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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 IPWAVE Working Group A. Petrescu 3 Internet-Draft CEA, LIST 4 Intended status: Standards Track N. Benamar 5 Expires: December 21, 2018 Moulay Ismail University 6 J. Haerri 7 Eurecom 8 J. Lee 9 Sangmyung University 10 T. Ernst 11 YoGoKo 12 June 19, 2018 14 Transmission of IPv6 Packets over IEEE 802.11 Networks operating in mode 15 Outside the Context of a Basic Service Set (IPv6-over-80211-OCB) 16 draft-ietf-ipwave-ipv6-over-80211ocb-25 18 Abstract 20 In order to transmit IPv6 packets on IEEE 802.11 networks running 21 outside the context of a basic service set (OCB, earlier "802.11p") 22 there is a need to define a few parameters such as the supported 23 Maximum Transmission Unit size on the 802.11-OCB link, the header 24 format preceding the IPv6 header, the Type value within it, and 25 others. This document describes these parameters for IPv6 and IEEE 26 802.11-OCB networks; it portrays the layering of IPv6 on 802.11-OCB 27 similarly to other known 802.11 and Ethernet layers - by using an 28 Ethernet Adaptation Layer. 30 Status of This Memo 32 This Internet-Draft is submitted in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at https://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on December 21, 2018. 47 Copyright Notice 49 Copyright (c) 2018 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (https://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 65 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 66 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 4 67 4. IPv6 over 802.11-OCB . . . . . . . . . . . . . . . . . . . . 5 68 4.1. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 5 69 4.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 5 70 4.2.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 5 71 4.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 7 72 4.4. Address Mapping . . . . . . . . . . . . . . . . . . . . . 7 73 4.4.1. Address Mapping -- Unicast . . . . . . . . . . . . . 7 74 4.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 7 75 4.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 7 76 4.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 8 77 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 78 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 79 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 80 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 81 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 82 9.1. Normative References . . . . . . . . . . . . . . . . . . 11 83 9.2. Informative References . . . . . . . . . . . . . . . . . 13 84 Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 15 85 Appendix B. 802.11p . . . . . . . . . . . . . . . . . . . . . . 23 86 Appendix C. Aspects introduced by the OCB mode to 802.11 . . . . 23 87 Appendix D. Changes Needed on a software driver 802.11a to 88 become a 802.11-OCB driver . . . 28 89 Appendix E. EtherType Protocol Discrimination (EPD) . . . . . . 29 90 Appendix F. Design Considerations . . . . . . . . . . . . . . . 30 91 F.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 30 92 F.2. Reliability Requirements . . . . . . . . . . . . . . . . 30 93 F.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 31 94 F.4. MAC Address Generation . . . . . . . . . . . . . . . . . 32 96 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 32 97 Appendix H. Implementation Status . . . . . . . . . . . . . . . 32 98 H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 33 99 H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 36 100 Appendix I. Extra Terminology . . . . . . . . . . . . . . . . . 38 101 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 103 1. Introduction 105 This document describes the transmission of IPv6 packets on IEEE Std 106 802.11-OCB networks [IEEE-802.11-2016] (a.k.a "802.11p" see 107 Appendix B, Appendix C and Appendix D). This involves the layering 108 of IPv6 networking on top of the IEEE 802.11 MAC layer, with an LLC 109 layer. Compared to running IPv6 over the Ethernet MAC layer, there 110 is no modification expected to IEEE Std 802.11 MAC and Logical Link 111 sublayers: IPv6 works fine directly over 802.11-OCB too, with an LLC 112 layer. 114 The IPv6 network layer operates on 802.11-OCB in the same manner as 115 operating on Ethernet, but there are two kinds of exceptions: 117 o Exceptions due to different operation of IPv6 network layer on 118 802.11 than on Ethernet. To satisfy these exceptions, this 119 document describes an Ethernet Adaptation Layer between Ethernet 120 headers and 802.11 headers. The Ethernet Adaptation Layer is 121 described Section 4.2.1. The operation of IP on Ethernet is 122 described in [RFC1042], [RFC2464] and 123 [I-D.hinden-6man-rfc2464bis]. 125 o Exceptions due to the OCB nature of 802.11-OCB compared to 802.11. 126 This has impacts on security, privacy, subnet structure and 127 handover behaviour. For security and privacy recommendations see 128 Section 5 and Section 4.5. The subnet structure is described in 129 Section 4.6. The handover behaviour on OCB links is not described 130 in this document. 132 In the published literature, many documents describe aspects and 133 problems related to running IPv6 over 802.11-OCB: 134 [I-D.ietf-ipwave-vehicular-networking-survey]. 136 2. Terminology 138 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 139 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 140 document are to be interpreted as described in RFC 2119 [RFC2119]. 142 IP-OBU (Internet Protocol On-Board Unit): an IP-OBU is a computer 143 situated in a vehicle such as an automobile, bicycle, or similar. It 144 has at least one IP interface that runs in mode OCB of 802.11, and 145 that has an "OBU" transceiver. See the definition of the term "OBU" 146 in section Appendix I. 148 IP-RSU (IP Road-Side Unit): an IP-RSU is situated along the road. An 149 IP-RSU has at least two distinct IP-enabled interfaces; at least one 150 interface is operated in mode OCB of IEEE 802.11 and is IP-enabled. 151 An IP-RSU is similar to a Wireless Termination Point (WTP), as 152 defined in [RFC5415], or an Access Point (AP), as defined in IEEE 153 documents, or an Access Network Router (ANR) defined in [RFC3753], 154 with one key particularity: the wireless PHY/MAC layer of at least 155 one of its IP-enabled interfaces is configured to operate in 156 802.11-OCB mode. The IP-RSU communicates with the IP-OBU in the 157 vehicle over 802.11 wireless link operating in OCB mode. 159 OCB (outside the context of a basic service set - BSS): A mode of 160 operation in which a STA is not a member of a BSS and does not 161 utilize IEEE Std 802.11 authentication, association, or data 162 confidentiality. 164 802.11-OCB: mode specified in IEEE Std 802.11-2016 when the MIB 165 attribute dot11OCBActivited is true. Note: compliance with standards 166 and regulations set in different countries when using the 5.9GHz 167 frequency band is required. 169 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 171 The IEEE 802.11-OCB Networks are used for vehicular communications, 172 as 'Wireless Access in Vehicular Environments'. The IP communication 173 scenarios for these environments have been described in several 174 documents; in particular, we refer the reader to 175 [I-D.ietf-ipwave-vehicular-networking-survey], that lists some 176 scenarios and requirements for IP in Intelligent Transportation 177 Systems. 179 The link model is the following: STA --- 802.11-OCB --- STA. In 180 vehicular networks, STAs can be IP-RSUs and/or IP-OBUs. While 181 802.11-OCB is clearly specified, and the use of IPv6 over such link 182 is not radically new, the operating environment (vehicular networks) 183 brings in new perspectives. 185 The mechanisms for forming and terminating, discovering, peering and 186 mobility management for 802.11-OCB links are not described in this 187 document. 189 4. IPv6 over 802.11-OCB 191 4.1. Maximum Transmission Unit (MTU) 193 The default MTU for IP packets on 802.11-OCB MUST be 1500 octets. It 194 is the same value as IPv6 packets on Ethernet links, as specified in 195 [RFC2464]. This value of the MTU respects the recommendation that 196 every link on the Internet must have a minimum MTU of 1280 octets 197 (stated in [RFC8200], and the recommendations therein, especially 198 with respect to fragmentation). 200 4.2. Frame Format 202 IP packets MUST be transmitted over 802.11-OCB media as QoS Data 203 frames whose format is specified in IEEE Std 802.11. 205 The IPv6 packet transmitted on 802.11-OCB MUST be immediately 206 preceded by a Logical Link Control (LLC) header and an 802.11 header. 207 In the LLC header, and in accordance with the EtherType Protocol 208 Discrimination (EPD), the value of the Type field MUST be set to 209 0x86DD (IPv6). In the 802.11 header, the value of the Subtype sub- 210 field in the Frame Control field MUST be set to 8 (i.e. 'QoS Data'); 211 the value of the Traffic Identifier (TID) sub-field of the QoS 212 Control field of the 802.11 header MUST be set to binary 001 (i.e. 213 User Priority 'Background', QoS Access Category 'AC_BK'). 215 To simplify the Application Programming Interface (API) between the 216 operating system and the 802.11-OCB media, device drivers MAY 217 implement an Ethernet Adaptation Layer that translates Ethernet II 218 frames to the 802.11 format and vice versa. An Ethernet Adaptation 219 Layer is described in Section 4.2.1. 