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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) == Unused Reference: 'ITU.X691' is defined on line 2004, but no explicit reference was found in the text ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) == Outdated reference: draft-ietf-ecrit-car-crash has been published as RFC 8148 Summary: 1 error (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). 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: August 14, 2017 Individual 6 February 10, 2017 8 Next-Generation Pan-European eCall 9 draft-ietf-ecrit-ecall-26.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 media 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 SIP INFO 24 requests. 26 Although this specification is designed to meet the requirements of 27 European next-generation eCall, it is specified generically such that 28 the technology can be re-used or extended to suit requirements across 29 jurisdictions. 31 Status of This Memo 33 This Internet-Draft is submitted in full conformance with the 34 provisions of BCP 78 and BCP 79. 36 Internet-Drafts are working documents of the Internet Engineering 37 Task Force (IETF). Note that other groups may also distribute 38 working documents as Internet-Drafts. The list of current Internet- 39 Drafts is at http://datatracker.ietf.org/drafts/current/. 41 Internet-Drafts are draft documents valid for a maximum of six months 42 and may be updated, replaced, or obsoleted by other documents at any 43 time. It is inappropriate to use Internet-Drafts as reference 44 material or to cite them other than as "work in progress." 46 This Internet-Draft will expire on August 14, 2017. 48 Copyright Notice 50 Copyright (c) 2017 IETF Trust and the persons identified as the 51 document authors. All rights reserved. 53 This document is subject to BCP 78 and the IETF Trust's Legal 54 Provisions Relating to IETF Documents 55 (http://trustee.ietf.org/license-info) in effect on the date of 56 publication of this document. Please review these documents 57 carefully, as they describe your rights and restrictions with respect 58 to this document. Code Components extracted from this document must 59 include Simplified BSD License text as described in Section 4.e of 60 the Trust Legal Provisions and are provided without warranty as 61 described in the Simplified BSD License. 63 Table of Contents 65 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 66 2. Document Scope . . . . . . . . . . . . . . . . . . . . . . . 4 67 3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5 68 4. eCall Requirements . . . . . . . . . . . . . . . . . . . . . 7 69 5. Vehicle Data . . . . . . . . . . . . . . . . . . . . . . . . 7 70 6. Data Transport . . . . . . . . . . . . . . . . . . . . . . . 7 71 7. Call Setup . . . . . . . . . . . . . . . . . . . . . . . . . 10 72 8. Test Calls . . . . . . . . . . . . . . . . . . . . . . . . . 11 73 9. The Metadata/Control Object . . . . . . . . . . . . . . . . . 11 74 9.1. The Control Block . . . . . . . . . . . . . . . . . . . . 13 75 9.1.1. The element . . . . . . . . . . . . . . . . . . 13 76 9.1.1.1. Attributes of the element . . . . . . . . . 14 77 9.1.1.2. Child Element of the element . . . . . . . 14 78 9.1.1.3. Ack Examples . . . . . . . . . . . . . . . . . . 15 79 9.1.2. The element . . . . . . . . . . . . . 15 80 9.1.2.1. Child Element of the element . . . 15 81 9.1.2.2. Capabilities Example . . . . . . . . . . . . . . 16 82 9.1.3. The element . . . . . . . . . . . . . . . . 16 83 9.1.3.1. Attributes of the element . . . . . . . 17 84 9.1.3.2. Request Example . . . . . . . . . . . . . . . . . 18 85 10. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 18 86 11. Security Considerations . . . . . . . . . . . . . . . . . . . 24 87 12. Privacy Considerations . . . . . . . . . . . . . . . . . . . 25 88 13. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . 26 89 14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 90 14.1. The EmergencyCallData Media Subtree . . . . . . . . . . 28 91 14.2. Service URN Registrations . . . . . . . . . . . . . . . 29 92 14.3. MIME Media Type Registration for 93 'application/emergencyCallData.eCall.MSD' . . . . . . . 29 94 14.4. MIME Media Type Registration for 95 'application/emergencyCallData.control+xml' . . . . . . 31 97 14.5. Registration of the 'eCall.MSD' entry in the Emergency 98 Call Additional Data Types registry . . . . . . . . . . 32 99 14.6. Registration of the 'control' entry in the Emergency 100 Call Additional Data Types registry . . . . . . . . . . 32 101 14.7. Registration for 102 urn:ietf:params:xml:ns:EmergencyCallData:control . . . . 33 103 14.8. Registry Creation . . . . . . . . . . . . . . . . . . . 33 104 14.8.1. Emergency Call Action Registry . . . . . . . . . . . 33 105 14.8.2. Emergency Call Action Failure Reason Registry . . . 34 106 14.9. The emergencyCallData.eCall.MSD INFO package . . . . . . 35 107 14.9.1. Overall Description . . . . . . . . . . . . . . . . 35 108 14.9.2. Applicability . . . . . . . . . . . . . . . . . . . 36 109 14.9.3. Info Package Name . . . . . . . . . . . . . . . . . 36 110 14.9.4. Info Package Parameters . . . . . . . . . . . . . . 36 111 14.9.5. SIP Option-Tags . . . . . . . . . . . . . . . . . . 37 112 14.9.6. INFO Request Body Parts . . . . . . . . . . . . . . 37 113 14.9.7. Info Package Usage Restrictions . . . . . . . . . . 37 114 14.9.8. Rate of INFO Requests . . . . . . . . . . . . . . . 37 115 14.9.9. Info Package Security Considerations . . . . . . . . 38 116 14.9.10. Implementation Details . . . . . . . . . . . . . . . 38 117 14.9.11. Examples . . . . . . . . . . . . . . . . . . . . . . 38 118 15. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 38 119 16. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 38 120 17. Changes from Previous Versions . . . . . . . . . . . . . . . 38 121 17.1. Changes from draft-ietf-19 to draft-ietf-20 . . . . . . 38 122 17.2. Changes from draft-ietf-18 to draft-ietf-19 . . . . . . 39 123 17.3. Changes from draft-ietf-17 to draft-ietf-18 . . . . . . 39 124 17.4. Changes from draft-ietf-16 to draft-ietf-17 . . . . . . 39 125 17.5. Changes from draft-ietf-15 to draft-ietf-16 . . . . . . 39 126 17.6. Changes from draft-ietf-14 to draft-ietf-15 . . . . . . 39 127 17.7. Changes from draft-ietf-13 to draft-ietf-14 . . . . . . 39 128 17.8. Changes from draft-ietf-12 to draft-ietf-13 . . . . . . 39 129 17.9. Changes from draft-ietf-11 to draft-ietf-12 . . . . . . 40 130 17.10. Changes from draft-ietf-09 to draft-ietf-11 . . . . . . 40 131 17.11. Changes from draft-ietf-08 to draft-ietf-09 . . . . . . 40 132 17.12. Changes from draft-ietf-07 to draft-ietf-08 . . . . . . 40 133 17.13. Changes from draft-ietf-06 to draft-ietf-07 . . . . . . 41 134 17.14. Changes from draft-ietf-05 to draft-ietf-06 . . . . . . 41 135 17.15. Changes from draft-ietf-04 to draft-ietf-05 . . . . . . 41 136 17.16. Changes from draft-ietf-03 to draft-ietf-04 . . . . . . 41 137 17.17. Changes from draft-ietf-02 to draft-ietf-03 . . . . . . 41 138 17.18. Changes from draft-ietf-01 to draft-ietf-02 . . . . . . 42 139 17.19. Changes from draft-ietf-00 to draft-ietf-01 . . . . . . 42 140 17.20. Changes from draft-gellens-03 to draft-ietf-00 . . . . . 42 141 17.21. Changes from draft-gellens-02 to -03 . . . . . . . . . . 42 142 17.22. Changes from draft-gellens-01 to -02 . . . . . . . . . . 43 143 17.23. Changes from draft-gellens-00 to -01 . . . . . . . . . . 43 144 18. References . . . . . . . . . . . . . . . . . . . . . . . . . 43 145 18.1. Normative References . . . . . . . . . . . . . . . . . . 43 146 18.2. Informative references . . . . . . . . . . . . . . . . . 44 147 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 46 149 1. Terminology 151 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 152 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 153 document are to be interpreted as described in [RFC2119]. 155 This document re-uses terminology defined in Section 3 of [RFC5012]. 157 Additionally, we use the following abbreviations: 159 +--------+----------------------------------------+ 160 | Term | Expansion | 161 +--------+----------------------------------------+ 162 | 3GPP | 3rd Generation Partnership Project | 163 | | | 164 | CEN | European Committee for Standardization | 165 | | | 166 | EENA | European Emergency Number Association | 167 | | | 168 | ESInet | Emergency Services IP network | 169 | | | 170 | IMS | IP Multimedia Subsystem | 171 | | | 172 | IVS | In-Vehicle System | 173 | | | 174 | MNO | Mobile Network Operator | 175 | | | 176 | MSD | Minimum Set of Data | 177 | | | 178 | PSAP | Public Safety Answering Point | 179 +--------+----------------------------------------+ 181 2. Document Scope 183 This document is focused on the signaling, data exchange, and 184 protocol needs of next-generation eCall (NG-eCall, also referred to 185 as packet-switched eCall or all-IP eCall) within the SIP framework 186 for emergency calls (as described in [RFC6443] and [RFC6881]). eCall 187 itself is specified by 3GPP (3rd Generation Partnership Project) and 188 CEN (European Committee for Standardization) and these specifications 189 include far greater scope than is covered here. 191 The eCall service operates over cellular wireless communication, but 192 this document does not address cellular-specific details, nor client 193 domain selection (e.g., circuit-switched versus packet-switched). 194 All such aspects are the purview of their respective standards 195 bodies. The scope of this document is limited to eCall operating 196 within a SIP-based environment (e.g., 3GPP IMS Emergency Calling 197 [TS23.167]). 199 Although this specification is designed to meet the requirements of 200 pan-European next-generation eCall, it is specified generically such 201 that the technology can be re-used or extended to suit requirements 202 across jurisdictions (see, e.g., [I-D.ietf-ecrit-car-crash]), and 203 extension points are provided to facilitate this. 205 Note that vehicles designed for multiple regions might need to 206 support eCall and other Advanced Automatic Crash Notification (AACN) 207 systems (such as described in [I-D.ietf-ecrit-car-crash]), but this 208 is out of scope of this document. 