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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reference: RFC 5226 (Obsoleted by RFC 8126) ** Downref: Normative reference to an Informational RFC: RFC 6443 == Outdated reference: draft-ietf-ecrit-car-crash has been published as RFC 8148 Summary: 3 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--).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 6, 2017 Individual 6 October 3, 2016 8 Next-Generation Pan-European eCall 9 draft-ietf-ecrit-ecall-14.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 Blocks for the eCall vehicle data and metadata/ 23 control data. 25 Status of This Memo 27 This Internet-Draft is submitted in full conformance with the 28 provisions of BCP 78 and BCP 79. 30 Internet-Drafts are working documents of the Internet Engineering 31 Task Force (IETF). Note that other groups may also distribute 32 working documents as Internet-Drafts. The list of current Internet- 33 Drafts is at http://datatracker.ietf.org/drafts/current/. 35 Internet-Drafts are draft documents valid for a maximum of six months 36 and may be updated, replaced, or obsoleted by other documents at any 37 time. It is inappropriate to use Internet-Drafts as reference 38 material or to cite them other than as "work in progress." 40 This Internet-Draft will expire on April 6, 2017. 42 Copyright Notice 44 Copyright (c) 2016 IETF Trust and the persons identified as the 45 document authors. All rights reserved. 47 This document is subject to BCP 78 and the IETF Trust's Legal 48 Provisions Relating to IETF Documents 49 (http://trustee.ietf.org/license-info) in effect on the date of 50 publication of this document. Please review these documents 51 carefully, as they describe your rights and restrictions with respect 52 to this document. Code Components extracted from this document must 53 include Simplified BSD License text as described in Section 4.e of 54 the Trust Legal Provisions and are provided without warranty as 55 described in the Simplified BSD License. 57 Table of Contents 59 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 60 2. Document Scope . . . . . . . . . . . . . . . . . . . . . . . 4 61 3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5 62 4. eCall Requirements . . . . . . . . . . . . . . . . . . . . . 6 63 5. Vehicle Data . . . . . . . . . . . . . . . . . . . . . . . . 6 64 6. Data Transport . . . . . . . . . . . . . . . . . . . . . . . 7 65 7. Call Setup . . . . . . . . . . . . . . . . . . . . . . . . . 9 66 8. Test Calls . . . . . . . . . . . . . . . . . . . . . . . . . 10 67 9. The Metadata/Control Object . . . . . . . . . . . . . . . . . 10 68 9.1. The Control Block . . . . . . . . . . . . . . . . . . . . 12 69 9.1.1. The element . . . . . . . . . . . . . . . . . . 13 70 9.1.1.1. Attributes of the element . . . . . . . . . 13 71 9.1.1.2. Child Element of the element . . . . . . . 13 72 9.1.1.3. Ack Examples . . . . . . . . . . . . . . . . . . 14 73 9.1.2. The element . . . . . . . . . . . . . 15 74 9.1.2.1. Child Elements of the element . . 15 75 9.1.2.2. Capabilities Example . . . . . . . . . . . . . . 15 76 9.1.3. The element . . . . . . . . . . . . . . . . 16 77 9.1.3.1. Attributes of the element . . . . . . . 16 78 9.1.3.2. Request Example . . . . . . . . . . . . . . . . . 18 79 10. The emergencyCallData.eCall.MSD INFO package . . . . . . . . 18 80 10.1. Overall Description . . . . . . . . . . . . . . . . . . 18 81 10.2. Applicability . . . . . . . . . . . . . . . . . . . . . 19 82 10.3. Info Package Name . . . . . . . . . . . . . . . . . . . 19 83 10.4. Info Package Parameters . . . . . . . . . . . . . . . . 19 84 10.5. SIP Option-Tags . . . . . . . . . . . . . . . . . . . . 19 85 10.6. INFO Request Body Parts . . . . . . . . . . . . . . . . 20 86 10.7. Info Package Usage Restrictions . . . . . . . . . . . . 20 87 10.8. Rate of INFO Requests . . . . . . . . . . . . . . . . . 20 88 10.9. Info Package Security Considerations . . . . . . . . . . 20 89 10.10. Implementation Details . . . . . . . . . . . . . . . . . 21 90 10.11. Examples . . . . . . . . . . . . . . . . . . . . . . . . 21 91 11. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 21 92 12. Security Considerations . . . . . . . . . . . . . . . . . . . 26 93 13. Privacy Considerations . . . . . . . . . . . . . . . . . . . 27 94 14. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . 27 95 15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30 96 15.1. Service URN Registrations . . . . . . . . . . . . . . . 30 97 15.2. MIME Content-type Registration for 98 'application/emergencyCallData.eCall.MSD+per' . . . . . 31 99 15.3. MIME Content-type Registration for 100 'application/emergencyCallData.control+xml' . . . . . . 32 101 15.4. Registration of the 'eCall.MSD' entry in the Emergency 102 Call Additional Data Blocks registry . . . . . . . . . . 34 103 15.5. Registration of the 'control' entry in the Emergency 104 Call Additional Data Blocks registry . . . . . . . . . . 34 105 15.6. Registration of the emergencyCallData.eCall Info Package 34 106 15.7. URN Sub-Namespace Registration . . . . . . . . . . . . . 34 107 15.7.1. Registration for urn:ietf:params:xml:ns:eCall . . . 34 108 15.7.2. Registration for urn:ietf:params:xml:ns:control . . 35 109 15.8. Registry creation . . . . . . . . . . . . . . . . . . . 36 110 15.8.1. Action Registry . . . . . . . . . . . . . . . . . . 36 111 15.8.2. Reason Registry . . . . . . . . . . . . . . . . . . 37 112 16. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 38 113 17. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 38 114 18. Changes from Previous Versions . . . . . . . . . . . . . . . 38 115 18.1. Changes from draft-ietf-13 to draft-ietf-14 . . . . . . 38 116 18.2. Changes from draft-ietf-12 to draft-ietf-13 . . . . . . 38 117 18.3. Changes from draft-ietf-11 to draft-ietf-12 . . . . . . 38 118 18.4. Changes from draft-ietf-09 to draft-ietf-11 . . . . . . 38 119 18.5. Changes from draft-ietf-08 to draft-ietf-09 . . . . . . 39 120 18.6. Changes from draft-ietf-07 to draft-ietf-08 . . . . . . 39 121 18.7. Changes from draft-ietf-06 to draft-ietf-07 . . . . . . 40 122 18.8. Changes from draft-ietf-05 to draft-ietf-06 . . . . . . 40 123 18.9. Changes from draft-ietf-04 to draft-ietf-05 . . . . . . 40 124 18.10. Changes from draft-ietf-03 to draft-ietf-04 . . . . . . 40 125 18.11. Changes from draft-ietf-02 to draft-ietf-03 . . . . . . 40 126 18.12. Changes from draft-ietf-01 to draft-ietf-02 . . . . . . 40 127 18.13. Changes from draft-ietf-00 to draft-ietf-01 . . . . . . 41 128 18.14. Changes from draft-gellens-03 to draft-ietf-00 . . . . . 41 129 18.15. Changes from draft-gellens-02 to -03 . . . . . . . . . . 41 130 18.16. Changes from draft-gellens-01 to -02 . . . . . . . . . . 41 131 18.17. Changes from draft-gellens-00 to -01 . . . . . . . . . . 41 132 19. References . . . . . . . . . . . . . . . . . . . . . . . . . 41 133 19.1. Normative References . . . . . . . . . . . . . . . . . . 42 134 19.2. Informative references . . . . . . . . . . . . . . . . . 43 135 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 44 137 1. Terminology 139 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 140 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 141 document are to be interpreted as described in [RFC2119]. 143 This document re-uses terminology defined in Section 3 of [RFC5012]. 145 Additionally, we use the following abbreviations: 147 +--------+----------------------------------------+ 148 | Term | Expansion | 149 +--------+----------------------------------------+ 150 | 3GPP | 3rd Generation Partnership Project | 151 | | | 152 | CEN | European Committee for Standardization | 153 | | | 154 | EENA | European Emergency Number Association | 155 | | | 156 | ESInet | Emergency Services IP network | 157 | | | 158 | IMS | IP Multimedia Subsystem | 159 | | | 160 | IVS | In-Vehicle System | 161 | | | 162 | MNO | Mobile Network Operator | 163 | | | 164 | MSD | Minimum Set of Data | 165 | | | 166 | PSAP | Public Safety Answering Point | 167 +--------+----------------------------------------+ 169 2. Document Scope 171 This document is focused on the signaling, data exchange, and 172 protocol needs of next-generation eCall (NG-eCall, also referred to 173 as packet-switched eCall or all-IP eCall) within the SIP framework 174 for emergency calls, as described in [RFC6443] and [RFC6881]. eCall 175 itself is specified by 3GPP and CEN and these specifications include 176 far greater scope than is covered here. 178 The eCall service operates over cellular wireless communication, but 179 this document does not address cellular-specific details, nor client 180 domain selection (e.g., circuit-switched versus packet-switched). 