221 4.2.1. Ethernet Adaptation Layer 223 An 'adaptation' layer is inserted between a MAC layer and the 224 Networking layer. This is used to transform some parameters between 225 their form expected by the IP stack and the form provided by the MAC 226 layer. 228 An Ethernet Adaptation Layer makes an 802.11 MAC look to IP 229 Networking layer as a more traditional Ethernet layer. At reception, 230 this layer takes as input the IEEE 802.11 header and the Logical-Link 231 Layer Control Header and produces an Ethernet II Header. At sending, 232 the reverse operation is performed. 234 The operation of the Ethernet Adaptation Layer is depicted by the 235 double arrow in Figure 1. 237 +------------------+------------+-------------+---------+-----------+ 238 | 802.11 header | LLC Header | IPv6 Header | Payload |.11 Trailer| 239 +------------------+------------+-------------+---------+-----------+ 240 \ / \ / 241 --------------------------- -------- 242 \---------------------------------------------/ 243 ^ 244 | 245 802.11-to-Ethernet Adaptation Layer 246 | 247 v 248 +---------------------+-------------+---------+ 249 | Ethernet II Header | IPv6 Header | Payload | 250 +---------------------+-------------+---------+ 252 Figure 1: Operation of the Ethernet Adaptation Layer 254 The Receiver and Transmitter Address fields in the 802.11 header MUST 255 contain the same values as the Destination and the Source Address 256 fields in the Ethernet II Header, respectively. The value of the 257 Type field in the LLC Header MUST be the same as the value of the 258 Type field in the Ethernet II Header. That value MUST be set to 259 0x86DD (IPv6). 261 The ".11 Trailer" contains solely a 4-byte Frame Check Sequence. 263 The placement of IPv6 networking layer on Ethernet Adaptation Layer 264 is illustrated in Figure 2. 266 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 | IPv6 | 268 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 269 | Ethernet Adaptation Layer | 270 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 271 | 802.11 MAC | 272 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 273 | 802.11 PHY | 274 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 276 Figure 2: Ethernet Adaptation Layer stacked with other layers 278 (in the above figure, a 802.11 profile is represented; this is used 279 also for 802.11-OCB profile.) 281 4.3. Link-Local Addresses 283 The link-local address of an 802.11-OCB interface is formed in the 284 same manner as on an Ethernet interface. This manner is described in 285 section 5 of [RFC2464]. Additionally, if stable identifiers are 286 needed, it is RECOMMENDED to follow the Recommendation on Stable IPv6 287 Interface Identifiers [RFC8064]. Additionally, if semantically 288 opaque Interface Identifiers are needed, a potential method for 289 generating semantically opaque Interface Identifiers with IPv6 290 Stateless Address Autoconfiguration is given in [RFC7217]. 292 4.4. Address Mapping 294 Unicast and multicast address mapping MUST follow the procedures 295 specified for Ethernet interfaces in sections 6 and 7 of [RFC2464]. 297 4.4.1. Address Mapping -- Unicast 299 The procedure for mapping IPv6 unicast addresses into Ethernet link- 300 layer addresses is described in [RFC4861]. 302 4.4.2. Address Mapping -- Multicast 304 The multicast address mapping is performed according to the method 305 specified in section 7 of [RFC2464]. The meaning of the value "3333" 306 mentioned in that section 7 of [RFC2464] is defined in section 2.3.1 307 of [RFC7042]. 309 Transmitting IPv6 packets to multicast destinations over 802.11 links 310 proved to have some performance issues 311 [I-D.perkins-intarea-multicast-ieee802]. These issues may be 312 exacerbated in OCB mode. Solutions for these problems should 313 consider the OCB mode of operation. 315 4.5. Stateless Autoconfiguration 317 The Interface Identifier for an 802.11-OCB interface is formed using 318 the same rules as the Interface Identifier for an Ethernet interface; 319 the RECOMMENDED method for forming stable Interface Identifiers 320 (IIDs) is described in [RFC8064]. The method of forming IIDs 321 described in section 4 of [RFC2464] MAY be used during transition 322 time. 324 The bits in the interface identifier have no generic meaning and the 325 identifier should be treated as an opaque value. The bits 326 'Universal' and 'Group' in the identifier of an 802.11-OCB interface 327 are significant, as this is an IEEE link-layer address. The details 328 of this significance are described in [RFC7136]. 330 As with all Ethernet and 802.11 interface identifiers ([RFC7721]), 331 the identifier of an 802.11-OCB interface may involve privacy, MAC 332 address spoofing and IP address hijacking risks. A vehicle embarking 333 an OBU or an IP-OBU whose egress interface is 802.11-OCB may expose 334 itself to eavesdropping and subsequent correlation of data; this may 335 reveal data considered private by the vehicle owner; there is a risk 336 of being tracked; see the privacy considerations described in 337 Appendix F. 339 If stable Interface Identifiers are needed in order to form IPv6 340 addresses on 802.11-OCB links, it is recommended to follow the 341 recommendation in [RFC8064]. Additionally, if semantically opaque 342 Interface Identifiers are needed, a potential method for generating 343 semantically opaque Interface Identifiers with IPv6 Stateless Address 344 Autoconfiguration is given in [RFC7217]. 346 4.6. Subnet Structure 348 A subnet is formed by the external 802.11-OCB interfaces of vehicles 349 that are in close range (not their on-board interfaces). This 350 ephemeral subnet structure is strongly influenced by the mobility of 351 vehicles: the 802.11 hidden node effects appear. On another hand, 352 the structure of the internal subnets in each car is relatively 353 stable. 355 The 802.11 networks in OCB mode may be considered as 'ad-hoc' 356 networks. The addressing model for such networks is described in 357 [RFC5889]. 359 The operation of the Neighbor Discovery protocol (ND) over 802.11-OCB 360 links is different than over 802.11 links. In OCB, the link layer 361 does not ensure that all associated members receive all messages, 362 because there is no association operation. Neighbor Discovery (ND) 363 is used over 802.11-OCB. 365 The operation of the Mobile IPv6 protocol over 802.11-OCB links is 366 different than on other links. The Movement Detection operation 367 (section 11.5.1 of [RFC6275]) can not rely on Neighbor Unreachability 368 Detection operation of the Neighbor Discovery protocol, for the 369 reason mentioned in the previous paragraph. Also, the 802.11-OCB 370 link layer is not a lower layer that can provide an indication that a 371 link layer handover has occured. The operation of the Mobile IPv6 372 protocol over 802.11-OCB is not specified in this document. 374 5. Security Considerations 376 Any security mechanism at the IP layer or above that may be carried 377 out for the general case of IPv6 may also be carried out for IPv6 378 operating over 802.11-OCB. 380 The OCB operation is stripped off of all existing 802.11 link-layer 381 security mechanisms. There is no encryption applied below the 382 network layer running on 802.11-OCB. At application layer, the IEEE 383 1609.2 document [IEEE-1609.2] does provide security services for 384 certain applications to use; application-layer mechanisms are out-of- 385 scope of this document. On another hand, a security mechanism 386 provided at networking layer, such as IPsec [RFC4301], may provide 387 data security protection to a wider range of applications. 389 802.11-OCB does not provide any cryptographic protection, because it 390 operates outside the context of a BSS (no Association Request/ 391 Response, no Challenge messages). Any attacker can therefore just 392 sit in the near range of vehicles, sniff the network (just set the 393 interface card's frequency to the proper range) and perform attacks 394 without needing to physically break any wall. Such a link is less 395 protected than commonly used links (wired link or protected 802.11). 397 The potential attack vectors are: MAC address spoofing, IP address 398 and session hijacking and privacy violation. 400 Within the IPsec Security Architecture [RFC4301], the IPsec AH and 401 ESP headers [RFC4302] and [RFC4303] respectively, its multicast 402 extensions [RFC5374], HTTPS [RFC2818] and SeND [RFC3971] protocols 403 can be used to protect communications. Further, the assistance of 404 proper Public Key Infrastructure (PKI) protocols [RFC4210] is 405 necessary to establish credentials. More IETF protocols are 406 available in the toolbox of the IP security protocol designer. 407 Certain ETSI protocols related to security protocols in Intelligent 408 Transportation Systems are described in [ETSI-sec-archi]. 410 As with all Ethernet and 802.11 interface identifiers, there may 411 exist privacy risks in the use of 802.11-OCB interface identifiers. 412 Moreover, in outdoors vehicular settings, the privacy risks are more 413 important than in indoors settings. New risks are induced by the 414 possibility of attacker sniffers deployed along routes which listen 415 for IP packets of vehicles passing by. For this reason, in the 416 802.11-OCB deployments, there is a strong necessity to use protection 417 tools such as dynamically changing MAC addresses. This may help 418 mitigate privacy risks to a certain level. On another hand, it may 419 have an impact in the way typical IPv6 address auto-configuration is 420 performed for vehicles (SLAAC would rely on MAC addresses and would 421 hence dynamically change the affected IP address), in the way the 422 IPv6 Privacy addresses were used, and other effects. 