210 3. Introduction 212 Emergency calls made from vehicles (e.g., in the event of a crash) 213 assist in significantly reducing road deaths and injuries by allowing 214 emergency services to be aware of the incident, the state of the 215 vehicle, the location of the vehicle, and to have a voice channel 216 with the vehicle occupants. This enables a quick and appropriate 217 response. 219 The European Commission initiative of eCall was conceived in the late 220 1990s, and has evolved to a European Parliament decision requiring 221 the implementation of a compliant in-vehicle system (IVS) in new 222 vehicles and the deployment of eCall in the European Member States in 223 the very near future. Other regions are developing eCall-compatible 224 systems. 226 The pan-European eCall system is a standardized and mandated 227 mechanism for emergency calls by vehicles, providing a voice channel 228 and transmission of data. eCall establishes procedures for such 229 calls to be placed by in-vehicle systems, recognized and processed by 230 the mobile network, and routed to a specialized PSAP where the 231 vehicle data is available to assist the call taker in assessing and 232 responding to the situation. eCall provides a standard set of 233 vehicle, sensor (e.g., crash related), and location data. 235 An eCall can be either user-initiated or automatically triggered. 236 Automatically triggered eCalls indicate a car crash or some other 237 serious incident. Manually triggered eCalls might be reports of 238 witnessed crashes or serious hazards. PSAPs might apply specific 239 operational handling to manual and automatic eCalls. 241 Legacy eCall is standardized (by 3GPP [SDO-3GPP] and CEN [CEN]) as a 242 3GPP circuit-switched call over GSM (2G) or UMTS (3G). Flags in the 243 call setup mark the call as an eCall, and further indicate if the 244 call was automatically or manually triggered. The call is routed to 245 an eCall-capable PSAP, a voice channel is established between the 246 vehicle and the PSAP, and an eCall in-band modem is used to carry a 247 defined set of vehicle, sensor (e.g., crash related), and location 248 data (the Minimum Set of Data or MSD) within the voice channel. The 249 same in-band mechanism is used for the PSAP to acknowledge successful 250 receipt of the MSD, and to request the vehicle to send a new MSD 251 (e.g., to check if the state of or location of the vehicle or its 252 occupants has changed). NG-eCall moves from circuit switched to all- 253 IP, and carries the vehicle data and eCall signaling as additional 254 data carried with the call. This document describes how IETF 255 mechanisms for IP-based emergency calls (including [RFC6443] and 256 [RFC7852]) are used to provide the signaling and data exchange of the 257 next generation of pan-European eCall. 259 The European Telecommunications Standards Institute (ETSI) [SDO-ETSI] 260 has published a Technical Report titled "Mobile Standards Group 261 (MSG); eCall for VoIP" [MSG_TR] that presents findings and 262 recommendations regarding support for eCall in an all-IP environment. 263 The recommendations include the use of 3GPP IMS emergency calling 264 with additional elements identifying the call as an eCall and as 265 carrying eCall data and with mechanisms for carrying the data and 266 eCall signaling. 3GPP IMS emergency services support multimedia, 267 providing the ability to carry voice, text, and video. This 268 capability is referred to within 3GPP as Multimedia Emergency 269 Services (MMES). 271 A transition period will exist during which time the various entities 272 involved in initiating and handling an eCall might support next- 273 generation eCall, legacy eCall, or both. The issues of migration and 274 co-existence during the transition period are outside the scope of 275 this document. 277 This document indicates how to use IP-based emergency services 278 mechanisms to support next-generation eCall. 280 This document also registers MIME media types and an Emergency Call 281 Additional Data Block for the eCall vehicle data (MSD) and metadata/ 282 control data, and an INFO package to enable carrying this data in SIP 283 INFO requests. 285 The MSD is carried in the MIME type 'application/ 286 emergencyCallData.eCall.MSD' and the metadata/control block is 287 carried in the MIME type 'application/emergencyCallData.control+xml' 288 (both of which are registered in Section 14). An INFO package is 289 defined (in Section 14.9) to enable these MIME types to be carried in 290 SIP INFO requests, per [RFC6086]. 292 4. eCall Requirements 294 eCall requirements are specified by CEN in [EN_16072] and by 3GPP in 295 [TS22.101] clauses 10.7 and A.27 and [TS24.229] section 4.7.6. 296 Requirements specific to vehicle data are contained in EN 15722 297 [msd]. 299 5. Vehicle Data 301 Pan-European eCall provides a standardized and mandated set of 302 vehicle related data (including VIN, vehicle type, propulsion type, 303 current and optionally previous location coordinates, and number of 304 occupants), known as the Minimum Set of Data (MSD). The European 305 Committee for Standardization (CEN) has specified this data in EN 306 15722 [msd], along with both ASN.1 and XML encodings. Both circuit- 307 switched eCall and this document use the ASN.1 PER encoding, which is 308 specified in Annex A of EN 15722 [msd] (the XML encoding specified in 309 Annex C is not used in this document, per 3GPP [SDO-3GPP]). 311 This document registers the 'application/emergencyCallData.eCall.MSD' 312 MIME media type to enable the MSD to be carried in SIP. As an ASN.1 313 PER encoded object, the data is binary and transported using binary 314 content transfer encoding within SIP messages. This document also 315 adds the 'eCall.MSD' entry to the Emergency Call Additional Data 316 Types registry to enable the MSD to be recognized as such in a SIP- 317 based eCall emergency call. (See [RFC7852] for more information 318 about the registry and how it is used.) 320 See Section 6 for a discussion of how the MSD vehicle data is 321 conveyed in an NG-eCall. 323 6. Data Transport 325 [RFC7852] establishes a general mechanism for conveying blocks of 326 data within a SIP emergency call. This document makes use of that 327 mechanism to include vehicle data (the MSD, see Section 5) and/or 328 metadata/control information (see Section 9) within SIP messages. 329 This document also registers an INFO package (in Section 14.9) to 330 enable eCall related data blocks to be carried in SIP INFO requests 331 (per [RFC6086], new INFO usages require the definition of an INFO 332 package). 334 Note that if other data sets need to be transmitted in the future, 335 the appropriate signalling mechanism for such data needs to be 336 evaluated, including factors such as the size and frequency of such 337 data. 339 An In-Vehicle System (IVS) transmits an MSD (see Section 5) by 340 encoding it per Annex A of EN 15722 [msd], and including it as a MIME 341 body part within a SIP message per [RFC7852]. The body part is 342 identified by its MIME media type ('application/ 343 emergencyCallData.eCall.MSD') in the Content-Type header field of the 344 body part. The body part is assigned a unique identifier which is 345 listed in a Content-ID header field in the body part. The SIP 346 message is marked as containing the MSD by adding (or appending to) a 347 Call-Info header field at the top level of the SIP message. This 348 Call-Info header field contains a CID URL referencing the body part's 349 unique identifier, and a 'purpose' parameter identifying the data as 350 the eCall MSD per the Emergency Call Additional Data Types registry 351 entry; the 'purpose' parameter's value is 352 'emergencyCallData.eCall.MSD'. Per [RFC6086], an MSD is carried in a 353 SIP INFO request by using the INFO package defined in Section 14.9. 355 A PSAP or IVS transmits a metadata/control object (see Section 9) by 356 encoding it per the description in this document, and including it 357 within a SIP message as a MIME body part per [RFC7852]. The body 358 part is identified by its MIME media type ('application/ 359 emergencyCallData.control+xml') in the Content-Type header field of 360 the body part. The body part is assigned a unique identifier which 361 is listed in a Content-ID header field in the body part. The SIP 362 message is marked as containing the metadata/control object by adding 363 (or appending to) a Call-Info header field at the top level of the 364 SIP message. This Call-Info header field contains a CID URL 365 referencing the body part's unique identifier, and a 'purpose' 366 parameter identifying the data as an eCall metadata/control block per 367 the Emergency Call Additional Data Types registry entry; the 368 'purpose' parameter's value is 'emergencyCallData.control'. Per 369 [RFC6086], a metadata/control object is carried in a SIP INFO request 370 by using the INFO package defined in Section 14.9. 372 An MSD or a metadata/control block is always enclosed in a multipart 373 (normally multipart/mixed) body part (even if it would otherwise be 374 the only body part in the SIP message), since as of the date of this 375 document, the use of Content-ID as a SIP header field is not defined 376 (while it is defined for use as a MIME header field). 378 A body part containing an MSD or metadata/control object has a 379 Content-Disposition header field value containing "By-Reference". 381 An In-Vehicle System (IVS) initiating an NG-eCall includes an MSD as 382 a body part within the initial INVITE, and optionally also includes a 383 metadata/control object informing the PSAP of its capabilities as 384 another body part. The MSD body part (and metadata/control and PIDF- 385 LO body parts if included) have a Content-Disposition header field 386 with the value "By-Reference; handling=optional". Specifying 387 "handling=optional" prevents the SIP INVITE request from being 388 rejected if it is processed by a legacy element (e.g., a gateway 389 between SIP and circuit-switched environments) that does not 390 understand the MSD (or metadata/control object or PIDF-LO). The PSAP 391 creates a metadata/control object acknowledging receipt of the MSD 392 and includes it as a body part within the SIP final response to the 393 SIP INVITE request per [RFC7852]. A metadata/control object is not 394 included in provisional (e.g., 180) responses. 