181 All such aspects are the purview of their respective standards 182 bodies. The scope of this document is limited to eCall operating 183 within a SIP-based environment (e.g., 3GPP IMS Emergency Calling). 185 The technical contents of this document also provide a basis for 186 reuse and extension for other vehicle-initiated emergency call 187 systems. 189 Vehicles designed for multiple regions might need to support eCall 190 and other Advanced Automatic Crash Notification (AACN) systems, such 191 as described in [I-D.ietf-ecrit-car-crash]. 193 3. Introduction 195 Emergency calls made from vehicles (e.g., in the event of a crash) 196 assist in significantly reducing road deaths and injuries by allowing 197 emergency services to be aware of the incident, the state of the 198 vehicle, the location of the vehicle, and to have a voice channel 199 with the vehicle occupants. This enables a quick and appropriate 200 response. 202 The European Commission initiative of eCall was conceived in the late 203 1990s, and has evolved to a European Parliament decision requiring 204 the implementation of a compliant in-vehicle system (IVS) in new 205 vehicles and the deployment of eCall in the European Member States in 206 the very near future. Other regions are developing eCall-compatible 207 systems. 209 The pan-European eCall system provides a standardized and mandated 210 mechanism for emergency calls by vehicles. eCall establishes 211 procedures for such calls to be placed by in-vehicle systems, 212 recognized and processed by the mobile network, and routed to a 213 specialized PSAP where the vehicle data is available to assist the 214 call taker in assessing and responding to the situation. eCall 215 provides a standard set of vehicle, sensor (e.g., crash related), and 216 location data. 218 An eCall can be either user-initiated or automatically triggered. 219 Automatically triggered eCalls indicate a car crash or some other 220 serious incident. Manually triggered eCalls might be reports of 221 witnessed crashes or serious hazards. PSAPs might apply specific 222 operational handling to manual and automatic eCalls. 224 Legacy eCall is standardized (by 3GPP [SDO-3GPP] and CEN [CEN]) as a 225 3GPP circuit-switched call over GSM (2G) or UMTS (3G). Flags in the 226 call setup mark the call as an eCall, and further indicate if the 227 call was automatically or manually triggered. The call is routed to 228 an eCall-capable PSAP, a voice channel is established between the 229 vehicle and the PSAP, and an eCall in-band modem is used to carry a 230 defined set of vehicle, sensor (e.g., crash related), and location 231 data (the Minimum Set of Data or MSD) within the voice channel. The 232 same in-band mechanism is used for the PSAP to acknowledge successful 233 receipt of the MSD, and to request the vehicle to send a new MSD 234 (e.g., to check if the state of or location of the vehicle or its 235 occupants has changed). NG-eCall moves from circuit switched to all- 236 IP, and carries the vehicle data and eCall signaling as additional 237 data carried with the call. This document describes how IETF 238 mechanisms for IP-based emergency calls, including [RFC6443] and 239 [RFC7852] are used to provide the signaling and data exchange of the 240 next generation of pan-European eCall. 242 The European Telecommunications Standards Institute (ETSI) [SDO-ETSI] 243 has published a Technical Report titled "Mobile Standards Group 244 (MSG); eCall for VoIP" [MSG_TR] that presents findings and 245 recommendations regarding support for eCall in an all-IP environment. 246 The recommendations include the use of 3GPP IMS emergency calling 247 with additional elements identifying the call as an eCall and as 248 carrying eCall data and with mechanisms for carrying the data and 249 eCall signaling. 3GPP IMS emergency services support multimedia, 250 providing the ability to carry voice, text, and video. This 251 capability is referred to within 3GPP as Multimedia Emergency 252 Services (MMES). 254 A transition period will exist during which time the various entities 255 involved in initiating and handling an eCall might support next- 256 generation eCall, legacy eCall, or both. The issues of migration and 257 co-existence during the transition period are outside the scope of 258 this document. 260 The MSD is carried in the MIME type 'application/ 261 emergencyCallData.eCall.MSD+per' and the metadata/control block is 262 carried in the MIME type 'application/emergencyCallData.control+xml' 263 (both of which are registered in Section 15) An INFO package is 264 defined (in Section 10) to enable these MIME types to be carried in 265 SIP INFO requests, per [RFC6086]. 267 4. eCall Requirements 269 eCall requirements are specified by CEN in [EN_16072] and by 3GPP in 270 [TS22.101] clauses 10.7 and A.27. Requirements specific to vehicle 271 data are contained in EN 15722 [msd]. 273 5. Vehicle Data 275 Pan-European eCall provides a standardized and mandated set of 276 vehicle related data, known as the Minimum Set of Data (MSD). The 277 European Committee for Standardization (CEN) has specified this data 278 in EN 15722 [msd], along with both ASN.1 and XML encodings. Both 279 circuit-switched eCall and this document use the ASN.1 PER encoding, 280 which is specified in Annex A of EN 15722 [msd] (the XML encoding 281 specified in Annex C is not used in this document). 283 This document registers the 'application/ 284 emergencyCallData.eCall.MSD+per' MIME Content-Type to enable the MSD 285 to be carried in SIP. As an ASN.1 PER encoded object, the data is 286 binary and transported using binary content transfer encoding within 287 SIP messages. This document also adds the 'eCall.MSD' entry to the 288 Emergency Call Additional Data Blocks registry to enable the MSD to 289 be recognized as such in a SIP-based eCall emergency call. (See 291 [RFC7852] for more information about the registry and how it is 292 used.) 294 See Section 6 for a discussion of how the MSD vehicle data is 295 conveyed in an NG-eCall. 297 6. Data Transport 299 [RFC7852] establishes a general mechanism for attaching blocks of 300 data to a SIP emergency call. This mechanism permits certain 301 emergency call MIME types to be attached to SIP messages. This 302 document makes use of that mechanism. This document also registers 303 an INFO package (in Section 10) to enable eCall related data blocks 304 to be carried in SIP INFO requests (per [RFC6086], new INFO usages 305 require the definition of an INFO package). 307 Note that if other data sets need to be transmitted in the future, 308 the appropriate signalling mechanism for such data needs to be 309 evaluated, including factors such as the size and frequency of such 310 data. 312 An In-Vehicle System (IVS) transmits the MSD (see Section 5) by 313 encoding it per Annex A of EN 15722 [msd] and attaching it to a SIP 314 message as a MIME body part per [RFC7852]. The body part is 315 identified by its MIME content-type ('application/ 316 emergencyCallData.eCall.MSD+per') in the Content-Type header field of 317 the body part. The body part is assigned a unique identifier which 318 is listed in a Content-ID header field in the body part. The SIP 319 message is marked as containing the MSD by adding (or appending to) a 320 Call-Info header field at the top level of the SIP message. This 321 Call-Info header field contains a CID URL referencing the body part's 322 unique identifier, and a 'purpose' parameter identifying the data as 323 the eCall MSD per the Emergency Call Additional Data Blocks registry 324 entry; the 'purpose' parameter's value is 325 'emergencyCallData.eCall.MSD'. Per [RFC6086], an MSD is carried in a 326 SIP INFO request by using the INFO package defined in Section 10. 