the voice channel. The 239 same in-band mechanism is used for the PSAP to acknowledge successful 240 receipt of the MSD, and to request the vehicle to send a new MSD 241 (e.g., to check if the state of or location of the vehicle or its 242 occupants has changed). NG-eCall moves from circuit switched to all- 243 IP, and carries the vehicle data and eCall signaling as additional 244 data carried with the call. This document describes how IETF 245 mechanisms for IP-based emergency calls, including [RFC6443] and 246 [RFC7852] are used to provide the signaling and data exchange of the 247 next generation of pan-European eCall. 249 The European Telecommunications Standards Institute (ETSI) [SDO-ETSI] 250 has published a Technical Report titled "Mobile Standards Group 251 (MSG); eCall for VoIP" [MSG_TR] that presents findings and 252 recommendations regarding support for eCall in an all-IP environment. 253 The recommendations include the use of 3GPP IMS emergency calling 254 with additional elements identifying the call as an eCall and as 255 carrying eCall data and with mechanisms for carrying the data and 256 eCall signaling. 3GPP IMS emergency services support multimedia, 257 providing the ability to carry voice, text, and video. This 258 capability is referred to within 3GPP as Multimedia Emergency 259 Services (MMES). 261 A transition period will exist during which time the various entities 262 involved in initiating and handling an eCall might support next- 263 generation eCall, legacy eCall, or both. The issues of migration and 264 co-existence during the transition period are outside the scope of 265 this document. 267 This document indicates how to use IP-based emergency services 268 mechanisms to support next-generation eCall. 270 This document also registers MIME Content Types and an Emergency Call 271 Additional Data Block for the eCall vehicle data (MSD) and metadata/ 272 control data, and an INFO package to enable carrying this data in 273 INFO requests. 275 The MSD is carried in the MIME type 'application/ 276 emergencyCallData.eCall.MSD+per' and the metadata/control block is 277 carried in the MIME type 'application/emergencyCallData.control+xml' 278 (both of which are registered in Section 15) An INFO package is 279 defined (in Section 10) to enable these MIME types to be carried in 280 SIP INFO requests, per [RFC6086]. 282 4. eCall Requirements 284 eCall requirements are specified by CEN in [EN_16072] and by 3GPP in 285 [TS22.101] clauses 10.7 and A.27. Requirements specific to vehicle 286 data are contained in EN 15722 [msd]. 288 5. Vehicle Data 290 Pan-European eCall provides a standardized and mandated set of 291 vehicle related data, known as the Minimum Set of Data (MSD). The 292 European Committee for Standardization (CEN) has specified this data 293 in EN 15722 [msd], along with both ASN.1 and XML encodings. Both 294 circuit-switched eCall and this document use the ASN.1 PER encoding, 295 which is specified in Annex A of EN 15722 [msd] (the XML encoding 296 specified in Annex C is not used in this document). 298 This document registers the 'application/ 299 emergencyCallData.eCall.MSD+per' MIME Content-Type to enable the MSD 300 to be carried in SIP. As an ASN.1 PER encoded object, the data is 301 binary and transported using binary content transfer encoding within 302 SIP messages. This document also adds the 'eCall.MSD' entry to the 303 Emergency Call Additional Data Blocks registry to enable the MSD to 304 be recognized as such in a SIP-based eCall emergency call. (See 305 [RFC7852] for more information about the registry and how it is 306 used.) 308 See Section 6 for a discussion of how the MSD vehicle data is 309 conveyed in an NG-eCall. 311 6. Data Transport 313 [RFC7852] establishes a general mechanism for attaching blocks of 314 data to a SIP emergency call. This mechanism permits certain 315 emergency call MIME types to be attached to SIP messages. This 316 document makes use of that mechanism. This document also registers 317 an INFO package (in Section 10) to enable eCall related data blocks 318 to be carried in SIP INFO requests (per [RFC6086], new INFO usages 319 require the definition of an INFO package). 321 Note that if other data sets need to be transmitted in the future, 322 the appropriate signalling mechanism for such data needs to be 323 evaluated, including factors such as the size and frequency of such 324 data. 326 An In-Vehicle System (IVS) transmits an MSD (see Section 5) by 327 encoding it per Annex A of EN 15722 [msd] and attaching it to a SIP 328 message as a MIME body part per [RFC7852]. The body part is 329 identified by its MIME content-type ('application/ 330 emergencyCallData.eCall.MSD+per') in the Content-Type header field of 331 the body part. The body part is assigned a unique identifier which 332 is listed in a Content-ID header field in the body part. The SIP 333 message is marked as containing the MSD by adding (or appending to) a 334 Call-Info header field at the top level of the SIP message. This 335 Call-Info header field contains a CID URL referencing the body part's 336 unique identifier, and a 'purpose' parameter identifying the data as 337 the eCall MSD per the Emergency Call Additional Data Blocks registry 338 entry; the 'purpose' parameter's value is 339 'emergencyCallData.eCall.MSD'. Per [RFC6086], an MSD is carried in a 340 SIP INFO request by using the INFO package defined in Section 10. 342 A PSAP or IVS transmits a metadata/control object (see Section 9) by 343 encoding it per the description in this document and attaching it to 344 a SIP message as a MIME body part per [RFC7852]. The body part is 345 identified by its MIME content-type ('application/ 346 emergencyCallData.control+xml') in the Content-Type header field of 347 the body part. The body part is assigned a unique identifier which 348 is listed in a Content-ID header field in the body part. The SIP 349 message is marked as containing the metadata/control object by adding 350 (or appending to) a Call-Info header field at the top level of the 351 SIP message. This Call-Info header field contains a CID URL 352 referencing the body part's unique identifier, and a 'purpose' 353 parameter identifying the data as an eCall metadata/control block per 354 the Emergency Call Additional Data Blocks registry entry; the 355 'purpose' parameter's value is 'emergencyCallData.control'. Per 356 [RFC6086], a metadata/control object is carried in a SIP INFO request 357 by using the INFO package defined in Section 10. 359 An MSD or a metadata/control block is always enclosed in a multipart 360 body part (even if it would otherwise be the only body part in the 361 SIP message), since as of the date of this document, the use of 362 Content-ID as a SIP header field is not defined (while it is defined 363 for use as a MIME header field). 365 A body part containing an MSD or metadata/control object has a 366 Content-Disposition header field value containing "By-Reference". 368 An In-Vehicle System (IVS) initiating an NG-eCall attaches an MSD to 369 the initial INVITE and optionally attaches a metadata/control object 370 informing the PSAP of its capabilities. The MSD body part (and 371 metadata/control and PIDF-LO body parts if included) have a Content- 372 Disposition header field with the value "By-Reference; 373 handling=optional". Specifying "handling=optional" prevents the 374 INVITE from being rejected if it is processed by a legacy element 375 (e.g., a gateway between SIP and circuit-switched environments) that 376 does not understand the MSD (or metadata/control object or PIDF-LO). 377 The PSAP creates a metadata/control object acknowledging receipt of 378 the MSD and attaches it to the SIP final response to the INVITE. A 379 metadata/control object is not attached to provisional (e.g., 180) 380 responses. 382 A PSAP is able to reject a call while indicating that it is aware of 383 the situation by including a metadata/control object acknowledging 384 the MSD and containing "received=true" in a final response using SIP 385 response code 600 (Busy Everywhere), 486 (Busy Here), or 603 386 (Decline). 