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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 17, 2018 Moulay Ismail University 6 J. Haerri 7 Eurecom 8 J. Lee 9 Sangmyung University 10 T. Ernst 11 YoGoKo 12 June 15, 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-24 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 17, 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 . . . 27 89 Appendix E. EtherType Protocol Discrimination (EPD) . . . . . . 28 90 Appendix F. Design Considerations . . . . . . . . . . . . . . . 29 91 F.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 29 92 F.2. Reliability Requirements . . . . . . . . . . . . . . . . 30 93 F.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 30 94 F.4. MAC Address Generation . . . . . . . . . . . . . . . . . 31 96 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 31 97 Appendix H. Implementation Status . . . . . . . . . . . . . . . 32 98 H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 33 99 H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 35 100 Appendix I. Extra Terminology . . . . . . . . . . . . . . . . . 37 101 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38 103 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). This involves the layering of IPv6 networking on top of 108 the IEEE 802.11 MAC layer, with an LLC layer. Compared to running 109 IPv6 over the Ethernet MAC layer, there is no modification expected 110 to IEEE Std 802.11 MAC and Logical Link sublayers: IPv6 works fine 111 directly over 802.11-OCB too, with an LLC layer. 113 The IPv6 network layer operates on 802.11-OCB in the same manner as 114 operating on Ethernet, but there are two kinds of exceptions: 116 o Exceptions due to different operation of IPv6 network layer on 117 802.11 than on Ethernet. To satisfy these exceptions, this 118 document describes an Ethernet Adaptation Layer between Ethernet 119 headers and 802.11 headers. The Ethernet Adaptation Layer is 120 described Section 4.2.1. The operation of IP on Ethernet is 121 described in [RFC1042], [RFC2464] and 122 [I-D.hinden-6man-rfc2464bis]. 124 o Exceptions due to the OCB nature of 802.11-OCB compared to 802.11. 125 This has impacts on security, privacy, subnet structure and 126 handover behaviour. For security and privacy recommendations see 127 Section 5 and Section 4.5. The subnet structure is described in 128 Section 4.6. The handover behaviour on OCB links is not described 129 in this document. 131 In the published literature, many documents describe aspects and 132 problems related to running IPv6 over 802.11-OCB: 133 [I-D.ietf-ipwave-vehicular-networking-survey]. 135 2. Terminology 137 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 138 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 139 document are to be interpreted as described in RFC 2119 [RFC2119]. 141 IP-OBU (Internet Protocol On-Board Unit): an IP-OBU is a computer 142 situated in a vehicle such as an automobile, bicycle, or similar. It 143 has at least one IP interface that runs in mode OCB of 802.11, and 144 that has an "OBU" transceiver. See the definition of the term "OBU" 145 in section Appendix I. 147 IP-RSU (IP Road-Side Unit): an IP-RSU is situated along the road. An 148 IP-RSU has at least two distinct IP-enabled interfaces; at least one 149 interface is operated in mode OCB of IEEE 802.11 and is IP-enabled. 150 An IP-RSU is similar to a Wireless Termination Point (WTP), as 151 defined in [RFC5415], or an Access Point (AP), as defined in IEEE 152 documents, or an Access Network Router (ANR) defined in [RFC3753], 153 with one key particularity: the wireless PHY/MAC layer of at least 154 one of its IP-enabled interfaces is configured to operate in 155 802.11-OCB mode. The IP-RSU communicates with the IP-OBU in the 156 vehicle over 802.11 wireless link operating in OCB mode. 158 OCB (outside the context of a basic service set - BSS): A mode of 159 operation in which a STA is not a member of a BSS and does not 160 utilize IEEE Std 802.11 authentication, association, or data 161 confidentiality. 163 802.11-OCB: mode specified in IEEE Std 802.11-2016 when the MIB 164 attribute dot11OCBActivited is true. Note: compliance with standards 165 and regulations set in different countries when using the 5.9GHz 166 frequency band is required. 168 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 170 The IEEE 802.11-OCB Networks are used for vehicular communications, 171 as 'Wireless Access in Vehicular Environments'. The IP communication 172 scenarios for these environments have been described in several 173 documents; in particular, we refer the reader to 174 [I-D.ietf-ipwave-vehicular-networking-survey], that lists some 175 scenarios and requirements for IP in Intelligent Transportation 176 Systems. 178 The link model is the following: STA --- 802.11-OCB --- STA. In 179 vehicular networks, STAs can be IP-RSUs and/or IP-OBUs. While 180 802.11-OCB is clearly specified, and the use of IPv6 over such link 181 is not radically new, the operating environment (vehicular networks) 182 brings in new perspectives. 184 The mechanisms for forming and terminating, discovering, peering and 185 mobility management for 802.11-OCB links are not described in this 186 document. 188 4. IPv6 over 802.11-OCB 190 4.1. Maximum Transmission Unit (MTU) 192 The default MTU for IP packets on 802.11-OCB MUST be 1500 octets. It 193 is the same value as IPv6 packets on Ethernet links, as specified in 194 [RFC2464]. This value of the MTU respects the recommendation that 195 every link on the Internet must have a minimum MTU of 1280 octets 196 (stated in [RFC8200], and the recommendations therein, especially 197 with respect to fragmentation). 199 4.2. Frame Format 201 IP packets MUST be transmitted over 802.11-OCB media as QoS Data 202 frames whose format is specified in IEEE Std 802.11. 204 The IPv6 packet transmitted on 802.11-OCB MUST be immediately 205 preceded by a Logical Link Control (LLC) header and an 802.11 header. 206 In the LLC header, and in accordance with the EtherType Protocol 207 Discrimination (EPD), the value of the Type field MUST be set to 208 0x86DD (IPv6). In the 802.11 header, the value of the Subtype sub- 209 field in the Frame Control field MUST be set to 8 (i.e. 'QoS Data'); 210 the value of the Traffic Identifier (TID) sub-field of the QoS 211 Control field of the 802.11 header MUST be set to binary 001 (i.e. 212 User Priority 'Background', QoS Access Category 'AC_BK'). 214 To simplify the Application Programming Interface (API) between the 215 operating system and the 802.11-OCB media, device drivers MAY 216 implement an Ethernet Adaptation Layer that translates Ethernet II 217 frames to the 802.11 format and vice versa. An Ethernet Adaptation 218 Layer is described in Section 4.2.1. 220 4.2.1. Ethernet Adaptation Layer 222 An 'adaptation' layer is inserted between a MAC layer and the 223 Networking layer. This is used to transform some parameters between 224 their form expected by the IP stack and the form provided by the MAC 225 layer. 227 An Ethernet Adaptation Layer makes an 802.11 MAC look to IP 228 Networking layer as a more traditional Ethernet layer. At reception, 229 this layer takes as input the IEEE 802.11 header and the Logical-Link 230 Layer Control Header and produces an Ethernet II Header. At sending, 231 the reverse operation is performed. 233 The operation of the Ethernet Adaptation Layer is depicted by the 234 double arrow in Figure 1. 236 +------------------+------------+-------------+---------+-----------+ 237 | 802.11 header | LLC Header | IPv6 Header | Payload |.11 Trailer| 238 +------------------+------------+-------------+---------+-----------+ 239 \ / \ / 240 --------------------------- -------- 241 \---------------------------------------------/ 242 ^ 243 | 244 802.11-to-Ethernet Adaptation Layer 245 | 246 v 247 +---------------------+-------------+---------+ 248 | Ethernet II Header | IPv6 Header | Payload | 249 +---------------------+-------------+---------+ 251 Figure 1: Operation of the Ethernet Adaptation Layer 253 The Receiver and Transmitter Address fields in the 802.11 header MUST 254 contain the same values as the Destination and the Source Address 255 fields in the Ethernet II Header, respectively. The value of the 256 Type field in the LLC Header MUST be the same as the value of the 257 Type field in the Ethernet II Header. That value MUST be set to 258 0x86DD (IPv6). 260 The ".11 Trailer" contains solely a 4-byte Frame Check Sequence. 262 The placement of IPv6 networking layer on Ethernet Adaptation Layer 263 is illustrated in Figure 2. 265 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 266 | IPv6 | 267 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 268 | Ethernet Adaptation Layer | 269 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 270 | 802.11 MAC | 271 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 272 | 802.11 PHY | 273 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 275 Figure 2: Ethernet Adaptation Layer stacked with other layers 277 (in the above figure, a 802.11 profile is represented; this is used 278 also for 802.11-OCB profile.) 