396 A PSAP is able to reject a call while indicating that it is aware of 397 the situation by including a metadata/control object acknowledging 398 the MSD and containing "received=true" within a final response using 399 SIP response code 600 (Busy Everywhere), 486 (Busy Here), or 603 400 (Decline), per [RFC7852]. 402 If the IVS receives an acknowledgment for an MSD containing 403 "received=false", this indicates that the PSAP was unable to properly 404 decode or process the MSD. The IVS action is not defined (e.g., it 405 might only log an error). Since the PSAP is able to request an 406 updated MSD during the call, if an initial MSD is unsatisfactory in 407 any way, the PSAP can choose to request another one. 409 A PSAP can request that the vehicle send an updated MSD during a call 410 (e.g., upon manual request of the PSAP call taker who suspects 411 vehicle state may have changed.) To do so, the PSAP creates a 412 metadata/control object requesting an MSD and includes it within a 413 SIP INFO request sent within the dialog. The IVS then includes an 414 updated MSD within a SIP INFO request and sends it within the dialog. 415 If the IVS is unable to send an MSD, it instead sends a metadata/ 416 control object acknowledging the request with the 'success' parameter 417 set to 'false' and a 'reason' parameter (and optionally a 'details' 418 parameter) indicating why the request could not be accomplished. Per 419 [RFC6086], metadata/control objects and MSDs are sent using the INFO 420 package defined in Section 14.9. In addition, to align with how an 421 MSD or metadata/control block is transmitted in a SIP message other 422 than an INFO request, a Call-Info header field is included in the SIP 423 INFO request to reference the MSD or metadata/control block per 424 [RFC7852]. See Section 14.9 for information about the use of SIP 425 INFO requests to carry data within an eCall. 427 The IVS is not expected to send an unsolicited MSD after the initial 428 INVITE. 430 This document does not mandate support for the data blocks defined in 431 [RFC7852]. 433 7. Call Setup 435 In circuit-switched eCall, the IVS places a special form of a 112 436 emergency call which carries an eCall flag (indicating that the call 437 is an eCall and also if the call was manually or automatically 438 triggered); the mobile network operator (MNO) recognizes the eCall 439 flag and routes the call to an eCall-capable PSAP; vehicle data is 440 transmitted to the PSAP via the eCall in-band modem (in the voice 441 channel). 443 ///----\\\ 112 voice call with eCall flag +------+ 444 ||| IVS |||---------------------------------------->+ PSAP | 445 \\\----/// vehicle data via eCall in-band modem +------+ 447 Figure 1: circuit-switched eCall 449 For NG-eCall, the IVS establishes an emergency call using a Request- 450 URI indicating a manual or automatic eCall; the MNO (or ESInet) 451 recognizes the eCall URN and routes the call to an NG-eCall capable 452 PSAP; the PSAP interprets the vehicle data sent with the call and 453 makes it available to the call taker. 455 ///----\\\ IMS emergency call with eCall URN +------+ 456 IVS ----------------------------------------->+ PSAP | 457 \\\----/// vehicle data included in call setup +------+ 459 Figure 2: NG-eCall 461 See Section 6 for information on how the MSD is transported within an 462 NG-eCall. 464 This document adds new service URN children within the "sos" 465 subservice. These URNs provide the mechanism by which an eCall is 466 identified, and differentiate between manually and automatically 467 triggered eCalls (which might be subject to different treatment, 468 depending on policy). The two service URNs are: 469 urn:service:sos.ecall.automatic and urn:service:sos.ecall.manual, 470 which requests resources associated with an emergency call placed by 471 an in-vehicle system, carrying a standardized set of data related to 472 the vehicle and incident. These are registered in Section 14.2 474 Call routing is outside the scope of this document. 476 8. Test Calls 478 eCall requires the ability to place test calls (see [TS22.101] clause 479 10.7 and [EN_16062] clause 7.2.2). These are calls that are 480 recognized and treated to some extent as eCalls but are not given 481 emergency call treatment and are not handled by call takers. The 482 specific handling of test eCalls is not itself standardized; 483 typically, the test call facility allows the IVS or user to verify 484 that an eCall can be successfully established with voice 485 communication. The IVS might also be able to verify that the MSD was 486 successfully received. 488 A service URN starting with "test." indicates a test call. For 489 eCall, "urn:service:test.sos.ecall" indicates such a test feature. 490 This functionality is defined in [RFC6881]. 492 This document specifies "urn:service:test.sos.ecall" for eCall test 493 calls. This is registered in Section 14.2 495 The circuit switched eCall test call facility is a non-emergency 496 number so does not get treated as an emergency call. For NG-eCall, 497 MNOs, emergency authorities, and PSAPs can determine how to treat a 498 vehicle call requesting the "test" service URN so that the desired 499 functionality is tested, but this is outside the scope of this 500 document. 502 9. The Metadata/Control Object 504 eCall requires the ability for the PSAP to acknowledge successful 505 receipt of an MSD sent by the IVS, and for the PSAP to request that 506 the IVS send an MSD (e.g., the call taker can initiate a request for 507 a new MSD to see if there have been changes in the vehicle's state, 508 e.g., location, direction, number of fastened seatbelts). 510 This document defines a block of metadata/control data as an XML 511 structure containing elements used for eCall and other related 512 emergency call systems and extension points. (This metadata/control 513 block is in effect a high-level protocol between the PSAP and IVS.) 514 When the PSAP sends a metadata/control block in response to data sent 515 by the IVS in a SIP request other than INFO (e.g., the MSD in the 516 initial INVITE), the metadata/control block is sent in the SIP 517 response to that request (e.g., the response to the INVITE request). 518 When the PSAP sends a control block in other circumstances (e.g., 519 mid-call), the control block is transmitted from the PSAP to the IVS 520 in a SIP INFO request within the established dialog. The IVS sends 521 the requested data (the MSD) in a new SIP INFO request (per 522 [RFC6086]). This mechanism flexibly allows the PSAP to send eCall- 523 specific data to the IVS and the IVS to respond. SIP INFO requests 524 are sent using an appropriate SIP INFO Package. See Section 6 for 525 more information on sending a metadata/control block within a SIP 526 message. See Section 14.9 for information about the use of SIP INFO 527 requests to carry data within an eCall. 529 When the IVS includes an unsolicited MSD in a SIP request (e.g., the 530 initial INVITE), the PSAP sends a metadata/control block indicating 531 successful/unsuccessful receipt of the MSD in the SIP response to the 532 request. This also informs the IVS that an NG-eCall is in operation. 533 If the IVS receives a SIP final response without the metadata/control 534 block, it indicates that the SIP dialog is not an NG-eCall (e.g., 535 some part of the call is being handled as a legacy call). When the 536 IVS sends a solicited MSD (e.g., in a SIP INFO request sent following 537 receipt of a SIP INFO request containing a metadata/control block 538 requesting an MSD), the PSAP does not send a metadata/control block 539 indicating successful or unsuccessful receipt of the MSD. (Normal 540 SIP retransmission handles non-receipt of requested data; note that, 541 per [RFC6086], a 200 OK response to a SIP INFO request indicates only 542 that the receiver has successfully received and accepted the SIP INFO 543 request, it says nothing about the acceptability of the payload.) If 544 the IVS receives a request to send an MSD but it is unable to do so 545 for any reason, the IVS sends a metadata/control object acknowledging 546 the request and containing "success=false" and "reason" set to an 547 appropriate code. 549 This provides flexibility to handle various circumstances. For 550 example, if a PSAP is unable to accept an eCall (e.g., due to 551 overload or too many calls from the same location), it can reject the 552 INVITE. Since a metadata/control object is also included in the SIP 553 response that rejects the call, the IVS knows if the PSAP received 554 the MSD, and can inform the vehicle occupants that the PSAP 555 successfully received the vehicle location and information but can't 556 talk to the occupants at that time. Especially for SIP response 557 codes that indicate an inability to conduct a call (as opposed to a 558 technical inability to process the request), the IVS can also 559 determine that the call was successful on a technical level (e.g., 560 not helpful to retry as circuit-switched). (Note that there could be 561 edge cases where the PSAP response is not received by the IVS, e.g., 562 if an intermediary sends a CANCEL, and an error response is forwarded 563 towards the IVS before the error response from the PSAP is received, 564 the response will be dropped, but these are unlikely to occur here.) 566 The metadata/control block is carried in the MIME type 'application/ 567 emergencyCallData.control+xml'. 569 The metadata/control block is designed for use with pan-European 570 eCall and also eCall-like systems (i.e., in other regions), and has 571 extension points. Note that eCall-like systems might define their 572 own vehicle data blocks, and so might need to register a new INFO 573 package to accommodate the new data MIME media type and the metadata/ 574 control object. 576 9.1. The Control Block 578 The control block is an XML data structure allowing for 579 acknowledgments, requests, and capabilities information. It is 580 carried in a body part with a specific MIME media type. Three 581 elements are defined for use within a control block: 583 ack Acknowledges receipt of data or a request. 