424 6. IANA Considerations 426 No request to IANA. 428 7. Contributors 430 Christian Huitema, Tony Li. 432 Romain Kuntz contributed extensively about IPv6 handovers between 433 links running outside the context of a BSS (802.11-OCB links). 435 Tim Leinmueller contributed the idea of the use of IPv6 over 436 802.11-OCB for distribution of certificates. 438 Marios Makassikis, Jose Santa Lozano, Albin Severinson and Alexey 439 Voronov provided significant feedback on the experience of using IP 440 messages over 802.11-OCB in initial trials. 442 Michelle Wetterwald contributed extensively the MTU discussion, 443 offered the ETSI ITS perspective, and reviewed other parts of the 444 document. 446 8. Acknowledgements 448 The authors would like to thank Witold Klaudel, Ryuji Wakikawa, 449 Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan 450 Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray 451 Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan, 452 Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne, 453 Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark, 454 Bob Moskowitz, Andrew Dryden, Georg Mayer, Dorothy Stanley, Sandra 455 Cespedes, Mariano Falcitelli, Sri Gundavelli, Abdussalam Baryun, 456 Margaret Cullen, Erik Kline, Carlos Jesus Bernardos Cano, Ronald in 457 't Velt, Katrin Sjoberg, Roland Bless, Tijink Jasja, Kevin Smith, 458 Brian Carpenter, Julian Reschke, Mikael Abrahamsson and William 459 Whyte. Their valuable comments clarified particular issues and 460 generally helped to improve the document. 462 Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB 463 drivers for linux and described how. 465 For the multicast discussion, the authors would like to thank Owen 466 DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and 467 participants to discussions in network working groups. 469 The authors would like to thank participants to the Birds-of- 470 a-Feather "Intelligent Transportation Systems" meetings held at IETF 471 in 2016. 473 9. References 475 9.1. Normative References 477 [RFC1042] Postel, J. and J. Reynolds, "Standard for the transmission 478 of IP datagrams over IEEE 802 networks", STD 43, RFC 1042, 479 DOI 10.17487/RFC1042, February 1988, 480 . 482 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 483 Requirement Levels", BCP 14, RFC 2119, 484 DOI 10.17487/RFC2119, March 1997, 485 . 487 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 488 Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, 489 . 491 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, 492 DOI 10.17487/RFC2818, May 2000, 493 . 495 [RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related 496 Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004, 497 . 499 [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, 500 "SEcure Neighbor Discovery (SEND)", RFC 3971, 501 DOI 10.17487/RFC3971, March 2005, 502 . 504 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 505 "Randomness Requirements for Security", BCP 106, RFC 4086, 506 DOI 10.17487/RFC4086, June 2005, 507 . 509 [RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen, 510 "Internet X.509 Public Key Infrastructure Certificate 511 Management Protocol (CMP)", RFC 4210, 512 DOI 10.17487/RFC4210, September 2005, 513 . 515 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 516 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 517 December 2005, . 519 [RFC4302] Kent, S., "IP Authentication Header", RFC 4302, 520 DOI 10.17487/RFC4302, December 2005, 521 . 523 [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", 524 RFC 4303, DOI 10.17487/RFC4303, December 2005, 525 . 527 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 528 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 529 DOI 10.17487/RFC4861, September 2007, 530 . 532 [RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast 533 Extensions to the Security Architecture for the Internet 534 Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008, 535 . 537 [RFC5415] Calhoun, P., Ed., Montemurro, M., Ed., and D. Stanley, 538 Ed., "Control And Provisioning of Wireless Access Points 539 (CAPWAP) Protocol Specification", RFC 5415, 540 DOI 10.17487/RFC5415, March 2009, 541 . 543 [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing 544 Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, 545 September 2010, . 547 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 548 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 549 2011, . 551 [RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and 552 IETF Protocol and Documentation Usage for IEEE 802 553 Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042, 554 October 2013, . 556 [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 557 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, 558 February 2014, . 560 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 561 Interface Identifiers with IPv6 Stateless Address 562 Autoconfiguration (SLAAC)", RFC 7217, 563 DOI 10.17487/RFC7217, April 2014, 564 . 566 [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy 567 Considerations for IPv6 Address Generation Mechanisms", 568 RFC 7721, DOI 10.17487/RFC7721, March 2016, 569 . 571 [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu, 572 "Recommendation on Stable IPv6 Interface Identifiers", 573 RFC 8064, DOI 10.17487/RFC8064, February 2017, 574 . 576 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 577 (IPv6) Specification", STD 86, RFC 8200, 578 DOI 10.17487/RFC8200, July 2017, 579 . 581 9.2. Informative References 583 [ETSI-sec-archi] 584 "ETSI TS 102 940 V1.2.1 (2016-11), ETSI Technical 585 Specification, Intelligent Transport Systems (ITS); 586 Security; ITS communications security architecture and 587 security management, November 2016. Downloaded on 588 September 9th, 2017, freely available from ETSI website at 589 URL http://www.etsi.org/deliver/ 590 etsi_ts/102900_102999/102940/01.02.01_60/ 591 ts_102940v010201p.pdf". 593 [I-D.hinden-6man-rfc2464bis] 594 Crawford, M. and R. Hinden, "Transmission of IPv6 Packets 595 over Ethernet Networks", draft-hinden-6man-rfc2464bis-02 596 (work in progress), March 2017. 598 [I-D.ietf-ipwave-vehicular-networking-survey] 599 Jeong, J., Cespedes, S., Benamar, N., Haerri, J., and M. 600 Wetterwald, "Survey on IP-based Vehicular Networking for 601 Intelligent Transportation Systems", draft-ietf-ipwave- 602 vehicular-networking-survey-00 (work in progress), July 603 2017. 605 [I-D.perkins-intarea-multicast-ieee802] 606 Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, 607 "Multicast Considerations over IEEE 802 Wireless Media", 608 draft-perkins-intarea-multicast-ieee802-03 (work in 609 progress), July 2017. 611 [IEEE-1609.2] 612 "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access 613 in Vehicular Environments (WAVE) -- Security Services for 614 Applications and Management Messages. Example URL 615 http://ieeexplore.ieee.org/document/7426684/ accessed on 616 August 17th, 2017.". 618 [IEEE-1609.3] 619 "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access 620 in Vehicular Environments (WAVE) -- Networking Services. 621 Example URL http://ieeexplore.ieee.org/document/7458115/ 622 accessed on August 17th, 2017.". 624 [IEEE-1609.4] 625 "IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access 626 in Vehicular Environments (WAVE) -- Multi-Channel 627 Operation. Example URL 628 http://ieeexplore.ieee.org/document/7435228/ accessed on 629 August 17th, 2017.". 631 [IEEE-802.11-2016] 632 "IEEE Standard 802.11-2016 - IEEE Standard for Information 633 Technology - Telecommunications and information exchange 634 between systems Local and metropolitan area networks - 635 Specific requirements - Part 11: Wireless LAN Medium 636 Access Control (MAC) and Physical Layer (PHY) 637 Specifications. Status - Active Standard. Description 638 retrieved freely on September 12th, 2017, at URL 639 https://standards.ieee.org/findstds/ 640 standard/802.11-2016.html". 642 [IEEE-802.11p-2010] 643 "IEEE Std 802.11p (TM)-2010, IEEE Standard for Information 644 Technology - Telecommunications and information exchange 645 between systems - Local and metropolitan area networks - 646 Specific requirements, Part 11: Wireless LAN Medium Access 647 Control (MAC) and Physical Layer (PHY) Specifications, 648 Amendment 6: Wireless Access in Vehicular Environments; 649 document freely available at URL 650 http://standards.ieee.org/getieee802/ 651 download/802.11p-2010.pdf retrieved on September 20th, 652 2013.". 654 Appendix A. ChangeLog 656 The changes are listed in reverse chronological order, most recent 657 changes appearing at the top of the list. 659 -25: added a reference to 'IEEE Management Information Base', instead 660 of just 'Management Information Base'; added ref to further 661 appendices in the introductory phrases; improved text for IID 662 formation for SLAAC, inserting recommendation for RFC8064 before 663 RFC2464. 665 From draft-ietf-ipwave-ipv6-over-80211ocb-23 to draft-ietf-ipwave- 666 ipv6-over-80211ocb-24 668 o Nit: wrote "IPWAVE Working Group" on the front page, instead of 669 "Network Working Group". 671 o Addressed the comments on 6MAN: replaced a sentence about ND 672 problem with "is used over 802.11-OCB". 