388 If the IVS receives an acknowledgment for an MSD containing 389 "received=false", this indicates that the PSAP was unable to properly 390 decode or process the MSD. The IVS action is not defined (e.g., it 391 might only log an error). Since the PSAP is able to request an 392 updated MSD during the call, if an initial MSD is unsatisfactory in 393 any way, the PSAP can choose to request another one. 395 A PSAP can request that the vehicle send an updated MSD during a 396 call. To do so, the PSAP creates a metadata/control object 397 requesting an MSD and attaches it to a SIP INFO request and sends it 398 within the dialog. The IVS then attaches an updated MSD to a SIP 399 INFO request and sends it within the dialog. If the IVS is unable to 400 send an MSD, it instead sends a metadata/control object acknowledging 401 the request with the 'success' parameter set to 'false' and a 402 'reason' parameter (and optionally a 'details' parameter) indicating 403 why the request could not be accomplished. Per [RFC6086], metadata/ 404 control objects and MSDs are sent using the INFO package defined in 405 Section 10 . In addition, to align with how an MSD or metadata/ 406 control block is transmitted in a SIP message other than an INFO 407 request, a Call-Info header field is included in the SIP INFO request 408 to reference the MSD or metadata/control block. See Section 10 for 409 information about the use of INFO requests to carry data within an 410 eCall. 412 The IVS is not expected to send an unsolicited MSD after the initial 413 INVITE. 415 Support for the data blocks defined in [RFC7852] is NOT REQUIRED for 416 conformance with this document. 418 7. Call Setup 420 In circuit-switched eCall, the IVS places a special form of a 112 421 emergency call which carries an eCall flag (indicating that the call 422 is an eCall and also if the call was manually or automatically 423 triggered); the mobile network operator (MNO) recognizes the eCall 424 flag and routes the call to an eCall-capable PSAP; vehicle data is 425 transmitted to the PSAP via the eCall in-band modem (in the voice 426 channel). 428 ///----\\\ 112 voice call with eCall flag +------+ 429 ||| IVS |||---------------------------------------->+ PSAP | 430 \\\----/// vehicle data via eCall in-band modem +------+ 432 Figure 1: circuit-switched eCall 434 For NG-eCall, the IVS establishes an emergency call using a Request- 435 URI indicating a manual or automatic eCall; the MNO (or ESInet) 436 recognizes the eCall URN and routes the call to an NG-eCall capable 437 PSAP; the PSAP interpets the vehicle data sent with the call and 438 makes it available to the call taker. 440 ///----\\\ IMS emergency call with eCall URN +------+ 441 IVS ----------------------------------------->+ PSAP | 442 \\\----/// vehicle data included in call setup +------+ 444 Figure 2: NG-eCall 446 See Section 6 for information on how the MSD is transported within an 447 NG-eCall. 449 This document registers new service URN children within the "sos" 450 subservice. These URNs provide the mechanism by which an eCall is 451 identified, and differentiate between manually and automatically 452 triggered eCalls (which might be subject to different treatment, 453 depending on policy). The two service URNs are: 454 urn:service:sos.ecall.automatic and urn:service:sos.ecall.manual, 455 which requests resources associated with an emergency call placed by 456 an in-vehicle system, carrying a standardized set of data related to 457 the vehicle and incident. 459 Call routing is outside the scope of this document. 461 8. Test Calls 463 eCall requires the ability to place test calls (see [TS22.101] clause 464 10.7 and [EN_16062] clause 7.2.2). These are calls that are 465 recognized and treated to some extent as eCalls but are not given 466 emergency call treatment and are not handled by call takers. The 467 specific handling of test eCalls is not itself standardized; 468 typically, the test call facility allows the IVS or user to verify 469 that an eCall can be successfully established with voice 470 communication. The IVS might also be able to verify that the MSD was 471 successfully received. 473 A service URN starting with "test." indicates a test call. For 474 eCall, "urn:service:test.sos.ecall" indicates such a test feature. 475 This functionality is defined in [RFC6881]. 477 This document registers "urn:service:test.sos.ecall" for eCall test 478 calls. 480 The CS-eCall test call facility is a non-emergency number so does not 481 get treated as an emergency call. For NG-eCall, MNOs, emergency 482 authorities, and PSAPs can determine how to treat a vehicle call 483 requesting the "test" service URN so that the desired functionality 484 is tested, but this is outside the scope of this document. 486 9. The Metadata/Control Object 488 eCall requires the ability for the PSAP to acknowledge successful 489 receipt of an MSD sent by the IVS, and for the PSAP to request that 490 the IVS send an MSD (e.g., the call taker can initiate a request for 491 a new MSD to see if there have been changes in the vehicle's state, 492 e.g., location, direction, number of fastened seatbelts). 494 This document defines a block of metadata/control data as an XML 495 structure containing elements used for eCall and other related 496 emergency call systems and extension points. (This metadata/control 497 block is in effect a high-level protocol between the PSAP and IVS.) 498 When the PSAP sends a metadata/control block in response to data sent 499 by the IVS in a SIP request other than INFO (e.g., the MSD in the 500 initial INVITE), the metadata/control block is sent in the SIP 501 response to that request (e.g., the response to the INVITE request). 502 When the PSAP sends a control block in other circumstances (e.g., 503 mid-call), the control block is transmitted from the PSAP to the IVS 504 in a SIP INFO request within the established dialog. The IVS sends 505 the requested data (the MSD) in a new INFO request (per [RFC6086]). 506 This mechanism flexibly allows the PSAP to send eCall-specific data 507 to the IVS and the IVS to respond. INFO requests are sent using an 508 appropriate INFO Package. See Section 6 for more information on 509 attaching a metadata/control block to a SIP message. See Section 10 510 for information about the use of INFO requests to carry data within 511 an eCall. 513 When the IVS includes an unsolicited MSD in a SIP request (e.g., the 514 initial INVITE), the PSAP sends a metadata/control block indicating 515 successful/unsuccessful receipt of the MSD in the SIP response to the 516 request. This also informs the IVS that an NG-eCall is in operation. 517 If the IVS receives a SIP response without the metadata/control 518 block, it indicates that the SIP dialog is not an NG-eCall (e.g., 519 some part of the call is being handled as a legacy call). When the 520 IVS sends a solicited MSD (e.g., in a SIP INFO request sent following 521 receipt of a SIP INFO request containing a metadata/control block 522 requesting an MSD), the PSAP does not send a metadata/control block 523 indicating successful or unsuccessful receipt of the MSD. (Normal 524 SIP retransmission handles non-receipt of requested data; note that, 525 per [RFC6086], a 200 OK response to an INFO request indicates only 526 that the receiver has successfully received and accepted the INFO 527 request, it says nothing about the acceptability of the payload.) If 528 the IVS receives a request to send an MSD but it is unable to do so 529 for any reason, the IVS sends a metadata/control object acknowledging 530 the request and containing "success=false" and "reason" set to an 531 appropriate code. 533 This provides flexibility to handle various circumstances. For 534 example, if a PSAP is unable to accept an eCall (e.g., due to 535 overload or too many calls from the same location), it can reject the 536 INVITE. Since a metadata/control object is also included in the SIP 537 response that rejects the call, the IVS knows if the PSAP received 538 the MSD, and can inform the vehicle occupants that the PSAP 539 successfully received the vehicle location and information but can't 540 talk to the occupants at that time. Especially for SIP response 541 codes that indicate an inability to conduct a call (as opposed to a 542 technical inability to process the request), the IVS can also 543 determine that the call was successful on a technical level (e.g., 544 not helpful to retry as a CS-eCall). (Note that there could be edge 545 cases where the PSAP response is not received by the IVS, e.g., if an 546 intermediary sends a CANCEL, and an error response is forwarded 547 towards the IVS before the error response from the PSAP is received, 548 the response will be dropped, but these are unlikely to occur here.) 550 The metadata/control block is carried in the MIME type 'application/ 551 emergencyCallData.control+xml'. 