280 4.3. Link-Local Addresses 282 The link-local address of an 802.11-OCB interface is formed in the 283 same manner as on an Ethernet interface. This manner is described in 284 section 5 of [RFC2464]. Additionally, if stable identifiers are 285 needed, it is RECOMMENDED to follow the Recommendation on Stable IPv6 286 Interface Identifiers [RFC8064]. Additionally, if semantically 287 opaque Interface Identifiers are needed, a potential method for 288 generating semantically opaque Interface Identifiers with IPv6 289 Stateless Address Autoconfiguration is given in [RFC7217]. 291 4.4. Address Mapping 293 Unicast and multicast address mapping MUST follow the procedures 294 specified for Ethernet interfaces in sections 6 and 7 of [RFC2464]. 296 4.4.1. Address Mapping -- Unicast 298 The procedure for mapping IPv6 unicast addresses into Ethernet link- 299 layer addresses is described in [RFC4861]. 301 4.4.2. Address Mapping -- Multicast 303 The multicast address mapping is performed according to the method 304 specified in section 7 of [RFC2464]. The meaning of the value "3333" 305 mentioned in that section 7 of [RFC2464] is defined in section 2.3.1 306 of [RFC7042]. 308 Transmitting IPv6 packets to multicast destinations over 802.11 links 309 proved to have some performance issues 310 [I-D.perkins-intarea-multicast-ieee802]. These issues may be 311 exacerbated in OCB mode. Solutions for these problems should 312 consider the OCB mode of operation. 314 4.5. Stateless Autoconfiguration 316 The Interface Identifier for an 802.11-OCB interface is formed using 317 the same rules as the Interface Identifier for an Ethernet interface; 318 this is described in section 4 of [RFC2464]. No changes are needed, 319 but some care must be taken when considering the use of the Stateless 320 Address Auto-Configuration procedure. 322 The bits in the interface identifier have no generic meaning and the 323 identifier should be treated as an opaque value. The bits 324 'Universal' and 'Group' in the identifier of an 802.11-OCB interface 325 are significant, as this is an IEEE link-layer address. The details 326 of this significance are described in [RFC7136]. 328 As with all Ethernet and 802.11 interface identifiers ([RFC7721]), 329 the identifier of an 802.11-OCB interface may involve privacy, MAC 330 address spoofing and IP address hijacking risks. A vehicle embarking 331 an OBU or an IP-OBU whose egress interface is 802.11-OCB may expose 332 itself to eavesdropping and subsequent correlation of data; this may 333 reveal data considered private by the vehicle owner; there is a risk 334 of being tracked; see the privacy considerations described in 335 Appendix F. 337 If stable Interface Identifiers are needed in order to form IPv6 338 addresses on 802.11-OCB links, it is recommended to follow the 339 recommendation in [RFC8064]. Additionally, if semantically opaque 340 Interface Identifiers are needed, a potential method for generating 341 semantically opaque Interface Identifiers with IPv6 Stateless Address 342 Autoconfiguration is given in [RFC7217]. 344 4.6. Subnet Structure 346 A subnet is formed by the external 802.11-OCB interfaces of vehicles 347 that are in close range (not their on-board interfaces). This 348 ephemeral subnet structure is strongly influenced by the mobility of 349 vehicles: the 802.11 hidden node effects appear. On another hand, 350 the structure of the internal subnets in each car is relatively 351 stable. 353 The 802.11 networks in OCB mode may be considered as 'ad-hoc' 354 networks. The addressing model for such networks is described in 355 [RFC5889]. 357 The operation of the Neighbor Discovery protocol (ND) over 802.11-OCB 358 links is different than over 802.11 links. In OCB, the link layer 359 does not ensure that all associated members receive all messages, 360 because there is no association operation. Neighbor Discovery (ND) 361 is used over 802.11-OCB. 363 The operation of the Mobile IPv6 protocol over 802.11-OCB links is 364 different than on other links. The Movement Detection operation 365 (section 11.5.1 of [RFC6275]) can not rely on Neighbor Unreachability 366 Detection operation of the Neighbor Discovery protocol, for the 367 reason mentioned in the previous paragraph. Also, the 802.11-OCB 368 link layer is not a lower layer that can provide an indication that a 369 link layer handover has occured. The operation of the Mobile IPv6 370 protocol over 802.11-OCB is not specified in this document. 372 5. Security Considerations 374 Any security mechanism at the IP layer or above that may be carried 375 out for the general case of IPv6 may also be carried out for IPv6 376 operating over 802.11-OCB. 378 The OCB operation is stripped off of all existing 802.11 link-layer 379 security mechanisms. There is no encryption applied below the 380 network layer running on 802.11-OCB. At application layer, the IEEE 381 1609.2 document [IEEE-1609.2] does provide security services for 382 certain applications to use; application-layer mechanisms are out-of- 383 scope of this document. On another hand, a security mechanism 384 provided at networking layer, such as IPsec [RFC4301], may provide 385 data security protection to a wider range of applications. 387 802.11-OCB does not provide any cryptographic protection, because it 388 operates outside the context of a BSS (no Association Request/ 389 Response, no Challenge messages). Any attacker can therefore just 390 sit in the near range of vehicles, sniff the network (just set the 391 interface card's frequency to the proper range) and perform attacks 392 without needing to physically break any wall. Such a link is less 393 protected than commonly used links (wired link or protected 802.11). 395 The potential attack vectors are: MAC address spoofing, IP address 396 and session hijacking and privacy violation. 398 Within the IPsec Security Architecture [RFC4301], the IPsec AH and 399 ESP headers [RFC4302] and [RFC4303] respectively, its multicast 400 extensions [RFC5374], HTTPS [RFC2818] and SeND [RFC3971] protocols 401 can be used to protect communications. Further, the assistance of 402 proper Public Key Infrastructure (PKI) protocols [RFC4210] is 403 necessary to establish credentials. More IETF protocols are 404 available in the toolbox of the IP security protocol designer. 405 Certain ETSI protocols related to security protocols in Intelligent 406 Transportation Systems are described in [ETSI-sec-archi]. 408 As with all Ethernet and 802.11 interface identifiers, there may 409 exist privacy risks in the use of 802.11-OCB interface identifiers. 410 Moreover, in outdoors vehicular settings, the privacy risks are more 411 important than in indoors settings. New risks are induced by the 412 possibility of attacker sniffers deployed along routes which listen 413 for IP packets of vehicles passing by. For this reason, in the 414 802.11-OCB deployments, there is a strong necessity to use protection 415 tools such as dynamically changing MAC addresses. This may help 416 mitigate privacy risks to a certain level. On another hand, it may 417 have an impact in the way typical IPv6 address auto-configuration is 418 performed for vehicles (SLAAC would rely on MAC addresses and would 419 hence dynamically change the affected IP address), in the way the 420 IPv6 Privacy addresses were used, and other effects. 422 6. IANA Considerations 424 No request to IANA. 426 7. Contributors 428 Christian Huitema, Tony Li. 430 Romain Kuntz contributed extensively about IPv6 handovers between 431 links running outside the context of a BSS (802.11-OCB links). 433 Tim Leinmueller contributed the idea of the use of IPv6 over 434 802.11-OCB for distribution of certificates. 436 Marios Makassikis, Jose Santa Lozano, Albin Severinson and Alexey 437 Voronov provided significant feedback on the experience of using IP 438 messages over 802.11-OCB in initial trials. 440 Michelle Wetterwald contributed extensively the MTU discussion, 441 offered the ETSI ITS perspective, and reviewed other parts of the 442 document. 444 8. Acknowledgements 446 The authors would like to thank Witold Klaudel, Ryuji Wakikawa, 447 Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan 448 Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray 449 Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan, 450 Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne, 451 Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark, 452 Bob Moskowitz, Andrew Dryden, Georg Mayer, Dorothy Stanley, Sandra 453 Cespedes, Mariano Falcitelli, Sri Gundavelli, Abdussalam Baryun, 454 Margaret Cullen, Erik Kline, Carlos Jesus Bernardos Cano, Ronald in 455 't Velt, Katrin Sjoberg, Roland Bless, Russ Housley, Tijink Jasja, 456 Kevin Smith and William Whyte. Their valuable comments clarified 457 particular issues and generally helped to improve the document. 459 Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB 460 drivers for linux and described how. 462 For the multicast discussion, the authors would like to thank Owen 463 DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and 464 participants to discussions in network working groups. 