674 From draft-ietf-ipwave-ipv6-over-80211ocb-22 to draft-ietf-ipwave- 675 ipv6-over-80211ocb-23 677 o No content modifications, but check the entire draft chain on 678 IPv6-only: xml2rfc, submission on tools.ietf.org and datatracker. 680 From draft-ietf-ipwave-ipv6-over-80211ocb-21 to draft-ietf-ipwave- 681 ipv6-over-80211ocb-22 683 o Corrected typo, use dash in "802.11-OCB" instead of space. 685 o Improved the Frame Format section: MUST use QoSData, specify the 686 values within; clarified the Ethernet Adaptation Layer text. 688 From draft-ietf-ipwave-ipv6-over-80211ocb-20 to draft-ietf-ipwave- 689 ipv6-over-80211ocb-21 691 o Corrected a few nits and added names in Acknowledgments section. 693 o Removed unused reference to old Internet Draft tsvwg about QoS. 695 From draft-ietf-ipwave-ipv6-over-80211ocb-19 to draft-ietf-ipwave- 696 ipv6-over-80211ocb-20 698 o Reduced the definition of term "802.11-OCB". 700 o Left out of this specification which 802.11 header to use to 701 transmit IP packets in OCB mode (QoS Data header, Data header, or 702 any other). 704 o Added 'MUST' use an Ethernet Adaptation Layer, instead of 'is 705 using' an Ethernet Adaptation Layer. 707 From draft-ietf-ipwave-ipv6-over-80211ocb-18 to draft-ietf-ipwave- 708 ipv6-over-80211ocb-19 710 o Removed the text about fragmentation. 712 o Removed the mentioning of WSMP and GeoNetworking. 714 o Removed the explanation of the binary representation of the 715 EtherType. 717 o Rendered normative the paragraph about unicast and multicast 718 address mapping. 720 o Removed paragraph about addressing model, subnet structure and 721 easiness of using LLs. 723 o Clarified the Type/Subtype field in the 802.11 Header. 725 o Used RECOMMENDED instead of recommended, for the stable interface 726 identifiers. 728 From draft-ietf-ipwave-ipv6-over-80211ocb-17 to draft-ietf-ipwave- 729 ipv6-over-80211ocb-18 731 o Improved the MTU and fragmentation paragraph. 733 From draft-ietf-ipwave-ipv6-over-80211ocb-16 to draft-ietf-ipwave- 734 ipv6-over-80211ocb-17 736 o Susbtituted "MUST be increased" to "is increased" in the MTU 737 section, about fragmentation. 739 From draft-ietf-ipwave-ipv6-over-80211ocb-15 to draft-ietf-ipwave- 740 ipv6-over-80211ocb-16 742 o Removed the definition of the 'WiFi' term and its occurences. 743 Clarified a phrase that used it in Appendix C "Aspects introduced 744 by the OCB mode to 802.11". 746 o Added more normative words: MUST be 0x86DD, MUST fragment if size 747 larger than MTU, Sequence number in 802.11 Data header MUST be 748 increased. 750 From draft-ietf-ipwave-ipv6-over-80211ocb-14 to draft-ietf-ipwave- 751 ipv6-over-80211ocb-15 753 o Added normative term MUST in two places in section "Ethernet 754 Adaptation Layer". 756 From draft-ietf-ipwave-ipv6-over-80211ocb-13 to draft-ietf-ipwave- 757 ipv6-over-80211ocb-14 759 o Created a new Appendix titled "Extra Terminology" that contains 760 terms DSRC, DSRCS, OBU, RSU as defined outside IETF. Some of them 761 are used in the main Terminology section. 763 o Added two paragraphs explaining that ND and Mobile IPv6 have 764 problems working over 802.11-OCB, yet their adaptations is not 765 specified in this document. 767 From draft-ietf-ipwave-ipv6-over-80211ocb-12 to draft-ietf-ipwave- 768 ipv6-over-80211ocb-13 770 o Substituted "IP-OBU" for "OBRU", and "IP-RSU" for "RSRU" 771 throughout and improved OBU-related definitions in the Terminology 772 section. 774 From draft-ietf-ipwave-ipv6-over-80211ocb-11 to draft-ietf-ipwave- 775 ipv6-over-80211ocb-12 777 o Improved the appendix about "MAC Address Generation" by expressing 778 the technique to be an optional suggestion, not a mandatory 779 mechanism. 781 From draft-ietf-ipwave-ipv6-over-80211ocb-10 to draft-ietf-ipwave- 782 ipv6-over-80211ocb-11 784 o Shortened the paragraph on forming/terminating 802.11-OCB links. 786 o Moved the draft tsvwg-ieee-802-11 to Informative References. 788 From draft-ietf-ipwave-ipv6-over-80211ocb-09 to draft-ietf-ipwave- 789 ipv6-over-80211ocb-10 791 o Removed text requesting a new Group ID for multicast for OCB. 793 o Added a clarification of the meaning of value "3333" in the 794 section Address Mapping -- Multicast. 796 o Added note clarifying that in Europe the regional authority is not 797 ETSI, but "ECC/CEPT based on ENs from ETSI". 799 o Added note stating that the manner in which two STAtions set their 800 communication channel is not described in this document. 802 o Added a time qualifier to state that the "each node is represented 803 uniquely at a certain point in time." 805 o Removed text "This section may need to be moved" (the "Reliability 806 Requirements" section). This section stays there at this time. 808 o In the term definition "802.11-OCB" added a note stating that "any 809 implementation should comply with standards and regulations set in 810 the different countries for using that frequency band." 812 o In the RSU term definition, added a sentence explaining the 813 difference between RSU and RSRU: in terms of number of interfaces 814 and IP forwarding. 816 o Replaced "with at least two IP interfaces" with "with at least two 817 real or virtual IP interfaces". 819 o Added a term in the Terminology for "OBU". However the definition 820 is left empty, as this term is defined outside IETF. 822 o Added a clarification that it is an OBU or an OBRU in this phrase 823 "A vehicle embarking an OBU or an OBRU". 825 o Checked the entire document for a consistent use of terms OBU and 826 OBRU. 828 o Added note saying that "'p' is a letter identifying the 829 Ammendment". 831 o Substituted lower case for capitals SHALL or MUST in the 832 Appendices. 834 o Added reference to RFC7042, helpful in the 3333 explanation. 835 Removed reference to individual submission draft-petrescu-its- 836 scenario-reqs and added reference to draft-ietf-ipwave-vehicular- 837 networking-survey. 839 o Added figure captions, figure numbers, and references to figure 840 numbers instead of 'below'. Replaced "section Section" with 841 "section" throughout. 843 o Minor typographical errors. 845 From draft-ietf-ipwave-ipv6-over-80211ocb-08 to draft-ietf-ipwave- 846 ipv6-over-80211ocb-09 848 o Significantly shortened the Address Mapping sections, by text 849 copied from RFC2464, and rather referring to it. 851 o Moved the EPD description to an Appendix on its own. 853 o Shortened the Introduction and the Abstract. 855 o Moved the tutorial section of OCB mode introduced to .11, into an 856 appendix. 858 o Removed the statement that suggests that for routing purposes a 859 prefix exchange mechanism could be needed. 861 o Removed refs to RFC3963, RFC4429 and RFC6775; these are about ND, 862 MIP/NEMO and oDAD; they were referred in the handover discussion 863 section, which is out. 865 o Updated a reference from individual submission to now a WG item in 866 IPWAVE: the survey document. 868 o Added term definition for WiFi. 870 o Updated the authorship and expanded the Contributors section. 872 o Corrected typographical errors. 874 From draft-ietf-ipwave-ipv6-over-80211ocb-07 to draft-ietf-ipwave- 875 ipv6-over-80211ocb-08 877 o Removed the per-channel IPv6 prohibition text. 879 o Corrected typographical errors. 881 From draft-ietf-ipwave-ipv6-over-80211ocb-06 to draft-ietf-ipwave- 882 ipv6-over-80211ocb-07 884 o Added new terms: OBRU and RSRU ('R' for Router). Refined the 885 existing terms RSU and OBU, which are no longer used throughout 886 the document. 888 o Improved definition of term "802.11-OCB". 890 o Clarified that OCB does not "strip" security, but that the 891 operation in OCB mode is "stripped off of all .11 security". 893 o Clarified that theoretical OCB bandwidth speed is 54mbits, but 894 that a commonly observed bandwidth in IP-over-OCB is 12mbit/s. 896 o Corrected typographical errors, and improved some phrasing. 898 From draft-ietf-ipwave-ipv6-over-80211ocb-05 to draft-ietf-ipwave- 899 ipv6-over-80211ocb-06 901 o Updated references of 802.11-OCB document from -2012 to the IEEE 902 802.11-2016. 904 o In the LL address section, and in SLAAC section, added references 905 to 7217 opaque IIDs and 8064 stable IIDs. 907 From draft-ietf-ipwave-ipv6-over-80211ocb-04 to draft-ietf-ipwave- 908 ipv6-over-80211ocb-05 910 o Lengthened the title and cleanded the abstract. 912 o Added text suggesting LLs may be easy to use on OCB, rather than 913 GUAs based on received prefix. 915 o Added the risks of spoofing and hijacking. 917 o Removed the text speculation on adoption of the TSA message. 919 o Clarified that the ND protocol is used. 921 o Clarified what it means "No association needed". 923 o Added some text about how two STAs discover each other. 925 o Added mention of external (OCB) and internal network (stable), in 926 the subnet structure section. 928 o Added phrase explaining that both .11 Data and .11 QoS Data 929 headers are currently being used, and may be used in the future. 931 o Moved the packet capture example into an Appendix Implementation 932 Status. 934 o Suggested moving the reliability requirements appendix out into 935 another document. 937 o Added a IANA Consiserations section, with content, requesting for 938 a new multicast group "all OCB interfaces". 940 o Added new OBU term, improved the RSU term definition, removed the 941 ETTC term, replaced more occurences of 802.11p, 802.11-OCB with 942 802.11-OCB. 944 o References: 946 * Added an informational reference to ETSI's IPv6-over- 947 GeoNetworking. 949 * Added more references to IETF and ETSI security protocols. 951 * Updated some references from I-D to RFC, and from old RFC to 952 new RFC numbers. 