553 The metadata/control block is designed for use with pan-European 554 eCall and also eCall-like systems (i.e., in other regions), and has 555 extension points. Note that eCall-like systems might define their 556 own vehicle data blocks, and so might need to register a new INFO 557 package to accomodate the new data content type and the metadata/ 558 control object. 560 9.1. The Control Block 562 The control block is an XML data structure allowing for 563 acknowledgments, requests, and capabilities information. It is 564 carried in a body part with a specific MIME content type. Three 565 elements are defined for use within a control block: 567 ack Acknowledges receipt of data or a request. 569 capabilities Used in a control block sent from the IVS to the PSAP 570 (e.g., in the initial INVITE) to inform the PSAP of the 571 vehicle capabilities. Child elements contain all 572 actions and data types supported by the vehicle. It is 573 OPTIONAL for the IVS to send this block. Omitting the 574 block indicates that the IVS supports only the 575 mandatory functionality defined in this document. 577 request Used in a control block sent by the PSAP to the IVS, to 578 request the vehicle to perform an action. 580 The element indicates the object being acknowledged and reports 581 success or failure. 583 The element contains attributes to indicate the request and 584 to supply related information. The 'action' attribute is mandatory 585 and indicates the specific action. An IANA registry is created in 586 Section 15.8.1 to contain the allowed values. 588 The element has child elements to indicate 589 the actions supported by the IVS. 591 9.1.1. The element 593 The element acknowledges receipt of an eCall data object or 594 request. An element references the Content-ID of the object 595 being acknowledged. The PSAP MUST send an element 596 acknowledging receipt of an unsolicited MSD (e.g., sent by the IVS in 597 the INVITE); this element indicates if the PSAP considers the 598 MSD successfully received or not. An element is not sent for a 599 element. 601 The element has the following attributes: 603 9.1.1.1. Attributes of the element 605 The element has the following attributes: 607 Name: ref 608 Usage: Mandatory 609 Type: anyURI 610 Direction: Sent in either direction 611 Description: References the Content-ID of the body part being 612 acknowledged. 613 Example: 615 Name: received 616 Usage: Conditional: mandatory in an element sent by a PSAP 617 Type: Boolean 618 Direction: In this document, sent from the PSAP to the IVS 619 Description: Indicates if the referenced object was considered 620 successfully received or not. 621 Example: 623 9.1.1.2. Child Element of the element 625 For extensibility, the element has the following child element: 627 Name: actionResult 628 Usage: Optional 629 Direction: Sent from the IVS to the PSAP 630 Description: An element indicates the result of an 631 action (other than a successfully executed 'send-data' action). 632 The element contains an element for each 633 element that is not a successfully executed 'send-data' 634 action. The element has the following attributes: 636 Name: action 637 Usage: Mandatory 638 Type: token 639 Description: Contains the value of the 'action' attribute of the 640 element 642 Name: success 643 Usage: Mandatory 644 Type: Boolean 645 Description: Indicates if the action was successfully 646 accomplished 648 Name: reason 649 Usage: Conditional 650 Type: token 651 Description: Used when 'success' is "false", this attribute 652 contains a reason code for a failure. A registry for reason 653 codes is defined in Section 15.8.2. 655 Name: details 656 Usage: optional 657 Type: string 658 Description: Contains further explanation of the circumstances of 659 a success or failure. The contents are implementation-specific 660 and human-readable. 662 9.1.1.3. Ack Examples 664 665 671 673 675 Figure 3: Ack Example from PSAP to IVS 677 9.1.2. The element 679 The element is transmitted by the IVS to indicate to 680 the PSAP its capabilities. No attributes for this element are 681 currently defined. The following child elements are defined: 683 9.1.2.1. Child Elements of the element 685 The element has the following child elements: 687 Name: request 688 Usage: Mandatory 689 Description: The element contains a child 690 element per action supported by the vehicle. 692 Examples: 693 695 It is OPTIONAL for the IVS to support the element. If 696 the IVS does not send a element, this indicates that 697 the only action supported by the IVS is 'send-data' with 698 'datatype' set to 'eCall.MSD'. 700 9.1.2.2. Capabilities Example 701 702 707 708 709 711 713 Figure 4: Capabilities Example 715 9.1.3. The element 717 A element appears one or more times on its own or as a 718 child of a element. It allows the PSAP to request 719 that the IVS perform an action. The only action that MUST be 720 supported is to send an MSD. The following attributes and child 721 elements are defined: 723 9.1.3.1. Attributes of the element 725 The element has the following attributes: 727 Name: action 728 Usage: Mandatory 729 Type: token 730 Direction: Sent in either direction 731 Description: Identifies the action that the vehicle is requested to 732 perform (in a element within a element, 733 indicates an action that the vehicle is capable of performing). 734 An IANA registry is established in Section 15.8.1 to contain the 735 allowed values. 736 Example: action="send-data" 738 Name: msgid 739 Usage: Conditional 740 Type: int 741 Direction: Sent in either direction 742 Description: Defined for extensibility. 743 Example: msgid="3" 745 Name: persistance 746 Usage: Optional 747 Type: duration 748 Direction: Sent in either direction 749 Description: Defined for extensibility. Specifies how long to carry 750 on the specified action. If absent, the default is for the 751 duration of the call. 752 Example: persistance="PT1H" 754 Name: datatype 755 Usage: Conditional 756 Type: token 757 Direction: Sent in either direction 758 Description: Mandatory with a "send-data" action within a 759 element that is not within a element. Specifies 760 the data block that the IVS is requested to transmit, using the 761 same identifier as in the 'purpose' attribute set in a Call-Info 762 header field to point to the data block. Permitted values are 763 contained in the 'Emergency Call Data Types' IANA registry 764 established in [RFC7852]. Only the "eCall.MSD" value is mandatory 765 to support. 766 Example: datatype="eCall.MSD" 768 Name: supported-values 769 Usage: Conditional 770 Type: string 771 Direction: Sent from the IVS to the PSAP 772 Description: Defined for extensibility. Used in a element 773 that is a child of a element, this attribute lists 774 all supported values of the action type. Permitted values depend 775 on the action value. Multiple values are separated with a 776 semicolon. 778 Name: requested-state 779 Usage: Conditional 780 Type: token 781 Direction: Sent from the PSAP to the IVS 782 Description: Defined for extension. Indicates the requested state 783 of an element associated with the request type. Permitted values 784 depend on the request type. 786 Name: element-ID 787 Usage: Conditional 788 Type: token 789 Direction: Sent from the PSAP to the IVS 790 Description: Defined for extension. Identifies the element to be 791 acted on. Permitted values depend on the request type. 793 9.1.3.2. Request Example 795 796 802 804 806 Figure 5: Request Example 808 10. The emergencyCallData.eCall.MSD INFO package 810 This document registers the 'emergencyCallData.eCall.MSD' INFO 811 package. 