466 The authors would like to thank participants to the Birds-of- 467 a-Feather "Intelligent Transportation Systems" meetings held at IETF 468 in 2016. 470 9. References 472 9.1. Normative References 474 [RFC1042] Postel, J. and J. Reynolds, "Standard for the transmission 475 of IP datagrams over IEEE 802 networks", STD 43, RFC 1042, 476 DOI 10.17487/RFC1042, February 1988, 477 . 479 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 480 Requirement Levels", BCP 14, RFC 2119, 481 DOI 10.17487/RFC2119, March 1997, 482 . 484 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 485 Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, 486 . 488 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, 489 DOI 10.17487/RFC2818, May 2000, 490 . 492 [RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related 493 Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004, 494 . 496 [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, 497 "SEcure Neighbor Discovery (SEND)", RFC 3971, 498 DOI 10.17487/RFC3971, March 2005, 499 . 501 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 502 "Randomness Requirements for Security", BCP 106, RFC 4086, 503 DOI 10.17487/RFC4086, June 2005, 504 . 506 [RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen, 507 "Internet X.509 Public Key Infrastructure Certificate 508 Management Protocol (CMP)", RFC 4210, 509 DOI 10.17487/RFC4210, September 2005, 510 . 512 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 513 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 514 December 2005, . 516 [RFC4302] Kent, S., "IP Authentication Header", RFC 4302, 517 DOI 10.17487/RFC4302, December 2005, 518 . 520 [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", 521 RFC 4303, DOI 10.17487/RFC4303, December 2005, 522 . 524 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 525 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 526 DOI 10.17487/RFC4861, September 2007, 527 . 529 [RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast 530 Extensions to the Security Architecture for the Internet 531 Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008, 532 . 534 [RFC5415] Calhoun, P., Ed., Montemurro, M., Ed., and D. Stanley, 535 Ed., "Control And Provisioning of Wireless Access Points 536 (CAPWAP) Protocol Specification", RFC 5415, 537 DOI 10.17487/RFC5415, March 2009, 538 . 540 [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing 541 Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, 542 September 2010, . 544 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 545 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 546 2011, . 548 [RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and 549 IETF Protocol and Documentation Usage for IEEE 802 550 Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042, 551 October 2013, . 553 [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 554 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, 555 February 2014, . 557 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 558 Interface Identifiers with IPv6 Stateless Address 559 Autoconfiguration (SLAAC)", RFC 7217, 560 DOI 10.17487/RFC7217, April 2014, 561 . 563 [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy 564 Considerations for IPv6 Address Generation Mechanisms", 565 RFC 7721, DOI 10.17487/RFC7721, March 2016, 566 . 568 [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu, 569 "Recommendation on Stable IPv6 Interface Identifiers", 570 RFC 8064, DOI 10.17487/RFC8064, February 2017, 571 . 573 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 574 (IPv6) Specification", STD 86, RFC 8200, 575 DOI 10.17487/RFC8200, July 2017, 576 . 578 9.2. Informative References 580 [ETSI-sec-archi] 581 "ETSI TS 102 940 V1.2.1 (2016-11), ETSI Technical 582 Specification, Intelligent Transport Systems (ITS); 583 Security; ITS communications security architecture and 584 security management, November 2016. Downloaded on 585 September 9th, 2017, freely available from ETSI website at 586 URL http://www.etsi.org/deliver/ 587 etsi_ts/102900_102999/102940/01.02.01_60/ 588 ts_102940v010201p.pdf". 590 [I-D.hinden-6man-rfc2464bis] 591 Crawford, M. and R. Hinden, "Transmission of IPv6 Packets 592 over Ethernet Networks", draft-hinden-6man-rfc2464bis-02 593 (work in progress), March 2017. 595 [I-D.ietf-ipwave-vehicular-networking-survey] 596 Jeong, J., Cespedes, S., Benamar, N., Haerri, J., and M. 597 Wetterwald, "Survey on IP-based Vehicular Networking for 598 Intelligent Transportation Systems", draft-ietf-ipwave- 599 vehicular-networking-survey-00 (work in progress), July 600 2017. 602 [I-D.perkins-intarea-multicast-ieee802] 603 Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, 604 "Multicast Considerations over IEEE 802 Wireless Media", 605 draft-perkins-intarea-multicast-ieee802-03 (work in 606 progress), July 2017. 608 [IEEE-1609.2] 609 "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access 610 in Vehicular Environments (WAVE) -- Security Services for 611 Applications and Management Messages. Example URL 612 http://ieeexplore.ieee.org/document/7426684/ accessed on 613 August 17th, 2017.". 615 [IEEE-1609.3] 616 "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access 617 in Vehicular Environments (WAVE) -- Networking Services. 618 Example URL http://ieeexplore.ieee.org/document/7458115/ 619 accessed on August 17th, 2017.". 621 [IEEE-1609.4] 622 "IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access 623 in Vehicular Environments (WAVE) -- Multi-Channel 624 Operation. Example URL 625 http://ieeexplore.ieee.org/document/7435228/ accessed on 626 August 17th, 2017.". 628 [IEEE-802.11-2016] 629 "IEEE Standard 802.11-2016 - IEEE Standard for Information 630 Technology - Telecommunications and information exchange 631 between systems Local and metropolitan area networks - 632 Specific requirements - Part 11: Wireless LAN Medium 633 Access Control (MAC) and Physical Layer (PHY) 634 Specifications. Status - Active Standard. Description 635 retrieved freely on September 12th, 2017, at URL 636 https://standards.ieee.org/findstds/ 637 standard/802.11-2016.html". 639 [IEEE-802.11p-2010] 640 "IEEE Std 802.11p (TM)-2010, IEEE Standard for Information 641 Technology - Telecommunications and information exchange 642 between systems - Local and metropolitan area networks - 643 Specific requirements, Part 11: Wireless LAN Medium Access 644 Control (MAC) and Physical Layer (PHY) Specifications, 645 Amendment 6: Wireless Access in Vehicular Environments; 646 document freely available at URL 647 http://standards.ieee.org/getieee802/ 648 download/802.11p-2010.pdf retrieved on September 20th, 649 2013.". 651 Appendix A. ChangeLog 653 The changes are listed in reverse chronological order, most recent 654 changes appearing at the top of the list. 656 From draft-ietf-ipwave-ipv6-over-80211ocb-23 to draft-ietf-ipwave- 657 ipv6-over-80211ocb-24 659 o Nit: wrote "IPWAVE Working Group" on the front page, instead of 660 "Network Working Group". 662 o Addressed the comments on 6MAN: replaced a sentence about ND 663 problem with "is used over 802.11-OCB". 665 From draft-ietf-ipwave-ipv6-over-80211ocb-22 to draft-ietf-ipwave- 666 ipv6-over-80211ocb-23 668 o No content modifications, but check the entire draft chain on 669 IPv6-only: xml2rfc, submission on tools.ietf.org and datatracker. 671 From draft-ietf-ipwave-ipv6-over-80211ocb-21 to draft-ietf-ipwave- 672 ipv6-over-80211ocb-22 674 o Corrected typo, use dash in "802.11-OCB" instead of space. 676 o Improved the Frame Format section: MUST use QoSData, specify the 677 values within; clarified the Ethernet Adaptation Layer text. 679 From draft-ietf-ipwave-ipv6-over-80211ocb-20 to draft-ietf-ipwave- 680 ipv6-over-80211ocb-21 682 o Corrected a few nits and added names in Acknowledgments section. 684 o Removed unused reference to old Internet Draft tsvwg about QoS. 686 From draft-ietf-ipwave-ipv6-over-80211ocb-19 to draft-ietf-ipwave- 687 ipv6-over-80211ocb-20 689 o Reduced the definition of term "802.11-OCB". 691 o Left out of this specification which 802.11 header to use to 692 transmit IP packets in OCB mode (QoS Data header, Data header, or 693 any other). 695 o Added 'MUST' use an Ethernet Adaptation Layer, instead of 'is 696 using' an Ethernet Adaptation Layer. 698 From draft-ietf-ipwave-ipv6-over-80211ocb-18 to draft-ietf-ipwave- 699 ipv6-over-80211ocb-19 701 o Removed the text about fragmentation. 703 o Removed the mentioning of WSMP and GeoNetworking. 705 o Removed the explanation of the binary representation of the 706 EtherType. 708 o Rendered normative the paragraph about unicast and multicast 709 address mapping. 711 o Removed paragraph about addressing model, subnet structure and 712 easiness of using LLs. 714 o Clarified the Type/Subtype field in the 802.11 Header. 716 o Used RECOMMENDED instead of recommended, for the stable interface 717 identifiers. 719 From draft-ietf-ipwave-ipv6-over-80211ocb-17 to draft-ietf-ipwave- 720 ipv6-over-80211ocb-18 722 o Improved the MTU and fragmentation paragraph. 