954 * Added reference to multicast extensions to IPsec architecture 955 RFC. 957 * Added a reference to 2464-bis. 959 * Removed FCC informative references, because not used. 961 o Updated the affiliation of one author. 963 o Reformulation of some phrases for better readability, and 964 correction of typographical errors. 966 From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave- 967 ipv6-over-80211ocb-04 969 o Removed a few informative references pointing to Dx draft IEEE 970 1609 documents. 972 o Removed outdated informative references to ETSI documents. 974 o Added citations to IEEE 1609.2, .3 and .4-2016. 976 o Minor textual issues. 978 From draft-ietf-ipwave-ipv6-over-80211ocb-02 to draft-ietf-ipwave- 979 ipv6-over-80211ocb-03 981 o Keep the previous text on multiple addresses, so remove talk about 982 MIP6, NEMOv6 and MCoA. 984 o Clarified that a 'Beacon' is an IEEE 802.11 frame Beacon. 986 o Clarified the figure showing Infrastructure mode and OCB mode side 987 by side. 989 o Added a reference to the IP Security Architecture RFC. 991 o Detailed the IPv6-per-channel prohibition paragraph which reflects 992 the discussion at the last IETF IPWAVE WG meeting. 994 o Added section "Address Mapping -- Unicast". 996 o Added the ".11 Trailer" to pictures of 802.11 frames. 998 o Added text about SNAP carrying the Ethertype. 1000 o New RSU definition allowing for it be both a Router and not 1001 necessarily a Router some times. 1003 o Minor textual issues. 1005 From draft-ietf-ipwave-ipv6-over-80211ocb-01 to draft-ietf-ipwave- 1006 ipv6-over-80211ocb-02 1008 o Replaced almost all occurences of 802.11p with 802.11-OCB, leaving 1009 only when explanation of evolution was necessary. 1011 o Shortened by removing parameter details from a paragraph in the 1012 Introduction. 1014 o Moved a reference from Normative to Informative. 1016 o Added text in intro clarifying there is no handover spec at IEEE, 1017 and that 1609.2 does provide security services. 1019 o Named the contents the fields of the EthernetII header (including 1020 the Ethertype bitstring). 1022 o Improved relationship between two paragraphs describing the 1023 increase of the Sequence Number in 802.11 header upon IP 1024 fragmentation. 1026 o Added brief clarification of "tracking". 1028 From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave- 1029 ipv6-over-80211ocb-01 1031 o Introduced message exchange diagram illustrating differences 1032 between 802.11 and 802.11 in OCB mode. 1034 o Introduced an appendix listing for information the set of 802.11 1035 messages that may be transmitted in OCB mode. 1037 o Removed appendix sections "Privacy Requirements", "Authentication 1038 Requirements" and "Security Certificate Generation". 1040 o Removed appendix section "Non IP Communications". 1042 o Introductory phrase in the Security Considerations section. 1044 o Improved the definition of "OCB". 1046 o Introduced theoretical stacked layers about IPv6 and IEEE layers 1047 including EPD. 1049 o Removed the appendix describing the details of prohibiting IPv6 on 1050 certain channels relevant to 802.11-OCB. 1052 o Added a brief reference in the privacy text about a precise clause 1053 in IEEE 1609.3 and .4. 1055 o Clarified the definition of a Road Side Unit. 1057 o Removed the discussion about security of WSA (because is non-IP). 1059 o Removed mentioning of the GeoNetworking discussion. 1061 o Moved references to scientific articles to a separate 'overview' 1062 draft, and referred to it. 1064 Appendix B. 802.11p 1066 The term "802.11p" is an earlier definition. The behaviour of 1067 "802.11p" networks is rolled in the document IEEE Std 802.11-2016. 1068 In that document the term 802.11p disappears. Instead, each 802.11p 1069 feature is conditioned by the IEEE Management Information Base (MIB) 1070 attribute "OCBActivated" [IEEE-802.11-2016]. Whenever OCBActivated 1071 is set to true the IEEE Std 802.11-OCB state is activated. For 1072 example, an 802.11 STAtion operating outside the context of a basic 1073 service set has the OCBActivated flag set. Such a station, when it 1074 has the flag set, uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. 1076 Appendix C. Aspects introduced by the OCB mode to 802.11 1078 In the IEEE 802.11-OCB mode, all nodes in the wireless range can 1079 directly communicate with each other without involving authentication 1080 or association procedures. At link layer, it is necessary to set the 1081 same channel number (or frequency) on two stations that need to 1082 communicate with each other. The manner in which stations set their 1083 channel number is not specified in this document. Stations STA1 and 1084 STA2 can exchange IP packets if they are set on the same channel. At 1085 IP layer, they then discover each other by using the IPv6 Neighbor 1086 Discovery protocol. 1088 Briefly, the IEEE 802.11-OCB mode has the following properties: 1090 o The use by each node of a 'wildcard' BSSID (i.e., each bit of the 1091 BSSID is set to 1) 1093 o No IEEE 802.11 Beacon frames are transmitted 1095 o No authentication is required in order to be able to communicate 1097 o No association is needed in order to be able to communicate 1099 o No encryption is provided in order to be able to communicate 1101 o Flag dot11OCBActivated is set to true 1103 All the nodes in the radio communication range (IP-OBU and IP-RSU) 1104 receive all the messages transmitted (IP-OBU and IP-RSU) within the 1105 radio communications range. The eventual conflict(s) are resolved by 1106 the MAC CDMA function. 1108 The message exchange diagram in Figure 3 illustrates a comparison 1109 between traditional 802.11 and 802.11 in OCB mode. The 'Data' 1110 messages can be IP packets such as HTTP or others. Other 802.11 1111 management and control frames (non IP) may be transmitted, as 1112 specified in the 802.11 standard. For information, the names of 1113 these messages as currently specified by the 802.11 standard are 1114 listed in Appendix G. 1116 STA AP STA1 STA2 1117 | | | | 1118 |<------ Beacon -------| |<------ Data -------->| 1119 | | | | 1120 |---- Probe Req. ----->| |<------ Data -------->| 1121 |<--- Probe Res. ------| | | 1122 | | |<------ Data -------->| 1123 |---- Auth Req. ------>| | | 1124 |<--- Auth Res. -------| |<------ Data -------->| 1125 | | | | 1126 |---- Asso Req. ------>| |<------ Data -------->| 1127 |<--- Asso Res. -------| | | 1128 | | |<------ Data -------->| 1129 |<------ Data -------->| | | 1130 |<------ Data -------->| |<------ Data -------->| 1132 (i) 802.11 Infrastructure mode (ii) 802.11-OCB mode 1134 Figure 3: Difference between messages exchanged on 802.11 (left) and 1135 802.11-OCB (right) 1137 The interface 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010 1138 [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, 1139 titled "Amendment 6: Wireless Access in Vehicular Environments". 1140 Since then, this amendment has been integrated in IEEE 802.11(TM) 1141 -2012 and -2016 [IEEE-802.11-2016]. 1143 In document 802.11-2016, anything qualified specifically as 1144 "OCBActivated", or "outside the context of a basic service" set to be 1145 true, then it is actually referring to OCB aspects introduced to 1146 802.11. 1148 In order to delineate the aspects introduced by 802.11-OCB to 802.11, 1149 we refer to the earlier [IEEE-802.11p-2010]. The amendment is 1150 concerned with vehicular communications, where the wireless link is 1151 similar to that of Wireless LAN (using a PHY layer specified by 1152 802.11a/b/g/n), but which needs to cope with the high mobility factor 1153 inherent in scenarios of communications between moving vehicles, and 1154 between vehicles and fixed infrastructure deployed along roads. 1155 While 'p' is a letter identifying the Ammendment, just like 'a, b, g' 1156 and 'n' are, 'p' is concerned more with MAC modifications, and a 1157 little with PHY modifications; the others are mainly about PHY 1158 modifications. It is possible in practice to combine a 'p' MAC with 1159 an 'a' PHY by operating outside the context of a BSS with OFDM at 1160 5.4GHz and 5.9GHz. 1162 The 802.11-OCB links are specified to be compatible as much as 1163 possible with the behaviour of 802.11a/b/g/n and future generation 1164 IEEE WLAN links. From the IP perspective, an 802.11-OCB MAC layer 1165 offers practically the same interface to IP as the 802.11a/b/g/n and 1166 802.3. A packet sent by an IP-OBU may be received by one or multiple 1167 IP-RSUs. The link-layer resolution is performed by using the IPv6 1168 Neighbor Discovery protocol. 1170 To support this similarity statement (IPv6 is layered on top of LLC 1171 on top of 802.11-OCB, in the same way that IPv6 is layered on top of 1172 LLC on top of 802.11a/b/g/n (for WLAN) or layered on top of LLC on 1173 top of 802.3 (for Ethernet)) it is useful to analyze the differences 1174 between 802.11-OCB and 802.11 specifications. During this analysis, 1175 we note that whereas 802.11-OCB lists relatively complex and numerous 1176 changes to the MAC layer (and very little to the PHY layer), there 1177 are only a few characteristics which may be important for an 1178 implementation transmitting IPv6 packets on 802.11-OCB links. 1180 The most important 802.11-OCB point which influences the IPv6 1181 functioning is the OCB characteristic; an additional, less direct 1182 influence, is the maximum bandwidth afforded by the PHY modulation/ 1183 demodulation methods and channel access specified by 802.11-OCB. The 1184 maximum bandwidth theoretically possible in 802.11-OCB is 54 Mbit/s 1185 (when using, for example, the following parameters: 20 MHz channel; 1186 modulation 64-QAM; coding rate R is 3/4); in practice of IP-over- 1187 802.11-OCB a commonly observed figure is 12Mbit/s; this bandwidth 1188 allows the operation of a wide range of protocols relying on IPv6. 