813 Both endpoints (the IVS and the PSAP equipment) include 814 'emergencyCallData.eCall.MSD' in a Recv-Info header field per 815 [RFC6086] to indicate ability to receive INFO requests carrying data 816 as described here. 818 Support for the 'emergencyCallData.eCall.MSD' INFO package indicates 819 the ability to receive eCall related body parts as specified in [TBD: 820 THIS DOCUMENT]. 822 An INFO request message carrying body parts related to an emergency 823 call as described in [TBD: THIS DOCUMENT] has an Info-Package header 824 field set to 'emergencyCallData.eCall.MSD' per [RFC6086]. 826 The requirements of Section 10 of [RFC6086] are addressed in the 827 following sections. 829 10.1. Overall Description 831 This section describes "what type of information is carried in INFO 832 requests associated with the Info Package, and for what types of 833 applications and functionalities UAs can use the Info Package." 835 INFO requests associated with the emergencyCallData.eCall.MSD INFO 836 package carry data associated with emergency calls as defined in 837 [TBD: THIS DOCUMENT]. The application is vehicle-initiated emergency 838 calls established using SIP. The functionality is to carry vehicle 839 data and metadata/control information between vehicles and PSAPs. 840 Refer to [TBD: THIS DOCUMENT] for more information. 842 10.2. Applicability 844 This section describes "why the Info Package mechanism, rather than 845 some other mechanism, has been chosen for the specific use-case...." 847 The use of INFO is based on an analysis of the requirements against 848 the intent and effects of INFO versus other approaches (which 849 included SIP MESSAGE, SIP OPTIONS, SIP re-INVITE, media plane 850 transport, and non-SIP protocols). In particular, the transport of 851 emergency call data blocks occurs within a SIP emergency dialog, per 852 Section 6, and is normally carried in the initial INVITE and its 853 response; the use of INFO only occurs when emergency-call-related 854 data needs to be sent mid-call. While MESSAGE could be used, it is 855 not tied to a SIP dialog as is INFO and thus might not be associated 856 with the dialog. SIP OPTIONS or re-INVITE could also be used, but is 857 seen as less clean than INFO. SUBSCRIBE/NOTIFY could be coerced into 858 service, but the semantics are not a good fit, e.g., the subscribe/ 859 notify mechanism provides one-way communication consisting of (often 860 multiple) notifications from notifier to subscriber indicating that 861 certain events in notifier have occurred, whereas what's needed here 862 is two-way communication of data related to the emergency dialog. 863 Use of the media plane mechanisms was discounted because the number 864 of messages needing to be exchanged in a dialog is normally zero or 865 very few, and the size of the data is likewise very small. The 866 overhead caused by user plane setup (e.g., to use MSRP as transport) 867 would be disproportionately large. 869 Based on the the analyses, the SIP INFO method was chosen to provide 870 for mid-call data transport. 872 10.3. Info Package Name 874 The info package name is emergencyCallData.eCall.MSD 876 10.4. Info Package Parameters 878 None 880 10.5. SIP Option-Tags 882 None 884 10.6. INFO Request Body Parts 886 The body for an emergencyCallData.eCall.MSD info package is a 887 multipart body which MAY contain zero or one application/ 888 emergencyCallData.eCall.MSD+per part (containing an MSD) and zero or 889 more application/emergencyCallData.control+xml (containing a 890 metadata/control object) parts. 892 The body parts are sent per [RFC6086], and in addition, to align with 893 with how these body parts are sent in SIP messages other than INFO 894 requests, each associated body part is referenced by a Call-Info 895 header field at the top level of the SIP message. The body part has 896 a Content-Disposition header field set to "By-Reference". 898 An MSD or metadata/control block is always enclosed in a multipart 899 body part (even if it would otherwise be the only body part in the 900 SIP message), since as of the date of this document, the use of 901 Content-ID as a SIP header field is not defined (while it is defined 902 for use as a MIME header field). 904 See [TBD: THIS DOCUMENT] for more information. 906 10.7. Info Package Usage Restrictions 908 Usage is limited to vehicle-initiated emergency calls as defined in 909 [TBD: THIS DOCUMENT]. 911 10.8. Rate of INFO Requests 913 The rate of SIP INFO requests associated with the 914 emergencyCallData.eCall.MSD info package is normally quite low (most 915 dialogs are likely to contain zero INFO requests, while others can be 916 expected to carry an occasional request). 918 10.9. Info Package Security Considerations 920 The MIME content type registations for the data blocks that can be 921 carried using this INFO package contains a discussion of the security 922 and/or privacy considerations specific to that data block. The 923 "Security Considerations" and "Privacy Considerations" sections of 924 [TBD: THIS DOCUMENT] discuss security and privacy considerations of 925 the data carried in eCalls. 927 10.10. Implementation Details 929 See [TBD: THIS DOCUMENT] for protocol details. 931 10.11. Examples 933 See [TBD: THIS DOCUMENT] for protocol examples. 935 11. Examples 937 Figure 6 illustrates an eCall. The call uses the request URI 938 'urn:service:sos.ecall.automatic' service URN and is recognized as an 939 eCall, and further as one that was invoked automatically by the IVS 940 due to a crash or other serious incident. In this example, the 941 originating network routes the call to an ESInet which routes the 942 call to the appropriate NG-eCall capable PSAP. The emergency call is 943 received by the ESInet's Emergency Services Routing Proxy (ESRP), as 944 the entry point into the ESInet. The ESRP routes the call to a PSAP, 945 where it is received by a call taker. In deployments where there is 946 no ESInet, the originating network routes the call directly to the 947 appropriate NG-eCall capable PSAP, an illustration of which would be 948 identical to the one below except without an ESInet or ESRP. 950 +------------+ +---------------------------------------+ 951 | | | +-------+ | 952 | | | | PSAP2 | | 953 | | | +-------+ | 954 | | | | 955 | | | +------+ +-------+ | 956 Vehicle-->| |--+->| ESRP |---->| PSAP1 |--> Call-Taker | 957 | | | +------+ +-------+ | 958 | | | | 959 | | | +-------+ | 960 | | | | PSAP3 | | 961 | Originating| | +-------+ | 962 | Mobile | | | 963 | Network | | ESInet | 964 +------------+ +---------------------------------------+ 966 Figure 6: Example of NG-eCall Message Flow 968 Figure 7 illustrates an eCall call flow with a mid-call PSAP request 969 for an updated MSD. The call flow shows the IVS initiating an 970 emergency call, including the MSD in the INVITE. The PSAP includes 971 in the 200 OK response a metadata/control object acknowledging 972 receipt of the MSD. During the call, the PSAP sends a request for an 973 MSD in an INFO request. The IVS sends the requested MSD in a new 974 INFO request. 976 IVS PSAP 977 |(1) INVITE (eCall MSD) | 978 |------------------------------------------->| 979 | | 980 |(2) 200 OK (eCall metadata [ack MSD]) | 981 |<-------------------------------------------| 982 | | 983 |(3) start media stream(s) | 984 |............................................| 985 | | 986 |(4) INFO (eCall metadata [request MSD]) | 987 |<-------------------------------------------| 988 | | 989 |(5) 200 OK | 990 |------------------------------------------->| 991 | | 992 |(6) INFO (eCall MSD) | 993 |------------------------------------------->| 994 | | 995 |(7) 200 OK | 996 |<-------------------------------------------| 997 | | 998 |(8) BYE | 999 |<-------------------------------------------| 1000 | | 1001 |(9) end media streams | 1002 |............................................| 1003 | | 1004 |(10) 200 OK | 1005 |------------------------------------------->| 1007 Figure 7: NG-eCall Call Flow Illustration 1009 The example, shown in Figure 8, illustrates a SIP eCall INVITE that 1010 contains an MSD. For simplicity, the example does not show all SIP 1011 headers, nor the SDP contents, nor does it show any additional data 1012 blocks added by the IVS or the originating mobile network. Because 1013 the MSD is encoded in ASN.1 PER, which is a binary encoding, its 1014 contents cannot be included in a text document. 