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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Petrescu 3 Internet-Draft CEA, LIST 4 Intended status: Standards Track N. Benamar 5 Expires: August 26, 2018 Moulay Ismail University 6 J. Haerri 7 Eurecom 8 J. Lee 9 Sangmyung University 10 T. Ernst 11 YoGoKo 12 February 22, 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-19.txt 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 August 26, 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 . . . . . . . . . . . . . 8 74 4.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 8 75 4.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 8 76 4.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 9 77 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 78 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 79 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 80 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 81 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 82 9.1. Normative References . . . . . . . . . . . . . . . . . . 11 83 9.2. Informative References . . . . . . . . . . . . . . . . . 14 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. The OCB mode requires 165 transmission of QoS data frames (IEEE Std 802.11e), half-clocked 166 operation (IEEE Std 802.11j), and use of 5.9 GHz frequency band. 167 Nota: any implementation should comply with standards and regulations 168 set in the different countries for using that frequency band. 170 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 172 The IEEE 802.11-OCB Networks are used for vehicular communications, 173 as 'Wireless Access in Vehicular Environments'. The IP communication 174 scenarios for these environments have been described in several 175 documents; in particular, we refer the reader to 176 [I-D.ietf-ipwave-vehicular-networking-survey], that lists some 177 scenarios and requirements for IP in Intelligent Transportation 178 Systems. 180 The link model is the following: STA --- 802.11-OCB --- STA. In 181 vehicular networks, STAs can be IP-RSUs and/or IP-OBUs. While 182 802.11-OCB is clearly specified, and the use of IPv6 over such link 183 is not radically new, the operating environment (vehicular networks) 184 brings in new perspectives. 186 The mechanisms for forming and terminating, discovering, peering and 187 mobility management for 802.11-OCB links are not described in this 188 document. 190 4. IPv6 over 802.11-OCB 192 4.1. Maximum Transmission Unit (MTU) 194 The default MTU for IP packets on 802.11-OCB MUST be 1500 octets. It 195 is the same value as IPv6 packets on Ethernet links, as specified in 196 [RFC2464]. This value of the MTU respects the recommendation that 197 every link on the Internet must have a minimum MTU of 1280 octets 198 (stated in [RFC8200], and the recommendations therein, especially 199 with respect to fragmentation). 201 4.2. Frame Format 203 IP packets are transmitted over 802.11-OCB as standard Ethernet 204 packets. As with all 802.11 frames, an Ethernet adaptation layer is 205 used with 802.11-OCB as well. This Ethernet Adaptation Layer 206 performing 802.11-to-Ethernet is described in Section 4.2.1. The 207 Ethernet Type code (EtherType) for IPv6 MUST be 0x86DD (hexadecimal 208 86DD, or otherwise #86DD). 210 The Frame format for transmitting IPv6 on 802.11-OCB networks is the 211 same as transmitting IPv6 on Ethernet networks, and is described in 212 section 3 of [RFC2464]. 214 4.2.1. Ethernet Adaptation Layer 216 An 'adaptation' layer is inserted between a MAC layer and the 217 Networking layer. This is used to transform some parameters between 218 their form expected by the IP stack and the form provided by the MAC 219 layer. 221 An Ethernet Adaptation Layer makes an 802.11 MAC look to IP 222 Networking layer as a more traditional Ethernet layer. At reception, 223 this layer takes as input the IEEE 802.11 Data Header and the 224 Logical-Link Layer Control Header and produces an Ethernet II Header. 225 At sending, the reverse operation is performed. 227 The operation of the Ethernet Adaptation Layer is depicted by the 228 double arrow in Figure 1. 230 +--------------------+------------+-------------+---------+-----------+ 231 | 802.11 Data Header | LLC Header | IPv6 Header | Payload |.11 Trailer| 232 +--------------------+------------+-------------+---------+-----------+ 233 \ / \ / 234 ----------------------------- -------- 235 \---------------------------------------------/ 236 ^ 237 | 238 802.11-to-Ethernet Adaptation Layer 239 | 240 v 241 +---------------------+-------------+---------+ 242 | Ethernet II Header | IPv6 Header | Payload | 243 +---------------------+-------------+---------+ 245 Figure 1: Operation of the Ethernet Adaptation Layer 247 The Receiver and Transmitter Address fields in the 802.11 Data Header 248 MUST contain the same values as the Destination and the Source 249 Address fields in the Ethernet II Header, respectively. The value of 250 the Type field in the LLC Header MUST be the same as the value of the 251 Type field in the Ethernet II Header. 253 The ".11 Trailer" contains solely a 4-byte Frame Check Sequence. 255 In OCB mode, IPv6 packets MAY be transmitted either as "IEEE 802.11 256 Data" or alternatively as "IEEE 802.11 QoS Data", as illustrated in 257 Figure 2. 259 +--------------------+-------------+-------------+---------+-----------+ 260 | 802.11 Data Header | LLC Header | IPv6 Header | Payload |.11 Trailer| 261 +--------------------+-------------+-------------+---------+-----------+ 263 or 265 +--------------------+-------------+-------------+---------+-----------+ 266 | 802.11 QoS Data Hdr| LLC Header | IPv6 Header | Payload |.11 Trailer| 267 +--------------------+-------------+-------------+---------+-----------+ 269 Figure 2: 802.11 Data Header or 802.11 QoS Data Header 271 The distinction between the two formats is given by the value of the 272 field "Subtype" in the Frame Control Field. The value of the field 273 "Subtype" in the 802.11 Data header is 0x0. The value of the field 274 "Subtype" in the 802.11 QoS header is 8. 276 The mapping between qos-related fields in the IPv6 header (e.g. 277 "Traffic Class", "Flow label") and fields in the "802.11 QoS Data 278 Header" (e.g. "QoS Control") are not specified in this document. 279 Guidance for a potential mapping is provided in 280 [I-D.ietf-tsvwg-ieee-802-11], although it is not specific to OCB 281 mode. 283 The placement of IPv6 networking layer on Ethernet Adaptation Layer 284 is illustrated in Figure 3. 286 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 287 | IPv6 | 288 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 289 | Ethernet Adaptation Layer | 290 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 291 | 802.11 MAC | 292 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 293 | 802.11 PHY | 294 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 296 Figure 3: Ethernet Adaptation Layer stacked with other layers 298 (in the above figure, a 802.11 profile is represented; this is used 299 also for 802.11 OCB profile.) 301 Other alternative views of layering are EtherType Protocol 302 Discrimination (EPD), see Appendix E, and SNAP see [RFC1042]. 304 4.3. Link-Local Addresses 306 The link-local address of an 802.11-OCB interface is formed in the 307 same manner as on an Ethernet interface. This manner is described in 308 section 5 of [RFC2464]. Additionally, if stable identifiers are 309 needed, it is RECOMMENDED to follow the Recommendation on Stable IPv6 310 Interface Identifiers [RFC8064]. Additionally, if semantically 311 opaque Interface Identifiers are needed, a potential method for 312 generating semantically opaque Interface Identifiers with IPv6 313 Stateless Address Autoconfiguration is given in [RFC7217]. 315 4.4. Address Mapping 317 Unicast and multicast address mapping MUST follow the procedures 318 specified for Ethernet interfaces in sections 6 and 7 of [RFC2464]. 320 4.4.1. Address Mapping -- Unicast 322 The procedure for mapping IPv6 unicast addresses into Ethernet link- 323 layer addresses is described in [RFC4861]. 325 4.4.2. Address Mapping -- Multicast 327 The multicast address mapping is performed according to the method 328 specified in section 7 of [RFC2464]. The meaning of the value "3333" 329 mentioned in that section 7 of [RFC2464] is defined in section 2.3.1 330 of [RFC7042]. 332 Transmitting IPv6 packets to multicast destinations over 802.11 links 333 proved to have some performance issues 334 [I-D.perkins-intarea-multicast-ieee802]. These issues may be 335 exacerbated in OCB mode. Solutions for these problems should 336 consider the OCB mode of operation. 