724 From draft-ietf-ipwave-ipv6-over-80211ocb-16 to draft-ietf-ipwave- 725 ipv6-over-80211ocb-17 727 o Susbtituted "MUST be increased" to "is increased" in the MTU 728 section, about fragmentation. 730 From draft-ietf-ipwave-ipv6-over-80211ocb-15 to draft-ietf-ipwave- 731 ipv6-over-80211ocb-16 733 o Removed the definition of the 'WiFi' term and its occurences. 734 Clarified a phrase that used it in Appendix C "Aspects introduced 735 by the OCB mode to 802.11". 737 o Added more normative words: MUST be 0x86DD, MUST fragment if size 738 larger than MTU, Sequence number in 802.11 Data header MUST be 739 increased. 741 From draft-ietf-ipwave-ipv6-over-80211ocb-14 to draft-ietf-ipwave- 742 ipv6-over-80211ocb-15 744 o Added normative term MUST in two places in section "Ethernet 745 Adaptation Layer". 747 From draft-ietf-ipwave-ipv6-over-80211ocb-13 to draft-ietf-ipwave- 748 ipv6-over-80211ocb-14 750 o Created a new Appendix titled "Extra Terminology" that contains 751 terms DSRC, DSRCS, OBU, RSU as defined outside IETF. Some of them 752 are used in the main Terminology section. 754 o Added two paragraphs explaining that ND and Mobile IPv6 have 755 problems working over 802.11-OCB, yet their adaptations is not 756 specified in this document. 758 From draft-ietf-ipwave-ipv6-over-80211ocb-12 to draft-ietf-ipwave- 759 ipv6-over-80211ocb-13 761 o Substituted "IP-OBU" for "OBRU", and "IP-RSU" for "RSRU" 762 throughout and improved OBU-related definitions in the Terminology 763 section. 765 From draft-ietf-ipwave-ipv6-over-80211ocb-11 to draft-ietf-ipwave- 766 ipv6-over-80211ocb-12 768 o Improved the appendix about "MAC Address Generation" by expressing 769 the technique to be an optional suggestion, not a mandatory 770 mechanism. 772 From draft-ietf-ipwave-ipv6-over-80211ocb-10 to draft-ietf-ipwave- 773 ipv6-over-80211ocb-11 775 o Shortened the paragraph on forming/terminating 802.11-OCB links. 777 o Moved the draft tsvwg-ieee-802-11 to Informative References. 779 From draft-ietf-ipwave-ipv6-over-80211ocb-09 to draft-ietf-ipwave- 780 ipv6-over-80211ocb-10 782 o Removed text requesting a new Group ID for multicast for OCB. 784 o Added a clarification of the meaning of value "3333" in the 785 section Address Mapping -- Multicast. 787 o Added note clarifying that in Europe the regional authority is not 788 ETSI, but "ECC/CEPT based on ENs from ETSI". 790 o Added note stating that the manner in which two STAtions set their 791 communication channel is not described in this document. 793 o Added a time qualifier to state that the "each node is represented 794 uniquely at a certain point in time." 796 o Removed text "This section may need to be moved" (the "Reliability 797 Requirements" section). This section stays there at this time. 799 o In the term definition "802.11-OCB" added a note stating that "any 800 implementation should comply with standards and regulations set in 801 the different countries for using that frequency band." 803 o In the RSU term definition, added a sentence explaining the 804 difference between RSU and RSRU: in terms of number of interfaces 805 and IP forwarding. 807 o Replaced "with at least two IP interfaces" with "with at least two 808 real or virtual IP interfaces". 810 o Added a term in the Terminology for "OBU". However the definition 811 is left empty, as this term is defined outside IETF. 813 o Added a clarification that it is an OBU or an OBRU in this phrase 814 "A vehicle embarking an OBU or an OBRU". 816 o Checked the entire document for a consistent use of terms OBU and 817 OBRU. 819 o Added note saying that "'p' is a letter identifying the 820 Ammendment". 822 o Substituted lower case for capitals SHALL or MUST in the 823 Appendices. 825 o Added reference to RFC7042, helpful in the 3333 explanation. 826 Removed reference to individual submission draft-petrescu-its- 827 scenario-reqs and added reference to draft-ietf-ipwave-vehicular- 828 networking-survey. 830 o Added figure captions, figure numbers, and references to figure 831 numbers instead of 'below'. Replaced "section Section" with 832 "section" throughout. 834 o Minor typographical errors. 836 From draft-ietf-ipwave-ipv6-over-80211ocb-08 to draft-ietf-ipwave- 837 ipv6-over-80211ocb-09 839 o Significantly shortened the Address Mapping sections, by text 840 copied from RFC2464, and rather referring to it. 842 o Moved the EPD description to an Appendix on its own. 844 o Shortened the Introduction and the Abstract. 846 o Moved the tutorial section of OCB mode introduced to .11, into an 847 appendix. 849 o Removed the statement that suggests that for routing purposes a 850 prefix exchange mechanism could be needed. 852 o Removed refs to RFC3963, RFC4429 and RFC6775; these are about ND, 853 MIP/NEMO and oDAD; they were referred in the handover discussion 854 section, which is out. 856 o Updated a reference from individual submission to now a WG item in 857 IPWAVE: the survey document. 859 o Added term definition for WiFi. 861 o Updated the authorship and expanded the Contributors section. 863 o Corrected typographical errors. 865 From draft-ietf-ipwave-ipv6-over-80211ocb-07 to draft-ietf-ipwave- 866 ipv6-over-80211ocb-08 868 o Removed the per-channel IPv6 prohibition text. 870 o Corrected typographical errors. 872 From draft-ietf-ipwave-ipv6-over-80211ocb-06 to draft-ietf-ipwave- 873 ipv6-over-80211ocb-07 875 o Added new terms: OBRU and RSRU ('R' for Router). Refined the 876 existing terms RSU and OBU, which are no longer used throughout 877 the document. 879 o Improved definition of term "802.11-OCB". 881 o Clarified that OCB does not "strip" security, but that the 882 operation in OCB mode is "stripped off of all .11 security". 884 o Clarified that theoretical OCB bandwidth speed is 54mbits, but 885 that a commonly observed bandwidth in IP-over-OCB is 12mbit/s. 887 o Corrected typographical errors, and improved some phrasing. 889 From draft-ietf-ipwave-ipv6-over-80211ocb-05 to draft-ietf-ipwave- 890 ipv6-over-80211ocb-06 891 o Updated references of 802.11-OCB document from -2012 to the IEEE 892 802.11-2016. 894 o In the LL address section, and in SLAAC section, added references 895 to 7217 opaque IIDs and 8064 stable IIDs. 897 From draft-ietf-ipwave-ipv6-over-80211ocb-04 to draft-ietf-ipwave- 898 ipv6-over-80211ocb-05 900 o Lengthened the title and cleanded the abstract. 902 o Added text suggesting LLs may be easy to use on OCB, rather than 903 GUAs based on received prefix. 905 o Added the risks of spoofing and hijacking. 907 o Removed the text speculation on adoption of the TSA message. 909 o Clarified that the ND protocol is used. 911 o Clarified what it means "No association needed". 913 o Added some text about how two STAs discover each other. 915 o Added mention of external (OCB) and internal network (stable), in 916 the subnet structure section. 918 o Added phrase explaining that both .11 Data and .11 QoS Data 919 headers are currently being used, and may be used in the future. 921 o Moved the packet capture example into an Appendix Implementation 922 Status. 924 o Suggested moving the reliability requirements appendix out into 925 another document. 927 o Added a IANA Consiserations section, with content, requesting for 928 a new multicast group "all OCB interfaces". 930 o Added new OBU term, improved the RSU term definition, removed the 931 ETTC term, replaced more occurences of 802.11p, 802.11-OCB with 932 802.11-OCB. 934 o References: 936 * Added an informational reference to ETSI's IPv6-over- 937 GeoNetworking. 939 * Added more references to IETF and ETSI security protocols. 941 * Updated some references from I-D to RFC, and from old RFC to 942 new RFC numbers. 944 * Added reference to multicast extensions to IPsec architecture 945 RFC. 947 * Added a reference to 2464-bis. 949 * Removed FCC informative references, because not used. 951 o Updated the affiliation of one author. 953 o Reformulation of some phrases for better readability, and 954 correction of typographical errors. 956 From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave- 957 ipv6-over-80211ocb-04 959 o Removed a few informative references pointing to Dx draft IEEE 960 1609 documents. 962 o Removed outdated informative references to ETSI documents. 964 o Added citations to IEEE 1609.2, .3 and .4-2016. 966 o Minor textual issues. 968 From draft-ietf-ipwave-ipv6-over-80211ocb-02 to draft-ietf-ipwave- 969 ipv6-over-80211ocb-03 971 o Keep the previous text on multiple addresses, so remove talk about 972 MIP6, NEMOv6 and MCoA. 974 o Clarified that a 'Beacon' is an IEEE 802.11 frame Beacon. 976 o Clarified the figure showing Infrastructure mode and OCB mode side 977 by side. 979 o Added a reference to the IP Security Architecture RFC. 981 o Detailed the IPv6-per-channel prohibition paragraph which reflects 982 the discussion at the last IETF IPWAVE WG meeting. 984 o Added section "Address Mapping -- Unicast". 986 o Added the ".11 Trailer" to pictures of 802.11 frames. 988 o Added text about SNAP carrying the Ethertype. 990 o New RSU definition allowing for it be both a Router and not 991 necessarily a Router some times. 993 o Minor textual issues. 