328 A PSAP or IVS transmits a metadata/control object (see Section 9) by 329 encoding it per the description in this document and attaching it to 330 a SIP message as a MIME body part per [RFC7852]. The body part is 331 identified by its MIME content-type ('application/ 332 emergencyCallData.control+xml') in the Content-Type header field of 333 the body part. The body part is assigned a unique identifier which 334 is listed in a Content-ID header field in the body part. The SIP 335 message is marked as containing the metadata/control object by adding 336 (or appending to) a Call-Info header field at the top level of the 337 SIP message. This Call-Info header field contains a CID URL 338 referencing the body part's unique identifier, and a 'purpose' 339 parameter identifying the data as an eCall metadata/control block per 340 the Emergency Call Additional Data Blocks registry entry; the 341 'purpose' parameter's value is 'emergencyCallData.control'. Per 342 [RFC6086], a metadata/control object is carried in a SIP INFO request 343 by using the INFO package defined in Section 10. 345 As is necessary with message bodies, if an MSD or a metadata/control 346 block is sent in the same message with another body part, a 347 multipart/mixed body part encloses all body parts. In some cases, 348 there are intermediate multipart body parts between the top level 349 multipart/mixed and the body part containing the MSD or metadata/ 350 control object. 352 A body part containing an MSD or metadata/control object has a 353 Content-Disposition header field value containing "By-Reference" 354 unless it is the only body part in a SIP INFO request, in which case, 355 per [RFC6086], "INFO-Package" is used. 357 An In-Vehicle System (IVS) initiating an NG-eCall attaches the MSD to 358 the initial INVITE and optionally attaches a metadata/control object 359 informing the PSAP of its capabilities. The MSD body part (and 360 metadata/control and PIDF-LO body parts if included) have a Content- 361 Disposition header field with the value "By-Reference; 362 handling=optional". Specifying handling=optional prevents the INVITE 363 from being rejected if it is processed by a legacy element (e.g., a 364 gateway between SIP and circuit-switched environments) that does not 365 understand the MSD (or metadata/control object or PIDF-LO). The PSAP 366 creates a metadata/control object acknowledging receipt of the MSD 367 and attaches it to the SIP final response to the INVITE. The 368 metadata/control object is not attached to provisional (e.g., 180) 369 responses. 371 If the IVS receives an acknowledgment for an MSD with received=false, 372 it indicates some fault with the transfer of the MSD, the MSD 373 content, or the PSAP's ability to properly receive, decode and act on 374 the MSD. The IVS action is not defined (e.g., it might only log an 375 error). Since the PSAP is able to request an updated MSD during the 376 call, if an initial MSD is unsatisfactory in any way, the PSAP can 377 choose to request another one. 379 A PSAP can request that the vehicle send an updated MSD during a 380 call. To do so, the PSAP creates a metadata/control object 381 requesting an MSD and attaches it to a SIP INFO request and sends it 382 within the dialog. The IVS then attaches an updated MSD to a SIP 383 INFO request and sends it within the dialog. If the IVS is unable to 384 send an MSD, it instead sends a metadata/control object acknowledging 385 the request with the 'success' parameter set to 'false' and a 386 'reason' parameter (and optionally a 'details' parameter) indicating 387 why the request cannot be accomplished. Per [RFC6086], metadata/ 388 control objects and MSDs are sent using the INFO package defined in 389 Section 10 . In addition, to align with how an MSD or metadata/ 390 control block is transmitted in a SIP message other than an INFO 391 request, one or more Call-Info header fields are included in the SIP 392 INFO request to reference the MSD or metadata/control block. See 393 Section 10 for information about the use of INFO requests to carry 394 data within an eCall. 396 The IVS is not expected to send an unsolicited MSD during the call. 398 Support for the data blocks defined in [RFC7852] is NOT REQUIRED for 399 conformance with this document. 401 7. Call Setup 403 In circuit-switched eCall, the IVS places a special form of a 112 404 emergency call which carries an eCall flag (indicating that the call 405 is an eCall and also if the call was manually or automatically 406 triggered); the mobile network operator (MNO) recognizes the eCall 407 flag and routes the call to an eCall-capable PSAP; vehicle data is 408 transmitted to the PSAP via the eCall in-band modem (in the voice 409 channel). 411 ///----\\\ 112 voice call with eCall flag +------+ 412 ||| IVS |||---------------------------------------->+ PSAP | 413 \\\----/// vehicle data via eCall in-band modem +------+ 415 Figure 1: circuit-switched eCall 417 For NG-eCall, the IVS establishes an emergency call using a Request- 418 URI indicating a manual or automatic eCall; the MNO (or ESInet) 419 recognizes the eCall URN and routes the call to an NG-eCall capable 420 PSAP; the PSAP interpets the vehicle data sent with the call and 421 makes it available to the call taker. 423 ///----\\\ IMS emergency call with eCall URN +------+ 424 IVS ----------------------------------------->+ PSAP | 425 \\\----/// vehicle data included in call setup +------+ 427 Figure 2: NG-eCall 429 See Section 6 for information on how the MSD is transported within an 430 NG-eCall. 432 This document registers new service URN children within the "sos" 433 subservice. These URNs provide the mechanism by which an eCall is 434 identified, and differentiate between manually and automatically 435 triggered eCalls (which might be subject to different treatment, 436 depending on policy). The two service URNs are: 437 urn:service:sos.ecall.automatic and urn:service:sos.ecall.manual, 438 which requests resources associated with an emergency call placed by 439 an in-vehicle system, carrying a standardized set of data related to 440 the vehicle and incident. 442 Call routing is outside the scope of this document. 444 8. Test Calls 446 eCall requires the ability to place test calls (see [TS22.101] clause 447 10.7 and [EN_16062] clause 7.2.2). These are calls that are 448 recognized and treated to some extent as eCalls but are not given 449 emergency call treatment and are not handled by call takers. The 450 specific handling of test eCalls is not itself standardized; 451 typically, the test call facility allows the IVS or user to verify 452 that an eCall can be successfully established with voice 453 communication. The IVS might also be able to verify that the MSD was 454 successfully received. 456 A service URN starting with "test." indicates a test call. For 457 eCall, "urn:service:test.sos.ecall" indicates such a test feature. 458 This functionality is defined in [RFC6881]. 460 This document registers "urn:service:test.sos.ecall" for eCall test 461 calls. 463 The CS-eCall test call facility is a non-emergency number so does not 464 get treated as an emergency call. For NG-eCall, MNOs, emergency 465 authorities, and PSAPs can determine how to treat a vehicle call 466 requesting the "test" service URN so that the desired functionality 467 is tested, but this is outside the scope of this document. 469 9. The Metadata/Control Object 471 eCall requires the ability for the PSAP to acknowledge successful 472 receipt of an MSD sent by the IVS, and for the PSAP to request that 473 the IVS send an MSD (e.g., the call taker can initiate a request for 474 a new MSD to see if there have been changes in the vehicle's state, 475 e.g., location, direction, number of fastened seatbelts). 