338 4.5. Stateless Autoconfiguration 340 The Interface Identifier for an 802.11-OCB interface is formed using 341 the same rules as the Interface Identifier for an Ethernet interface; 342 this is described in section 4 of [RFC2464]. No changes are needed, 343 but some care must be taken when considering the use of the Stateless 344 Address Auto-Configuration procedure. 346 The bits in the interface identifier have no generic meaning and the 347 identifier should be treated as an opaque value. The bits 348 'Universal' and 'Group' in the identifier of an 802.11-OCB interface 349 are significant, as this is an IEEE link-layer address. The details 350 of this significance are described in [RFC7136]. 352 As with all Ethernet and 802.11 interface identifiers ([RFC7721]), 353 the identifier of an 802.11-OCB interface may involve privacy, MAC 354 address spoofing and IP address hijacking risks. A vehicle embarking 355 an OBU or an IP-OBU whose egress interface is 802.11-OCB may expose 356 itself to eavesdropping and subsequent correlation of data; this may 357 reveal data considered private by the vehicle owner; there is a risk 358 of being tracked; see the privacy considerations described in 359 Appendix F. 361 If stable Interface Identifiers are needed in order to form IPv6 362 addresses on 802.11-OCB links, it is recommended to follow the 363 recommendation in [RFC8064]. Additionally, if semantically opaque 364 Interface Identifiers are needed, a potential method for generating 365 semantically opaque Interface Identifiers with IPv6 Stateless Address 366 Autoconfiguration is given in [RFC7217]. 368 4.6. Subnet Structure 370 A subnet is formed by the external 802.11-OCB interfaces of vehicles 371 that are in close range (not their on-board interfaces). This 372 ephemeral subnet structure is strongly influenced by the mobility of 373 vehicles: the 802.11 hidden node effects appear. On another hand, 374 the structure of the internal subnets in each car is relatively 375 stable. 377 The 802.11 networks in OCB mode may be considered as 'ad-hoc' 378 networks. The addressing model for such networks is described in 379 [RFC5889]. 381 The operation of the Neighbor Discovery protocol (ND) over 802.11 OCB 382 links is different than over 802.11 links. In OCB, the link layer 383 does not ensure that all associated members receive all messages, 384 because there is no association operation. The operation of ND over 385 802.11 OCB is not specified in this document. 387 The operation of the Mobile IPv6 protocol over 802.11 OCB links is 388 different than on other links. The Movement Detection operation 389 (section 11.5.1 of [RFC6275]) can not rely on Neighbor Unreachability 390 Detection operation of the Neighbor Discovery protocol, for the 391 reason mentioned in the previous paragraph. Also, the 802.11 OCB 392 link layer is not a lower layer that can provide an indication that a 393 link layer handover has occured. The operation of the Mobile IPv6 394 protocol over 802.11 OCB is not specified in this document. 396 5. Security Considerations 398 Any security mechanism at the IP layer or above that may be carried 399 out for the general case of IPv6 may also be carried out for IPv6 400 operating over 802.11-OCB. 402 The OCB operation is stripped off of all existing 802.11 link-layer 403 security mechanisms. There is no encryption applied below the 404 network layer running on 802.11-OCB. At application layer, the IEEE 405 1609.2 document [IEEE-1609.2] does provide security services for 406 certain applications to use; application-layer mechanisms are out-of- 407 scope of this document. On another hand, a security mechanism 408 provided at networking layer, such as IPsec [RFC4301], may provide 409 data security protection to a wider range of applications. 411 802.11-OCB does not provide any cryptographic protection, because it 412 operates outside the context of a BSS (no Association Request/ 413 Response, no Challenge messages). Any attacker can therefore just 414 sit in the near range of vehicles, sniff the network (just set the 415 interface card's frequency to the proper range) and perform attacks 416 without needing to physically break any wall. Such a link is less 417 protected than commonly used links (wired link or protected 802.11). 419 The potential attack vectors are: MAC address spoofing, IP address 420 and session hijacking and privacy violation. 422 Within the IPsec Security Architecture [RFC4301], the IPsec AH and 423 ESP headers [RFC4302] and [RFC4303] respectively, its multicast 424 extensions [RFC5374], HTTPS [RFC2818] and SeND [RFC3971] protocols 425 can be used to protect communications. Further, the assistance of 426 proper Public Key Infrastructure (PKI) protocols [RFC4210] is 427 necessary to establish credentials. More IETF protocols are 428 available in the toolbox of the IP security protocol designer. 429 Certain ETSI protocols related to security protocols in Intelligent 430 Transportation Systems are described in [ETSI-sec-archi]. 432 As with all Ethernet and 802.11 interface identifiers, there may 433 exist privacy risks in the use of 802.11-OCB interface identifiers. 434 Moreover, in outdoors vehicular settings, the privacy risks are more 435 important than in indoors settings. New risks are induced by the 436 possibility of attacker sniffers deployed along routes which listen 437 for IP packets of vehicles passing by. For this reason, in the 438 802.11-OCB deployments, there is a strong necessity to use protection 439 tools such as dynamically changing MAC addresses. This may help 440 mitigate privacy risks to a certain level. On another hand, it may 441 have an impact in the way typical IPv6 address auto-configuration is 442 performed for vehicles (SLAAC would rely on MAC addresses and would 443 hence dynamically change the affected IP address), in the way the 444 IPv6 Privacy addresses were used, and other effects. 446 6. IANA Considerations 448 No request to IANA. 450 7. Contributors 452 Christian Huitema, Tony Li. 454 Romain Kuntz contributed extensively about IPv6 handovers between 455 links running outside the context of a BSS (802.11-OCB links). 457 Tim Leinmueller contributed the idea of the use of IPv6 over 458 802.11-OCB for distribution of certificates. 460 Marios Makassikis, Jose Santa Lozano, Albin Severinson and Alexey 461 Voronov provided significant feedback on the experience of using IP 462 messages over 802.11-OCB in initial trials. 464 Michelle Wetterwald contributed extensively the MTU discussion, 465 offered the ETSI ITS perspective, and reviewed other parts of the 466 document. 468 8. Acknowledgements 470 The authors would like to thank Witold Klaudel, Ryuji Wakikawa, 471 Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan 472 Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray 473 Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan, 474 Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne, 475 Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark, 476 Bob Moskowitz, Andrew (Dryden?), Georg Mayer, Dorothy Stanley, Sandra 477 Cespedes, Mariano Falcitelli, Sri Gundavelli, Abdussalam Baryun, 478 Margaret Cullen, Erik Kline, Carlos Jesus Bernardos Cano and William 479 Whyte. Their valuable comments clarified particular issues and 480 generally helped to improve the document. 482 Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB 483 drivers for linux and described how. 485 For the multicast discussion, the authors would like to thank Owen 486 DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and 487 participants to discussions in network working groups. 489 The authors would like to thank participants to the Birds-of- 490 a-Feather "Intelligent Transportation Systems" meetings held at IETF 491 in 2016. 493 9. References 495 9.1. Normative References 497 [RFC1042] Postel, J. and J. Reynolds, "Standard for the transmission 498 of IP datagrams over IEEE 802 networks", STD 43, RFC 1042, 499 DOI 10.17487/RFC1042, February 1988, 500 . 502 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 503 Requirement Levels", BCP 14, RFC 2119, 504 DOI 10.17487/RFC2119, March 1997, 505 . 507 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 508 Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, 509 . 511 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, 512 DOI 10.17487/RFC2818, May 2000, 513 . 515 [RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related 516 Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004, 517 . 519 [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, 520 "SEcure Neighbor Discovery (SEND)", RFC 3971, 521 DOI 10.17487/RFC3971, March 2005, 522 . 