995 From draft-ietf-ipwave-ipv6-over-80211ocb-01 to draft-ietf-ipwave- 996 ipv6-over-80211ocb-02 998 o Replaced almost all occurences of 802.11p with 802.11-OCB, leaving 999 only when explanation of evolution was necessary. 1001 o Shortened by removing parameter details from a paragraph in the 1002 Introduction. 1004 o Moved a reference from Normative to Informative. 1006 o Added text in intro clarifying there is no handover spec at IEEE, 1007 and that 1609.2 does provide security services. 1009 o Named the contents the fields of the EthernetII header (including 1010 the Ethertype bitstring). 1012 o Improved relationship between two paragraphs describing the 1013 increase of the Sequence Number in 802.11 header upon IP 1014 fragmentation. 1016 o Added brief clarification of "tracking". 1018 From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave- 1019 ipv6-over-80211ocb-01 1021 o Introduced message exchange diagram illustrating differences 1022 between 802.11 and 802.11 in OCB mode. 1024 o Introduced an appendix listing for information the set of 802.11 1025 messages that may be transmitted in OCB mode. 1027 o Removed appendix sections "Privacy Requirements", "Authentication 1028 Requirements" and "Security Certificate Generation". 1030 o Removed appendix section "Non IP Communications". 1032 o Introductory phrase in the Security Considerations section. 1034 o Improved the definition of "OCB". 1036 o Introduced theoretical stacked layers about IPv6 and IEEE layers 1037 including EPD. 1039 o Removed the appendix describing the details of prohibiting IPv6 on 1040 certain channels relevant to 802.11-OCB. 1042 o Added a brief reference in the privacy text about a precise clause 1043 in IEEE 1609.3 and .4. 1045 o Clarified the definition of a Road Side Unit. 1047 o Removed the discussion about security of WSA (because is non-IP). 1049 o Removed mentioning of the GeoNetworking discussion. 1051 o Moved references to scientific articles to a separate 'overview' 1052 draft, and referred to it. 1054 Appendix B. 802.11p 1056 The term "802.11p" is an earlier definition. The behaviour of 1057 "802.11p" networks is rolled in the document IEEE Std 802.11-2016. 1058 In that document the term 802.11p disappears. Instead, each 802.11p 1059 feature is conditioned by the Management Information Base (MIB) 1060 attribute "OCBActivated". Whenever OCBActivated is set to true the 1061 IEEE Std 802.11-OCB state is activated. For example, an 802.11 1062 STAtion operating outside the context of a basic service set has the 1063 OCBActivated flag set. Such a station, when it has the flag set, 1064 uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. 1066 Appendix C. Aspects introduced by the OCB mode to 802.11 1068 In the IEEE 802.11-OCB mode, all nodes in the wireless range can 1069 directly communicate with each other without involving authentication 1070 or association procedures. At link layer, it is necessary to set the 1071 same channel number (or frequency) on two stations that need to 1072 communicate with each other. The manner in which stations set their 1073 channel number is not specified in this document. Stations STA1 and 1074 STA2 can exchange IP packets if they are set on the same channel. At 1075 IP layer, they then discover each other by using the IPv6 Neighbor 1076 Discovery protocol. 1078 Briefly, the IEEE 802.11-OCB mode has the following properties: 1080 o The use by each node of a 'wildcard' BSSID (i.e., each bit of the 1081 BSSID is set to 1) 1083 o No IEEE 802.11 Beacon frames are transmitted 1084 o No authentication is required in order to be able to communicate 1086 o No association is needed in order to be able to communicate 1088 o No encryption is provided in order to be able to communicate 1090 o Flag dot11OCBActivated is set to true 1092 All the nodes in the radio communication range (IP-OBU and IP-RSU) 1093 receive all the messages transmitted (IP-OBU and IP-RSU) within the 1094 radio communications range. The eventual conflict(s) are resolved by 1095 the MAC CDMA function. 1097 The message exchange diagram in Figure 3 illustrates a comparison 1098 between traditional 802.11 and 802.11 in OCB mode. The 'Data' 1099 messages can be IP packets such as HTTP or others. Other 802.11 1100 management and control frames (non IP) may be transmitted, as 1101 specified in the 802.11 standard. For information, the names of 1102 these messages as currently specified by the 802.11 standard are 1103 listed in Appendix G. 1105 STA AP STA1 STA2 1106 | | | | 1107 |<------ Beacon -------| |<------ Data -------->| 1108 | | | | 1109 |---- Probe Req. ----->| |<------ Data -------->| 1110 |<--- Probe Res. ------| | | 1111 | | |<------ Data -------->| 1112 |---- Auth Req. ------>| | | 1113 |<--- Auth Res. -------| |<------ Data -------->| 1114 | | | | 1115 |---- Asso Req. ------>| |<------ Data -------->| 1116 |<--- Asso Res. -------| | | 1117 | | |<------ Data -------->| 1118 |<------ Data -------->| | | 1119 |<------ Data -------->| |<------ Data -------->| 1121 (i) 802.11 Infrastructure mode (ii) 802.11-OCB mode 1123 Figure 3: Difference between messages exchanged on 802.11 (left) and 1124 802.11-OCB (right) 1126 The interface 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010 1127 [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, 1128 titled "Amendment 6: Wireless Access in Vehicular Environments". 1130 Since then, this amendment has been integrated in IEEE 802.11(TM) 1131 -2012 and -2016 [IEEE-802.11-2016]. 1133 In document 802.11-2016, anything qualified specifically as 1134 "OCBActivated", or "outside the context of a basic service" set to be 1135 true, then it is actually referring to OCB aspects introduced to 1136 802.11. 1138 In order to delineate the aspects introduced by 802.11-OCB to 802.11, 1139 we refer to the earlier [IEEE-802.11p-2010]. The amendment is 1140 concerned with vehicular communications, where the wireless link is 1141 similar to that of Wireless LAN (using a PHY layer specified by 1142 802.11a/b/g/n), but which needs to cope with the high mobility factor 1143 inherent in scenarios of communications between moving vehicles, and 1144 between vehicles and fixed infrastructure deployed along roads. 1145 While 'p' is a letter identifying the Ammendment, just like 'a, b, g' 1146 and 'n' are, 'p' is concerned more with MAC modifications, and a 1147 little with PHY modifications; the others are mainly about PHY 1148 modifications. It is possible in practice to combine a 'p' MAC with 1149 an 'a' PHY by operating outside the context of a BSS with OFDM at 1150 5.4GHz and 5.9GHz. 1152 The 802.11-OCB links are specified to be compatible as much as 1153 possible with the behaviour of 802.11a/b/g/n and future generation 1154 IEEE WLAN links. From the IP perspective, an 802.11-OCB MAC layer 1155 offers practically the same interface to IP as the 802.11a/b/g/n and 1156 802.3. A packet sent by an IP-OBU may be received by one or multiple 1157 IP-RSUs. The link-layer resolution is performed by using the IPv6 1158 Neighbor Discovery protocol. 1160 To support this similarity statement (IPv6 is layered on top of LLC 1161 on top of 802.11-OCB, in the same way that IPv6 is layered on top of 1162 LLC on top of 802.11a/b/g/n (for WLAN) or layered on top of LLC on 1163 top of 802.3 (for Ethernet)) it is useful to analyze the differences 1164 between 802.11-OCB and 802.11 specifications. During this analysis, 1165 we note that whereas 802.11-OCB lists relatively complex and numerous 1166 changes to the MAC layer (and very little to the PHY layer), there 1167 are only a few characteristics which may be important for an 1168 implementation transmitting IPv6 packets on 802.11-OCB links. 1170 The most important 802.11-OCB point which influences the IPv6 1171 functioning is the OCB characteristic; an additional, less direct 1172 influence, is the maximum bandwidth afforded by the PHY modulation/ 1173 demodulation methods and channel access specified by 802.11-OCB. The 1174 maximum bandwidth theoretically possible in 802.11-OCB is 54 Mbit/s 1175 (when using, for example, the following parameters: 20 MHz channel; 1176 modulation 64-QAM; coding rate R is 3/4); in practice of IP-over- 1177 802.11-OCB a commonly observed figure is 12Mbit/s; this bandwidth 1178 allows the operation of a wide range of protocols relying on IPv6. 1180 o Operation Outside the Context of a BSS (OCB): the (earlier 1181 802.11p) 802.11-OCB links are operated without a Basic Service Set 1182 (BSS). This means that the frames IEEE 802.11 Beacon, Association 1183 Request/Response, Authentication Request/Response, and similar, 1184 are not used. The used identifier of BSS (BSSID) has a 1185 hexadecimal value always 0xffffffffffff (48 '1' bits, represented 1186 as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' 1187 BSSID), as opposed to an arbitrary BSSID value set by 1188 administrator (e.g. 'My-Home-AccessPoint'). The OCB operation - 1189 namely the lack of beacon-based scanning and lack of 1190 authentication - should be taken into account when the Mobile IPv6 1191 protocol [RFC6275] and the protocols for IP layer security 1192 [RFC4301] are used. The way these protocols adapt to OCB is not 1193 described in this document. 