1190 o Operation Outside the Context of a BSS (OCB): the (earlier 1191 802.11p) 802.11-OCB links are operated without a Basic Service Set 1192 (BSS). This means that the frames IEEE 802.11 Beacon, Association 1193 Request/Response, Authentication Request/Response, and similar, 1194 are not used. The used identifier of BSS (BSSID) has a 1195 hexadecimal value always 0xffffffffffff (48 '1' bits, represented 1196 as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' 1197 BSSID), as opposed to an arbitrary BSSID value set by 1198 administrator (e.g. 'My-Home-AccessPoint'). The OCB operation - 1199 namely the lack of beacon-based scanning and lack of 1200 authentication - should be taken into account when the Mobile IPv6 1201 protocol [RFC6275] and the protocols for IP layer security 1202 [RFC4301] are used. The way these protocols adapt to OCB is not 1203 described in this document. 1205 o Timing Advertisement: is a new message defined in 802.11-OCB, 1206 which does not exist in 802.11a/b/g/n. This message is used by 1207 stations to inform other stations about the value of time. It is 1208 similar to the time as delivered by a GNSS system (Galileo, GPS, 1209 ...) or by a cellular system. This message is optional for 1210 implementation. 1212 o Frequency range: this is a characteristic of the PHY layer, with 1213 almost no impact on the interface between MAC and IP. However, it 1214 is worth considering that the frequency range is regulated by a 1215 regional authority (ARCEP, ECC/CEPT based on ENs from ETSI, FCC, 1216 etc.); as part of the regulation process, specific applications 1217 are associated with specific frequency ranges. In the case of 1218 802.11-OCB, the regulator associates a set of frequency ranges, or 1219 slots within a band, to the use of applications of vehicular 1220 communications, in a band known as "5.9GHz". The 5.9GHz band is 1221 different from the 2.4GHz and 5GHz bands used by Wireless LAN. 1222 However, as with Wireless LAN, the operation of 802.11-OCB in 1223 "5.9GHz" bands is exempt from owning a license in EU (in US the 1224 5.9GHz is a licensed band of spectrum; for the fixed 1225 infrastructure an explicit FCC authorization is required; for an 1226 on-board device a 'licensed-by-rule' concept applies: rule 1227 certification conformity is required.) Technical conditions are 1228 different than those of the bands "2.4GHz" or "5GHz". The allowed 1229 power levels, and implicitly the maximum allowed distance between 1230 vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20 1231 dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum 1232 distance of approximately 1km, compared to approximately 50m. 1233 Additionally, specific conditions related to congestion avoidance, 1234 jamming avoidance, and radar detection are imposed on the use of 1235 DSRC (in US) and on the use of frequencies for Intelligent 1236 Transportation Systems (in EU), compared to Wireless LAN 1237 (802.11a/b/g/n). 1239 o 'Half-rate' encoding: as the frequency range, this parameter is 1240 related to PHY, and thus has not much impact on the interface 1241 between the IP layer and the MAC layer. 1243 o In vehicular communications using 802.11-OCB links, there are 1244 strong privacy requirements with respect to addressing. While the 1245 802.11-OCB standard does not specify anything in particular with 1246 respect to MAC addresses, in these settings there exists a strong 1247 need for dynamic change of these addresses (as opposed to the non- 1248 vehicular settings - real wall protection - where fixed MAC 1249 addresses do not currently pose some privacy risks). This is 1250 further described in Section 5. A relevant function is described 1251 in IEEE 1609.3-2016 [IEEE-1609.3], clause 5.5.1 and IEEE 1252 1609.4-2016 [IEEE-1609.4], clause 6.7. 1254 Other aspects particular to 802.11-OCB, which are also particular to 1255 802.11 (e.g. the 'hidden node' operation), may have an influence on 1256 the use of transmission of IPv6 packets on 802.11-OCB networks. The 1257 OCB subnet structure is described in Section 4.6. 1259 Appendix D. Changes Needed on a software driver 802.11a to become a 1260 802.11-OCB driver 1262 The 802.11p amendment modifies both the 802.11 stack's physical and 1263 MAC layers but all the induced modifications can be quite easily 1264 obtained by modifying an existing 802.11a ad-hoc stack. 1266 Conditions for a 802.11a hardware to be 802.11-OCB compliant: 1268 o The PHY entity shall be an orthogonal frequency division 1269 multiplexing (OFDM) system. It must support the frequency bands 1270 on which the regulator recommends the use of ITS communications, 1271 for example using IEEE 802.11-OCB layer, in France: 5875MHz to 1272 5925MHz. 1274 o The OFDM system must provide a "half-clocked" operation using 10 1275 MHz channel spacings. 1277 o The chip transmit spectrum mask must be compliant to the "Transmit 1278 spectrum mask" from the IEEE 802.11p amendment (but experimental 1279 environments tolerate otherwise). 1281 o The chip should be able to transmit up to 44.8 dBm when used by 1282 the US government in the United States, and up to 33 dBm in 1283 Europe; other regional conditions apply. 1285 Changes needed on the network stack in OCB mode: 1287 o Physical layer: 1289 * The chip must use the Orthogonal Frequency Multiple Access 1290 (OFDM) encoding mode. 1292 * The chip must be set in half-mode rate mode (the internal clock 1293 frequency is divided by two). 1295 * The chip must use dedicated channels and should allow the use 1296 of higher emission powers. This may require modifications to 1297 the local computer file that describes regulatory domains 1298 rules, if used by the kernel to enforce local specific 1299 restrictions. Such modifications to the local computer file 1300 must respect the location-specific regulatory rules. 1302 MAC layer: 1304 * All management frames (beacons, join, leave, and others) 1305 emission and reception must be disabled except for frames of 1306 subtype Action and Timing Advertisement (defined below). 1308 * No encryption key or method must be used. 1310 * Packet emission and reception must be performed as in ad-hoc 1311 mode, using the wildcard BSSID (ff:ff:ff:ff:ff:ff). 1313 * The functions related to joining a BSS (Association Request/ 1314 Response) and for authentication (Authentication Request/Reply, 1315 Challenge) are not called. 1317 * The beacon interval is always set to 0 (zero). 1319 * Timing Advertisement frames, defined in the amendment, should 1320 be supported. The upper layer should be able to trigger such 1321 frames emission and to retrieve information contained in 1322 received Timing Advertisements. 1324 Appendix E. EtherType Protocol Discrimination (EPD) 1326 A more theoretical and detailed view of layer stacking, and 1327 interfaces between the IP layer and 802.11-OCB layers, is illustrated 1328 in Figure 4. The IP layer operates on top of the EtherType Protocol 1329 Discrimination (EPD); this Discrimination layer is described in IEEE 1330 Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP 1331 (Link Layer Control Service Access Point). 1333 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1334 | IPv6 | 1335 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ 1336 { LLC_SAP } 802.11-OCB 1337 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary 1338 | EPD | | | 1339 | | MLME | | 1340 +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | 1341 | MAC Sublayer | | | 802.11-OCB 1342 | and ch. coord. | | SME | Services 1343 +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | 1344 | | PLME | | 1345 | PHY Layer | PLME_SAP | 1346 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1348 Figure 4: EtherType Protocol Discrimination 1350 Appendix F. Design Considerations 1352 The networks defined by 802.11-OCB are in many ways similar to other 1353 networks of the 802.11 family. In theory, the encapsulation of IPv6 1354 over 802.11-OCB could be very similar to the operation of IPv6 over 1355 other networks of the 802.11 family. However, the high mobility, 1356 strong link asymmetry and very short connection makes the 802.11-OCB 1357 link significantly different from other 802.11 networks. Also, the 1358 automotive applications have specific requirements for reliability, 1359 security and privacy, which further add to the particularity of the 1360 802.11-OCB link. 1362 F.1. Vehicle ID 1364 In automotive networks it is required that each node is represented 1365 uniquely at a certain point in time. Accordingly, a vehicle must be 1366 identified by at least one unique identifier. The current 1367 specification at ETSI and at IEEE 1609 identifies a vehicle by its 1368 MAC address, which is obtained from the 802.11-OCB Network Interface 1369 Card (NIC). 1371 In case multiple 802.11-OCB NICs are present in one car, implicitely 1372 multiple vehicle IDs will be generated. Additionally, some software 1373 generates a random MAC address each time the computer boots; this 1374 constitutes an additional difficulty. 1376 A mechanim to uniquely identify a vehicle irrespectively to the 1377 multiplicity of NICs, or frequent MAC address generation, is 1378 necessary. 