524 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 525 "Randomness Requirements for Security", BCP 106, RFC 4086, 526 DOI 10.17487/RFC4086, June 2005, 527 . 529 [RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen, 530 "Internet X.509 Public Key Infrastructure Certificate 531 Management Protocol (CMP)", RFC 4210, 532 DOI 10.17487/RFC4210, September 2005, 533 . 535 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 536 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 537 December 2005, . 539 [RFC4302] Kent, S., "IP Authentication Header", RFC 4302, 540 DOI 10.17487/RFC4302, December 2005, 541 . 543 [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", 544 RFC 4303, DOI 10.17487/RFC4303, December 2005, 545 . 547 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 548 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 549 DOI 10.17487/RFC4861, September 2007, 550 . 552 [RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast 553 Extensions to the Security Architecture for the Internet 554 Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008, 555 . 557 [RFC5415] Calhoun, P., Ed., Montemurro, M., Ed., and D. Stanley, 558 Ed., "Control And Provisioning of Wireless Access Points 559 (CAPWAP) Protocol Specification", RFC 5415, 560 DOI 10.17487/RFC5415, March 2009, 561 . 563 [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing 564 Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, 565 September 2010, . 567 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 568 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 569 2011, . 571 [RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and 572 IETF Protocol and Documentation Usage for IEEE 802 573 Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042, 574 October 2013, . 576 [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 577 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, 578 February 2014, . 580 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 581 Interface Identifiers with IPv6 Stateless Address 582 Autoconfiguration (SLAAC)", RFC 7217, 583 DOI 10.17487/RFC7217, April 2014, 584 . 586 [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy 587 Considerations for IPv6 Address Generation Mechanisms", 588 RFC 7721, DOI 10.17487/RFC7721, March 2016, 589 . 591 [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu, 592 "Recommendation on Stable IPv6 Interface Identifiers", 593 RFC 8064, DOI 10.17487/RFC8064, February 2017, 594 . 596 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 597 (IPv6) Specification", STD 86, RFC 8200, 598 DOI 10.17487/RFC8200, July 2017, 599 . 601 9.2. Informative References 603 [ETSI-sec-archi] 604 "ETSI TS 102 940 V1.2.1 (2016-11), ETSI Technical 605 Specification, Intelligent Transport Systems (ITS); 606 Security; ITS communications security architecture and 607 security management, November 2016. Downloaded on 608 September 9th, 2017, freely available from ETSI website at 609 URL http://www.etsi.org/deliver/ 610 etsi_ts/102900_102999/102940/01.02.01_60/ 611 ts_102940v010201p.pdf". 613 [I-D.hinden-6man-rfc2464bis] 614 Crawford, M. and R. Hinden, "Transmission of IPv6 Packets 615 over Ethernet Networks", draft-hinden-6man-rfc2464bis-02 616 (work in progress), March 2017. 618 [I-D.ietf-ipwave-vehicular-networking-survey] 619 Jeong, J., Cespedes, S., Benamar, N., Haerri, J., and M. 620 Wetterwald, "Survey on IP-based Vehicular Networking for 621 Intelligent Transportation Systems", draft-ietf-ipwave- 622 vehicular-networking-survey-00 (work in progress), July 623 2017. 625 [I-D.ietf-tsvwg-ieee-802-11] 626 Szigeti, T., Henry, J., and F. Baker, "Diffserv to IEEE 627 802.11 Mapping", draft-ietf-tsvwg-ieee-802-11-11 (work in 628 progress), December 2017. 630 [I-D.perkins-intarea-multicast-ieee802] 631 Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, 632 "Multicast Considerations over IEEE 802 Wireless Media", 633 draft-perkins-intarea-multicast-ieee802-03 (work in 634 progress), July 2017. 636 [IEEE-1609.2] 637 "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access 638 in Vehicular Environments (WAVE) -- Security Services for 639 Applications and Management Messages. Example URL 640 http://ieeexplore.ieee.org/document/7426684/ accessed on 641 August 17th, 2017.". 643 [IEEE-1609.3] 644 "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access 645 in Vehicular Environments (WAVE) -- Networking Services. 646 Example URL http://ieeexplore.ieee.org/document/7458115/ 647 accessed on August 17th, 2017.". 649 [IEEE-1609.4] 650 "IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access 651 in Vehicular Environments (WAVE) -- Multi-Channel 652 Operation. Example URL 653 http://ieeexplore.ieee.org/document/7435228/ accessed on 654 August 17th, 2017.". 656 [IEEE-802.11-2016] 657 "IEEE Standard 802.11-2016 - IEEE Standard for Information 658 Technology - Telecommunications and information exchange 659 between systems Local and metropolitan area networks - 660 Specific requirements - Part 11: Wireless LAN Medium 661 Access Control (MAC) and Physical Layer (PHY) 662 Specifications. Status - Active Standard. Description 663 retrieved freely on September 12th, 2017, at URL 664 https://standards.ieee.org/findstds/ 665 standard/802.11-2016.html". 667 [IEEE-802.11p-2010] 668 "IEEE Std 802.11p (TM)-2010, IEEE Standard for Information 669 Technology - Telecommunications and information exchange 670 between systems - Local and metropolitan area networks - 671 Specific requirements, Part 11: Wireless LAN Medium Access 672 Control (MAC) and Physical Layer (PHY) Specifications, 673 Amendment 6: Wireless Access in Vehicular Environments; 674 document freely available at URL 675 http://standards.ieee.org/getieee802/ 676 download/802.11p-2010.pdf retrieved on September 20th, 677 2013.". 679 Appendix A. ChangeLog 681 The changes are listed in reverse chronological order, most recent 682 changes appearing at the top of the list. 684 From draft-ietf-ipwave-ipv6-over-80211ocb-18 to draft-ietf-ipwave- 685 ipv6-over-80211ocb-19 687 o Removed the text about fragmentation. 689 o Removed the mentioning of WSMP and GeoNetworking. 691 o Removed the explanation of the binary representation of the 692 EtherType. 694 o Rendered normative the paragraph about unicast and multicast 695 address mapping. 697 o Removed paragraph about addressing model, subnet structure and 698 easiness of using LLs. 700 o Clarified the Type/Subtype field in the 802.11 Header. 702 o Used RECOMMENDED instead of recommended, for the stable interface 703 identifiers. 705 From draft-ietf-ipwave-ipv6-over-80211ocb-17 to draft-ietf-ipwave- 706 ipv6-over-80211ocb-18 708 o Improved the MTU and fragmentation paragraph. 710 From draft-ietf-ipwave-ipv6-over-80211ocb-16 to draft-ietf-ipwave- 711 ipv6-over-80211ocb-17 713 o Susbtituted "MUST be increased" to "is increased" in the MTU 714 section, about fragmentation. 716 From draft-ietf-ipwave-ipv6-over-80211ocb-15 to draft-ietf-ipwave- 717 ipv6-over-80211ocb-16 719 o Removed the definition of the 'WiFi' term and its occurences. 720 Clarified a phrase that used it in Appendix C "Aspects introduced 721 by the OCB mode to 802.11". 723 o Added more normative words: MUST be 0x86DD, MUST fragment if size 724 larger than MTU, Sequence number in 802.11 Data header MUST be 725 increased. 727 From draft-ietf-ipwave-ipv6-over-80211ocb-14 to draft-ietf-ipwave- 728 ipv6-over-80211ocb-15 730 o Added normative term MUST in two places in section "Ethernet 731 Adaptation Layer". 733 From draft-ietf-ipwave-ipv6-over-80211ocb-13 to draft-ietf-ipwave- 734 ipv6-over-80211ocb-14 736 o Created a new Appendix titled "Extra Terminology" that contains 737 terms DSRC, DSRCS, OBU, RSU as defined outside IETF. Some of them 738 are used in the main Terminology section. 740 o Added two paragraphs explaining that ND and Mobile IPv6 have 741 problems working over 802.11 OCB, yet their adaptations is not 742 specified in this document. 744 From draft-ietf-ipwave-ipv6-over-80211ocb-12 to draft-ietf-ipwave- 745 ipv6-over-80211ocb-13 747 o Substituted "IP-OBU" for "OBRU", and "IP-RSU" for "RSRU" 748 throughout and improved OBU-related definitions in the Terminology 749 section. 751 From draft-ietf-ipwave-ipv6-over-80211ocb-11 to draft-ietf-ipwave- 752 ipv6-over-80211ocb-12 754 o Improved the appendix about "MAC Address Generation" by expressing 755 the technique to be an optional suggestion, not a mandatory 756 mechanism. 758 From draft-ietf-ipwave-ipv6-over-80211ocb-10 to draft-ietf-ipwave- 759 ipv6-over-80211ocb-11 761 o Shortened the paragraph on forming/terminating 802.11-OCB links. 763 o Moved the draft tsvwg-ieee-802-11 to Informative References. 