1195 o Timing Advertisement: is a new message defined in 802.11-OCB, 1196 which does not exist in 802.11a/b/g/n. This message is used by 1197 stations to inform other stations about the value of time. It is 1198 similar to the time as delivered by a GNSS system (Galileo, GPS, 1199 ...) or by a cellular system. This message is optional for 1200 implementation. 1202 o Frequency range: this is a characteristic of the PHY layer, with 1203 almost no impact on the interface between MAC and IP. However, it 1204 is worth considering that the frequency range is regulated by a 1205 regional authority (ARCEP, ECC/CEPT based on ENs from ETSI, FCC, 1206 etc.); as part of the regulation process, specific applications 1207 are associated with specific frequency ranges. In the case of 1208 802.11-OCB, the regulator associates a set of frequency ranges, or 1209 slots within a band, to the use of applications of vehicular 1210 communications, in a band known as "5.9GHz". The 5.9GHz band is 1211 different from the 2.4GHz and 5GHz bands used by Wireless LAN. 1212 However, as with Wireless LAN, the operation of 802.11-OCB in 1213 "5.9GHz" bands is exempt from owning a license in EU (in US the 1214 5.9GHz is a licensed band of spectrum; for the fixed 1215 infrastructure an explicit FCC authorization is required; for an 1216 on-board device a 'licensed-by-rule' concept applies: rule 1217 certification conformity is required.) Technical conditions are 1218 different than those of the bands "2.4GHz" or "5GHz". The allowed 1219 power levels, and implicitly the maximum allowed distance between 1220 vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20 1221 dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum 1222 distance of approximately 1km, compared to approximately 50m. 1223 Additionally, specific conditions related to congestion avoidance, 1224 jamming avoidance, and radar detection are imposed on the use of 1225 DSRC (in US) and on the use of frequencies for Intelligent 1226 Transportation Systems (in EU), compared to Wireless LAN 1227 (802.11a/b/g/n). 1229 o 'Half-rate' encoding: as the frequency range, this parameter is 1230 related to PHY, and thus has not much impact on the interface 1231 between the IP layer and the MAC layer. 1233 o In vehicular communications using 802.11-OCB links, there are 1234 strong privacy requirements with respect to addressing. While the 1235 802.11-OCB standard does not specify anything in particular with 1236 respect to MAC addresses, in these settings there exists a strong 1237 need for dynamic change of these addresses (as opposed to the non- 1238 vehicular settings - real wall protection - where fixed MAC 1239 addresses do not currently pose some privacy risks). This is 1240 further described in Section 5. A relevant function is described 1241 in IEEE 1609.3-2016 [IEEE-1609.3], clause 5.5.1 and IEEE 1242 1609.4-2016 [IEEE-1609.4], clause 6.7. 1244 Other aspects particular to 802.11-OCB, which are also particular to 1245 802.11 (e.g. the 'hidden node' operation), may have an influence on 1246 the use of transmission of IPv6 packets on 802.11-OCB networks. The 1247 OCB subnet structure is described in Section 4.6. 1249 Appendix D. Changes Needed on a software driver 802.11a to become a 1250 802.11-OCB driver 1252 The 802.11p amendment modifies both the 802.11 stack's physical and 1253 MAC layers but all the induced modifications can be quite easily 1254 obtained by modifying an existing 802.11a ad-hoc stack. 1256 Conditions for a 802.11a hardware to be 802.11-OCB compliant: 1258 o The PHY entity shall be an orthogonal frequency division 1259 multiplexing (OFDM) system. It must support the frequency bands 1260 on which the regulator recommends the use of ITS communications, 1261 for example using IEEE 802.11-OCB layer, in France: 5875MHz to 1262 5925MHz. 1264 o The OFDM system must provide a "half-clocked" operation using 10 1265 MHz channel spacings. 1267 o The chip transmit spectrum mask must be compliant to the "Transmit 1268 spectrum mask" from the IEEE 802.11p amendment (but experimental 1269 environments tolerate otherwise). 1271 o The chip should be able to transmit up to 44.8 dBm when used by 1272 the US government in the United States, and up to 33 dBm in 1273 Europe; other regional conditions apply. 1275 Changes needed on the network stack in OCB mode: 1277 o Physical layer: 1279 * The chip must use the Orthogonal Frequency Multiple Access 1280 (OFDM) encoding mode. 1282 * The chip must be set in half-mode rate mode (the internal clock 1283 frequency is divided by two). 1285 * The chip must use dedicated channels and should allow the use 1286 of higher emission powers. This may require modifications to 1287 the local computer file that describes regulatory domains 1288 rules, if used by the kernel to enforce local specific 1289 restrictions. Such modifications to the local computer file 1290 must respect the location-specific regulatory rules. 1292 MAC layer: 1294 * All management frames (beacons, join, leave, and others) 1295 emission and reception must be disabled except for frames of 1296 subtype Action and Timing Advertisement (defined below). 1298 * No encryption key or method must be used. 1300 * Packet emission and reception must be performed as in ad-hoc 1301 mode, using the wildcard BSSID (ff:ff:ff:ff:ff:ff). 1303 * The functions related to joining a BSS (Association Request/ 1304 Response) and for authentication (Authentication Request/Reply, 1305 Challenge) are not called. 1307 * The beacon interval is always set to 0 (zero). 1309 * Timing Advertisement frames, defined in the amendment, should 1310 be supported. The upper layer should be able to trigger such 1311 frames emission and to retrieve information contained in 1312 received Timing Advertisements. 1314 Appendix E. EtherType Protocol Discrimination (EPD) 1316 A more theoretical and detailed view of layer stacking, and 1317 interfaces between the IP layer and 802.11-OCB layers, is illustrated 1318 in Figure 4. The IP layer operates on top of the EtherType Protocol 1319 Discrimination (EPD); this Discrimination layer is described in IEEE 1320 Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP 1321 (Link Layer Control Service Access Point). 1323 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1324 | IPv6 | 1325 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ 1326 { LLC_SAP } 802.11-OCB 1327 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary 1328 | EPD | | | 1329 | | MLME | | 1330 +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | 1331 | MAC Sublayer | | | 802.11-OCB 1332 | and ch. coord. | | SME | Services 1333 +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | 1334 | | PLME | | 1335 | PHY Layer | PLME_SAP | 1336 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1338 Figure 4: EtherType Protocol Discrimination 1340 Appendix F. Design Considerations 1342 The networks defined by 802.11-OCB are in many ways similar to other 1343 networks of the 802.11 family. In theory, the encapsulation of IPv6 1344 over 802.11-OCB could be very similar to the operation of IPv6 over 1345 other networks of the 802.11 family. However, the high mobility, 1346 strong link asymmetry and very short connection makes the 802.11-OCB 1347 link significantly different from other 802.11 networks. Also, the 1348 automotive applications have specific requirements for reliability, 1349 security and privacy, which further add to the particularity of the 1350 802.11-OCB link. 1352 F.1. Vehicle ID 1354 In automotive networks it is required that each node is represented 1355 uniquely at a certain point in time. Accordingly, a vehicle must be 1356 identified by at least one unique identifier. The current 1357 specification at ETSI and at IEEE 1609 identifies a vehicle by its 1358 MAC address, which is obtained from the 802.11-OCB Network Interface 1359 Card (NIC). 1361 In case multiple 802.11-OCB NICs are present in one car, implicitely 1362 multiple vehicle IDs will be generated. Additionally, some software 1363 generates a random MAC address each time the computer boots; this 1364 constitutes an additional difficulty. 1366 A mechanim to uniquely identify a vehicle irrespectively to the 1367 multiplicity of NICs, or frequent MAC address generation, is 1368 necessary. 1370 F.2. Reliability Requirements 1372 The dynamically changing topology, short connectivity, mobile 1373 transmitter and receivers, different antenna heights, and many-to- 1374 many communication types, make IEEE 802.11-OCB links significantly 1375 different from other IEEE 802.11 links. Any IPv6 mechanism operating 1376 on IEEE 802.11-OCB link must support strong link asymmetry, spatio- 1377 temporal link quality, fast address resolution and transmission. 1379 IEEE 802.11-OCB strongly differs from other 802.11 systems to operate 1380 outside of the context of a Basic Service Set. This means in 1381 practice that IEEE 802.11-OCB does not rely on a Base Station for all 1382 Basic Service Set management. In particular, IEEE 802.11-OCB shall 1383 not use beacons. Any IPv6 mechanism requiring L2 services from IEEE 1384 802.11 beacons must support an alternative service. 