477 This document defines a block of metadata/control data as an XML 478 structure containing elements used for eCall and other vehicle- 479 initiated emergency call systems (i.e., in other regions) and 480 extension points. (This metadata/control block is in effect a high- 481 level protocol between the PSAP and IVS.) When the PSAP sends a 482 metadata/control block in response to data sent by the IVS in a SIP 483 request other than INFO (e.g., the MSD in the initial INVITE), the 484 metadata/control block is sent in the SIP response to that request 485 (e.g., the response to the INVITE request). When the PSAP sends a 486 control block in other circumstances (e.g., mid-call), the control 487 block is transmitted from the PSAP to the IVS in a SIP INFO request 488 within the established dialog. The IVS sends the requested data (the 489 MSD) in a new INFO request (per [RFC6086]). This mechanism flexibly 490 allows the PSAP to send eCall-specific data to the IVS and the IVS to 491 respond. INFO requests are sent using an appropriate INFO Package. 492 See Section 6 for more information on attaching a metadata/control 493 block to a SIP message. See Section 10 for information about the use 494 of INFO requests to carry data within an eCall. 496 This mechanism requires 498 o An XML definition of the control object 499 o Extension points for use by eCall-like systems in other regions 500 o A MIME type registration for the control object (so it can be 501 carried in SIP messages and responses) 502 o An entry in the Emergency Call Additional Data Blocks registry so 503 that the control block can be recognized as emergency call 504 specific data within SIP messages 505 o An Info-Package registration per [RFC6086] permitting the 506 metadata/control block and the MSD within INFO requests 508 When the IVS includes an unsolicited MSD in a SIP request (e.g., the 509 initial INVITE), the PSAP sends a metadata/control block indicating 510 successful/unsuccessful receipt of the MSD in the SIP response to the 511 request. This also informs the IVS that an NG-eCall is in operation. 512 If the IVS receives a SIP response without the metadata/control 513 block, it indicates that the SIP dialog is not an NG-eCall (e.g., 514 some part of the call is being handled as a legacy call). When the 515 IVS sends a solicited MSD (e.g., in a SIP INFO request sent following 516 receipt of a SIP INFO request containing a metadata/control block 517 requesting an MSD), the PSAP does not send a metadata/control block 518 indicating successful or unsuccessful receipt of the MSD. (Normal 519 SIP retransmission handles non-receipt of requested data; if the IVS 520 sends a requested MSD in an INFO request and does not receive a SIP 521 status message for the INFO request, it resends it; if the PSAP 522 requests an MSD and does not receive a SIP status message for the 523 INFO request, it resends it.) If the IVS receives a request to send 524 an MSD but it is unable to do so for any reason, the IVS sends a 525 metadata/control object acknowledging the request and containing 526 "success=false" and "reason" set to an appropriate code. 528 This provides flexibility to handle various circumstances. For 529 example, if a PSAP is unable to accept an eCall (e.g., due to 530 overload or too many calls from the same location), it can reject the 531 INVITE. Since a metadata/control object is also included in the SIP 532 response that rejects the call, the IVS knows if the PSAP received 533 the MSD, and can inform the vehicle occupants that the PSAP 534 successfully received the vehicle location and information but can't 535 talk to the occupants at that time. Especially for SIP response 536 codes that indicate an inability to conduct a call (as opposed to a 537 technical inability to process the request), the IVS can also 538 determine that the call was successful on a technical level (e.g., 539 not helpful to retry as a CS-eCall). The SIP response codes 600 540 (Busy Everywhere), 486 (Busy Here), and 603 (Decline) are used when 541 the PSAP wants to reject a call but inform the vehicle occupants that 542 it is aware of the situation. (Note that there could be edge cases 543 where the PSAP response is not received by the IVS, e.g., if an 544 intermediary sends a CANCEL, and an error response is forwarded 545 towards the IVS before the error response from the PSAP is received, 546 the response will be dropped, but these are unlikely to occur here.) 548 The metadata/control block is carried in the MIME type 'application/ 549 emergencyCallData.control+xml'. 551 The metadata/control block is designed for use with pan-European 552 eCall and also eCall-like systems (i.e., in other regions), and has 553 extension points to accomodate variances. Note that eCall-like 554 systems might define their own vehicle data blocks, and so might need 555 to register a new INFO package to accomodate the new data content 556 type and the metadata/control object. 558 9.1. The Control Block 560 The control block is an XML data structure allowing for 561 acknowledgments, requests, and capabilities information. It is 562 carried in a body part with a specific MIME content type. Three 563 elements are defined for use within a control block: 565 ack Acknowledges receipt of data or a request. 567 capabilities: Used in a control block sent from the IVS to the PSAP 568 (e.g., in the initial INVITE) to inform the PSAP of the 569 vehicle capabilities. Child elements contain all 570 actions and data types supported by the vehicle. It is 571 OPTIONAL for the IVS to send this block. Omitting the 572 block indicates that the IVS supports only the 573 mandatory functionality defined in this document. 575 request Used in a control block sent by the PSAP to the IVS, to 576 request the vehicle to perform an action. 578 The element indicates the object being acknowledged and reports 579 success or failure. 581 The element contains attributes to indicate the request and 582 to supply related information. The 'action' attribute is mandatory 583 and indicates the specific action. An IANA registry is created in 584 Section 15.8.1 to contain the allowed values. 586 The element has child elements to indicate 587 the actions supported by the IVS. 589 9.1.1. The element 591 The element acknowledges receipt of an eCall data object or 592 request. An element references the unique ID of the data 593 object being acknowledged. The PSAP MUST send an element 594 acknowledging receipt of an unsolicited MSD (e.g., sent by the IVS in 595 the INVITE); this element indicates if the PSAP considers the 596 MSD successfully received or not. An element is not sent for a 597 element. 599 The element has the following attributes: 601 9.1.1.1. Attributes of the element 603 The element has the following attributes: 605 Name: ref 606 Usage: Mandatory 607 Type: anyURI 608 Direction: In this document, sent from the PSAP to the IVS 609 Description: References the Content-ID of the body part being 610 acknowledged. 611 Example: 613 Name: received 614 Usage: Conditional: mandatory in an >ack< element sent by a PSAP 615 Type: Boolean 616 Direction: In this document, sent from the PSAP to the IVS 617 Description: Indicates if the referenced object was considered 618 successfully received or not. 619 Example: 621 9.1.1.2. Child Element of the element 623 For extensibility, the element has the following child element: 625 Name: actionResult 626 Usage: Optional 627 Direction: Provided for extension, sent from the IVS to the PSAP 628 Description: An element indicates the result of an 629 action (other than a 'send-data' action). When an element 630 is in response to a control object with multiple 631 elements, the element contains an element for 632 each element that is not a 'send-data' action. The 633 element has the following attributes: 635 Name: action 636 Usage: Mandatory 637 Type: token 638 Direction: In this document, sent from the PSAP to the IVS 639 Description: Contains the value of the 'action' attribute of the 640 element 642 Name: success 643 Usage: Mandatory 644 Type: Boolean 645 Direction: Sent from the IVS to the PSAP 646 Description: Indicates if the action was successfully 647 accomplished 649 Name: reason 650 Usage: Conditional 651 Type: token 652 Direction: Sent from the IVS to the PSAP 653 Description: Used when 'success' is "false", this attribute 654 contains a reason code for a failure. A registry for reason 655 codes is defined in Section 15.8.2. 657 Name: details 658 Usage: optional 659 Type: string 660 Direction: Sent from the IVS to the PSAP 661 Description: Contains further explanation of the circumstances of 662 a success or failure. The contents are implementation-specific 663 and human-readable. 