585 capabilities Used in a control block sent from the IVS to the PSAP 586 (e.g., in the initial INVITE) to inform the PSAP of the 587 vehicle capabilities. Child elements contain all 588 actions and data types supported by the vehicle. It is 589 OPTIONAL for the IVS to send this block. Omitting the 590 block indicates that the IVS supports only the 591 mandatory functionality defined in this document. 593 request Used in a control block sent by the PSAP to the IVS, to 594 request the vehicle to perform an action. 596 The element indicates the object being acknowledged and reports 597 success or failure. 599 The element contains attributes to indicate the request and 600 to supply related information. The 'action' attribute is mandatory 601 and indicates the specific action. An IANA registry is created in 602 Section 14.8.1 to contain the allowed values. 604 The element has child elements to indicate 605 the actions supported by the IVS. 607 9.1.1. The element 609 The element acknowledges receipt of an eCall data object or 610 request. An element references the Content-ID of the object 611 being acknowledged. The PSAP MUST send an element 612 acknowledging receipt of an unsolicited MSD (e.g., sent by the IVS in 613 the INVITE); this element indicates if the PSAP considers the 614 MSD successfully received or not. An element is not sent for a 615 element. 617 The element has the following attributes: 619 9.1.1.1. Attributes of the element 621 The element has the following attributes: 623 Name: ref 624 Usage: Mandatory 625 Type: anyURI 626 Direction: Sent in either direction 627 Description: References the Content-ID of the body part being 628 acknowledged. 629 Example: 631 Name: received 632 Usage: Conditional: mandatory in an element sent by a PSAP 633 Type: Boolean 634 Direction: In this document, sent from the PSAP to the IVS 635 Description: Indicates if the referenced object was considered 636 successfully received or not. 637 Example: 639 9.1.1.2. Child Element of the element 641 For extensibility, the element has the following child element: 643 Name: actionResult 644 Usage: Optional 645 Direction: Sent from the IVS to the PSAP 646 Description: An element indicates the result of an 647 action (other than a successfully executed 'send-data' action). 648 The element contains an element for each 649 element that is not a successfully executed 'send-data' 650 action. The element has the following attributes: 652 Name: action 653 Usage: Mandatory 654 Type: token 655 Description: Contains the value of the 'action' attribute of the 656 element 658 Name: success 659 Usage: Mandatory 660 Type: Boolean 661 Description: Indicates if the action was successfully 662 accomplished 664 Name: reason 665 Usage: Conditional 666 Type: token 667 Description: Used when 'success' is "false", this attribute 668 contains a reason code for a failure. A registry for reason 669 codes is defined in Section 14.8.2. The initial values are: 670 damaged (required components are damaged), data-unsupported 671 (the data item referenced in a 'send-data' request is not 672 supported), security-failure (the authenticity of the request 673 or the authority of the requestor could not be verified), 674 unable (a generic error for use when no other code is 675 appropriate), and unsupported (the 'action' value is not 676 supported). 678 Name: details 679 Usage: optional 680 Type: string 681 Description: Contains further explanation of the circumstances of 682 a success or failure. The contents are implementation-specific 683 and human-readable. This is intended for internal use and 684 troubleshooting, not for display to vehicle occupants. 686 9.1.1.3. Ack Examples 688 689 693 695 697 Figure 3: Ack Example from PSAP to IVS 699 9.1.2. The element 701 The element is transmitted by the IVS to indicate to 702 the PSAP its capabilities. No attributes for this element are 703 currently defined. The following child elements are defined: 705 9.1.2.1. Child Element of the element 707 The element has the following child element: 709 Name: request 710 Usage: Mandatory 711 Description: The element contains a child 712 element per action supported by the vehicle. 714 Example: 716 718 720 722 It is OPTIONAL for the IVS to support the element. If 723 the IVS does not send a element, this indicates that 724 the only action supported by the IVS is 'send-data' with 725 'datatype' set to 'eCall.MSD'. 727 9.1.2.2. Capabilities Example 729 730 733 734 735 737 739 Figure 4: Capabilities Example 741 9.1.3. The element 743 A element appears one or more times on its own or as a 744 child of a element. It allows the PSAP to request 745 that the IVS perform an action. The only action that MUST be 746 supported is to send an MSD. The following attributes and child 747 elements are defined: 749 9.1.3.1. Attributes of the element 751 The element has the following attributes: 753 Name: action 754 Usage: Mandatory 755 Type: token 756 Direction: Sent in either direction 757 Description: Identifies the action that the vehicle is requested to 758 perform (in a element within a element, 759 indicates an action that the vehicle is capable of performing). 760 An IANA registry is established in Section 14.8.1 to contain the 761 allowed values. 762 Example: action="send-data" 764 Name: int-id 765 Usage: Conditional 766 Type: int 767 Direction: Sent in either direction 768 Description: Defined for extensibility. Documents that make use of 769 it are expected to explain when it is required and how it is used. 770 Example: int-id="3" 772 Name: persistence 773 Usage: Optional 774 Type: xs:duration 775 Direction: Sent in either direction 776 Description: Defined for extensibility. Specifies how long to carry 777 on the specified action. If absent, the default is for the 778 duration of the call. 779 Example: persistence="PT1H" 781 Name: datatype 782 Usage: Conditional 783 Type: token 784 Direction: Sent in either direction 785 Description: Mandatory with a "send-data" action within a 786 element that is not within a element. Specifies 787 the data block that the IVS is requested to transmit, using the 788 same identifier as in the 'purpose' attribute set in a Call-Info 789 header field to point to the data block. Permitted values are 790 contained in the 'Emergency Call Data Types' IANA registry 791 established in [RFC7852]. Only the "eCall.MSD" value is mandatory 792 to support. 793 Example: datatype="eCall.MSD" 795 Name: supported-values 796 Usage: Conditional 797 Type: string 798 Direction: Sent from the IVS to the PSAP 799 Description: Defined for extensibility. Used in a element 800 that is a child of a element, this attribute lists 801 all supported values of the action type. Permitted values depend 802 on the action value. Multiple values are separated with a 803 semicolon. White space is ignored. Documents that make use of it 804 are expected to explain when it is required, the permitted values, 805 and how it is used. 807 Name: requested-state 808 Usage: Conditional 809 Type: token 810 Direction: Sent from the PSAP to the IVS 811 Description: Defined for extension. Indicates the requested state 812 of an element associated with the request type. Permitted values 813 depend on the request type. Documents that make use of it are 814 expected to explain when it is required, the permitted values, and 815 how it is used. 817 Name: element-id 818 Usage: Conditional 819 Type: token 820 Direction: Sent from the PSAP to the IVS 821 Description: Defined for extension. Identifies the element to be 822 acted on. Permitted values depend on the request type. Documents 823 that make use of it are expected to explain when it is required, 824 the permitted values, and how it is used. 826 9.1.3.2. Request Example 828 829 832 834 836 Figure 5: Request Example 838 10. Examples 840 Figure 6 illustrates an eCall. The call uses the request URI 841 'urn:service:sos.ecall.automatic' service URN and is recognized as an 842 eCall, and further as one that was invoked automatically by the IVS 843 due to a crash or other serious incident. In this example, the 844 originating network routes the call to an ESInet which routes the 845 call to the appropriate NG-eCall capable PSAP. The emergency call is 846 received by the ESInet's Emergency Services Routing Proxy (ESRP), as 847 the entry point into the ESInet. The ESRP routes the call to a PSAP, 848 where it is received by a call taker. In deployments where there is 849 no ESInet, the originating network routes the call directly to the 850 appropriate NG-eCall capable PSAP, an illustration of which would be 851 identical to the one below except without an ESInet or ESRP. 853 +------------+ +---------------------------------------+ 854 | | | +-------+ | 855 | | | | PSAP2 | | 856 | | | +-------+ | 857 | | | | 858 | | | +------+ +-------+ | 859 Vehicle-->| |--+->| ESRP |---->| PSAP1 |--> Call-Taker | 860 | | | +------+ +-------+ | 861 | | | | 862 | | | +-------+ | 863 | | | | PSAP3 | | 864 | Originating| | +-------+ | 865 | Mobile | | | 866 | Network | | ESInet | 867 +------------+ +---------------------------------------+ 869 Figure 6: Example of NG-eCall Message Flow 871 Figure 7 illustrates an eCall call flow with a mid-call PSAP request 872 for an updated MSD. The call flow shows the IVS initiating an 873 emergency call, including the MSD in the INVITE. The PSAP includes 874 in the 200 OK response a metadata/control object acknowledging 875 receipt of the MSD. During the call, the PSAP sends a request for an 876 MSD in an INFO request. The IVS sends the requested MSD in a new 877 INFO request. 879 IVS PSAP 880 |(1) INVITE (eCall MSD) | 881 |------------------------------------------->| 882 | | 883 |(2) 200 OK (eCall metadata [ack MSD]) | 884 |<-------------------------------------------| 885 | | 886 |(3) start media stream(s) | 887 |............................................