765 From draft-ietf-ipwave-ipv6-over-80211ocb-09 to draft-ietf-ipwave- 766 ipv6-over-80211ocb-10 768 o Removed text requesting a new Group ID for multicast for OCB. 770 o Added a clarification of the meaning of value "3333" in the 771 section Address Mapping -- Multicast. 773 o Added note clarifying that in Europe the regional authority is not 774 ETSI, but "ECC/CEPT based on ENs from ETSI". 776 o Added note stating that the manner in which two STAtions set their 777 communication channel is not described in this document. 779 o Added a time qualifier to state that the "each node is represented 780 uniquely at a certain point in time." 782 o Removed text "This section may need to be moved" (the "Reliability 783 Requirements" section). This section stays there at this time. 785 o In the term definition "802.11-OCB" added a note stating that "any 786 implementation should comply with standards and regulations set in 787 the different countries for using that frequency band." 789 o In the RSU term definition, added a sentence explaining the 790 difference between RSU and RSRU: in terms of number of interfaces 791 and IP forwarding. 793 o Replaced "with at least two IP interfaces" with "with at least two 794 real or virtual IP interfaces". 796 o Added a term in the Terminology for "OBU". However the definition 797 is left empty, as this term is defined outside IETF. 799 o Added a clarification that it is an OBU or an OBRU in this phrase 800 "A vehicle embarking an OBU or an OBRU". 802 o Checked the entire document for a consistent use of terms OBU and 803 OBRU. 805 o Added note saying that "'p' is a letter identifying the 806 Ammendment". 808 o Substituted lower case for capitals SHALL or MUST in the 809 Appendices. 811 o Added reference to RFC7042, helpful in the 3333 explanation. 812 Removed reference to individual submission draft-petrescu-its- 813 scenario-reqs and added reference to draft-ietf-ipwave-vehicular- 814 networking-survey. 816 o Added figure captions, figure numbers, and references to figure 817 numbers instead of 'below'. Replaced "section Section" with 818 "section" throughout. 820 o Minor typographical errors. 822 From draft-ietf-ipwave-ipv6-over-80211ocb-08 to draft-ietf-ipwave- 823 ipv6-over-80211ocb-09 825 o Significantly shortened the Address Mapping sections, by text 826 copied from RFC2464, and rather referring to it. 828 o Moved the EPD description to an Appendix on its own. 830 o Shortened the Introduction and the Abstract. 832 o Moved the tutorial section of OCB mode introduced to .11, into an 833 appendix. 835 o Removed the statement that suggests that for routing purposes a 836 prefix exchange mechanism could be needed. 838 o Removed refs to RFC3963, RFC4429 and RFC6775; these are about ND, 839 MIP/NEMO and oDAD; they were referred in the handover discussion 840 section, which is out. 842 o Updated a reference from individual submission to now a WG item in 843 IPWAVE: the survey document. 845 o Added term definition for WiFi. 847 o Updated the authorship and expanded the Contributors section. 849 o Corrected typographical errors. 851 From draft-ietf-ipwave-ipv6-over-80211ocb-07 to draft-ietf-ipwave- 852 ipv6-over-80211ocb-08 854 o Removed the per-channel IPv6 prohibition text. 856 o Corrected typographical errors. 858 From draft-ietf-ipwave-ipv6-over-80211ocb-06 to draft-ietf-ipwave- 859 ipv6-over-80211ocb-07 861 o Added new terms: OBRU and RSRU ('R' for Router). Refined the 862 existing terms RSU and OBU, which are no longer used throughout 863 the document. 865 o Improved definition of term "802.11-OCB". 867 o Clarified that OCB does not "strip" security, but that the 868 operation in OCB mode is "stripped off of all .11 security". 870 o Clarified that theoretical OCB bandwidth speed is 54mbits, but 871 that a commonly observed bandwidth in IP-over-OCB is 12mbit/s. 873 o Corrected typographical errors, and improved some phrasing. 875 From draft-ietf-ipwave-ipv6-over-80211ocb-05 to draft-ietf-ipwave- 876 ipv6-over-80211ocb-06 878 o Updated references of 802.11-OCB document from -2012 to the IEEE 879 802.11-2016. 881 o In the LL address section, and in SLAAC section, added references 882 to 7217 opaque IIDs and 8064 stable IIDs. 884 From draft-ietf-ipwave-ipv6-over-80211ocb-04 to draft-ietf-ipwave- 885 ipv6-over-80211ocb-05 887 o Lengthened the title and cleanded the abstract. 889 o Added text suggesting LLs may be easy to use on OCB, rather than 890 GUAs based on received prefix. 892 o Added the risks of spoofing and hijacking. 894 o Removed the text speculation on adoption of the TSA message. 896 o Clarified that the ND protocol is used. 898 o Clarified what it means "No association needed". 900 o Added some text about how two STAs discover each other. 902 o Added mention of external (OCB) and internal network (stable), in 903 the subnet structure section. 905 o Added phrase explaining that both .11 Data and .11 QoS Data 906 headers are currently being used, and may be used in the future. 908 o Moved the packet capture example into an Appendix Implementation 909 Status. 911 o Suggested moving the reliability requirements appendix out into 912 another document. 914 o Added a IANA Consiserations section, with content, requesting for 915 a new multicast group "all OCB interfaces". 917 o Added new OBU term, improved the RSU term definition, removed the 918 ETTC term, replaced more occurences of 802.11p, 802.11 OCB with 919 802.11-OCB. 921 o References: 923 * Added an informational reference to ETSI's IPv6-over- 924 GeoNetworking. 926 * Added more references to IETF and ETSI security protocols. 928 * Updated some references from I-D to RFC, and from old RFC to 929 new RFC numbers. 931 * Added reference to multicast extensions to IPsec architecture 932 RFC. 934 * Added a reference to 2464-bis. 936 * Removed FCC informative references, because not used. 938 o Updated the affiliation of one author. 940 o Reformulation of some phrases for better readability, and 941 correction of typographical errors. 943 From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave- 944 ipv6-over-80211ocb-04 946 o Removed a few informative references pointing to Dx draft IEEE 947 1609 documents. 949 o Removed outdated informative references to ETSI documents. 951 o Added citations to IEEE 1609.2, .3 and .4-2016. 953 o Minor textual issues. 955 From draft-ietf-ipwave-ipv6-over-80211ocb-02 to draft-ietf-ipwave- 956 ipv6-over-80211ocb-03 958 o Keep the previous text on multiple addresses, so remove talk about 959 MIP6, NEMOv6 and MCoA. 961 o Clarified that a 'Beacon' is an IEEE 802.11 frame Beacon. 963 o Clarified the figure showing Infrastructure mode and OCB mode side 964 by side. 966 o Added a reference to the IP Security Architecture RFC. 968 o Detailed the IPv6-per-channel prohibition paragraph which reflects 969 the discussion at the last IETF IPWAVE WG meeting. 971 o Added section "Address Mapping -- Unicast". 973 o Added the ".11 Trailer" to pictures of 802.11 frames. 975 o Added text about SNAP carrying the Ethertype. 977 o New RSU definition allowing for it be both a Router and not 978 necessarily a Router some times. 980 o Minor textual issues. 982 From draft-ietf-ipwave-ipv6-over-80211ocb-01 to draft-ietf-ipwave- 983 ipv6-over-80211ocb-02 984 o Replaced almost all occurences of 802.11p with 802.11-OCB, leaving 985 only when explanation of evolution was necessary. 987 o Shortened by removing parameter details from a paragraph in the 988 Introduction. 990 o Moved a reference from Normative to Informative. 992 o Added text in intro clarifying there is no handover spec at IEEE, 993 and that 1609.2 does provide security services. 995 o Named the contents the fields of the EthernetII header (including 996 the Ethertype bitstring). 998 o Improved relationship between two paragraphs describing the 999 increase of the Sequence Number in 802.11 header upon IP 1000 fragmentation. 1002 o Added brief clarification of "tracking". 1004 From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave- 1005 ipv6-over-80211ocb-01 1007 o Introduced message exchange diagram illustrating differences 1008 between 802.11 and 802.11 in OCB mode. 1010 o Introduced an appendix listing for information the set of 802.11 1011 messages that may be transmitted in OCB mode. 1013 o Removed appendix sections "Privacy Requirements", "Authentication 1014 Requirements" and "Security Certificate Generation". 1016 o Removed appendix section "Non IP Communications". 1018 o Introductory phrase in the Security Considerations section. 1020 o Improved the definition of "OCB". 1022 o Introduced theoretical stacked layers about IPv6 and IEEE layers 1023 including EPD. 1025 o Removed the appendix describing the details of prohibiting IPv6 on 1026 certain channels relevant to 802.11-OCB. 1028 o Added a brief reference in the privacy text about a precise clause 1029 in IEEE 1609.3 and .4. 