1016 INVITE urn:service:sos.ecall.automatic SIP/2.0 1017 To: urn:service:sos.ecall.automatic 1018 From: ;tag=9fxced76sl 1019 Call-ID: 3848276298220188511@atlanta.example.com 1020 Geolocation: 1021 Geolocation-Routing: no 1022 Call-Info: ; 1023 purpose=emergencyCallData.eCall.MSD 1024 Accept: application/sdp, application/pidf+xml, 1025 application/emergencyCallData.control+xml 1026 CSeq: 31862 INVITE 1027 Recv-Info: emergencyCallData.eCall.MSD 1028 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1029 SUBSCRIBE, NOTIFY, UPDATE 1030 Content-Type: multipart/mixed; boundary=boundary1 1031 Content-Length: ... 1033 --boundary1 1034 Content-Type: application/sdp 1036 ...Session Description Protocol (SDP) goes here... 1038 --boundary1 1039 Content-Type: application/emergencyCallData.eCall.MSD+per 1040 Content-ID: <1234567890@atlanta.example.com> 1041 Content-Disposition: by-reference;handling=optional 1043 ...MSD in ASN.1 PER encoding goes here... 1045 --boundary1-- 1047 Figure 8: SIP NG-eCall INVITE 1049 Continuing the example, Figure 9 illustrates a SIP 200 OK response to 1050 the INVITE of Figure 8, containing a control block acknowledging 1051 successful receipt of the eCall MSD. (For simplicity, the example 1052 does not show all SIP headers.) 1053 SIP/2.0 200 OK 1054 To: ;tag=9fxced76sl 1055 From: Exemplar PSAP 1056 Call-ID: 3848276298220188511@atlanta.example.com 1057 Call-Info: ; 1058 purpose=emergencyCallData.control 1059 Accept: application/sdp, application/pidf+xml, 1060 application/emergencyCallData.control+xml, 1061 application/emergencyCallData.eCall.MSD+per 1062 CSeq: 31862 INVITE 1063 Recv-Info: emergencyCallData.eCall.MSD 1064 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1065 SUBSCRIBE, NOTIFY, UPDATE 1066 Content-Type: multipart/mixed; boundary=boundaryX 1067 Content-Length: ... 1069 --boundaryX 1070 Content-Type: application/sdp 1072 ...Session Description Protocol (SDP) goes here... 1074 --boundaryX 1075 Content-Type: application/emergencyCallData.control+xml 1076 Content-ID: <2345678901@atlanta.example.com> 1077 Content-Disposition: by-reference 1079 1080 1086 1087 1089 --boundaryX-- 1091 Figure 9: 200 OK response to INVITE 1093 Figure 10 illustrates a SIP INFO request containing a metadata/ 1094 control block requesting an eCall MSD. (For simplicity, the example 1095 does not show all SIP headers.) 1096 INFO sip:+13145551111@example.com SIP/2.0 1097 To: ;tag=9fxced76sl 1098 From: Exemplar PSAP 1099 Call-ID: 3848276298220188511@atlanta.example.com 1100 Call-Info: ; 1101 purpose=emergencyCallData.control 1102 Accept: application/sdp, application/pidf+xml, 1103 application/emergencyCallData.control+xml, 1104 application/emergencyCallData.eCall.MSD+per 1105 CSeq: 41862 INFO 1106 Info-Package: emergencyCallData.eCall.MSD 1107 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1108 SUBSCRIBE, NOTIFY, UPDATE 1109 Content-Type: multipart/mixed; boundary=boundaryZZZ 1110 Content-Length: ... 1112 --boundaryZZZ 1113 Content-Disposition: by-reference 1114 Content-Type: application/emergencyCallData.control+xml 1115 Content-ID: <3456789012@atlanta.example.com> 1117 1118 1124 1126 1127 --boundaryZZZ-- 1129 Figure 10: INFO requesting MSD 1131 Figure 11 illustrates a SIP INFO request containing an MSD. For 1132 simplicity, the example does not show all SIP headers. Because the 1133 MSD is encoded in ASN.1 PER, which is a binary encoding, its contents 1134 cannot be included in a text document. 1136 INFO urn:service:sos.ecall.automatic SIP/2.0 1137 To: urn:service:sos.ecall.automatic 1138 From: ;tag=9fxced76sl 1139 Call-ID: 3848276298220188511@atlanta.example.com 1140 Call-Info: ; 1141 purpose=emergencyCallData.eCall.MSD 1142 Accept: application/sdp, application/pidf+xml, 1143 application/emergencyCallData.control+xml 1144 CSeq: 51862 INFO 1145 Info-Package: emergencyCallData.eCall.MSD 1146 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1147 SUBSCRIBE, NOTIFY, UPDATE 1148 Content-Type: multipart/mixed; boundary=boundaryLine 1149 Content-Length: ... 1151 --boundaryLine 1152 Content-Type: application/emergencyCallData.eCall.MSD+per 1153 Content-ID: <4567890123@atlanta.example.com> 1154 Content-Disposition: by-reference 1156 ...MSD in ASN.1 PER encoding goes here... 1158 --boundaryLine-- 1160 Figure 11: INFO containing MSD 1162 12. Security Considerations 1164 The security considerations described in [RFC5069] apply here. 1166 In addition to any network-provided location (which might be 1167 determined solely by the network, or in cooperation with or possibly 1168 entirely by the originating device), an eCall carries an IVS-supplied 1169 location within the MSD. This is likely to be useful to the PSAP, 1170 especially when no network-provided location is included, or when the 1171 two locations are independently determined. Even in situations where 1172 the network-supplied location is limited to the cell site, this can 1173 be useful as a sanity check on the device-supplied location contained 1174 in the MSD. 1176 The document [RFC7378] discusses trust issues regarding location 1177 provided by or determined in cooperation with end devices. 1179 Security considerations specific to the mechanism by which the PSAP 1180 sends acknowledgments and requests to the vehicle are discussed in 1181 the "Security Considerations" block of Section 15.3. 1183 Data received from external sources inherently carries implementation 1184 risks. For example, depending on the platform, buffer overflows can 1185 introduce remote code execution vulnerabilities, null characters can 1186 corrupt strings, numeric values used for internal calculations can 1187 result in underflow/overflow errors, malformed XML objects can expose 1188 parsing bugs, etc. Implementations need to be cognizant of the 1189 potential risks, observe best practices (which might include 1190 sufficiently capable static code analysis, fuzz testing, component 1191 isolation, avoiding use of unsafe coding techniques, third-party 1192 attack tests, signed software, over-the-air updates, etc.), and have 1193 multiple levels of protection. Implementors need to be aware that, 1194 potentially, the data objects described here and elsewhere might be 1195 malformed, might contain unexpected characters, excessively long 1196 attribute values, elements, etc. 1198 The security considerations discussed in [RFC7852] apply here (see 1199 especially the discussion of TLS, TLS versions, cypher suites, and 1200 PKI). 1202 When vehicle data or control/metadata is contained in a signed or 1203 encrypted body part, the enclosing multipart (e.g., multipart/signed 1204 or multipart/encrypted) has the same Content-ID as the enclosed data 1205 part. This allows an entity to identify and access the data blocks 1206 it is interested in without having to dive deeply into the message 1207 structure or decrypt parts it is not interested in. (The 'purpose' 1208 parameter in a Call-Info header field identifies the data and 1209 contains a CID URL pointing to the data block in the body, which has 1210 a matching Content-ID body part header field). 1212 13. Privacy Considerations 1214 The privacy considerations discussed in [RFC7852] apply here. The 1215 MSD carries some identifying and personal information (mostly about 1216 the vehicle and less about the owner), as well as location 1217 information, and so needs to be protected against unauthorized 1218 disclosure. Local regulations may impose additional privacy 1219 protection requirements. 1221 Privacy considerations specific to the data structure containing 1222 vehicle information are discussed in the "Security Considerations" 1223 block of Section 15.2. 1225 Privacy considerations specific to the mechanism by which the PSAP 1226 sends acknowledgments and requests to the vehicle are discussed in 1227 the "Security Considerations" block of Section 15.3. 1229 14. XML Schema 1231 This section defines an XML schema for the control block. The text 1232 description of the control block in Section 9.1 is normative and 1233 supersedes any conflicting aspect of this schema. 