665 9.1.1.3. Ack Examples 666 667 673 675 677 Figure 3: Ack Example from PSAP to IVS 679 9.1.2. The element 681 The element is transmitted by the IVS to indicate to 682 the PSAP its capabilities. No attributes for this element are 683 currently defined. The following child elements are defined: 685 9.1.2.1. Child Elements of the element 687 The element has the following child elements: 689 Name: request 690 Usage: Mandatory 691 Description: The element contains a child 692 element per action supported by the vehicle. 694 Examples: 695 697 It is OPTIONAL for the IVS to support the element. If 698 the IVS does not send a element, this indicates that 699 the only action supported by the IVS is 'send-data' with 700 'datatype' set to 'eCall.MSD'. 702 9.1.2.2. Capabilities Example 703 704 709 710 711 713 715 Figure 4: Capabilities Example 717 9.1.3. The element 719 A element appears one or more times on its own or as a 720 child of a element. It allows the PSAP to request 721 that the IVS perform an action. The only action that MUST be 722 supported is to send an MSD. The following attributes and child 723 elements are defined: 725 9.1.3.1. Attributes of the element 727 The element has the following attributes: 729 Name: action 730 Usage: Mandatory 731 Type: token 732 Direction: In this document, sent from the PSAP to the IVS; for 733 extension, sent from the IVS to the PSAP 734 Description: Identifies the action that the vehicle is requested to 735 perform. An IANA registry is established in Section 15.8.1 to 736 contain the allowed values. 737 Example: action="send-data" 739 Name: msgid 740 Usage: Conditional 741 Type: int 742 Direction: Sent from the PSAP to the IVS 743 Description: Defined for extensibility. 744 Example: msgid="3" 746 Name: persistance 747 Usage: Optional 748 Type: duration 749 Direction: Sent from the PSAP to the IVS 750 Description: Defined for extensibility. Specifies how long to carry 751 on the specified action. If absent, the default is for the 752 duration of the call. 753 Example: persistance="PT1H" 755 Name: datatype 756 Usage: Conditional 757 Type: token 758 Direction: In this document, sent from the PSAP to the IVS; as an 759 extension, sent from the IVS to the PSAP 760 Description: Mandatory with a "send-data" action within a 761 element that is not within a element. Specifies 762 the data block that the IVS is requested to transmit, using the 763 same identifier as in the 'purpose' attribute set in a Call-Info 764 header field to point to the data block. Permitted values are 765 contained in the 'Emergency Call Data Types' IANA registry 766 established in [RFC7852]. Only the "eCall.MSD" value is mandatory 767 to support. 768 Example: datatype="eCall.MSD" 770 Name: supported-values 771 Usage: Conditional 772 Type: string 773 Direction: Sent from the IVS to the PSAP 774 Description: Defined for extensibility. Used in a element 775 that is a child of a element, this attribute lists 776 all supported values of the action type. Permitted values depend 777 on the action value. Multiple values are separated with a 778 semicolon. 780 Name: requested-state 781 Usage: Conditional 782 Type: token 783 Direction: Sent from the PSAP to the IVS 784 Description: Defined for extension. Indicates the requested state 785 of an element associated with the request type. Permitted values 786 depend on the request type. 788 Name: element-ID 789 Usage: Conditional 790 Type: token 791 Direction: Sent from the PSAP to the IVS 792 Description: Defined for extension. Identifies the element to be 793 acted on. Permitted values depend on the request type. 795 9.1.3.2. Request Example 797 798 804 806 808 Figure 5: Request Example 810 10. The emergencyCallData.eCall.MSD INFO package 812 This document registers the 'emergencyCallData.eCall.MSD' INFO 813 package. 815 Both endpoints (the IVS and the PSAP equipment) include 816 'emergencyCallData.eCall.MSD' in a Recv-Info header field per 817 [RFC6086] to indicate ability to receive INFO requests carrying data 818 as described here. 820 Support for the 'emergencyCallData.eCall.MSD' INFO package indicates 821 the ability to receive eCall related body parts as specified in [TBD: 822 THIS DOCUMENT]. 824 An INFO request message carrying body parts related to an emergency 825 call as described in [TBD: THIS DOCUMENT] has an Info-Package header 826 field set to 'emergencyCallData.eCall.MSD' per [RFC6086]. 828 The requirements of Section 10 of [RFC6086] are addressed in the 829 following sections. 831 10.1. Overall Description 833 This section describes "what type of information is carried in INFO 834 requests associated with the Info Package, and for what types of 835 applications and functionalities UAs can use the Info Package." 837 INFO requests associated with the emergencyCallData.eCall.MSD INFO 838 package carry data associated with emergency calls as defined in 839 [TBD: THIS DOCUMENT]. The application is vehicle-initiated emergency 840 calls established using SIP. The functionality is to carry vehicle 841 data and metadata/control information between vehicles and PSAPs. 842 Refer to [TBD: THIS DOCUMENT] for more information. 844 10.2. Applicability 846 This section describes "why the Info Package mechanism, rather than 847 some other mechanism, has been chosen for the specific use-case...." 849 The use of INFO is based on an analysis of the requirements against 850 the intent and effects of INFO versus other approaches (which 851 included SIP MESSAGE, SIP OPTIONS, SIP re-INVITE, media plane 852 transport, and non-SIP protocols). In particular, the transport of 853 emergency call data blocks occurs within a SIP emergency dialog, per 854 Section 6, and is normally carried in the initial INVITE and its 855 response; the use of INFO only occurs when emergency-call-related 856 data needs to be sent mid-call. While MESSAGE could be used, it is 857 not tied to a SIP dialog as is INFO and thus might not be associated 858 with the dialog. SIP OPTIONS or re-INVITE could also be used, but is 859 seen as less clean than INFO. SUBSCRIBE/NOTIFY could be coerced into 860 service, but the semantics are not a good fit, e.g., the subscribe/ 861 notify mechanism provides one-way communication consisting of (often 862 multiple) notifications from notifier to subscriber indicating that 863 certain events in notifier have occurred, whereas what's needed here 864 is two-way communication of data related to the emergency dialog. 865 Use of the media plane mechanisms was discounted because the number 866 of messages needing to be exchanged in a dialog is normally zero or 867 very few, and the size of the data is likewise very small. The 868 overhead caused by user plane setup (e.g., to use MSRP as transport) 869 would be disproportionately large. 871 Based on the the analyses, the SIP INFO method was chosen to provide 872 for mid-call data transport. 874 10.3. Info Package Name 876 The info package name is emergencyCallData.eCall.MSD 878 10.4. Info Package Parameters 880 None 882 10.5. SIP Option-Tags 884 None 886 10.6. INFO Request Body Parts 888 The body for an emergencyCallData.eCall.MSD info package is: 890 o an application/emergencyCallData.eCall.MSD+per (containing an 891 MSD), or 893 o an application/emergencyCallData.control+xml (containing a 894 metadata/control object), or 896 o a multipart body containing: 898 * zero or one application/emergencyCallData.eCall.MSD+per part 899 (containing an MSD), 901 * zero or more application/emergencyCallData.control+xml 902 (containing a metadata/control object), 904 The body parts are sent per [RFC6086], and in addition, to align with 905 with how these body parts are sent in SIP messages other than INFO 906 requests, each associated body part is referenced by a Call-Info 907 header field at the top level of the SIP message. If the body part 908 is the only body part, it has a Content-Disposition header field 909 value of "INFO-Package". If the body part is contained within a 910 multipart, it has a Content-Disposition header field value of "By- 911 Reference". 913 See [TBD: THIS DOCUMENT] for more information. 915 10.7. Info Package Usage Restrictions 917 Usage is limited to vehicle-initiated emergency calls as defined in 918 [TBD: THIS DOCUMENT]. 