| 888 | | 889 |(4) INFO (eCall metadata [request MSD]) | 890 |<-------------------------------------------| 891 | | 892 |(5) 200 OK | 893 |------------------------------------------->| 894 | | 895 |(6) INFO (eCall MSD) | 896 |------------------------------------------->| 897 | | 898 |(7) 200 OK | 899 |<-------------------------------------------| 900 | | 901 |(8) BYE | 902 |<-------------------------------------------| 903 | | 904 |(9) end media streams | 905 |............................................| 906 | | 907 |(10) 200 OK | 908 |------------------------------------------->| 910 Figure 7: NG-eCall Call Flow Illustration 912 The example, shown in Figure 8, illustrates a SIP eCall INVITE 913 request containing an MSD. For simplicity, the example does not show 914 all SIP headers, nor the SDP contents, nor does it show any 915 additional data blocks added by the IVS or the originating mobile 916 network. Because the MSD is encoded in ASN.1 PER, which is a binary 917 encoding, its contents cannot be included in a text document. 919 INVITE urn:service:sos.ecall.automatic SIP/2.0 920 To: urn:service:sos.ecall.automatic 921 From: ;tag=9fxced76sl 922 Call-ID: 3848276298220188511@atlanta.example.com 923 Geolocation: 924 Geolocation-Routing: no 925 Call-Info: ; 926 purpose=emergencyCallData.eCall.MSD 927 Accept: application/sdp, application/pidf+xml, 928 application/emergencyCallData.control+xml 929 CSeq: 31862 INVITE 930 Recv-Info: emergencyCallData.eCall.MSD 931 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 932 SUBSCRIBE, NOTIFY, UPDATE 933 Content-Type: multipart/mixed; boundary=boundary1 934 Content-Length: ... 936 --boundary1 937 Content-Type: application/sdp 939 ...Session Description Protocol (SDP) goes here... 941 --boundary1 942 Content-Type: application/pidf+xml 943 Content-ID: 944 Content-Disposition: by-reference;handling=optional 946 ...PIDF-LO goes in here 948 --boundary1 949 Content-Type: application/emergencyCallData.eCall.MSD 950 Content-ID: <1234567890@atlanta.example.com> 951 Content-Disposition: by-reference;handling=optional 953 ...MSD in ASN.1 PER encoding goes here... 955 --boundary1-- 957 Figure 8: SIP NG-eCall INVITE 959 Continuing the example, Figure 9 illustrates a SIP 200 OK response to 960 the INVITE request of Figure 8, containing a control block 961 acknowledging successful receipt of the eCall MSD. (For simplicity, 962 the example does not show all SIP headers.) 963 SIP/2.0 200 OK 964 To: urn:service:sos.ecall.automatic;tag=8gydfe65t0 965 From: ;tag=9fxced76sl 966 Call-ID: 3848276298220188511@atlanta.example.com 967 Call-Info: ; 968 purpose=emergencyCallData.control 969 Accept: application/sdp, application/pidf+xml, 970 application/emergencyCallData.control+xml, 971 application/emergencyCallData.eCall.MSD 972 CSeq: 31862 INVITE 973 Recv-Info: emergencyCallData.eCall.MSD 974 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 975 SUBSCRIBE, NOTIFY, UPDATE 976 Content-Type: multipart/mixed; boundary=boundaryX 977 Content-Length: ... 979 --boundaryX 980 Content-Type: application/sdp 982 ...Session Description Protocol (SDP) goes here... 984 --boundaryX 985 Content-Type: application/emergencyCallData.control+xml 986 Content-ID: <2345678901@atlanta.example.com> 987 Content-Disposition: by-reference 989 990 993 994 996 --boundaryX-- 998 Figure 9: 200 OK response to INVITE 1000 Figure 10 illustrates a SIP INFO request containing a metadata/ 1001 control block requesting an eCall MSD. (For simplicity, the example 1002 does not show all SIP headers.) 1003 INFO sip:+13145551111@example.com SIP/2.0 1004 To: ;tag=9fxced76sl 1005 From: Exemplar PSAP ;tag=8gydfe65t0 1006 Call-ID: 3848276298220188511@atlanta.example.com 1007 Call-Info: ; 1008 purpose=emergencyCallData.control 1009 CSeq: 41862 INFO 1010 Info-Package: emergencyCallData.eCall.MSD 1011 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1012 SUBSCRIBE, NOTIFY, UPDATE 1013 Content-Type: multipart/mixed; boundary=boundaryZZZ 1014 Content-Disposition: Info-Package 1015 Content-Length: ... 1017 --boundaryZZZ 1018 Content-Disposition: by-reference 1019 Content-Type: application/emergencyCallData.control+xml 1020 Content-ID: <3456789012@atlanta.example.com> 1022 1023 1026 1028 1029 --boundaryZZZ-- 1031 Figure 10: INFO requesting MSD 1033 Figure 11 illustrates a SIP INFO request containing an MSD. For 1034 simplicity, the example does not show all SIP headers. Because the 1035 MSD is encoded in ASN.1 PER, which is a binary encoding, its contents 1036 cannot be included in a text document. 1038 INFO urn:service:sos.ecall.automatic SIP/2.0 1039 To: urn:service:sos.ecall.automatic;tag=8gydfe65t0 1040 From: ;tag=9fxced76sl 1041 Call-ID: 3848276298220188511@atlanta.example.com 1042 Call-Info: ; 1043 purpose=emergencyCallData.eCall.MSD 1044 CSeq: 51862 INFO 1045 Info-Package: emergencyCallData.eCall.MSD 1046 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1047 SUBSCRIBE, NOTIFY, UPDATE 1048 Content-Type: multipart/mixed; boundary=boundaryLine 1049 Content-Disposition: Info-Package 1050 Content-Length: ... 1052 --boundaryLine 1053 Content-Type: application/emergencyCallData.eCall.MSD 1054 Content-ID: <4567890123@atlanta.example.com> 1055 Content-Disposition: by-reference 1057 ...MSD in ASN.1 PER encoding goes here... 1059 --boundaryLine-- 1061 Figure 11: INFO containing MSD 1063 11. Security Considerations 1065 The security considerations described in [RFC5069] (on marking and 1066 routing emergency calls) apply here. 1068 In addition to any network-provided location (which might be 1069 determined solely by the network, or in cooperation with or possibly 1070 entirely by the originating device), an eCall carries an IVS-supplied 1071 location within the MSD. This is likely to be useful to the PSAP, 1072 especially when no network-provided location is included, or when the 1073 two locations are independently determined. Even in situations where 1074 the network-supplied location is limited to the cell site, this can 1075 be useful as a sanity check on the device-supplied location contained 1076 in the MSD. 1078 The document [RFC7378] discusses trust issues regarding location 1079 provided by or determined in cooperation with end devices. 1081 Security considerations specific to the mechanism by which the PSAP 1082 sends acknowledgments and requests to the vehicle are discussed in 1083 the "Security Considerations" block of Section 14.4. Note that an 1084 attacker that has access to and is capable of generating a response 1085 to the initial INVITE request could generate a 600 (Busy Everywhere), 1086 486 (Busy Here), or 603 (Decline) response that includes a metadata/ 1087 control object containing a reference to the MSD in the initial 1088 INVITE and a "received=true" field, which could result in the IVS 1089 perceiving the PSAP to be overloaded and hence not attempting to 1090 reinitiate the call. The risk can be mitigated as discussed in the 1091 "Security Considerations" block of Section 14.4. 1093 Data received from external sources inherently carries implementation 1094 risks. For example, depending on the platform, buffer overflows can 1095 introduce remote code execution vulnerabilities, null characters can 1096 corrupt strings, numeric values used for internal calculations can 1097 result in underflow/overflow errors, malformed XML objects can expose 1098 parsing bugs, etc. Implementations need to be cognizant of the 1099 potential risks, observe best practices (which might include 1100 sufficiently capable static code analysis, fuzz testing, component 1101 isolation, avoiding use of unsafe coding techniques, third-party 1102 attack tests, signed software, over-the-air updates, etc.), and have 1103 multiple levels of protection. Implementors need to be aware that, 1104 potentially, the data objects described here and elsewhere (including 1105 the MSD and metadata/control objects) might be malformed, might 1106 contain unexpected characters, excessively long attribute values, 1107 elements, etc. 1109 The security considerations discussed in [RFC7852] apply here (see 1110 especially the discussion of TLS, TLS versions, cipher suites, and 1111 PKI). 1113 When vehicle data or control/metadata is contained in a signed or 1114 encrypted body part, the enclosing multipart (e.g., multipart/signed 1115 or multipart/encrypted) has the same Content-ID as the enclosed data 1116 part. This allows an entity to identify and access the data blocks 1117 it is interested in without having to dive deeply into the message 1118 structure or decrypt parts it is not interested in. (The 'purpose' 1119 parameter in a Call-Info header field identifies the data and 1120 contains a CID URL pointing to the data block in the body, which has 1121 a matching Content-ID body part header field). 1123 12. Privacy Considerations 1125 The privacy considerations discussed in [RFC7852] apply here. The 1126 MSD carries some identifying and personal information (mostly about 1127 the vehicle and less about the owner), as well as location 1128 information, and so needs to be protected against unauthorized 1129 disclosure. Local regulations may impose additional privacy 1130 protection requirements. 1132 Privacy considerations specific to the data structure containing 1133 vehicle information are discussed in the "Security Considerations" 1134 block of Section 14.3. 1136 Privacy considerations specific to the mechanism by which the PSAP 1137 sends acknowledgments and requests to the vehicle are discussed in 1138 the "Security Considerations" block of Section 14.4. 1140 13. XML Schema 1142 This section defines an XML schema for the control block. The text 1143 description of the control block in Section 9.1 is normative and 1144 supersedes any conflicting aspect of this schema. 1146 1147 1155 1157 1160 1161 1162 1163 1164 1166 1167 1168 1171 1172 1173 1174 1175 1177 1178 1179 1180 1181 1183 1184 1187 1190 1192 1193 1194 conditionally mandatory 1195 when @success="false" 1196 to indicate reason code 1197 for a failure 1198 1199 1200 1201 1203 1205 1206 1207 1210 1211 1214 1216 1217 1218 1219 1221 1222 1223 1224 1225 1229 1232 1233 1234 1235 1236 1238 1239 1240 1241 1242 1245 1246 1248 1249 1251 1252 1254 1255 1257 1258 1259 1260 1262 1264 Figure 12: Control Block Schema 1266 14. IANA Considerations 1268 14.1. The EmergencyCallData Media Subtree 1270 This document establishes the "EmergencyCallData" media (MIME) 1271 subtype tree, a new media subtree rooted at "application/ 1272 EmergencyCallData". This subtree is used only for content associated 1273 with emergency communications. New subtypes in this subtree follow 1274 the rules specified in Section 3.1 of [RFC6838], with the additional 1275 restriction that the standards-related organization MUST be 1276 responsible for some aspect of emergency communications. 