1031 o Clarified the definition of a Road Side Unit. 1033 o Removed the discussion about security of WSA (because is non-IP). 1035 o Removed mentioning of the GeoNetworking discussion. 1037 o Moved references to scientific articles to a separate 'overview' 1038 draft, and referred to it. 1040 Appendix B. 802.11p 1042 The term "802.11p" is an earlier definition. The behaviour of 1043 "802.11p" networks is rolled in the document IEEE Std 802.11-2016. 1044 In that document the term 802.11p disappears. Instead, each 802.11p 1045 feature is conditioned by the Management Information Base (MIB) 1046 attribute "OCBActivated". Whenever OCBActivated is set to true the 1047 IEEE Std 802.11 OCB state is activated. For example, an 802.11 1048 STAtion operating outside the context of a basic service set has the 1049 OCBActivated flag set. Such a station, when it has the flag set, 1050 uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. 1052 Appendix C. Aspects introduced by the OCB mode to 802.11 1054 In the IEEE 802.11-OCB mode, all nodes in the wireless range can 1055 directly communicate with each other without involving authentication 1056 or association procedures. At link layer, it is necessary to set the 1057 same channel number (or frequency) on two stations that need to 1058 communicate with each other. The manner in which stations set their 1059 channel number is not specified in this document. Stations STA1 and 1060 STA2 can exchange IP packets if they are set on the same channel. At 1061 IP layer, they then discover each other by using the IPv6 Neighbor 1062 Discovery protocol. 1064 Briefly, the IEEE 802.11-OCB mode has the following properties: 1066 o The use by each node of a 'wildcard' BSSID (i.e., each bit of the 1067 BSSID is set to 1) 1069 o No IEEE 802.11 Beacon frames are transmitted 1071 o No authentication is required in order to be able to communicate 1073 o No association is needed in order to be able to communicate 1075 o No encryption is provided in order to be able to communicate 1077 o Flag dot11OCBActivated is set to true 1079 All the nodes in the radio communication range (IP-OBU and IP-RSU) 1080 receive all the messages transmitted (IP-OBU and IP-RSU) within the 1081 radio communications range. The eventual conflict(s) are resolved by 1082 the MAC CDMA function. 1084 The message exchange diagram in Figure 4 illustrates a comparison 1085 between traditional 802.11 and 802.11 in OCB mode. The 'Data' 1086 messages can be IP packets such as HTTP or others. Other 802.11 1087 management and control frames (non IP) may be transmitted, as 1088 specified in the 802.11 standard. For information, the names of 1089 these messages as currently specified by the 802.11 standard are 1090 listed in Appendix G. 1092 STA AP STA1 STA2 1093 | | | | 1094 |<------ Beacon -------| |<------ Data -------->| 1095 | | | | 1096 |---- Probe Req. ----->| |<------ Data -------->| 1097 |<--- Probe Res. ------| | | 1098 | | |<------ Data -------->| 1099 |---- Auth Req. ------>| | | 1100 |<--- Auth Res. -------| |<------ Data -------->| 1101 | | | | 1102 |---- Asso Req. ------>| |<------ Data -------->| 1103 |<--- Asso Res. -------| | | 1104 | | |<------ Data -------->| 1105 |<------ Data -------->| | | 1106 |<------ Data -------->| |<------ Data -------->| 1108 (i) 802.11 Infrastructure mode (ii) 802.11-OCB mode 1110 Figure 4: Difference between messages exchanged on 802.11 (left) and 1111 802.11-OCB (right) 1113 The interface 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010 1114 [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, 1115 titled "Amendment 6: Wireless Access in Vehicular Environments". 1116 Since then, this amendment has been integrated in IEEE 802.11(TM) 1117 -2012 and -2016 [IEEE-802.11-2016]. 1119 In document 802.11-2016, anything qualified specifically as 1120 "OCBActivated", or "outside the context of a basic service" set to be 1121 true, then it is actually referring to OCB aspects introduced to 1122 802.11. 1124 In order to delineate the aspects introduced by 802.11-OCB to 802.11, 1125 we refer to the earlier [IEEE-802.11p-2010]. The amendment is 1126 concerned with vehicular communications, where the wireless link is 1127 similar to that of Wireless LAN (using a PHY layer specified by 1128 802.11a/b/g/n), but which needs to cope with the high mobility factor 1129 inherent in scenarios of communications between moving vehicles, and 1130 between vehicles and fixed infrastructure deployed along roads. 1131 While 'p' is a letter identifying the Ammendment, just like 'a, b, g' 1132 and 'n' are, 'p' is concerned more with MAC modifications, and a 1133 little with PHY modifications; the others are mainly about PHY 1134 modifications. It is possible in practice to combine a 'p' MAC with 1135 an 'a' PHY by operating outside the context of a BSS with OFDM at 1136 5.4GHz and 5.9GHz. 1138 The 802.11-OCB links are specified to be compatible as much as 1139 possible with the behaviour of 802.11a/b/g/n and future generation 1140 IEEE WLAN links. From the IP perspective, an 802.11-OCB MAC layer 1141 offers practically the same interface to IP as the 802.11a/b/g/n and 1142 802.3. A packet sent by an IP-OBU may be received by one or multiple 1143 IP-RSUs. The link-layer resolution is performed by using the IPv6 1144 Neighbor Discovery protocol. 1146 To support this similarity statement (IPv6 is layered on top of LLC 1147 on top of 802.11-OCB, in the same way that IPv6 is layered on top of 1148 LLC on top of 802.11a/b/g/n (for WLAN) or layered on top of LLC on 1149 top of 802.3 (for Ethernet)) it is useful to analyze the differences 1150 between 802.11-OCB and 802.11 specifications. During this analysis, 1151 we note that whereas 802.11-OCB lists relatively complex and numerous 1152 changes to the MAC layer (and very little to the PHY layer), there 1153 are only a few characteristics which may be important for an 1154 implementation transmitting IPv6 packets on 802.11-OCB links. 1156 The most important 802.11-OCB point which influences the IPv6 1157 functioning is the OCB characteristic; an additional, less direct 1158 influence, is the maximum bandwidth afforded by the PHY modulation/ 1159 demodulation methods and channel access specified by 802.11-OCB. The 1160 maximum bandwidth theoretically possible in 802.11-OCB is 54 Mbit/s 1161 (when using, for example, the following parameters: 20 MHz channel; 1162 modulation 64-QAM; coding rate R is 3/4); in practice of IP-over- 1163 802.11-OCB a commonly observed figure is 12Mbit/s; this bandwidth 1164 allows the operation of a wide range of protocols relying on IPv6. 1166 o Operation Outside the Context of a BSS (OCB): the (earlier 1167 802.11p) 802.11-OCB links are operated without a Basic Service Set 1168 (BSS). This means that the frames IEEE 802.11 Beacon, Association 1169 Request/Response, Authentication Request/Response, and similar, 1170 are not used. The used identifier of BSS (BSSID) has a 1171 hexadecimal value always 0xffffffffffff (48 '1' bits, represented 1172 as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' 1173 BSSID), as opposed to an arbitrary BSSID value set by 1174 administrator (e.g. 'My-Home-AccessPoint'). The OCB operation - 1175 namely the lack of beacon-based scanning and lack of 1176 authentication - should be taken into account when the Mobile IPv6 1177 protocol [RFC6275] and the protocols for IP layer security 1178 [RFC4301] are used. The way these protocols adapt to OCB is not 1179 described in this document. 1181 o Timing Advertisement: is a new message defined in 802.11-OCB, 1182 which does not exist in 802.11a/b/g/n. This message is used by 1183 stations to inform other stations about the value of time. It is 1184 similar to the time as delivered by a GNSS system (Galileo, GPS, 1185 ...) or by a cellular system. This message is optional for 1186 implementation. 