1235 1236 1238 1246 1249 1252 1253 1254 1255 1256 1258 1259 1260 1263 1264 1265 1266 1267 1269 1270 1271 1272 1273 1275 1276 1279 1282 1284 1285 conditionally 1286 mandatory when @success='false" 1287 to indicate reason code for a 1288 failure 1289 1290 1291 1293 1294 1295 1296 1299 1300 1303 1305 1306 1307 1308 1310 1311 1312 1313 1314 1318 1321 1322 1323 1325 1326 1328 1329 1330 1331 1332 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1348 1350 Figure 12: Control Block Schema 1352 15. IANA Considerations 1354 This document formalizes the "EmergencyCallData" media (MIME) subtype 1355 tree. This tree is used only for content associated with emergency 1356 communications. New subtypes in this tree can be registered by the 1357 IETF or by other standards organizations working with emergency 1358 communications, using the "Specification Required" rule, which 1359 implies expert review. The designated expert is the ECRIT working 1360 group. 1362 15.1. Service URN Registrations 1364 IANA is requested to register the URN 'urn:service:sos.ecall' under 1365 the sub-services 'sos' registry defined in Section 4.2 of [RFC5031]. 1367 This service requests resources associated with an emergency call 1368 placed by an in-vehicle system, carrying a standardized set of data 1369 related to the vehicle and incident. Two sub-services are registered 1370 as well: 1372 urn:service:sos.ecall.manual 1374 Used with an eCall invoked due to manual interaction by a vehicle 1375 occupant. 1377 urn:service:sos.ecall.automatic 1379 Used with an eCall invoked automatically, for example, due to a 1380 crash or other serious incident. 1382 IANA is also requested to register the URN 1383 'urn:service:test.sos.ecall' under the sub-service 'test' registry 1384 defined in Setcion 17.2 of [RFC6881]. 1386 15.2. MIME Content-type Registration for 'application/ 1387 emergencyCallData.eCall.MSD+per' 1389 IANA is requested to add application/emergencyCallData.eCall.MSD+per 1390 as a MIME content type, with a reference to this document, in 1391 accordance to the procedures of RFC 6838 [RFC6838] and guidelines in 1392 RFC 7303 [RFC7303]. 1394 MIME media type name: application 1396 MIME subtype name: emergencyCallData.eCall.MSD+per 1398 Mandatory parameters: none 1400 Optional parameters: none 1402 Encoding scheme: binary 1404 Encoding considerations: Uses ASN.1 PER, which is a binary 1405 encoding; when transported in SIP, binary content transfer 1406 encoding is used. 1408 Security considerations: This content type is designed to carry 1409 vehicle and incident-related data during an emergency call. This 1410 data contains personal information including vehicle VIN, 1411 location, direction, etc. Appropriate precautions need to be 1412 taken to limit unauthorized access, inappropriate disclosure to 1413 third parties, and eavesdropping of this information. In general, 1414 it is acceptable for the data to be unprotected while briefly in 1415 transit within the Mobile Network Operator (MNO); the MNO is 1416 trusted to not permit the data to be accessed by third parties. 1417 Sections 7 and Section 8 of [RFC7852] contain more discussion. 1419 Interoperability considerations: None 1420 Published specification: Annex A of EN 15722 [msd] 1422 Applications which use this media type: Pan-European eCall 1423 compliant systems 1425 Additional information: None 1427 Magic Number: None 1429 File Extension: None 1431 Macintosh file type code: 'BINA' 1433 Person and email address for further information: Randall Gellens, 1434 rg+ietf@randy.pensive.org 1436 Intended usage: LIMITED USE 1438 Author: The MSD specification was produced by the European 1439 Committee For Standardization (CEN). For contact information, 1440 please see . 1442 Change controller: The European Committee For Standardization 1443 (CEN) 1445 15.3. MIME Content-type Registration for 'application/ 1446 emergencyCallData.control+xml' 1448 IANA is requested to add application/emergencyCallData.control+xml as 1449 a MIME content type, with a reference to this document, in accordance 1450 to the procedures of RFC 6838 [RFC6838] and guidelines in RFC 7303 1451 [RFC7303]. 1453 MIME media type name: application 1455 MIME subtype name: emergencyCallData.control+xml 1457 Mandatory parameters: none 1459 Optional parameters: charset 1461 Indicates the character encoding of the XML content. 1463 Encoding considerations: Uses XML, which can employ 8-bit 1464 characters, depending on the character encoding used. See 1465 Section 3.2 of RFC 7303 [RFC7303]. 1467 Security considerations: 1469 This content type carries metadata and control information and 1470 requests, such as from a Public Safety Answering Point (PSAP) 1471 to an In-Vehicle System (IVS) during an emergency call. 1473 Metadata (such as an acknowledgment that data sent by the IVS 1474 to the PSAP was successfully received) has limited privacy and 1475 security implications. Control information (such as requests 1476 from the PSAP that the vehicle perform an action) has some 1477 privacy and security implications. The privacy concern arises 1478 from the ability to request the vehicle to transmit a data set, 1479 which as described in Section 15.2, can contain personal 1480 information. The security concern is the ability to request 1481 the vehicle to perform an action. Control information needs to 1482 originate only from a PSAP or other emergency services 1483 provider, and not be modified en-route. The level of integrity 1484 of the cellular network over which the emergency call is placed 1485 is a consideration: when the IVS initiates an eCall over a 1486 cellular network, in most cases it relies on the MNO to route 1487 the call to a PSAP. (Calls placed using other means, such as 1488 Wi-Fi or over-the-top services, generally incur somewhat higher 1489 levels of risk than calls placed "natively" using cellular 1490 networks.) A call-back from a PSAP merits additional 1491 consideration, since current mechanisms are not ideal for 1492 verifying that such a call is indeed a call-back from a PSAP in 1493 response to an emergency call placed by the IVS. See the 1494 discussion in Section 12 and the PSAP Callback document 1495 [RFC7090]. 1497 Sections 7 and Section 8 of [RFC7852] contain more discussion. 1499 Interoperability considerations: None 1501 Published specification: This document 1503 Applications which use this media type: Pan-European eCall 1504 compliant systems 1506 Additional information: None 1508 Magic Number: None 1510 File Extension: .xml 1512 Macintosh file type code: 'TEXT' 1514 Person and email address for further information: Randall Gellens, 1515 rg+ietf@randy.pensive.org 1516 Intended usage: LIMITED USE 1518 Author: The IETF ECRIT WG. 1520 Change controller: The IETF ECRIT WG. 1522 15.4. Registration of the 'eCall.MSD' entry in the Emergency Call 1523 Additional Data Blocks registry 1525 This specification requests IANA to add the 'eCall.MSD' entry to the 1526 Emergency Call Additional Data Blocks registry, with a reference to 1527 this document. 1529 15.5. Registration of the 'control' entry in the Emergency Call 1530 Additional Data Blocks registry 1532 This specification requests IANA to add the 'control' entry to the 1533 Emergency Call Additional Data Blocks registry, with a reference to 1534 this document. 1536 15.6. Registration of the emergencyCallData.eCall Info Package 1538 IANA is requested to add emergencyCallData.eCall to the Info Packages 1539 Registry under "Session Initiation Protocol (SIP) Parameters", with a 1540 reference to this document. 1542 15.7. URN Sub-Namespace Registration 1544 15.7.1. Registration for urn:ietf:params:xml:ns:eCall 1546 This section registers a new XML namespace, as per the guidelines in 1547 RFC 3688 [RFC3688]. 1549 URI: urn:ietf:params:xml:ns:eCall 1551 Registrant Contact: IETF, ECRIT working group, , as 1552 delegated by the IESG . 1554 XML: 1556 BEGIN 1557 1558 1560 1561 1562 1564 Namespace for eCall Data 1565 1566 1567

Namespace for eCall Data

1568

See [TBD: This document].

1569 1570 1571 END 1573 15.7.2. Registration for urn:ietf:params:xml:ns:control 1575 This section registers a new XML namespace, as per the guidelines in 1576 RFC 3688 [RFC3688]. 1578 URI: urn:ietf:params:xml:ns:control 1580 Registrant Contact: IETF, ECRIT working group, , as 1581 delegated by the IESG . 1583 XML: 1585 BEGIN 1586 1587 1589 1590 1591 1593 Namespace for eCall Data: 1594 Control Block 1595 1596 1597

Namespace for eCall Data

1598

Control Block

1599

See [TBD: This document].