1278 This subtree initially contains the following subtypes (defined here 1279 or in [RFC7852]): 1281 emergencyCallData.control+xml 1282 EmergencyCallData.Comment+xml 1283 EmergencyCallData.DeviceInfo+xml 1284 EmergencyCallData.MSD 1285 EmergencyCallData.ProviderInfo+xml 1286 EmergencyCallData.ServiceInfo+xml 1287 EmergencyCallData.SubscriberInfo+xml 1289 14.2. Service URN Registrations 1291 IANA is requested to register the URN 'urn:service:sos.ecall' under 1292 the sub-services 'sos' registry defined in Section 4.2 of [RFC5031]. 1294 This service requests resources associated with an emergency call 1295 placed by an in-vehicle system, carrying a standardized set of data 1296 related to the vehicle and incident. Two sub-services are registered 1297 as well: 1299 urn:service:sos.ecall.manual 1301 Used with an eCall invoked due to manual interaction by a vehicle 1302 occupant. 1304 urn:service:sos.ecall.automatic 1306 Used with an eCall invoked automatically, for example, due to a 1307 crash or other serious incident. 1309 IANA is also requested to register the URN 1310 'urn:service:test.sos.ecall' under the sub-service 'test' registry 1311 defined in Setcion 17.2 of [RFC6881]. This service requests 1312 resources associated with a test (non-emergency) call placed by an 1313 in-vehicle system. See Section 8 for more information on the test 1314 eCall request URN. 1316 14.3. MIME Media Type Registration for 'application/ 1317 emergencyCallData.eCall.MSD' 1319 IANA is requested to add application/emergencyCallData.eCall.MSD as a 1320 MIME media type, with a reference to this document, in accordance to 1321 the procedures of RFC 6838 [RFC6838] and guidelines in RFC 7303 1322 [RFC7303]. 1324 MIME media type name: application 1326 MIME subtype name: emergencyCallData.eCall.MSD 1328 Mandatory parameters: none 1330 Optional parameters: none 1332 Encoding scheme: binary 1334 Encoding considerations: Uses ASN.1 PER, which is a binary 1335 encoding; when transported in SIP, binary content transfer 1336 encoding is used. 1338 Security considerations: This media type is designed to carry 1339 vehicle and incident-related data during an emergency call. This 1340 data contains personal information including vehicle VIN, 1341 location, direction, etc. Appropriate precautions need to be 1342 taken to limit unauthorized access, inappropriate disclosure to 1343 third parties, and eavesdropping of this information. Sections 9 1344 and Section 10 of [RFC7852] contain more discussion. 1346 Interoperability considerations: None 1348 Published specification: Annex A of EN 15722 [msd] 1350 Applications which use this media type: Pan-European eCall 1351 compliant systems 1353 Additional information: None 1355 Magic Number: None 1357 File Extension: None 1359 Macintosh file type code: 'BINA' 1361 Person and email address for further information: Randall Gellens, 1362 rg+ietf@randy.pensive.org 1364 Intended usage: LIMITED USE 1366 Author: The MSD specification was produced by the European 1367 Committee For Standardization (CEN). For contact information, 1368 please see . 1370 Change controller: The European Committee For Standardization 1371 (CEN) 1373 14.4. MIME Media Type Registration for 'application/ 1374 emergencyCallData.control+xml' 1376 IANA is requested to add application/emergencyCallData.control+xml as 1377 a MIME media type, with a reference to this document, in accordance 1378 to the procedures of RFC 6838 [RFC6838] and guidelines in RFC 7303 1379 [RFC7303]. 1381 MIME media type name: application 1383 MIME subtype name: emergencyCallData.control+xml 1385 Mandatory parameters: none 1387 Optional parameters: charset 1389 Indicates the character encoding of the XML content. 1391 Encoding considerations: Uses XML, which can employ 8-bit 1392 characters, depending on the character encoding used. See 1393 Section 3.2 of RFC 7303 [RFC7303]. 1395 Security considerations: 1397 This media type carries metadata and control information and 1398 requests, such as from a Public Safety Answering Point (PSAP) 1399 to an In-Vehicle System (IVS) during an emergency call. 1401 Metadata (such as an acknowledgment that data sent by the IVS 1402 to the PSAP was successfully received) has limited privacy and 1403 security implications. Control information (such as requests 1404 from the PSAP that the vehicle perform an action) has some 1405 privacy and security implications. The privacy concern arises 1406 from the ability to request the vehicle to transmit a data set, 1407 which as described in Section 14.3, can contain personal 1408 information. The security concern is the ability to request 1409 the vehicle to perform an action. Control information needs to 1410 originate only from a PSAP or other emergency services 1411 provider, and not be modified en-route. The level of integrity 1412 of the cellular network over which the emergency call is placed 1413 is a consideration: when the IVS initiates an eCall over a 1414 cellular network, in most cases it relies on the MNO to route 1415 the call to a PSAP. (Calls placed using other means, such as 1416 Wi-Fi or over-the-top services, generally incur somewhat higher 1417 levels of risk than calls placed "natively" using cellular 1418 networks.) A call-back from a PSAP merits additional 1419 consideration, since current mechanisms are not ideal for 1420 verifying that such a call is indeed a call-back from a PSAP in 1421 response to an emergency call placed by the IVS. See the 1422 discussion in Section 11 and the PSAP Callback document 1423 [RFC7090]. 1425 Sections 7 and Section 8 of [RFC7852] contain more discussion. 1427 Interoperability considerations: None 1429 Published specification: This document 1431 Applications which use this media type: Pan-European eCall 1432 compliant systems 1434 Additional information: None 1436 Magic Number: None 1438 File Extension: .xml 1440 Macintosh file type code: 'TEXT' 1442 Person and email address for further information: Randall Gellens, 1443 rg+ietf@randy.pensive.org 1445 Intended usage: LIMITED USE 1447 Author: The IETF ECRIT WG. 1449 Change controller: The IETF ECRIT WG. 1451 14.5. Registration of the 'eCall.MSD' entry in the Emergency Call 1452 Additional Data Types registry 1454 This specification requests IANA to add the 'eCall.MSD' entry to the 1455 Emergency Call Additional Data Types registry, with a reference to 1456 this document; the 'Data About' value is 'The Call'. 1458 14.6. Registration of the 'control' entry in the Emergency Call 1459 Additional Data Types registry 1461 This specification requests IANA to add the 'control' entry to the 1462 Emergency Call Additional Data Types registry, with a reference to 1463 this document; the 'Data About' value is 'The Call'. 1465 14.7. Registration for urn:ietf:params:xml:ns:EmergencyCallData:control 1467 This section registers a new XML namespace, as per the guidelines in 1468 RFC 3688 [RFC3688]. 1470 URI: urn:ietf:params:xml:ns:EmergencyCallData:control 1472 Registrant Contact: IETF, ECRIT working group, , as 1473 delegated by the IESG . 1475 XML: 1477 BEGIN 1478 1479 1481 1482 1483 1485 Namespace for Emergency Call Data Control Block 1486 1487 1488

Namespace for Emergency Call Data Control Block

1489

See [TBD: This document].

1490 1491 1492 END 1494 14.8. Registry Creation 1496 This document creates a new registry called "Emergency Call Metadata/ 1497 Control Data". The following sub-registries are created for this 1498 registry. 1500 14.8.1. Emergency Call Action Registry 1502 This document creates a new sub-registry called "Emergency Call 1503 Action". As defined in [RFC5226], this registry operates under 1504 "Expert Review" rules. The expert should determine that the proposed 1505 action is within the purview of a vehicle, is sufficiently 1506 distinguishable from other actions, and the action is clearly and 1507 fully described. In most cases, a published and stable document is 1508 referenced for the description of the action. 1510 The content of this registry includes: 1512 Name: The identifier to be used in the 'action' attribute of a 1513 control element. 1515 Description: A description of the action. In most cases this will 1516 be a reference to a published and stable document. The 1517 description MUST specify if any attributes or child elements are 1518 optional or mandatory, and describe the action to be taken by the 1519 vehicle. 1521 The initial set of values is listed in Table 2. 1523 +-----------+--------------------------------------+ 1524 | Name | Description | 1525 +-----------+--------------------------------------+ 1526 | send-data | See Section 9.1.3.1 of this document | 1527 +-----------+--------------------------------------+ 1529 Table 2: Emergency Call Action Registry Initial Values 1531 14.8.2. Emergency Call Action Failure Reason Registry 1533 This document creates a new sub-registry called "Emergency Call 1534 Action Failure Reason" which contains values for the 'reason' 1535 attribute of the element. As defined in [RFC5226], 1536 this registry operates under "Expert Review" rules. The expert 1537 should determine that the proposed reason is sufficiently 1538 distinguishable from other reasons and that the proposed description 1539 is understandable and correctly worded. 1541 The content of this registry includes: 1543 ID: A short string identifying the reason, for use in the 'reason' 1544 attribute of an element. 1546 Description: A description of the reason. 1548 The initial set of values is listed in Table 3. 