920 10.8. Rate of INFO Requests 922 The rate of SIP INFO requests associated with the 923 emergencyCallData.eCall.MSD info package is normally quite low (most 924 dialogs are likely to contain zero INFO requests, while others can be 925 expected to carry an occasional request). 927 10.9. Info Package Security Considerations 929 The MIME content type registations for the data blocks that can be 930 carried using this INFO package contains a discussion of the security 931 and/or privacy considerations specific to that data block. The 932 "Security Considerations" and "Privacy Considerations" sections of 934 [TBD: THIS DOCUMENT] discuss security and privacy considerations of 935 the data carried in eCalls. 937 10.10. Implementation Details 939 See [TBD: THIS DOCUMENT] for protocol details. 941 10.11. Examples 943 See [TBD: THIS DOCUMENT] for protocol examples. 945 11. Examples 947 Figure 6 illustrates an eCall. The call uses the request URI 948 'urn:service:sos.ecall.automatic' service URN and is recognized as an 949 eCall, and further as one that was invoked automatically by the IVS 950 due to a crash or other serious incident. In this example, the 951 originating network routes the call to an ESInet which routes the 952 call to the appropriate NG-eCall capable PSAP. The emergency call is 953 received by the ESInet's Emergency Services Routing Proxy (ESRP), as 954 the entry point into the ESInet. The ESRP routes the call to a PSAP, 955 where it is received by a call taker. In deployments where there is 956 no ESInet, the originating network routes the call directly to the 957 appropriate NG-eCall capable PSAP, an illustration of which would be 958 identical to the one below except without an ESInet or ESRP. 960 +------------+ +---------------------------------------+ 961 | | | +-------+ | 962 | | | | PSAP2 | | 963 | | | +-------+ | 964 | | | | 965 | | | +------+ +-------+ | 966 Vehicle-->| |--+->| ESRP |---->| PSAP1 |--> Call-Taker | 967 | | | +------+ +-------+ | 968 | | | | 969 | | | +-------+ | 970 | | | | PSAP3 | | 971 | Originating| | +-------+ | 972 | Mobile | | | 973 | Network | | ESInet | 974 +------------+ +---------------------------------------+ 976 Figure 6: Example of NG-eCall Message Flow 978 Figure 7 illustrates an eCall call flow with a mid-call PSAP request 979 for an updated MSD. The call flow shows the IVS initiating an 980 emergency call, including the MSD in the INVITE. The PSAP includes 981 in the 200 OK response a metadata/control object acknowledging 982 receipt of the MSD. During the call, the PSAP sends a request for an 983 MSD in an INFO request. The IVS sends the requested MSD in a new 984 INFO request. 986 IVS PSAP 987 |(1) INVITE (eCall MSD) | 988 |------------------------------------------->| 989 | | 990 |(2) 200 OK (eCall metadata [ack MSD]) | 991 |<-------------------------------------------| 992 | | 993 |(3) start media stream(s) | 994 |............................................| 995 | | 996 |(4) INFO (eCall metadata [request MSD]) | 997 |<-------------------------------------------| 998 | | 999 |(5) 200 OK | 1000 |------------------------------------------->| 1001 | | 1002 |(6) INFO (eCall MSD) | 1003 |------------------------------------------->| 1004 | | 1005 |(7) 200 OK | 1006 |<-------------------------------------------| 1007 | | 1008 |(8) BYE | 1009 |<-------------------------------------------| 1010 | | 1011 |(9) end media streams | 1012 |............................................| 1013 | | 1014 |(10) 200 OK | 1015 |------------------------------------------->| 1017 Figure 7: NG-eCall Call Flow Illustration 1019 The example, shown in Figure 8, illustrates a SIP eCall INVITE that 1020 contains an MSD. For simplicity, the example does not show all SIP 1021 headers, nor the SDP contents, nor does it show any additional data 1022 blocks added by the IVS or the originating mobile network. Because 1023 the MSD is encoded in ASN.1 PER, which is a binary encoding, its 1024 contents cannot be included in a text document. 1026 INVITE urn:service:sos.ecall.automatic SIP/2.0 1027 To: urn:service:sos.ecall.automatic 1028 From: ;tag=9fxced76sl 1029 Call-ID: 3848276298220188511@atlanta.example.com 1030 Geolocation: 1031 Geolocation-Routing: no 1032 Call-Info: ; 1033 purpose=emergencyCallData.eCall.MSD 1034 Accept: application/sdp, application/pidf+xml, 1035 application/emergencyCallData.control+xml 1036 CSeq: 31862 INVITE 1037 Recv-Info: emergencyCallData.eCall.MSD 1038 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1039 SUBSCRIBE, NOTIFY, UPDATE 1040 Content-Type: multipart/mixed; boundary=boundary1 1041 Content-Length: ... 1043 --boundary1 1044 Content-Type: application/sdp 1046 ...Session Description Protocol (SDP) goes here... 1048 --boundary1 1049 Content-Type: application/emergencyCallData.eCall.MSD+per 1050 Content-ID: <1234567890@atlanta.example.com> 1051 Content-Disposition: by-reference;handling=optional 1053 ...MSD in ASN.1 PER encoding goes here... 1055 --boundary1-- 1057 Figure 8: SIP NG-eCall INVITE 1059 Continuing the example, Figure 9 illustrates a SIP 200 OK response to 1060 the INVITE of Figure 8, containing a control block acknowledging 1061 successful receipt of the eCall MSD. (For simplicity, the example 1062 does not show all SIP headers.) 1063 SIP/2.0 200 OK 1064 To: ;tag=9fxced76sl 1065 From: Exemplar PSAP 1066 Call-ID: 3848276298220188511@atlanta.example.com 1067 Call-Info: ; 1068 purpose=emergencyCallData.control 1069 Accept: application/sdp, application/pidf+xml, 1070 application/emergencyCallData.control+xml, 1071 application/emergencyCallData.eCall.MSD+per 1072 CSeq: 31862 INVITE 1073 Recv-Info: emergencyCallData.eCall.MSD 1074 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1075 SUBSCRIBE, NOTIFY, UPDATE 1076 Content-Type: multipart/mixed; boundary=boundaryX 1077 Content-Length: ... 1079 --boundaryX 1080 Content-Type: application/sdp 1082 ...Session Description Protocol (SDP) goes here... 1084 --boundaryX 1085 Content-Type: application/emergencyCallData.control+xml 1086 Content-ID: <2345678901@atlanta.example.com> 1087 Content-Disposition: by-reference 1089 1090 1096 1098 1100 --boundaryX-- 1102 Figure 9: 200 OK response to INVITE 1104 Figure 10 illustrates an INFO request containing an eCall metadata/ 1105 control block requesting an eCall MSD. (For simplicity, the example 1106 does not show all SIP headers.) 1107 INFO sip:+13145551111@example.com SIP/2.0 1108 To: ;tag=9fxced76sl 1109 From: Exemplar PSAP 1110 Call-ID: 3848276298220188511@atlanta.example.com 1111 Call-Info: ; 1112 purpose=emergencyCallData.control 1113 Accept: application/sdp, application/pidf+xml, 1114 application/emergencyCallData.control+xml, 1115 application/emergencyCallData.eCall.MSD+per 1116 CSeq: 41862 INFO 1117 Info-Package: emergencyCallData.eCall.MSD 1118 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1119 SUBSCRIBE, NOTIFY, UPDATE 1120 Content-Disposition: info-package 1121 Content-Type: application/emergencyCallData.control+xml 1122 Content-ID: <3456789012@atlanta.example.com> 1124 1125 1131 1133 1135 Figure 10: INFO requesting MSD 1137 Figure 11 illustrates a SIP eCall INFO that contains an MSD. For 1138 simplicity, the example does not show all SIP headers. Because the 1139 MSD is encoded in ASN.1 PER, which is a binary encoding, its contents 1140 cannot be included in a text document. 1142 INFO urn:service:sos.ecall.automatic SIP/2.0 1143 To: urn:service:sos.ecall.automatic 1144 From: ;tag=9fxced76sl 1145 Call-ID: 3848276298220188511@atlanta.example.com 1146 Call-Info: ; 1147 purpose=emergencyCallData.eCall.MSD 1148 Accept: application/sdp, application/pidf+xml, 1149 application/emergencyCallData.control+xml 1150 CSeq: 51862 INFO 1151 Info-Package: emergencyCallData.eCall.MSD 1152 Allow: INVITE, ACK, PRACK, INFO, OPTIONS, CANCEL, REFER, BYE, 1153 SUBSCRIBE, NOTIFY, UPDATE 1154 Content-Type: application/emergencyCallData.eCall.MSD+per 1155 Content-ID: <4567890123@atlanta.example.com> 1156 Content-Disposition: info-package 1158 ...MSD in ASN.1 PER encoding goes here... 