1380 F.2. Reliability Requirements 1382 The dynamically changing topology, short connectivity, mobile 1383 transmitter and receivers, different antenna heights, and many-to- 1384 many communication types, make IEEE 802.11-OCB links significantly 1385 different from other IEEE 802.11 links. Any IPv6 mechanism operating 1386 on IEEE 802.11-OCB link must support strong link asymmetry, spatio- 1387 temporal link quality, fast address resolution and transmission. 1389 IEEE 802.11-OCB strongly differs from other 802.11 systems to operate 1390 outside of the context of a Basic Service Set. This means in 1391 practice that IEEE 802.11-OCB does not rely on a Base Station for all 1392 Basic Service Set management. In particular, IEEE 802.11-OCB shall 1393 not use beacons. Any IPv6 mechanism requiring L2 services from IEEE 1394 802.11 beacons must support an alternative service. 1396 Channel scanning being disabled, IPv6 over IEEE 802.11-OCB must 1397 implement a mechanism for transmitter and receiver to converge to a 1398 common channel. 1400 Authentication not being possible, IPv6 over IEEE 802.11-OCB must 1401 implement an distributed mechanism to authenticate transmitters and 1402 receivers without the support of a DHCP server. 1404 Time synchronization not being available, IPv6 over IEEE 802.11-OCB 1405 must implement a higher layer mechanism for time synchronization 1406 between transmitters and receivers without the support of a NTP 1407 server. 1409 The IEEE 802.11-OCB link being asymmetric, IPv6 over IEEE 802.11-OCB 1410 must disable management mechanisms requesting acknowledgements or 1411 replies. 1413 The IEEE 802.11-OCB link having a short duration time, IPv6 over IEEE 1414 802.11-OCB should implement fast IPv6 mobility management mechanisms. 1416 F.3. Multiple interfaces 1418 There are considerations for 2 or more IEEE 802.11-OCB interface 1419 cards per vehicle. For each vehicle taking part in road traffic, one 1420 IEEE 802.11-OCB interface card could be fully allocated for Non IP 1421 safety-critical communication. Any other IEEE 802.11-OCB may be used 1422 for other type of traffic. 1424 The mode of operation of these other wireless interfaces is not 1425 clearly defined yet. One possibility is to consider each card as an 1426 independent network interface, with a specific MAC Address and a set 1427 of IPv6 addresses. Another possibility is to consider the set of 1428 these wireless interfaces as a single network interface (not 1429 including the IEEE 802.11-OCB interface used by Non IP safety 1430 critical communications). This will require specific logic to 1431 ensure, for example, that packets meant for a vehicle in front are 1432 actually sent by the radio in the front, or that multiple copies of 1433 the same packet received by multiple interfaces are treated as a 1434 single packet. Treating each wireless interface as a separate 1435 network interface pushes such issues to the application layer. 1437 Certain privacy requirements imply that if these multiple interfaces 1438 are represented by many network interface, a single renumbering event 1439 shall cause renumbering of all these interfaces. If one MAC changed 1440 and another stayed constant, external observers would be able to 1441 correlate old and new values, and the privacy benefits of 1442 randomization would be lost. 1444 The privacy requirements of Non IP safety-critical communications 1445 imply that if a change of pseudonyme occurs, renumbering of all other 1446 interfaces shall also occur. 1448 F.4. MAC Address Generation 1450 In 802.11-OCB networks, the MAC addresses may change during well 1451 defined renumbering events. A 'randomized' MAC address has the 1452 following characteristics: 1454 o Bit "Local/Global" set to "locally admninistered". 1456 o Bit "Unicast/Multicast" set to "Unicast". 1458 o The 46 remaining bits are set to a random value, using a random 1459 number generator that meets the requirements of [RFC4086]. 1461 To meet the randomization requirements for the 46 remaining bits, a 1462 hash function may be used. For example, the SHA256 hash function may 1463 be used with input a 256 bit local secret, the "nominal" MAC Address 1464 of the interface, and a representation of the date and time of the 1465 renumbering event. 1467 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode 1469 For information, at the time of writing, this is the list of IEEE 1470 802.11 messages that may be transmitted in OCB mode, i.e. when 1471 dot11OCBActivated is true in a STA: 1473 o The STA may send management frames of subtype Action and, if the 1474 STA maintains a TSF Timer, subtype Timing Advertisement; 1476 o The STA may send control frames, except those of subtype PS-Poll, 1477 CF-End, and CF-End plus CFAck; 1479 o The STA may send data frames of subtype Data, Null, QoS Data, and 1480 QoS Null. 1482 Appendix H. Implementation Status 1484 This section describes an example of an IPv6 Packet captured over a 1485 IEEE 802.11-OCB link. 1487 By way of example we show that there is no modification in the 1488 headers when transmitted over 802.11-OCB networks - they are 1489 transmitted like any other 802.11 and Ethernet packets. 1491 We describe an experiment of capturing an IPv6 packet on an 1492 802.11-OCB link. In topology depicted in Figure 5, the packet is an 1493 IPv6 Router Advertisement. This packet is emitted by a Router on its 1494 802.11-OCB interface. The packet is captured on the Host, using a 1495 network protocol analyzer (e.g. Wireshark); the capture is performed 1496 in two different modes: direct mode and 'monitor' mode. The topology 1497 used during the capture is depicted below. 1499 The packet is captured on the Host. The Host is an IP-OBU containing 1500 an 802.11 interface in format PCI express (an ITRI product). The 1501 kernel runs the ath5k software driver with modifications for OCB 1502 mode. The capture tool is Wireshark. The file format for save and 1503 analyze is 'pcap'. The packet is generated by the Router. The 1504 Router is an IP-RSU (ITRI product). 1506 +--------+ +-------+ 1507 | | 802.11-OCB Link | | 1508 ---| Router |--------------------------------| Host | 1509 | | | | 1510 +--------+ +-------+ 1512 Figure 5: Topology for capturing IP packets on 802.11-OCB 1514 During several capture operations running from a few moments to 1515 several hours, no message relevant to the BSSID contexts were 1516 captured (no Association Request/Response, Authentication Req/Resp, 1517 Beacon). This shows that the operation of 802.11-OCB is outside the 1518 context of a BSSID. 1520 Overall, the captured message is identical with a capture of an IPv6 1521 packet emitted on a 802.11b interface. The contents are precisely 1522 similar. 1524 H.1. Capture in Monitor Mode 1526 The IPv6 RA packet captured in monitor mode is illustrated below. 1527 The radio tap header provides more flexibility for reporting the 1528 characteristics of frames. The Radiotap Header is prepended by this 1529 particular stack and operating system on the Host machine to the RA 1530 packet received from the network (the Radiotap Header is not present 1531 on the air). The implementation-dependent Radiotap Header is useful 1532 for piggybacking PHY information from the chip's registers as data in 1533 a packet understandable by userland applications using Socket 1534 interfaces (the PHY interface can be, for example: power levels, data 1535 rate, ratio of signal to noise). 1537 The packet present on the air is formed by IEEE 802.11 Data Header, 1538 Logical Link Control Header, IPv6 Base Header and ICMPv6 Header. 1540 Radiotap Header v0 1541 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1542 |Header Revision| Header Pad | Header length | 1543 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1544 | Present flags | 1545 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1546 | Data Rate | Pad | 1547 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1549 IEEE 802.11 Data Header 1550 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1551 | Type/Subtype and Frame Ctrl | Duration | 1552 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1553 | Receiver Address... 1554 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1555 ... Receiver Address | Transmitter Address... 1556 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1557 ... Transmitter Address | 1558 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1559 | BSS Id... 1560 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1561 ... BSS Id | Frag Number and Seq Number | 1562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1564 Logical-Link Control Header 1565 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1566 | DSAP |I| SSAP |C| Control field | Org. code... 1567 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1568 ... Organizational Code | Type | 1569 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1571 IPv6 Base Header 1572 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1573 |Version| Traffic Class | Flow Label | 1574 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1575 | Payload Length | Next Header | Hop Limit | 1576 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1577 | | 1578 + + 1579 | | 1580 + Source Address + 1581 | | 1582 + + 1583 | | 1584 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1585 | | 1586 + + 1587 | | 1588 + Destination Address + 1589 | | 1590 + + 1591 | | 1592 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1594 Router Advertisement 1595 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1596 | Type | Code | Checksum | 1597 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1598 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1599 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1600 | Reachable Time | 1601 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1602 | Retrans Timer | 1603 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1604 | Options ... 