1550 +------------------+------------------------------------------------+ 1551 | ID | Description | 1552 +------------------+------------------------------------------------+ 1553 | damaged | Required components are damaged. | 1554 | | | 1555 | data-unsupported | The data item referenced in a 'send-data' | 1556 | | request is not supported. | 1557 | | | 1558 | security-failure | The authenticity of the request or the | 1559 | | authority of the requestor could not be | 1560 | | verified. | 1561 | | | 1562 | unable | The action could not be accomplished (a | 1563 | | generic error for use when no other code is | 1564 | | appropriate). | 1565 | | | 1566 | unsupported | The 'action' value is not supported. | 1567 +------------------+------------------------------------------------+ 1569 Table 3: Emergency Call Action Failure Reason Registry Initial Values 1571 14.9. The emergencyCallData.eCall.MSD INFO package 1573 This document registers the 'emergencyCallData.eCall.MSD' INFO 1574 package. 1576 Both endpoints (the IVS and the PSAP equipment) include 1577 'emergencyCallData.eCall.MSD' in a Recv-Info header field per 1578 [RFC6086] to indicate ability to receive INFO requests carrying data 1579 as described here. 1581 Support for the 'emergencyCallData.eCall.MSD' INFO package indicates 1582 the ability to receive eCall related body parts as specified in [TBD: 1583 THIS DOCUMENT]. 1585 An INFO request message carrying body parts related to an emergency 1586 call as described in [TBD: THIS DOCUMENT] has an Info-Package header 1587 field set to 'emergencyCallData.eCall.MSD' per [RFC6086]. 1589 The requirements of Section 10 of [RFC6086] are addressed in the 1590 following sections. 1592 14.9.1. Overall Description 1594 This section describes "what type of information is carried in INFO 1595 requests associated with the Info Package, and for what types of 1596 applications and functionalities UAs can use the Info Package." 1597 INFO requests associated with the emergencyCallData.eCall.MSD INFO 1598 package carry data associated with emergency calls as defined in 1599 [TBD: THIS DOCUMENT]. The application is vehicle-initiated emergency 1600 calls established using SIP. The functionality is to carry vehicle 1601 data and metadata/control information between vehicles and PSAPs. 1602 Refer to [TBD: THIS DOCUMENT] for more information. 1604 14.9.2. Applicability 1606 This section describes "why the Info Package mechanism, rather than 1607 some other mechanism, has been chosen for the specific use-case...." 1609 The use of the SIP INFO method is based on an analysis of the 1610 requirements against the intent and effects of the INFO method versus 1611 other approaches (which included the SIP MESSAGE method, the SIP 1612 OPTIONS method, the SIP re-INVITE method, media plane transport, and 1613 non-SIP protocols). In particular, the transport of emergency call 1614 data blocks occurs within a SIP emergency dialog, per Section 6, and 1615 is normally carried in the initial INVITE request and response; the 1616 use of the SIP INFO method only occurs when emergency-call-related 1617 data needs to be sent mid-call. While the SIP MESSAGE method could 1618 be used, it is not tied to a SIP dialog as is the SIP INFO method and 1619 thus might not be associated with the dialog. Either the SIP OPTIONS 1620 or re-INVITE methods could also be used, but is seen as less clean 1621 than the SIP INFO method. The SIP SUBSCRIBE/NOTIFY method could be 1622 coerced into service, but the semantics are not a good fit, e.g., the 1623 subscribe/notify mechanism provides one-way communication consisting 1624 of (often multiple) notifications from notifier to subscriber 1625 indicating that certain events in notifier have occurred, whereas 1626 what's needed here is two-way communication of data related to the 1627 emergency dialog. Use of the media plane mechanisms was discounted 1628 because the number of messages needing to be exchanged in a dialog is 1629 normally zero or very few, and the size of the data is likewise very 1630 small. The overhead caused by user plane setup (e.g., to use MSRP as 1631 transport) would be disproportionately large. 1633 Based on the analyses, the SIP INFO method was chosen to provide for 1634 mid-call data transport. 1636 14.9.3. Info Package Name 1638 The info package name is emergencyCallData.eCall.MSD 1640 14.9.4. Info Package Parameters 1642 None 1644 14.9.5. SIP Option-Tags 1646 None 1648 14.9.6. INFO Request Body Parts 1650 The body for an emergencyCallData.eCall.MSD info package is a 1651 multipart (normally multipart/mixed) body containing zero or one 1652 application/emergencyCallData.eCall.MSD part (containing an MSD) and 1653 zero or more application/emergencyCallData.control+xml (containing a 1654 metadata/control object) parts. At least one MSD or metadata/control 1655 body part is expected; the behavior upon receiving an INFO request 1656 with neither is undefined. 1658 The body parts are sent per [RFC6086], and in addition, to align with 1659 with how these body parts are sent in SIP messages other than INFO 1660 requests, each associated body part is referenced by a Call-Info 1661 header field at the top level of the SIP message. The body part has 1662 a Content-Disposition header field set to "By-Reference". 1664 An MSD or metadata/control block is always enclosed in a multipart 1665 body part (even if it would otherwise be the only body part in the 1666 SIP message), since as of the date of this document, the use of 1667 Content-ID as a SIP header field is not defined (while it is defined 1668 for use as a MIME header field). The innermost multipart that 1669 contains only body parts associated with the INFO package has a 1670 Content-Disposition value of Info-Package. 1672 See [TBD: THIS DOCUMENT] for more information. 1674 14.9.7. Info Package Usage Restrictions 1676 Usage is limited to vehicle-initiated emergency calls as defined in 1677 [TBD: THIS DOCUMENT]. 1679 14.9.8. Rate of INFO Requests 1681 The SIP INFO request is used within an established emergency call 1682 dialog for the PSAP to request the IVS to send an updated MSD, and 1683 for the IVS to send a requested MSD. Because this is normally done 1684 only on manual request of the PSAP call taker (who suspects some 1685 aspect of the vehicle state has changed), the rate of SIP INFO 1686 requests associated with the emergencyCallData.eCall.MSD info package 1687 is normally quite low (most dialogs are likely to contain zero INFO 1688 requests, while others might carry an occasional request). 1690 14.9.9. Info Package Security Considerations 1692 The MIME media type registrations specified for use with this INFO 1693 package (Section 14.3 and Section 14.4) contain a discussion of the 1694 security and/or privacy considerations specific to that data block. 1695 The "Security Considerations" and "Privacy Considerations" sections 1696 of [TBD: THIS DOCUMENT] discuss security and privacy considerations 1697 of the data carried in eCalls. 1699 14.9.10. Implementation Details 1701 See [TBD: THIS DOCUMENT] for protocol details. 1703 14.9.11. Examples 1705 See [TBD: THIS DOCUMENT] for protocol examples. 1707 15. Contributors 1709 Brian Rosen was a co-author of the original document upon which this 1710 document is based. 1712 16. Acknowledgements 1714 We would like to thank Bob Williams and Ban Al-Bakri for their 1715 feedback and suggestion; Rex Buddenberg, Lena Chaponniere, Alissa 1716 Cooper, Keith Drage, Stephen Edge, Wes George, Mirja Kuehlewind, 1717 Allison Mankin, Alexey Melnikov, Ivo Sedlacek, and James Winterbottom 1718 for their review and comments; Robert Sparks and Paul Kyzivat for 1719 their help with the SIP mechanisms; Mark Baker and Ned Freed for 1720 their help with the media subtype registration issue. We would like 1721 to thank Michael Montag, Arnoud van Wijk, Gunnar Hellstrom, and 1722 Ulrich Dietz for their help with the original document upon which 1723 this document is based. Christer Holmberg deserves special mention 1724 for his many detailed reviews. 1726 17. Changes from Previous Versions 1728 RFC Editor: Please remove this section prior to publication. 1730 17.1. Changes from draft-ietf-19 to draft-ietf-20 1732 o Fixed various nits 1734 17.2. Changes from draft-ietf-18 to draft-ietf-19 1736 o Added additional text to "Rate of Info Requests" 1737 o Added additional text to "Security Considerations" 1738 o Further corrected "content type" to "media type" 1740 17.3. Changes from draft-ietf-17 to draft-ietf-18 1742 o Added reference to 3GPP TS24.229 1743 o Clarified that an INFO request is expected to have at least one 1744 MSD or metadata/control body part 1745 o Fixed minor errors in examples 1746 o Corrected "content type" to "media type" 1747 o Deleted "xsi:schemaLocation" from examples 1749 17.4. Changes from draft-ietf-16 to draft-ietf-17 1751 o Clarify Content-Disposition value in INFO requests 1753 17.5. Changes from draft-ietf-15 to draft-ietf-16 1755 o Various clarifications and simplifications 1756 o Added reference to 3GPP 23.167 1758 17.6. Changes from draft-ietf-14 to draft-ietf-15 1760 o eCall body parts now always sent enclosed in multipart (even if 1761 only body part in SIP message) and hence always have a Content- 1762 Disposition of By-Reference 1763 o Fixed errors in attribute directionality text 1764 o Fixed typos. 1766 17.7. Changes from draft-ietf-13 to draft-ietf-14 1768 o Added text to the IANA Considerations to formalize the 1769 EmergencyCallData media subtree 1770 o Fixed some typos 1772 17.8. Changes from draft-ietf-12 to draft-ietf-13 1774 o Clarifications suggested by Christer 1775 o Corrections to Content-Disposition text and examples as suggested 1776 by Paul Kyzivat 1777 o Clarifications to Content-Disposition text and examples to clarify 1778 that handling=optional is only used in the initial INVITE 1780 17.9. Changes from draft-ietf-11 to draft-ietf-12 1782 o Fixed errors in examples found by Dale 1783 o Removed enclosing sub-section of INFO package registration section 1784 o Added text per Christer and Dale's suggestions that the MSD and 1785 metadata/control blocks are sent in INFO with a Call-Info header 1786 field referencing them 1787 o Deleted Call Routing section (7.1) in favor of a statement that 1788 call routing is outside the scope of the document 1789 o Other text changes per comments received from Christer and Ivo. 1791 17.10. Changes from draft-ietf-09 to draft-ietf-11 1793 o Renamed INFO package to emergencyCallData.eCall.MSD 1794 o Changed INFO package to only permit MSD and metadata/control MIME 1795 types 1796 o Moved element back from car-crash but made it 1797 OPTIONAL 1798 o Moved other extension points back from car-crash so that extension 1799 points are in base spec (and also to get XML schema to compile) 1800 o Text changes for clarification. 