1188 o Frequency range: this is a characteristic of the PHY layer, with 1189 almost no impact on the interface between MAC and IP. However, it 1190 is worth considering that the frequency range is regulated by a 1191 regional authority (ARCEP, ECC/CEPT based on ENs from ETSI, FCC, 1192 etc.); as part of the regulation process, specific applications 1193 are associated with specific frequency ranges. In the case of 1194 802.11-OCB, the regulator associates a set of frequency ranges, or 1195 slots within a band, to the use of applications of vehicular 1196 communications, in a band known as "5.9GHz". The 5.9GHz band is 1197 different from the 2.4GHz and 5GHz bands used by Wireless LAN. 1198 However, as with Wireless LAN, the operation of 802.11-OCB in 1199 "5.9GHz" bands is exempt from owning a license in EU (in US the 1200 5.9GHz is a licensed band of spectrum; for the fixed 1201 infrastructure an explicit FCC authorization is required; for an 1202 on-board device a 'licensed-by-rule' concept applies: rule 1203 certification conformity is required.) Technical conditions are 1204 different than those of the bands "2.4GHz" or "5GHz". The allowed 1205 power levels, and implicitly the maximum allowed distance between 1206 vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20 1207 dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum 1208 distance of approximately 1km, compared to approximately 50m. 1209 Additionally, specific conditions related to congestion avoidance, 1210 jamming avoidance, and radar detection are imposed on the use of 1211 DSRC (in US) and on the use of frequencies for Intelligent 1212 Transportation Systems (in EU), compared to Wireless LAN 1213 (802.11a/b/g/n). 1215 o 'Half-rate' encoding: as the frequency range, this parameter is 1216 related to PHY, and thus has not much impact on the interface 1217 between the IP layer and the MAC layer. 1219 o In vehicular communications using 802.11-OCB links, there are 1220 strong privacy requirements with respect to addressing. While the 1221 802.11-OCB standard does not specify anything in particular with 1222 respect to MAC addresses, in these settings there exists a strong 1223 need for dynamic change of these addresses (as opposed to the non- 1224 vehicular settings - real wall protection - where fixed MAC 1225 addresses do not currently pose some privacy risks). This is 1226 further described in Section 5. A relevant function is described 1227 in IEEE 1609.3-2016 [IEEE-1609.3], clause 5.5.1 and IEEE 1228 1609.4-2016 [IEEE-1609.4], clause 6.7. 1230 Other aspects particular to 802.11-OCB, which are also particular to 1231 802.11 (e.g. the 'hidden node' operation), may have an influence on 1232 the use of transmission of IPv6 packets on 802.11-OCB networks. The 1233 OCB subnet structure is described in Section 4.6. 1235 Appendix D. Changes Needed on a software driver 802.11a to become a 1236 802.11-OCB driver 1238 The 802.11p amendment modifies both the 802.11 stack's physical and 1239 MAC layers but all the induced modifications can be quite easily 1240 obtained by modifying an existing 802.11a ad-hoc stack. 1242 Conditions for a 802.11a hardware to be 802.11-OCB compliant: 1244 o The PHY entity shall be an orthogonal frequency division 1245 multiplexing (OFDM) system. It must support the frequency bands 1246 on which the regulator recommends the use of ITS communications, 1247 for example using IEEE 802.11-OCB layer, in France: 5875MHz to 1248 5925MHz. 1250 o The OFDM system must provide a "half-clocked" operation using 10 1251 MHz channel spacings. 1253 o The chip transmit spectrum mask must be compliant to the "Transmit 1254 spectrum mask" from the IEEE 802.11p amendment (but experimental 1255 environments tolerate otherwise). 1257 o The chip should be able to transmit up to 44.8 dBm when used by 1258 the US government in the United States, and up to 33 dBm in 1259 Europe; other regional conditions apply. 1261 Changes needed on the network stack in OCB mode: 1263 o Physical layer: 1265 * The chip must use the Orthogonal Frequency Multiple Access 1266 (OFDM) encoding mode. 1268 * The chip must be set in half-mode rate mode (the internal clock 1269 frequency is divided by two). 1271 * The chip must use dedicated channels and should allow the use 1272 of higher emission powers. This may require modifications to 1273 the local computer file that describes regulatory domains 1274 rules, if used by the kernel to enforce local specific 1275 restrictions. Such modifications to the local computer file 1276 must respect the location-specific regulatory rules. 1278 MAC layer: 1280 * All management frames (beacons, join, leave, and others) 1281 emission and reception must be disabled except for frames of 1282 subtype Action and Timing Advertisement (defined below). 1284 * No encryption key or method must be used. 1286 * Packet emission and reception must be performed as in ad-hoc 1287 mode, using the wildcard BSSID (ff:ff:ff:ff:ff:ff). 1289 * The functions related to joining a BSS (Association Request/ 1290 Response) and for authentication (Authentication Request/Reply, 1291 Challenge) are not called. 1293 * The beacon interval is always set to 0 (zero). 1295 * Timing Advertisement frames, defined in the amendment, should 1296 be supported. The upper layer should be able to trigger such 1297 frames emission and to retrieve information contained in 1298 received Timing Advertisements. 1300 Appendix E. EtherType Protocol Discrimination (EPD) 1302 A more theoretical and detailed view of layer stacking, and 1303 interfaces between the IP layer and 802.11-OCB layers, is illustrated 1304 in Figure 5. The IP layer operates on top of the EtherType Protocol 1305 Discrimination (EPD); this Discrimination layer is described in IEEE 1306 Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP 1307 (Link Layer Control Service Access Point). 1309 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1310 | IPv6 | 1311 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ 1312 { LLC_SAP } 802.11-OCB 1313 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary 1314 | EPD | | | 1315 | | MLME | | 1316 +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | 1317 | MAC Sublayer | | | 802.11-OCB 1318 | and ch. coord. | | SME | Services 1319 +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | 1320 | | PLME | | 1321 | PHY Layer | PLME_SAP | 1322 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1324 Figure 5: EtherType Protocol Discrimination 1326 Appendix F. Design Considerations 1328 The networks defined by 802.11-OCB are in many ways similar to other 1329 networks of the 802.11 family. In theory, the encapsulation of IPv6 1330 over 802.11-OCB could be very similar to the operation of IPv6 over 1331 other networks of the 802.11 family. However, the high mobility, 1332 strong link asymmetry and very short connection makes the 802.11-OCB 1333 link significantly different from other 802.11 networks. Also, the 1334 automotive applications have specific requirements for reliability, 1335 security and privacy, which further add to the particularity of the 1336 802.11-OCB link. 1338 F.1. Vehicle ID 1340 In automotive networks it is required that each node is represented 1341 uniquely at a certain point in time. Accordingly, a vehicle must be 1342 identified by at least one unique identifier. The current 1343 specification at ETSI and at IEEE 1609 identifies a vehicle by its 1344 MAC address, which is obtained from the 802.11-OCB Network Interface 1345 Card (NIC). 1347 In case multiple 802.11-OCB NICs are present in one car, implicitely 1348 multiple vehicle IDs will be generated. Additionally, some software 1349 generates a random MAC address each time the computer boots; this 1350 constitutes an additional difficulty. 1352 A mechanim to uniquely identify a vehicle irrespectively to the 1353 multiplicity of NICs, or frequent MAC address generation, is 1354 necessary. 1356 F.2. Reliability Requirements 1358 The dynamically changing topology, short connectivity, mobile 1359 transmitter and receivers, different antenna heights, and many-to- 1360 many communication types, make IEEE 802.11-OCB links significantly 1361 different from other IEEE 802.11 links. Any IPv6 mechanism operating 1362 on IEEE 802.11-OCB link must support strong link asymmetry, spatio- 1363 temporal link quality, fast address resolution and transmission. 1365 IEEE 802.11-OCB strongly differs from other 802.11 systems to operate 1366 outside of the context of a Basic Service Set. This means in 1367 practice that IEEE 802.11-OCB does not rely on a Base Station for all 1368 Basic Service Set management. In particular, IEEE 802.11-OCB shall 1369 not use beacons. Any IPv6 mechanism requiring L2 services from IEEE 1370 802.11 beacons must support an alternative service. 1372 Channel scanning being disabled, IPv6 over IEEE 802.11-OCB must 1373 implement a mechanism for transmitter and receiver to converge to a 1374 common channel. 1376 Authentication not being possible, IPv6 over IEEE 802.11-OCB must 1377 implement an distributed mechanism to authenticate transmitters and 1378 receivers without the support of a DHCP server. 1380 Time synchronization not being available, IPv6 over IEEE 802.11-OCB 1381 must implement a higher layer mechanism for time synchronization 1382 between transmitters and receivers without the support of a NTP 1383 server. 