1605 +-+-+-+-+-+-+-+-+-+-+-+- 1607 The value of the Data Rate field in the Radiotap header is set to 6 1608 Mb/s. This indicates the rate at which this RA was received. 1610 The value of the Transmitter address in the IEEE 802.11 Data Header 1611 is set to a 48bit value. The value of the destination address is 1612 33:33:00:00:00:1 (all-nodes multicast address). The value of the BSS 1613 Id field is ff:ff:ff:ff:ff:ff, which is recognized by the network 1614 protocol analyzer as being "broadcast". The Fragment number and 1615 sequence number fields are together set to 0x90C6. 1617 The value of the Organization Code field in the Logical-Link Control 1618 Header is set to 0x0, recognized as "Encapsulated Ethernet". The 1619 value of the Type field is 0x86DD (hexadecimal 86DD, or otherwise 1620 #86DD), recognized as "IPv6". 1622 A Router Advertisement is periodically sent by the router to 1623 multicast group address ff02::1. It is an icmp packet type 134. The 1624 IPv6 Neighbor Discovery's Router Advertisement message contains an 1625 8-bit field reserved for single-bit flags, as described in [RFC4861]. 1627 The IPv6 header contains the link local address of the router 1628 (source) configured via EUI-64 algorithm, and destination address set 1629 to ff02::1. Recent versions of network protocol analyzers (e.g. 1631 Wireshark) provide additional informations for an IP address, if a 1632 geolocalization database is present. In this example, the 1633 geolocalization database is absent, and the "GeoIP" information is 1634 set to unknown for both source and destination addresses (although 1635 the IPv6 source and destination addresses are set to useful values). 1636 This "GeoIP" can be a useful information to look up the city, 1637 country, AS number, and other information for an IP address. 1639 The Ethernet Type field in the logical-link control header is set to 1640 0x86dd which indicates that the frame transports an IPv6 packet. In 1641 the IEEE 802.11 data, the destination address is 33:33:00:00:00:01 1642 which is the corresponding multicast MAC address. The BSS id is a 1643 broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link 1644 duration between vehicles and the roadside infrastructure, there is 1645 no need in IEEE 802.11-OCB to wait for the completion of association 1646 and authentication procedures before exchanging data. IEEE 1647 802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s) 1648 and may start communicating as soon as they arrive on the 1649 communication channel. 1651 H.2. Capture in Normal Mode 1653 The same IPv6 Router Advertisement packet described above (monitor 1654 mode) is captured on the Host, in the Normal mode, and depicted 1655 below. 1657 Ethernet II Header 1658 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1659 | Destination... 1660 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1661 ...Destination | Source... 1662 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1663 ...Source | 1664 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1665 | Type | 1666 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1668 IPv6 Base Header 1669 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1670 |Version| Traffic Class | Flow Label | 1671 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1672 | Payload Length | Next Header | Hop Limit | 1673 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1674 | | 1675 + + 1676 | | 1677 + Source Address + 1678 | | 1679 + + 1680 | | 1681 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1682 | | 1683 + + 1684 | | 1685 + Destination Address + 1686 | | 1687 + + 1688 | | 1689 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1691 Router Advertisement 1692 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1693 | Type | Code | Checksum | 1694 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1695 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1696 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1697 | Reachable Time | 1698 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1699 | Retrans Timer | 1700 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1701 | Options ... 1702 +-+-+-+-+-+-+-+-+-+-+-+- 1704 One notices that the Radiotap Header, the IEEE 802.11 Data Header and 1705 the Logical-Link Control Headers are not present. On the other hand, 1706 a new header named Ethernet II Header is present. 1708 The Destination and Source addresses in the Ethernet II header 1709 contain the same values as the fields Receiver Address and 1710 Transmitter Address present in the IEEE 802.11 Data Header in the 1711 "monitor" mode capture. 1713 The value of the Type field in the Ethernet II header is 0x86DD 1714 (recognized as "IPv6"); this value is the same value as the value of 1715 the field Type in the Logical-Link Control Header in the "monitor" 1716 mode capture. 1718 The knowledgeable experimenter will no doubt notice the similarity of 1719 this Ethernet II Header with a capture in normal mode on a pure 1720 Ethernet cable interface. 1722 An Adaptation layer is inserted on top of a pure IEEE 802.11 MAC 1723 layer, in order to adapt packets, before delivering the payload data 1724 to the applications. It adapts 802.11 LLC/MAC headers to Ethernet II 1725 headers. In further detail, this adaptation consists in the 1726 elimination of the Radiotap, 802.11 and LLC headers, and in the 1727 insertion of the Ethernet II header. In this way, IPv6 runs straight 1728 over LLC over the 802.11-OCB MAC layer; this is further confirmed by 1729 the use of the unique Type 0x86DD. 1731 Appendix I. Extra Terminology 1733 The following terms are defined outside the IETF. They are used to 1734 define the main terms in the main terminology section Section 2. 1736 DSRC (Dedicated Short Range Communication): a term defined outside 1737 the IETF. The US Federal Communications Commission (FCC) Dedicated 1738 Short Range Communication (DSRC) is defined in the Code of Federal 1739 Regulations (CFR) 47, Parts 90 and 95. This Code is referred in the 1740 definitions below. At the time of the writing of this Internet 1741 Draft, the last update of this Code was dated October 1st, 2010. 1743 DSRCS (Dedicated Short-Range Communications Services): a term defined 1744 outside the IETF. The use of radio techniques to transfer data over 1745 short distances between roadside and mobile units, between mobile 1746 units, and between portable and mobile units to perform operations 1747 related to the improvement of traffic flow, traffic safety, and other 1748 intelligent transportation service applications in a variety of 1749 environments. DSRCS systems may also transmit status and 1750 instructional messages related to the units involve. [Ref. 47 CFR 1751 90.7 - Definitions] 1752 OBU (On-Board Unit): a term defined outside the IETF. An On-Board 1753 Unit is a DSRCS transceiver that is normally mounted in or on a 1754 vehicle, or which in some instances may be a portable unit. An OBU 1755 can be operational while a vehicle or person is either mobile or 1756 stationary. The OBUs receive and contend for time to transmit on one 1757 or more radio frequency (RF) channels. Except where specifically 1758 excluded, OBU operation is permitted wherever vehicle operation or 1759 human passage is permitted. The OBUs mounted in vehicles are 1760 licensed by rule under part 95 of the respective chapter and 1761 communicate with Roadside Units (RSUs) and other OBUs. Portable OBUs 1762 are also licensed by rule under part 95 of the respective chapter. 1763 OBU operations in the Unlicensed National Information Infrastructure 1764 (UNII) Bands follow the rules in those bands. - [CFR 90.7 - 1765 Definitions]. 1767 RSU (Road-Side Unit): a term defined outside of IETF. A Roadside 1768 Unit is a DSRC transceiver that is mounted along a road or pedestrian 1769 passageway. An RSU may also be mounted on a vehicle or is hand 1770 carried, but it may only operate when the vehicle or hand- carried 1771 unit is stationary. Furthermore, an RSU operating under the 1772 respectgive part is restricted to the location where it is licensed 1773 to operate. However, portable or hand-held RSUs are permitted to 1774 operate where they do not interfere with a site-licensed operation. 1775 A RSU broadcasts data to OBUs or exchanges data with OBUs in its 1776 communications zone. An RSU also provides channel assignments and 1777 operating instructions to OBUs in its communications zone, when 1778 required. - [CFR 90.7 - Definitions]. 1780 Authors' Addresses 1782 Alexandre Petrescu 1783 CEA, LIST 1784 CEA Saclay 1785 Gif-sur-Yvette , Ile-de-France 91190 1786 France 1788 Phone: +33169089223 1789 Email: Alexandre.Petrescu@cea.fr 1791 Nabil Benamar 1792 Moulay Ismail University 1793 Morocco 1795 Phone: +212670832236 1796 Email: n.benamar@est.umi.ac.ma 1797 Jerome Haerri 1798 Eurecom 1799 Sophia-Antipolis 06904 1800 France 1802 Phone: +33493008134 1803 Email: Jerome.Haerri@eurecom.fr 1805 Jong-Hyouk Lee 1806 Sangmyung University 1807 31, Sangmyeongdae-gil, Dongnam-gu 1808 Cheonan 31066 1809 Republic of Korea 1811 Email: jonghyouk@smu.ac.kr 1813 Thierry Ernst 1814 YoGoKo 1815 France 1817 Email: thierry.ernst@yogoko.fr