1600 1601 1602 END 1604 15.8. Registry creation 1606 This document creates a new registry called 'Metadata/Control Data'. 1607 The following sub-registries are created for this registry. 1609 15.8.1. Action Registry 1611 This document creates a new sub-registry called "Action Registry". 1612 As defined in [RFC5226], this registry operates under "Expert Review" 1613 rules. The expert should determine that the proposed action is 1614 within the purview of a vehicle, is sufficiently distinguishable from 1615 other actions, and the action is clearly and fully described. In 1616 most cases, a published and stable document is referenced for the 1617 description of the action. 1619 The content of this registry includes: 1621 Name: The identifier to be used in the 'action' attribute of a 1622 control element. 1624 Description: A description of the action. In most cases this will 1625 be a reference to a published and stable document. The 1626 description MUST specify if any attributes or child elements are 1627 optional or mandatory, and describe the action to be taken by the 1628 vehicle. 1630 The initial set of values is listed in Table 2. 1632 +-----------+--------------------------------------+ 1633 | Name | Description | 1634 +-----------+--------------------------------------+ 1635 | send-data | See Section 9.1.3.1 of this document | 1636 +-----------+--------------------------------------+ 1638 Table 2: Action Registry Initial Values 1640 15.8.2. Reason Registry 1642 This document creates a new sub-registry called "Reason Registry" 1643 which contains values for the 'reason' attribute of the 1644 element. As defined in [RFC5226], this registry 1645 operates under "Expert Review" rules. The expert should determine 1646 that the proposed reason is sufficiently distinguishable from other 1647 reasons and that the proposed description is understandable and 1648 correctly worded. 1650 The content of this registry includes: 1652 ID: A short string identifying the reason, for use in the 'reason' 1653 attribute of an element. 1655 Description: A description of the reason. 1657 The initial set of values is listed in Table 3. 1659 +------------------+------------------------------------------------+ 1660 | ID | Description | 1661 +------------------+------------------------------------------------+ 1662 | unsupported | The 'action' value is not supported. | 1663 | | | 1664 | damaged | Required components are damaged. | 1665 | | | 1666 | unable | The action could not be accomplished (a | 1667 | | generic error for use when no other code is | 1668 | | appropriate). | 1669 | | | 1670 | data-unsupported | The data item referenced in a 'send-data' | 1671 | | request is not supported. | 1672 | | | 1673 | security-failure | The authenticity of the request or the | 1674 | | authority of the requestor could not be | 1675 | | verified. | 1676 +------------------+------------------------------------------------+ 1678 Table 3: Reason Registry 1680 16. Contributors 1682 Brian Rosen was a co-author of the original document upon which this 1683 document is based. 1685 17. Acknowledgements 1687 We would like to thank Bob Williams and Ban Al-Bakri for their 1688 feedback and suggestion; Rex Buddenberg, Lena Chaponniere, Keith 1689 Drage, Stephen Edge, Wes George, Ivo Sedlacek, and James Winterbottom 1690 for their review and comments; Robert Sparks and Paul Kyzivat for 1691 their help with the SIP mechanisms; Mark Baker and Ned Freed for 1692 their help with the media subtype registration issue. We would like 1693 to thank Michael Montag, Arnoud van Wijk, Gunnar Hellstrom, and 1694 Ulrich Dietz for their help with the original document upon which 1695 this document is based. Christer Holmberg deserves special mention 1696 for his many detailed reviews. 1698 18. Changes from Previous Versions 1700 18.1. Changes from draft-ietf-15 to draft-ietf-16 1702 o Various clarifications and simplifications 1703 o Added reference to 3GPP 23.167 1705 18.2. Changes from draft-ietf-14 to draft-ietf-15 1707 o eCall body parts now always sent enclosed in multipart (even if 1708 only body part in SIP message) and hence always have a Content- 1709 Disposition of By-Reference 1710 o Fixed errors in attribute directionality text 1711 o Fixed typos. 1713 18.3. Changes from draft-ietf-13 to draft-ietf-14 1715 o Added text to the IANA Considerations to formalize the 1716 EmergencyCallData media subtree 1717 o Fixed some typos 1719 18.4. Changes from draft-ietf-12 to draft-ietf-13 1721 o Clarifications suggested by Christer 1722 o Corrections to Content-Disposition text and examples as suggested 1723 by Paul Kyzivat 1724 o Clarifications to Content-Disposition text and examples to clarify 1725 that handling=optional is only used in the initial INVITE 1727 18.5. Changes from draft-ietf-11 to draft-ietf-12 1729 o Fixed errors in examples found by Dale 1730 o Removed enclosing sub-section of INFO package registration section 1731 o Added text per Christer and Dale's suggestions that the MSD and 1732 metadata/control blocks are sent in INFO with a Call-Info header 1733 field referencing them 1734 o Deleted Call Routing section (7.1) in favor of a statement that 1735 call routing is outside the scope of the document 1736 o Other text changes per comments received from Christer and Ivo. 1738 18.6. Changes from draft-ietf-09 to draft-ietf-11 1740 o Renamed INFO package to emergencyCallData.eCall.MSD 1741 o Changed INFO package to only permit MSD and metadata/control MIME 1742 types 1743 o Moved element back from car-crash but made it 1744 OPTIONAL 1745 o Moved other extension points back from car-crash so that extension 1746 points are in base spec (and also to get XML schema to compile) 1747 o Text changes for clarification. 1749 18.7. Changes from draft-ietf-08 to draft-ietf-09 1751 o Created a new "Data Transport" section that describes how the MSD 1752 and metadata/control blocks are attached, and then referred to 1753 that section rather than repeat the information about the CID and 1754 Call-Info and so forth, which means most references to the 1755 additional-data draft have now been deleted 1756 o Mentioned edge cases where a PSAP response to INVITE isn't 1757 received by the IVS 1758 o Reworded description of which status codes are used when a PSAP 1759 wishes to reject a call but inform the vehicle occupants that it 1760 is aware of the situation to be more definite 1761 o Added examples showing INFO 1762 o Added references for eCall test call requirement 1763 o Described meaning of eCall URNs in Section 8 as well as in IANA 1764 registration 1766 18.8. Changes from draft-ietf-07 to draft-ietf-08 1768 o eCall MSD now encoded as ASN.1 PER, using binary content transfer 1769 encoding 1770 o Added text to point out aspects of call handling and metadata/ 1771 control usage, such as use in rejected calls, and solicited MSDs 1772 o Revised use of INFO to require that when a request for an MSD is 1773 sent in INFO, the MSD sent in response is in its own INFO, not the 1774 response to the requesting INFO 1776 o Added material to INFO package registation to comply with 1777 Section 10 of [RFC6086] 1778 o Moved material not required by 3GPP into 1779 [I-D.ietf-ecrit-car-crash], e.g., some of the eCall metadata/ 1780 control elements, attributes, and values 1781 o Revised test call wording to clarify that specific handling is out 1782 of scope 1783 o Revised wording throughout the document to simplify 1784 o Moved new Section 7.1 to be a subsection of 7 1785 o Moved new Section Section 10 to be a main section instead of a 1786 subsection of Section 9 1787 o Revised SIP INFO usage and package registration per advice from 1788 Robert Sparks and Paul Kyzivat 1790 18.9. Changes from draft-ietf-06 to draft-ietf-07 1792 o Fixed typo in Acknowledgements 1794 18.10. Changes from draft-ietf-05 to draft-ietf-06 1796 o Added additional security and privacy clarifications regarding 1797 signed and encrypted data 1798 o Additional security and privacy text 1799 o Deleted informative section on ESINets as unnecessary. 