1802 17.11. Changes from draft-ietf-08 to draft-ietf-09 1804 o Created a new "Data Transport" section that describes how the MSD 1805 and metadata/control blocks are attached, and then referred to 1806 that section rather than repeat the information about the CID and 1807 Call-Info and so forth, which means most references to the 1808 additional-data draft have now been deleted 1809 o Mentioned edge cases where a PSAP response to INVITE isn't 1810 received by the IVS 1811 o Reworded description of which status codes are used when a PSAP 1812 wishes to reject a call but inform the vehicle occupants that it 1813 is aware of the situation to be more definite 1814 o Added examples showing INFO 1815 o Added references for eCall test call requirement 1816 o Described meaning of eCall URNs in Section 8 as well as in IANA 1817 registration 1819 17.12. Changes from draft-ietf-07 to draft-ietf-08 1821 o eCall MSD now encoded as ASN.1 PER, using binary content transfer 1822 encoding 1823 o Added text to point out aspects of call handling and metadata/ 1824 control usage, such as use in rejected calls, and solicited MSDs 1825 o Revised use of INFO to require that when a request for an MSD is 1826 sent in INFO, the MSD sent in response is in its own INFO, not the 1827 response to the requesting INFO 1829 o Added material to INFO package registation to comply with 1830 Section 10 of [RFC6086] 1831 o Moved material not required by 3GPP into 1832 [I-D.ietf-ecrit-car-crash], e.g., some of the eCall metadata/ 1833 control elements, attributes, and values 1834 o Revised test call wording to clarify that specific handling is out 1835 of scope 1836 o Revised wording throughout the document to simplify 1837 o Moved new Section 7.1 to be a subsection of 7 1838 o Moved new Section Section 14.9 to be a main section instead of a 1839 subsection of Section 9 1840 o Revised SIP INFO usage and package registration per advice from 1841 Robert Sparks and Paul Kyzivat 1843 17.13. Changes from draft-ietf-06 to draft-ietf-07 1845 o Fixed typo in Acknowledgements 1847 17.14. Changes from draft-ietf-05 to draft-ietf-06 1849 o Added additional security and privacy clarifications regarding 1850 signed and encrypted data 1851 o Additional security and privacy text 1852 o Deleted informative section on ESINets as unnecessary. 1854 17.15. Changes from draft-ietf-04 to draft-ietf-05 1856 o Reworked the security and privacy considerations material in the 1857 document as a whole and in the MIME registation sections of the 1858 MSD and control objects 1859 o Clarified that the element can appear multiple 1860 times within an element 1861 o Fixed IMS definition 1862 o Added clarifying text for the 'msgid' attribute 1864 17.16. Changes from draft-ietf-03 to draft-ietf-04 1866 o Added Privacy Considerations section 1867 o Reworded most uses of non-normative "may", "should", "must", and 1868 "recommended." 1869 o Fixed nits in examples 1871 17.17. Changes from draft-ietf-02 to draft-ietf-03 1873 o Added request to enable cameras 1874 o Improved examples and XML schema 1875 o Clarifications and wording improvements 1877 17.18. Changes from draft-ietf-01 to draft-ietf-02 1879 o Added clarifying text reinforcing that the data exchange is for 1880 small blocks of data infrequently transmitted 1881 o Clarified that dynamic media is conveyed using SIP re-INVITE to 1882 establish a one-way media stream 1883 o Clarified that the scope is the needs of eCall within the SIP 1884 emergency call environment 1885 o Added informative statement that the document may be suitable for 1886 reuse by other ACN systems 1887 o Clarified that normative language for the control block applies to 1888 both IVS and PSAP 1889 o Removed 'ref', 'supported-mime', and elements 1890 o Minor wording improvements and clarifications 1892 17.19. Changes from draft-ietf-00 to draft-ietf-01 1894 o Added further discussion of test calls 1895 o Added further clarification to the document scope 1896 o Mentioned that multi-region vehicles may need to support other 1897 crash notification specifications in addition to eCall 1898 o Added details of the eCall metadata and control functionality 1899 o Added IANA registration for the MIME media type for the control 1900 object 1901 o Added IANA registries for protocol elements and tokens used in the 1902 control object 1903 o Minor wording improvements and clarifications 1905 17.20. Changes from draft-gellens-03 to draft-ietf-00 1907 o Renamed from draft-gellens- to draft-ietf-. 1908 o Added mention of and reference to ETSI TR "Mobile Standards Group 1909 (MSG); eCall for VoIP" 1910 o Added text to Introduction regarding migration/co-existence being 1911 out of scope 1912 o Added mention in Security Considerations that even if the network- 1913 supplied location is just the cell site, this can be useful as a 1914 sanity check on the IVS-supplied location 1915 o Minor wording improvements and clarifications 1917 17.21. Changes from draft-gellens-02 to -03 1919 o Clarifications and editorial improvements. 1921 17.22. Changes from draft-gellens-01 to -02 1923 o Minor wording improvements 1924 o Removed ".automatic" and ".manual" from 1925 "urn:service:test.sos.ecall" registration and discussion text. 1927 17.23. Changes from draft-gellens-00 to -01 1929 o Now using 'EmergencyCallData' for purpose parameter values and 1930 MIME subtypes, in accordance with changes to [RFC7852] 1931 o Added reference to RFC 6443 1932 o Fixed bug that caused Figure captions to not appear 1934 18. References 1936 18.1. Normative References 1938 [msd] CEN, , "Intelligent transport systems -- eSafety -- eCall 1939 minimum set of data (MSD), EN 15722", April 2015. 1941 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1942 Requirement Levels", BCP 14, RFC 2119, 1943 DOI 10.17487/RFC2119, March 1997, 1944 . 1946 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 1947 DOI 10.17487/RFC3688, January 2004, 1948 . 1950 [RFC5031] Schulzrinne, H., "A Uniform Resource Name (URN) for 1951 Emergency and Other Well-Known Services", RFC 5031, 1952 DOI 10.17487/RFC5031, January 2008, 1953 . 1955 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1956 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 1957 DOI 10.17487/RFC5226, May 2008, 1958 . 1960 [RFC6086] Holmberg, C., Burger, E., and H. Kaplan, "Session 1961 Initiation Protocol (SIP) INFO Method and Package 1962 Framework", RFC 6086, DOI 10.17487/RFC6086, January 2011, 1963 . 1965 [RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type 1966 Specifications and Registration Procedures", BCP 13, 1967 RFC 6838, DOI 10.17487/RFC6838, January 2013, 1968 . 1970 [RFC6881] Rosen, B. and J. Polk, "Best Current Practice for 1971 Communications Services in Support of Emergency Calling", 1972 BCP 181, RFC 6881, DOI 10.17487/RFC6881, March 2013, 1973 . 1975 [RFC7303] Thompson, H. and C. Lilley, "XML Media Types", RFC 7303, 1976 DOI 10.17487/RFC7303, July 2014, 1977 . 1979 [RFC7852] Gellens, R., Rosen, B., Tschofenig, H., Marshall, R., and 1980 J. Winterbottom, "Additional Data Related to an Emergency 1981 Call", RFC 7852, DOI 10.17487/RFC7852, July 2016, 1982 . 1984 18.2. Informative references 1986 [CEN] "European Committee for Standardization", 1987 . 1989 [EN_16062] 1990 CEN, , "Intelligent transport systems -- eSafety -- eCall 1991 High Level Application Requirements (HLAP) Using GSM/UMTS 1992 Circuit Switched Networks, EN 16062", April 2015. 1994 [EN_16072] 1995 CEN, , "Intelligent transport systems -- eSafety -- Pan- 1996 European eCall operating requirements, EN 16072", April 1997 2015. 1999 [I-D.ietf-ecrit-car-crash] 2000 Gellens, R., Rosen, B., and H. Tschofenig, "Next- 2001 Generation Vehicle-Initiated Emergency Calls", draft-ietf- 2002 ecrit-car-crash-23 (work in progress), January 2017. 2004 [ITU.X691] 2005 International Telecommunications Union, , "Information 2006 technology -- ASN.1 encoding rules: Specification of 2007 Packed Encoding Rules (PER), ITU-T X.691", July 2002, 2008 . 2011 [MSG_TR] ETSI, , "ETSI Mobile Standards Group (MSG); eCall for 2012 VoIP", ETSI Technical Report TR 103 140 V1.1.1 (2014-04), 2013 April 2014. 2015 [RFC5012] Schulzrinne, H. and R. Marshall, Ed., "Requirements for 2016 Emergency Context Resolution with Internet Technologies", 2017 RFC 5012, DOI 10.17487/RFC5012, January 2008, 2018 . 2020 [RFC5069] Taylor, T., Ed., Tschofenig, H., Schulzrinne, H., and M. 2021 Shanmugam, "Security Threats and Requirements for 2022 Emergency Call Marking and Mapping", RFC 5069, 2023 DOI 10.17487/RFC5069, January 2008, 2024 . 2026 [RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton, 2027 "Framework for Emergency Calling Using Internet 2028 Multimedia", RFC 6443, DOI 10.17487/RFC6443, December 2029 2011, . 2031 [RFC7090] Schulzrinne, H., Tschofenig, H., Holmberg, C., and M. 2032 Patel, "Public Safety Answering Point (PSAP) Callback", 2033 RFC 7090, DOI 10.17487/RFC7090, April 2014, 2034 . 2036 [RFC7378] Tschofenig, H., Schulzrinne, H., and B. Aboba, Ed., 2037 "Trustworthy Location", RFC 7378, DOI 10.17487/RFC7378, 2038 December 2014, . 2040 [SDO-3GPP] 2041 "3d Generation Partnership Project", 2042 . 2044 [SDO-ETSI] 2045 "European Telecommunications Standards Institute (ETSI)", 2046 . 2048 [TS22.101] 2049 3GPP, , "3GPP TS 22.101: Technical Specification Group 2050 Services and System Aspects; Service aspects; Service 2051 principles". 2053 [TS23.167] 2054 3GPP, , "3GPP TS 23.167: IP Multimedia Subsystem (IMS) 2055 emergency sessions". 2057 [TS24.229] 2058 3GPP, , "3GPP TS 24.229: IP multimedia call control 2059 protocol based on Session Initiation Protocol (SIP) and 2060 Session Description Protocol (SDP); Stage 3". 2062 Authors' Addresses 2064 Randall Gellens 2065 Core Technology Consulting 2067 Email: rg+ietf@randy.pensive.org 2069 Hannes Tschofenig 2070 Individual 2072 Email: Hannes.Tschofenig@gmx.net 2073 URI: http://www.tschofenig.priv.at