1385 The IEEE 802.11-OCB link being asymmetric, IPv6 over IEEE 802.11-OCB 1386 must disable management mechanisms requesting acknowledgements or 1387 replies. 1389 The IEEE 802.11-OCB link having a short duration time, IPv6 over IEEE 1390 802.11-OCB should implement fast IPv6 mobility management mechanisms. 1392 F.3. Multiple interfaces 1394 There are considerations for 2 or more IEEE 802.11-OCB interface 1395 cards per vehicle. For each vehicle taking part in road traffic, one 1396 IEEE 802.11-OCB interface card could be fully allocated for Non IP 1397 safety-critical communication. Any other IEEE 802.11-OCB may be used 1398 for other type of traffic. 1400 The mode of operation of these other wireless interfaces is not 1401 clearly defined yet. One possibility is to consider each card as an 1402 independent network interface, with a specific MAC Address and a set 1403 of IPv6 addresses. Another possibility is to consider the set of 1404 these wireless interfaces as a single network interface (not 1405 including the IEEE 802.11-OCB interface used by Non IP safety 1406 critical communications). This will require specific logic to 1407 ensure, for example, that packets meant for a vehicle in front are 1408 actually sent by the radio in the front, or that multiple copies of 1409 the same packet received by multiple interfaces are treated as a 1410 single packet. Treating each wireless interface as a separate 1411 network interface pushes such issues to the application layer. 1413 Certain privacy requirements imply that if these multiple interfaces 1414 are represented by many network interface, a single renumbering event 1415 shall cause renumbering of all these interfaces. If one MAC changed 1416 and another stayed constant, external observers would be able to 1417 correlate old and new values, and the privacy benefits of 1418 randomization would be lost. 1420 The privacy requirements of Non IP safety-critical communications 1421 imply that if a change of pseudonyme occurs, renumbering of all other 1422 interfaces shall also occur. 1424 F.4. MAC Address Generation 1426 In 802.11-OCB networks, the MAC addresses may change during well 1427 defined renumbering events. A 'randomized' MAC address has the 1428 following characteristics: 1430 o Bit "Local/Global" set to "locally admninistered". 1432 o Bit "Unicast/Multicast" set to "Unicast". 1434 o The 46 remaining bits are set to a random value, using a random 1435 number generator that meets the requirements of [RFC4086]. 1437 To meet the randomization requirements for the 46 remaining bits, a 1438 hash function may be used. For example, the SHA256 hash function may 1439 be used with input a 256 bit local secret, the "nominal" MAC Address 1440 of the interface, and a representation of the date and time of the 1441 renumbering event. 1443 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode 1445 For information, at the time of writing, this is the list of IEEE 1446 802.11 messages that may be transmitted in OCB mode, i.e. when 1447 dot11OCBActivated is true in a STA: 1449 o The STA may send management frames of subtype Action and, if the 1450 STA maintains a TSF Timer, subtype Timing Advertisement; 1452 o The STA may send control frames, except those of subtype PS-Poll, 1453 CF-End, and CF-End plus CFAck; 1455 o The STA may send data frames of subtype Data, Null, QoS Data, and 1456 QoS Null. 1458 Appendix H. Implementation Status 1460 This section describes an example of an IPv6 Packet captured over a 1461 IEEE 802.11-OCB link. 1463 By way of example we show that there is no modification in the 1464 headers when transmitted over 802.11-OCB networks - they are 1465 transmitted like any other 802.11 and Ethernet packets. 1467 We describe an experiment of capturing an IPv6 packet on an 1468 802.11-OCB link. In topology depicted in Figure 6, the packet is an 1469 IPv6 Router Advertisement. This packet is emitted by a Router on its 1470 802.11-OCB interface. The packet is captured on the Host, using a 1471 network protocol analyzer (e.g. Wireshark); the capture is performed 1472 in two different modes: direct mode and 'monitor' mode. The topology 1473 used during the capture is depicted below. 1475 The packet is captured on the Host. The Host is an IP-OBU containing 1476 an 802.11 interface in format PCI express (an ITRI product). The 1477 kernel runs the ath5k software driver with modifications for OCB 1478 mode. The capture tool is Wireshark. The file format for save and 1479 analyze is 'pcap'. The packet is generated by the Router. The 1480 Router is an IP-RSU (ITRI product). 1482 +--------+ +-------+ 1483 | | 802.11-OCB Link | | 1484 ---| Router |--------------------------------| Host | 1485 | | | | 1486 +--------+ +-------+ 1488 Figure 6: Topology for capturing IP packets on 802.11-OCB 1490 During several capture operations running from a few moments to 1491 several hours, no message relevant to the BSSID contexts were 1492 captured (no Association Request/Response, Authentication Req/Resp, 1493 Beacon). This shows that the operation of 802.11-OCB is outside the 1494 context of a BSSID. 1496 Overall, the captured message is identical with a capture of an IPv6 1497 packet emitted on a 802.11b interface. The contents are precisely 1498 similar. 1500 H.1. Capture in Monitor Mode 1502 The IPv6 RA packet captured in monitor mode is illustrated below. 1503 The radio tap header provides more flexibility for reporting the 1504 characteristics of frames. The Radiotap Header is prepended by this 1505 particular stack and operating system on the Host machine to the RA 1506 packet received from the network (the Radiotap Header is not present 1507 on the air). The implementation-dependent Radiotap Header is useful 1508 for piggybacking PHY information from the chip's registers as data in 1509 a packet understandable by userland applications using Socket 1510 interfaces (the PHY interface can be, for example: power levels, data 1511 rate, ratio of signal to noise). 1513 The packet present on the air is formed by IEEE 802.11 Data Header, 1514 Logical Link Control Header, IPv6 Base Header and ICMPv6 Header. 1516 Radiotap Header v0 1517 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1518 |Header Revision| Header Pad | Header length | 1519 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1520 | Present flags | 1521 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1522 | Data Rate | Pad | 1523 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1525 IEEE 802.11 Data Header 1526 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1527 | Type/Subtype and Frame Ctrl | Duration | 1528 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1529 | Receiver Address... 1530 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1531 ... Receiver Address | Transmitter Address... 1532 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1533 ... Transmitter Address | 1534 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1535 | BSS Id... 1536 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1537 ... BSS Id | Frag Number and Seq Number | 1538 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1540 Logical-Link Control Header 1541 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1542 | DSAP |I| SSAP |C| Control field | Org. code... 1543 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1544 ... Organizational Code | Type | 1545 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1547 IPv6 Base Header 1548 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1549 |Version| Traffic Class | Flow Label | 1550 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1551 | Payload Length | Next Header | Hop Limit | 1552 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1553 | | 1554 + + 1555 | | 1556 + Source Address + 1557 | | 1558 + + 1559 | | 1560 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1561 | | 1562 + + 1563 | | 1564 + Destination Address + 1565 | | 1566 + + 1567 | | 1568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1570 Router Advertisement 1571 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1572 | Type | Code | Checksum | 1573 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1574 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1575 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1576 | Reachable Time | 1577 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1578 | Retrans Timer | 1579 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1580 | Options ... 1581 +-+-+-+-+-+-+-+-+-+-+-+- 1583 The value of the Data Rate field in the Radiotap header is set to 6 1584 Mb/s. This indicates the rate at which this RA was received. 