1386 Channel scanning being disabled, IPv6 over IEEE 802.11-OCB must 1387 implement a mechanism for transmitter and receiver to converge to a 1388 common channel. 1390 Authentication not being possible, IPv6 over IEEE 802.11-OCB must 1391 implement an distributed mechanism to authenticate transmitters and 1392 receivers without the support of a DHCP server. 1394 Time synchronization not being available, IPv6 over IEEE 802.11-OCB 1395 must implement a higher layer mechanism for time synchronization 1396 between transmitters and receivers without the support of a NTP 1397 server. 1399 The IEEE 802.11-OCB link being asymmetric, IPv6 over IEEE 802.11-OCB 1400 must disable management mechanisms requesting acknowledgements or 1401 replies. 1403 The IEEE 802.11-OCB link having a short duration time, IPv6 over IEEE 1404 802.11-OCB should implement fast IPv6 mobility management mechanisms. 1406 F.3. Multiple interfaces 1408 There are considerations for 2 or more IEEE 802.11-OCB interface 1409 cards per vehicle. For each vehicle taking part in road traffic, one 1410 IEEE 802.11-OCB interface card could be fully allocated for Non IP 1411 safety-critical communication. Any other IEEE 802.11-OCB may be used 1412 for other type of traffic. 1414 The mode of operation of these other wireless interfaces is not 1415 clearly defined yet. One possibility is to consider each card as an 1416 independent network interface, with a specific MAC Address and a set 1417 of IPv6 addresses. Another possibility is to consider the set of 1418 these wireless interfaces as a single network interface (not 1419 including the IEEE 802.11-OCB interface used by Non IP safety 1420 critical communications). This will require specific logic to 1421 ensure, for example, that packets meant for a vehicle in front are 1422 actually sent by the radio in the front, or that multiple copies of 1423 the same packet received by multiple interfaces are treated as a 1424 single packet. Treating each wireless interface as a separate 1425 network interface pushes such issues to the application layer. 1427 Certain privacy requirements imply that if these multiple interfaces 1428 are represented by many network interface, a single renumbering event 1429 shall cause renumbering of all these interfaces. If one MAC changed 1430 and another stayed constant, external observers would be able to 1431 correlate old and new values, and the privacy benefits of 1432 randomization would be lost. 1434 The privacy requirements of Non IP safety-critical communications 1435 imply that if a change of pseudonyme occurs, renumbering of all other 1436 interfaces shall also occur. 1438 F.4. MAC Address Generation 1440 In 802.11-OCB networks, the MAC addresses may change during well 1441 defined renumbering events. A 'randomized' MAC address has the 1442 following characteristics: 1444 o Bit "Local/Global" set to "locally admninistered". 1446 o Bit "Unicast/Multicast" set to "Unicast". 1448 o The 46 remaining bits are set to a random value, using a random 1449 number generator that meets the requirements of [RFC4086]. 1451 To meet the randomization requirements for the 46 remaining bits, a 1452 hash function may be used. For example, the SHA256 hash function may 1453 be used with input a 256 bit local secret, the "nominal" MAC Address 1454 of the interface, and a representation of the date and time of the 1455 renumbering event. 1457 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode 1459 For information, at the time of writing, this is the list of IEEE 1460 802.11 messages that may be transmitted in OCB mode, i.e. when 1461 dot11OCBActivated is true in a STA: 1463 o The STA may send management frames of subtype Action and, if the 1464 STA maintains a TSF Timer, subtype Timing Advertisement; 1466 o The STA may send control frames, except those of subtype PS-Poll, 1467 CF-End, and CF-End plus CFAck; 1469 o The STA may send data frames of subtype Data, Null, QoS Data, and 1470 QoS Null. 1472 Appendix H. Implementation Status 1474 This section describes an example of an IPv6 Packet captured over a 1475 IEEE 802.11-OCB link. 1477 By way of example we show that there is no modification in the 1478 headers when transmitted over 802.11-OCB networks - they are 1479 transmitted like any other 802.11 and Ethernet packets. 1481 We describe an experiment of capturing an IPv6 packet on an 1482 802.11-OCB link. In topology depicted in Figure 5, the packet is an 1483 IPv6 Router Advertisement. This packet is emitted by a Router on its 1484 802.11-OCB interface. The packet is captured on the Host, using a 1485 network protocol analyzer (e.g. Wireshark); the capture is performed 1486 in two different modes: direct mode and 'monitor' mode. The topology 1487 used during the capture is depicted below. 1489 The packet is captured on the Host. The Host is an IP-OBU containing 1490 an 802.11 interface in format PCI express (an ITRI product). The 1491 kernel runs the ath5k software driver with modifications for OCB 1492 mode. The capture tool is Wireshark. The file format for save and 1493 analyze is 'pcap'. The packet is generated by the Router. The 1494 Router is an IP-RSU (ITRI product). 1496 +--------+ +-------+ 1497 | | 802.11-OCB Link | | 1498 ---| Router |--------------------------------| Host | 1499 | | | | 1500 +--------+ +-------+ 1502 Figure 5: Topology for capturing IP packets on 802.11-OCB 1504 During several capture operations running from a few moments to 1505 several hours, no message relevant to the BSSID contexts were 1506 captured (no Association Request/Response, Authentication Req/Resp, 1507 Beacon). This shows that the operation of 802.11-OCB is outside the 1508 context of a BSSID. 1510 Overall, the captured message is identical with a capture of an IPv6 1511 packet emitted on a 802.11b interface. The contents are precisely 1512 similar. 1514 H.1. Capture in Monitor Mode 1516 The IPv6 RA packet captured in monitor mode is illustrated below. 1517 The radio tap header provides more flexibility for reporting the 1518 characteristics of frames. The Radiotap Header is prepended by this 1519 particular stack and operating system on the Host machine to the RA 1520 packet received from the network (the Radiotap Header is not present 1521 on the air). The implementation-dependent Radiotap Header is useful 1522 for piggybacking PHY information from the chip's registers as data in 1523 a packet understandable by userland applications using Socket 1524 interfaces (the PHY interface can be, for example: power levels, data 1525 rate, ratio of signal to noise). 1527 The packet present on the air is formed by IEEE 802.11 Data Header, 1528 Logical Link Control Header, IPv6 Base Header and ICMPv6 Header. 1530 Radiotap Header v0 1531 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1532 |Header Revision| Header Pad | Header length | 1533 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1534 | Present flags | 1535 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1536 | Data Rate | Pad | 1537 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1539 IEEE 802.11 Data Header 1540 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1541 | Type/Subtype and Frame Ctrl | Duration | 1542 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1543 | Receiver Address... 1544 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1545 ... Receiver Address | Transmitter Address... 1546 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1547 ... Transmitter Address | 1548 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1549 | BSS Id... 1550 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1551 ... BSS Id | Frag Number and Seq Number | 1552 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1554 Logical-Link Control Header 1555 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1556 | DSAP |I| SSAP |C| Control field | Org. code... 1557 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1558 ... Organizational Code | Type | 1559 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1561 IPv6 Base Header 1562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1563 |Version| Traffic Class | Flow Label | 1564 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1565 | Payload Length | Next Header | Hop Limit | 1566 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1567 | | 1568 + + 1569 | | 1570 + Source Address + 1571 | | 1572 + + 1573 | | 1574 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1575 | | 1576 + + 1577 | | 1578 + Destination Address + 1579 | | 1580 + + 1581 | | 1582 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1584 Router Advertisement 1585 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1586 | Type | Code | Checksum | 1587 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1588 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1589 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1590 | Reachable Time | 1591 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1592 | Retrans Timer | 1593 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1594 | Options ... 