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 1285 1286 conditionally 1287 mandatory when @success='false" 1288 to indicate reason code for a 1289 failure 1290 1291 1292 1294 1295 1296 1297 1300 1301 1304 1306 1307 1308 1309 1311 1312 1313 1314 1315 1319 1322 1323 1324 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 1378 Used with an eCall invoked automatically, for example, due to a 1379 crash or other serious incident. 1381 IANA is also requested to register the URN 1382 'urn:service:test.sos.ecall' under the sub-service 'test' registry 1383 defined in Setcion 17.2 of [RFC6881]. 1385 15.2. MIME Content-type Registration for 'application/ 1386 emergencyCallData.eCall.MSD+per' 1388 IANA is requested to add application/emergencyCallData.eCall.MSD+per 1389 as a MIME content type, with a reference to this document, in 1390 accordance to the procedures of RFC 6838 [RFC6838] and guidelines in 1391 RFC 7303 [RFC7303]. 1393 MIME media type name: application 1395 MIME subtype name: emergencyCallData.eCall.MSD+per 1397 Mandatory parameters: none 1399 Optional parameters: none 1401 Encoding scheme: binary 1403 Encoding considerations: Uses ASN.1 PER, which is a binary 1404 encoding; when transported in SIP, binary content transfer 1405 encoding is used. 1407 Security considerations: This content type is designed to carry 1408 vehicle and incident-related data during an emergency call. This 1409 data contains personal information including vehicle VIN, 1410 location, direction, etc. Appropriate precautions need to be 1411 taken to limit unauthorized access, inappropriate disclosure to 1412 third parties, and eavesdropping of this information. In general, 1413 it is acceptable for the data to be unprotected while briefly in 1414 transit within the Mobile Network Operator (MNO); the MNO is 1415 trusted to not permit the data to be accessed by third parties. 1416 Sections 7 and Section 8 of [RFC7852] contain more discussion. 1418 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 1426 Magic Number: None 1428 File Extension: None 1430 Macintosh file type code: 'BINA' 1432 Person and email address for further information: Randall Gellens, 1433 rg+ietf@randy.pensive.org 1435 Intended usage: LIMITED USE 1437 Author: The MSD specification was produced by the European 1438 Committee For Standardization (CEN). For contact information, 1439 please see . 1441 Change controller: The European Committee For Standardization 1442 (CEN) 1444 15.3. MIME Content-type Registration for 'application/ 1445 emergencyCallData.control+xml' 1447 IANA is requested to add application/emergencyCallData.control+xml as 1448 a MIME content type, with a reference to this document, in accordance 1449 to the procedures of RFC 6838 [RFC6838] and guidelines in RFC 7303 1450 [RFC7303]. 1452 MIME media type name: application 1454 MIME subtype name: emergencyCallData.control+xml 1456 Mandatory parameters: none 1458 Optional parameters: charset 1460 Indicates the character encoding of the XML content. 1462 Encoding considerations: Uses XML, which can employ 8-bit 1463 characters, depending on the character encoding used. See 1464 Section 3.2 of RFC 7303 [RFC7303]. 1466 Security considerations: 1468 This content type carries metadata and control information and 1469 requests, such as from a Public Safety Answering Point (PSAP) 1470 to an In-Vehicle System (IVS) during an emergency call. 1472 Metadata (such as an acknowledgment that data sent by the IVS 1473 to the PSAP was successfully received) has limited privacy and 1474 security implications. Control information (such as requests 1475 from the PSAP that the vehicle perform an action) has some 1476 privacy and security implications. The privacy concern arises 1477 from the ability to request the vehicle to transmit a data set, 1478 which as described in Section 15.2, can contain personal 1479 information. The security concern is the ability to request 1480 the vehicle to perform an action. Control information needs to 1481 originate only from a PSAP or other emergency services 1482 provider, and not be modified en-route. The level of integrity 1483 of the cellular network over which the emergency call is placed 1484 is a consideration: when the IVS initiates an eCall over a 1485 cellular network, in most cases it relies on the MNO to route 1486 the call to a PSAP. (Calls placed using other means, such as 1487 Wi-Fi or over-the-top services, generally incur somewhat higher 1488 levels of risk than calls placed "natively" using cellular 1489 networks.) A call-back from a PSAP merits additional 1490 consideration, since current mechanisms are not ideal for 1491 verifying that such a call is indeed a call-back from a PSAP in 1492 response to an emergency call placed by the IVS. See the 1493 discussion in Section 12 and the PSAP Callback document 1494 [RFC7090]. 1496 Sections 7 and Section 8 of [RFC7852] contain more discussion. 1498 Interoperability considerations: None 1500 Published specification: This document 1502 Applications which use this media type: Pan-European eCall 1503 compliant systems 1505 Additional information: None 1507 Magic Number: None 1509 File Extension: .xml 1511 Macintosh file type code: 'TEXT' 1513 Person and email address for further information: Randall Gellens, 1514 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, Christer Holmberg, Ivo Sedlacek, and 1690 James Winterbottom for their review and comments; Robert Sparks and 1691 Paul Kyzivat for their help with the SIP mechanisms. We would like 1692 to thank Michael Montag, Arnoud van Wijk, Gunnar Hellstrom, and 1693 Ulrich Dietz for their help with the original document upon which 1694 this document is based. 1696 18. Changes from Previous Versions 1698 18.1. Changes from draft-ietf-13 to draft-ietf-14 1700 o Added text to the IANA Considerations to formalize the 1701 EmergencyCallData media subtree 1702 o Fixed some typos 1704 18.2. Changes from draft-ietf-12 to draft-ietf-13 1706 o Clarifications suggested by Christer 1707 o Corrections to Content-Disposition text and examples as suggested 1708 by Paul Kyzivat 1709 o Clarifications to Content-Disposition text and examples to clarify 1710 that handling=optional is only used in the initial INVITE 1712 18.3. Changes from draft-ietf-11 to draft-ietf-12 1714 o Fixed errors in examples found by Dale 1715 o Removed enclosing sub-section of INFO package registration section 1716 o Added text per Christer and Dale's suggestions that the MSD and 1717 metadata/control blocks are sent in INFO with a Call-Info header 1718 field referencing them 1719 o Deleted Call Routing section (7.1) in favor of a statement that 1720 call routing is outside the scope of the document 1721 o Other text changes per comments received from Christer and Ivo. 1723 18.4. Changes from draft-ietf-09 to draft-ietf-11 1725 o Renamed INFO package to emergencyCallData.eCall.MSD 1726 o Changed INFO package to only permit MSD and metadata/control MIME 1727 types 1729 o Moved element back from car-crash but made it 1730 OPTIONAL 1731 o Moved other extension points back from car-crash so that extension 1732 points are in base spec (and also to get XML schema to compile) 1733 o Text changes for clarification. 1735 18.5. Changes from draft-ietf-08 to draft-ietf-09 1737 o Created a new "Data Transport" section that describes how the MSD 1738 and metadata/control blocks are attached, and then referred to 1739 that section rather than repeat the information about the CID and 1740 Call-Info and so forth, which means most references to the 1741 additional-data draft have now been deleted 1742 o Mentioned edge cases where a PSAP response to INVITE isn't 1743 received by the IVS 1744 o Reworded description of which status codes are used when a PSAP 1745 wishes to reject a call but inform the vehicle occupants that it 1746 is aware of the situation to be more definite 1747 o Added examples showing INFO 1748 o Added references for eCall test call requirement 1749 o Described meaning of eCall URNs in Section 8 as well as in IANA 1750 registration 1752 18.6. Changes from draft-ietf-07 to draft-ietf-08 1754 o eCall MSD now encoded as ASN.1 PER, using binary content transfer 1755 encoding 1756 o Added text to point out aspects of call handling and metadata/ 1757 control usage, such as use in rejected calls, and solicited MSDs 1758 o Revised use of INFO to require that when a request for an MSD is 1759 sent in INFO, the MSD sent in response is in its own INFO, not the 1760 response to the requesting INFO 1761 o Added material to INFO package registation to comply with 1762 Section 10 of [RFC6086] 1763 o Moved material not required by 3GPP into 1764 [I-D.ietf-ecrit-car-crash], e.g., some of the eCall metadata/ 1765 control elements, attributes, and values 1766 o Revised test call wording to clarify that specific handling is out 1767 of scope 1768 o Revised wording throughout the document to simplify 1769 o Moved new Section 7.1 to be a subsection of 7 1770 o Moved new Section Section 10 to be a main section instead of a 1771 subsection of Section 9 1772 o Revised SIP INFO usage and package registration per advice from 1773 Robert Sparks and Paul Kyzivat 1775 18.7. Changes from draft-ietf-06 to draft-ietf-07 1777 o Fixed typo in Acknowledgements 1779 18.8. Changes from draft-ietf-05 to draft-ietf-06 1781 o Added additional security and privacy clarifications regarding 1782 signed and encrypted data 1783 o Additional security and privacy text 1784 o Deleted informative section on ESINets as unnecessary. 