1801 18.11. Changes from draft-ietf-04 to draft-ietf-05 1803 o Reworked the security and privacy considerations material in the 1804 document as a whole and in the MIME registation sections of the 1805 MSD and control objects 1806 o Clarified that the element can appear multiple 1807 times within an element 1808 o Fixed IMS definition 1809 o Added clarifying text for the 'msgid' attribute 1811 18.12. Changes from draft-ietf-03 to draft-ietf-04 1813 o Added Privacy Considerations section 1814 o Reworded most uses of non-normative "may", "should", "must", and 1815 "recommended." 1816 o Fixed nits in examples 1818 18.13. Changes from draft-ietf-02 to draft-ietf-03 1820 o Added request to enable cameras 1821 o Improved examples and XML schema 1822 o Clarifications and wording improvements 1824 18.14. Changes from draft-ietf-01 to draft-ietf-02 1826 o Added clarifying text reinforcing that the data exchange is for 1827 small blocks of data infrequently transmitted 1828 o Clarified that dynamic media is conveyed using SIP re-INVITE to 1829 establish a one-way media stream 1830 o Clarified that the scope is the needs of eCall within the SIP 1831 emergency call environment 1832 o Added informative statement that the document may be suitable for 1833 reuse by other ACN systems 1834 o Clarified that normative language for the control block applies to 1835 both IVS and PSAP 1836 o Removed 'ref', 'supported-mime', and elements 1837 o Minor wording improvements and clarifications 1839 18.15. Changes from draft-ietf-00 to draft-ietf-01 1841 o Added further discussion of test calls 1842 o Added further clarification to the document scope 1843 o Mentioned that multi-region vehicles may need to support other 1844 crash notification specifications in addition to eCall 1845 o Added details of the eCall metadata and control functionality 1846 o Added IANA registration for the MIME content type for the control 1847 object 1848 o Added IANA registries for protocol elements and tokens used in the 1849 control object 1850 o Minor wording improvements and clarifications 1852 18.16. Changes from draft-gellens-03 to draft-ietf-00 1854 o Renamed from draft-gellens- to draft-ietf-. 1855 o Added mention of and reference to ETSI TR "Mobile Standards Group 1856 (MSG); eCall for VoIP" 1857 o Added text to Introduction regarding migration/co-existence being 1858 out of scope 1859 o Added mention in Security Considerations that even if the network- 1860 supplied location is just the cell site, this can be useful as a 1861 sanity check on the IVS-supplied location 1862 o Minor wording improvements and clarifications 1864 18.17. Changes from draft-gellens-02 to -03 1866 o Clarifications and editorial improvements. 1868 18.18. Changes from draft-gellens-01 to -02 1870 o Minor wording improvements 1871 o Removed ".automatic" and ".manual" from 1872 "urn:service:test.sos.ecall" registration and discussion text. 1874 18.19. Changes from draft-gellens-00 to -01 1876 o Now using 'EmergencyCallData' for purpose parameter values and 1877 MIME subtypes, in accordance with changes to [RFC7852] 1878 o Added reference to RFC 6443 1879 o Fixed bug that caused Figure captions to not appear 1881 19. References 1883 19.1. Normative References 1885 [EN_16062] 1886 CEN, , "Intelligent transport systems - eSafety - eCall 1887 High Level Application Requirements (HLAP) Using GSM/UMTS 1888 Circuit Switched Networks, EN 16062", April 2015. 1890 [EN_16072] 1891 CEN, , "Intelligent transport systems - eSafety - Pan- 1892 European eCall operating requirements, EN 16072", April 1893 2015. 1895 [msd] CEN, , "Intelligent transport systems -- eSafety -- eCall 1896 minimum set of data (MSD), EN 15722", April 2015. 1898 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1899 Requirement Levels", BCP 14, RFC 2119, 1900 DOI 10.17487/RFC2119, March 1997, 1901 . 1903 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 1904 DOI 10.17487/RFC3688, January 2004, 1905 . 1907 [RFC5031] Schulzrinne, H., "A Uniform Resource Name (URN) for 1908 Emergency and Other Well-Known Services", RFC 5031, 1909 DOI 10.17487/RFC5031, January 2008, 1910 . 1912 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1913 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 1914 DOI 10.17487/RFC5226, May 2008, 1915 . 1917 [RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton, 1918 "Framework for Emergency Calling Using Internet 1919 Multimedia", RFC 6443, DOI 10.17487/RFC6443, December 1920 2011, . 1922 [RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type 1923 Specifications and Registration Procedures", BCP 13, 1924 RFC 6838, DOI 10.17487/RFC6838, January 2013, 1925 . 1927 [RFC6881] Rosen, B. and J. Polk, "Best Current Practice for 1928 Communications Services in Support of Emergency Calling", 1929 BCP 181, RFC 6881, DOI 10.17487/RFC6881, March 2013, 1930 . 1932 [RFC7303] Thompson, H. and C. Lilley, "XML Media Types", RFC 7303, 1933 DOI 10.17487/RFC7303, July 2014, 1934 . 1936 [RFC7852] Gellens, R., Rosen, B., Tschofenig, H., Marshall, R., and 1937 J. Winterbottom, "Additional Data Related to an Emergency 1938 Call", RFC 7852, DOI 10.17487/RFC7852, July 2016, 1939 . 1941 [TS22.101] 1942 3GPP, , "3GPP TS 22.101: Technical Specification Group 1943 Services and System Aspects; Service aspects; Service 1944 principles". 1946 19.2. Informative references 1948 [CEN] "European Committee for Standardization", 1949 . 1951 [I-D.ietf-ecrit-car-crash] 1952 Gellens, R., Rosen, B., and H. Tschofenig, "Next- 1953 Generation Vehicle-Initiated Emergency Calls", draft-ietf- 1954 ecrit-car-crash-12 (work in progress), September 2016. 1956 [MSG_TR] ETSI, , "ETSI Mobile Standards Group (MSG); eCall for 1957 VoIP", ETSI Technical Report TR 103 140 V1.1.1 (2014-04), 1958 April 2014. 1960 [RFC5012] Schulzrinne, H. and R. Marshall, Ed., "Requirements for 1961 Emergency Context Resolution with Internet Technologies", 1962 RFC 5012, DOI 10.17487/RFC5012, January 2008, 1963 . 1965 [RFC5069] Taylor, T., Ed., Tschofenig, H., Schulzrinne, H., and M. 1966 Shanmugam, "Security Threats and Requirements for 1967 Emergency Call Marking and Mapping", RFC 5069, 1968 DOI 10.17487/RFC5069, January 2008, 1969 . 1971 [RFC6086] Holmberg, C., Burger, E., and H. Kaplan, "Session 1972 Initiation Protocol (SIP) INFO Method and Package 1973 Framework", RFC 6086, DOI 10.17487/RFC6086, January 2011, 1974 . 1976 [RFC7090] Schulzrinne, H., Tschofenig, H., Holmberg, C., and M. 1977 Patel, "Public Safety Answering Point (PSAP) Callback", 1978 RFC 7090, DOI 10.17487/RFC7090, April 2014, 1979 . 1981 [RFC7378] Tschofenig, H., Schulzrinne, H., and B. Aboba, Ed., 1982 "Trustworthy Location", RFC 7378, DOI 10.17487/RFC7378, 1983 December 2014, . 1985 [SDO-3GPP] 1986 "3d Generation Partnership Project", 1987 . 1989 [SDO-ETSI] 1990 "European Telecommunications Standards Institute (ETSI)", 1991 . 1993 [TS23.167] 1994 3GPP, , "3GPP TS 23.167: IP Multimedia Subsystem (IMS) 1995 emergency sessions". 1997 Authors' Addresses 1999 Randall Gellens 2000 Core Technology Consulting 2002 Email: rg+ietf@randy.pensive.org 2004 Hannes Tschofenig 2005 Individual 2007 Email: Hannes.Tschofenig@gmx.net 2008 URI: http://www.tschofenig.priv.at