1595 +-+-+-+-+-+-+-+-+-+-+-+- 1597 The value of the Data Rate field in the Radiotap header is set to 6 1598 Mb/s. This indicates the rate at which this RA was received. 1600 The value of the Transmitter address in the IEEE 802.11 Data Header 1601 is set to a 48bit value. The value of the destination address is 1602 33:33:00:00:00:1 (all-nodes multicast address). The value of the BSS 1603 Id field is ff:ff:ff:ff:ff:ff, which is recognized by the network 1604 protocol analyzer as being "broadcast". The Fragment number and 1605 sequence number fields are together set to 0x90C6. 1607 The value of the Organization Code field in the Logical-Link Control 1608 Header is set to 0x0, recognized as "Encapsulated Ethernet". The 1609 value of the Type field is 0x86DD (hexadecimal 86DD, or otherwise 1610 #86DD), recognized as "IPv6". 1612 A Router Advertisement is periodically sent by the router to 1613 multicast group address ff02::1. It is an icmp packet type 134. The 1614 IPv6 Neighbor Discovery's Router Advertisement message contains an 1615 8-bit field reserved for single-bit flags, as described in [RFC4861]. 1617 The IPv6 header contains the link local address of the router 1618 (source) configured via EUI-64 algorithm, and destination address set 1619 to ff02::1. Recent versions of network protocol analyzers (e.g. 1620 Wireshark) provide additional informations for an IP address, if a 1621 geolocalization database is present. In this example, the 1622 geolocalization database is absent, and the "GeoIP" information is 1623 set to unknown for both source and destination addresses (although 1624 the IPv6 source and destination addresses are set to useful values). 1625 This "GeoIP" can be a useful information to look up the city, 1626 country, AS number, and other information for an IP address. 1628 The Ethernet Type field in the logical-link control header is set to 1629 0x86dd which indicates that the frame transports an IPv6 packet. In 1630 the IEEE 802.11 data, the destination address is 33:33:00:00:00:01 1631 which is the corresponding multicast MAC address. The BSS id is a 1632 broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link 1633 duration between vehicles and the roadside infrastructure, there is 1634 no need in IEEE 802.11-OCB to wait for the completion of association 1635 and authentication procedures before exchanging data. IEEE 1636 802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s) 1637 and may start communicating as soon as they arrive on the 1638 communication channel. 1640 H.2. Capture in Normal Mode 1642 The same IPv6 Router Advertisement packet described above (monitor 1643 mode) is captured on the Host, in the Normal mode, and depicted 1644 below. 1646 Ethernet II Header 1647 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1648 | Destination... 1649 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1650 ...Destination | Source... 1651 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1652 ...Source | 1653 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1654 | Type | 1655 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1657 IPv6 Base Header 1658 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1659 |Version| Traffic Class | Flow Label | 1660 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1661 | Payload Length | Next Header | Hop Limit | 1662 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1663 | | 1664 + + 1665 | | 1666 + Source Address + 1667 | | 1668 + + 1669 | | 1670 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1671 | | 1672 + + 1673 | | 1674 + Destination Address + 1675 | | 1676 + + 1677 | | 1678 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1680 Router Advertisement 1681 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1682 | Type | Code | Checksum | 1683 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1684 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1685 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1686 | Reachable Time | 1687 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1688 | Retrans Timer | 1689 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1690 | Options ... 1691 +-+-+-+-+-+-+-+-+-+-+-+- 1693 One notices that the Radiotap Header, the IEEE 802.11 Data Header and 1694 the Logical-Link Control Headers are not present. On the other hand, 1695 a new header named Ethernet II Header is present. 1697 The Destination and Source addresses in the Ethernet II header 1698 contain the same values as the fields Receiver Address and 1699 Transmitter Address present in the IEEE 802.11 Data Header in the 1700 "monitor" mode capture. 1702 The value of the Type field in the Ethernet II header is 0x86DD 1703 (recognized as "IPv6"); this value is the same value as the value of 1704 the field Type in the Logical-Link Control Header in the "monitor" 1705 mode capture. 1707 The knowledgeable experimenter will no doubt notice the similarity of 1708 this Ethernet II Header with a capture in normal mode on a pure 1709 Ethernet cable interface. 1711 An Adaptation layer is inserted on top of a pure IEEE 802.11 MAC 1712 layer, in order to adapt packets, before delivering the payload data 1713 to the applications. It adapts 802.11 LLC/MAC headers to Ethernet II 1714 headers. In further detail, this adaptation consists in the 1715 elimination of the Radiotap, 802.11 and LLC headers, and in the 1716 insertion of the Ethernet II header. In this way, IPv6 runs straight 1717 over LLC over the 802.11-OCB MAC layer; this is further confirmed by 1718 the use of the unique Type 0x86DD. 1720 Appendix I. Extra Terminology 1722 The following terms are defined outside the IETF. They are used to 1723 define the main terms in the main terminology section Section 2. 1725 DSRC (Dedicated Short Range Communication): a term defined outside 1726 the IETF. The US Federal Communications Commission (FCC) Dedicated 1727 Short Range Communication (DSRC) is defined in the Code of Federal 1728 Regulations (CFR) 47, Parts 90 and 95. This Code is referred in the 1729 definitions below. At the time of the writing of this Internet 1730 Draft, the last update of this Code was dated October 1st, 2010. 1732 DSRCS (Dedicated Short-Range Communications Services): a term defined 1733 outside the IETF. The use of radio techniques to transfer data over 1734 short distances between roadside and mobile units, between mobile 1735 units, and between portable and mobile units to perform operations 1736 related to the improvement of traffic flow, traffic safety, and other 1737 intelligent transportation service applications in a variety of 1738 environments. DSRCS systems may also transmit status and 1739 instructional messages related to the units involve. [Ref. 47 CFR 1740 90.7 - Definitions] 1741 OBU (On-Board Unit): a term defined outside the IETF. An On-Board 1742 Unit is a DSRCS transceiver that is normally mounted in or on a 1743 vehicle, or which in some instances may be a portable unit. An OBU 1744 can be operational while a vehicle or person is either mobile or 1745 stationary. The OBUs receive and contend for time to transmit on one 1746 or more radio frequency (RF) channels. Except where specifically 1747 excluded, OBU operation is permitted wherever vehicle operation or 1748 human passage is permitted. The OBUs mounted in vehicles are 1749 licensed by rule under part 95 of the respective chapter and 1750 communicate with Roadside Units (RSUs) and other OBUs. Portable OBUs 1751 are also licensed by rule under part 95 of the respective chapter. 1752 OBU operations in the Unlicensed National Information Infrastructure 1753 (UNII) Bands follow the rules in those bands. - [CFR 90.7 - 1754 Definitions]. 1756 RSU (Road-Side Unit): a term defined outside of IETF. A Roadside 1757 Unit is a DSRC transceiver that is mounted along a road or pedestrian 1758 passageway. An RSU may also be mounted on a vehicle or is hand 1759 carried, but it may only operate when the vehicle or hand- carried 1760 unit is stationary. Furthermore, an RSU operating under the 1761 respectgive part is restricted to the location where it is licensed 1762 to operate. However, portable or hand-held RSUs are permitted to 1763 operate where they do not interfere with a site-licensed operation. 1764 A RSU broadcasts data to OBUs or exchanges data with OBUs in its 1765 communications zone. An RSU also provides channel assignments and 1766 operating instructions to OBUs in its communications zone, when 1767 required. - [CFR 90.7 - Definitions]. 1769 Authors' Addresses 1771 Alexandre Petrescu 1772 CEA, LIST 1773 CEA Saclay 1774 Gif-sur-Yvette , Ile-de-France 91190 1775 France 1777 Phone: +33169089223 1778 Email: Alexandre.Petrescu@cea.fr 1780 Nabil Benamar 1781 Moulay Ismail University 1782 Morocco 1784 Phone: +212670832236 1785 Email: n.benamar@est.umi.ac.ma 1786 Jerome Haerri 1787 Eurecom 1788 Sophia-Antipolis 06904 1789 France 1791 Phone: +33493008134 1792 Email: Jerome.Haerri@eurecom.fr 1794 Jong-Hyouk Lee 1795 Sangmyung University 1796 31, Sangmyeongdae-gil, Dongnam-gu 1797 Cheonan 31066 1798 Republic of Korea 1800 Email: jonghyouk@smu.ac.kr 1802 Thierry Ernst 1803 YoGoKo 1804 France 1806 Email: thierry.ernst@yogoko.fr