1786 18.9. Changes from draft-ietf-04 to draft-ietf-05 1788 o Reworked the security and privacy considerations material in the 1789 document as a whole and in the MIME registation sections of the 1790 MSD and control objects 1791 o Clarified that the element can appear multiple 1792 times within an element 1793 o Fixed IMS definition 1794 o Added clarifying text for the 'msgid' attribute 1796 18.10. Changes from draft-ietf-03 to draft-ietf-04 1798 o Added Privacy Considerations section 1799 o Reworded most uses of non-normative "may", "should", "must", and 1800 "recommended." 1801 o Fixed nits in examples 1803 18.11. Changes from draft-ietf-02 to draft-ietf-03 1805 o Added request to enable cameras 1806 o Improved examples and XML schema 1807 o Clarifications and wording improvements 1809 18.12. Changes from draft-ietf-01 to draft-ietf-02 1811 o Added clarifying text reinforcing that the data exchange is for 1812 small blocks of data infrequently transmitted 1813 o Clarified that dynamic media is conveyed using SIP re-INVITE to 1814 establish a one-way media stream 1815 o Clarified that the scope is the needs of eCall within the SIP 1816 emergency call environment 1817 o Added informative statement that the document may be suitable for 1818 reuse by other ACN systems 1819 o Clarified that normative language for the control block applies to 1820 both IVS and PSAP 1821 o Removed 'ref', 'supported-mime', and elements 1822 o Minor wording improvements and clarifications 1824 18.13. Changes from draft-ietf-00 to draft-ietf-01 1826 o Added further discussion of test calls 1827 o Added further clarification to the document scope 1828 o Mentioned that multi-region vehicles may need to support other 1829 crash notification specifications in addition to eCall 1830 o Added details of the eCall metadata and control functionality 1831 o Added IANA registration for the MIME content type for the control 1832 object 1833 o Added IANA registries for protocol elements and tokens used in the 1834 control object 1835 o Minor wording improvements and clarifications 1837 18.14. Changes from draft-gellens-03 to draft-ietf-00 1839 o Renamed from draft-gellens- to draft-ietf-. 1840 o Added mention of and reference to ETSI TR "Mobile Standards Group 1841 (MSG); eCall for VoIP" 1842 o Added text to Introduction regarding migration/co-existence being 1843 out of scope 1844 o Added mention in Security Considerations that even if the network- 1845 supplied location is just the cell site, this can be useful as a 1846 sanity check on the IVS-supplied location 1847 o Minor wording improvements and clarifications 1849 18.15. Changes from draft-gellens-02 to -03 1851 o Clarifications and editorial improvements. 1853 18.16. Changes from draft-gellens-01 to -02 1855 o Minor wording improvements 1856 o Removed ".automatic" and ".manual" from 1857 "urn:service:test.sos.ecall" registration and discussion text. 1859 18.17. Changes from draft-gellens-00 to -01 1861 o Now using 'EmergencyCallData' for purpose parameter values and 1862 MIME subtypes, in accordance with changes to [RFC7852] 1863 o Added reference to RFC 6443 1864 o Fixed bug that caused Figure captions to not appear 1866 19. References 1867 19.1. Normative References 1869 [EN_16062] 1870 CEN, , "Intelligent transport systems - eSafety - eCall 1871 High Level Application Requirements (HLAP) Using GSM/UMTS 1872 Circuit Switched Networks, EN 16062", April 2015. 1874 [EN_16072] 1875 CEN, , "Intelligent transport systems - eSafety - Pan- 1876 European eCall operating requirements, EN 16072", April 1877 2015. 1879 [msd] CEN, , "Intelligent transport systems -- eSafety -- eCall 1880 minimum set of data (MSD), EN 15722", April 2015. 1882 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1883 Requirement Levels", BCP 14, RFC 2119, 1884 DOI 10.17487/RFC2119, March 1997, 1885 . 1887 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 1888 DOI 10.17487/RFC3688, January 2004, 1889 . 1891 [RFC5031] Schulzrinne, H., "A Uniform Resource Name (URN) for 1892 Emergency and Other Well-Known Services", RFC 5031, 1893 DOI 10.17487/RFC5031, January 2008, 1894 . 1896 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1897 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 1898 DOI 10.17487/RFC5226, May 2008, 1899 . 1901 [RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton, 1902 "Framework for Emergency Calling Using Internet 1903 Multimedia", RFC 6443, DOI 10.17487/RFC6443, December 1904 2011, . 1906 [RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type 1907 Specifications and Registration Procedures", BCP 13, 1908 RFC 6838, DOI 10.17487/RFC6838, January 2013, 1909 . 1911 [RFC6881] Rosen, B. and J. Polk, "Best Current Practice for 1912 Communications Services in Support of Emergency Calling", 1913 BCP 181, RFC 6881, DOI 10.17487/RFC6881, March 2013, 1914 . 1916 [RFC7303] Thompson, H. and C. Lilley, "XML Media Types", RFC 7303, 1917 DOI 10.17487/RFC7303, July 2014, 1918 . 1920 [RFC7852] Gellens, R., Rosen, B., Tschofenig, H., Marshall, R., and 1921 J. Winterbottom, "Additional Data Related to an Emergency 1922 Call", RFC 7852, DOI 10.17487/RFC7852, July 2016, 1923 . 1925 [TS22.101] 1926 3GPP, , "3GPP TS 22.101: Technical Specification Group 1927 Services and System Aspects; Service aspects; Service 1928 principles". 1930 19.2. Informative references 1932 [CEN] "European Committee for Standardization", 1933 . 1935 [I-D.ietf-ecrit-car-crash] 1936 Gellens, R., Rosen, B., and H. Tschofenig, "Next- 1937 Generation Vehicle-Initiated Emergency Calls", draft-ietf- 1938 ecrit-car-crash-12 (work in progress), September 2016. 1940 [MSG_TR] ETSI, , "ETSI Mobile Standards Group (MSG); eCall for 1941 VoIP", ETSI Technical Report TR 103 140 V1.1.1 (2014-04), 1942 April 2014. 1944 [RFC5012] Schulzrinne, H. and R. Marshall, Ed., "Requirements for 1945 Emergency Context Resolution with Internet Technologies", 1946 RFC 5012, DOI 10.17487/RFC5012, January 2008, 1947 . 1949 [RFC5069] Taylor, T., Ed., Tschofenig, H., Schulzrinne, H., and M. 1950 Shanmugam, "Security Threats and Requirements for 1951 Emergency Call Marking and Mapping", RFC 5069, 1952 DOI 10.17487/RFC5069, January 2008, 1953 . 1955 [RFC6086] Holmberg, C., Burger, E., and H. Kaplan, "Session 1956 Initiation Protocol (SIP) INFO Method and Package 1957 Framework", RFC 6086, DOI 10.17487/RFC6086, January 2011, 1958 . 1960 [RFC7090] Schulzrinne, H., Tschofenig, H., Holmberg, C., and M. 1961 Patel, "Public Safety Answering Point (PSAP) Callback", 1962 RFC 7090, DOI 10.17487/RFC7090, April 2014, 1963 . 1965 [RFC7378] Tschofenig, H., Schulzrinne, H., and B. Aboba, Ed., 1966 "Trustworthy Location", RFC 7378, DOI 10.17487/RFC7378, 1967 December 2014, . 1969 [SDO-3GPP] 1970 "3d Generation Partnership Project", 1971 . 1973 [SDO-ETSI] 1974 "European Telecommunications Standards Institute (ETSI)", 1975 . 1977 Authors' Addresses 1979 Randall Gellens 1980 Core Technology Consulting 1982 Email: rg+ietf@randy.pensive.org 1984 Hannes Tschofenig 1985 Individual 1987 Email: Hannes.Tschofenig@gmx.net 1988 URI: http://www.tschofenig.priv.at