1586 The value of the Transmitter address in the IEEE 802.11 Data Header 1587 is set to a 48bit value. The value of the destination address is 1588 33:33:00:00:00:1 (all-nodes multicast address). The value of the BSS 1589 Id field is ff:ff:ff:ff:ff:ff, which is recognized by the network 1590 protocol analyzer as being "broadcast". The Fragment number and 1591 sequence number fields are together set to 0x90C6. 1593 The value of the Organization Code field in the Logical-Link Control 1594 Header is set to 0x0, recognized as "Encapsulated Ethernet". The 1595 value of the Type field is 0x86DD (hexadecimal 86DD, or otherwise 1596 #86DD), recognized as "IPv6". 1598 A Router Advertisement is periodically sent by the router to 1599 multicast group address ff02::1. It is an icmp packet type 134. The 1600 IPv6 Neighbor Discovery's Router Advertisement message contains an 1601 8-bit field reserved for single-bit flags, as described in [RFC4861]. 1603 The IPv6 header contains the link local address of the router 1604 (source) configured via EUI-64 algorithm, and destination address set 1605 to ff02::1. Recent versions of network protocol analyzers (e.g. 1606 Wireshark) provide additional informations for an IP address, if a 1607 geolocalization database is present. In this example, the 1608 geolocalization database is absent, and the "GeoIP" information is 1609 set to unknown for both source and destination addresses (although 1610 the IPv6 source and destination addresses are set to useful values). 1611 This "GeoIP" can be a useful information to look up the city, 1612 country, AS number, and other information for an IP address. 1614 The Ethernet Type field in the logical-link control header is set to 1615 0x86dd which indicates that the frame transports an IPv6 packet. In 1616 the IEEE 802.11 data, the destination address is 33:33:00:00:00:01 1617 which is the corresponding multicast MAC address. The BSS id is a 1618 broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link 1619 duration between vehicles and the roadside infrastructure, there is 1620 no need in IEEE 802.11-OCB to wait for the completion of association 1621 and authentication procedures before exchanging data. IEEE 1622 802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s) 1623 and may start communicating as soon as they arrive on the 1624 communication channel. 1626 H.2. Capture in Normal Mode 1628 The same IPv6 Router Advertisement packet described above (monitor 1629 mode) is captured on the Host, in the Normal mode, and depicted 1630 below. 1632 Ethernet II Header 1633 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1634 | Destination... 1635 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1636 ...Destination | Source... 1637 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1638 ...Source | 1639 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1640 | Type | 1641 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1643 IPv6 Base Header 1644 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1645 |Version| Traffic Class | Flow Label | 1646 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1647 | Payload Length | Next Header | Hop Limit | 1648 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1649 | | 1650 + + 1651 | | 1652 + Source Address + 1653 | | 1654 + + 1655 | | 1656 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1657 | | 1658 + + 1659 | | 1660 + Destination Address + 1661 | | 1662 + + 1663 | | 1664 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1666 Router Advertisement 1667 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1668 | Type | Code | Checksum | 1669 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1670 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1671 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1672 | Reachable Time | 1673 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1674 | Retrans Timer | 1675 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1676 | Options ... 1677 +-+-+-+-+-+-+-+-+-+-+-+- 1679 One notices that the Radiotap Header, the IEEE 802.11 Data Header and 1680 the Logical-Link Control Headers are not present. On the other hand, 1681 a new header named Ethernet II Header is present. 1683 The Destination and Source addresses in the Ethernet II header 1684 contain the same values as the fields Receiver Address and 1685 Transmitter Address present in the IEEE 802.11 Data Header in the 1686 "monitor" mode capture. 1688 The value of the Type field in the Ethernet II header is 0x86DD 1689 (recognized as "IPv6"); this value is the same value as the value of 1690 the field Type in the Logical-Link Control Header in the "monitor" 1691 mode capture. 1693 The knowledgeable experimenter will no doubt notice the similarity of 1694 this Ethernet II Header with a capture in normal mode on a pure 1695 Ethernet cable interface. 1697 An Adaptation layer is inserted on top of a pure IEEE 802.11 MAC 1698 layer, in order to adapt packets, before delivering the payload data 1699 to the applications. It adapts 802.11 LLC/MAC headers to Ethernet II 1700 headers. In further detail, this adaptation consists in the 1701 elimination of the Radiotap, 802.11 and LLC headers, and in the 1702 insertion of the Ethernet II header. In this way, IPv6 runs straight 1703 over LLC over the 802.11-OCB MAC layer; this is further confirmed by 1704 the use of the unique Type 0x86DD. 1706 Appendix I. Extra Terminology 1708 The following terms are defined outside the IETF. They are used to 1709 define the main terms in the main terminology section Section 2. 1711 DSRC (Dedicated Short Range Communication): a term defined outside 1712 the IETF. The US Federal Communications Commission (FCC) Dedicated 1713 Short Range Communication (DSRC) is defined in the Code of Federal 1714 Regulations (CFR) 47, Parts 90 and 95. This Code is referred in the 1715 definitions below. At the time of the writing of this Internet 1716 Draft, the last update of this Code was dated October 1st, 2010. 1718 DSRCS (Dedicated Short-Range Communications Services): a term defined 1719 outside the IETF. The use of radio techniques to transfer data over 1720 short distances between roadside and mobile units, between mobile 1721 units, and between portable and mobile units to perform operations 1722 related to the improvement of traffic flow, traffic safety, and other 1723 intelligent transportation service applications in a variety of 1724 environments. DSRCS systems may also transmit status and 1725 instructional messages related to the units involve. [Ref. 47 CFR 1726 90.7 - Definitions] 1727 OBU (On-Board Unit): a term defined outside the IETF. An On-Board 1728 Unit is a DSRCS transceiver that is normally mounted in or on a 1729 vehicle, or which in some instances may be a portable unit. An OBU 1730 can be operational while a vehicle or person is either mobile or 1731 stationary. The OBUs receive and contend for time to transmit on one 1732 or more radio frequency (RF) channels. Except where specifically 1733 excluded, OBU operation is permitted wherever vehicle operation or 1734 human passage is permitted. The OBUs mounted in vehicles are 1735 licensed by rule under part 95 of the respective chapter and 1736 communicate with Roadside Units (RSUs) and other OBUs. Portable OBUs 1737 are also licensed by rule under part 95 of the respective chapter. 1738 OBU operations in the Unlicensed National Information Infrastructure 1739 (UNII) Bands follow the rules in those bands. - [CFR 90.7 - 1740 Definitions]. 1742 RSU (Road-Side Unit): a term defined outside of IETF. A Roadside 1743 Unit is a DSRC transceiver that is mounted along a road or pedestrian 1744 passageway. An RSU may also be mounted on a vehicle or is hand 1745 carried, but it may only operate when the vehicle or hand- carried 1746 unit is stationary. Furthermore, an RSU operating under the 1747 respectgive part is restricted to the location where it is licensed 1748 to operate. However, portable or hand-held RSUs are permitted to 1749 operate where they do not interfere with a site-licensed operation. 1750 A RSU broadcasts data to OBUs or exchanges data with OBUs in its 1751 communications zone. An RSU also provides channel assignments and 1752 operating instructions to OBUs in its communications zone, when 1753 required. - [CFR 90.7 - Definitions]. 1755 Authors' Addresses 1757 Alexandre Petrescu 1758 CEA, LIST 1759 CEA Saclay 1760 Gif-sur-Yvette , Ile-de-France 91190 1761 France 1763 Phone: +33169089223 1764 Email: Alexandre.Petrescu@cea.fr 1766 Nabil Benamar 1767 Moulay Ismail University 1768 Morocco 1770 Phone: +212670832236 1771 Email: n.benamar@est.umi.ac.ma 1772 Jerome Haerri 1773 Eurecom 1774 Sophia-Antipolis 06904 1775 France 1777 Phone: +33493008134 1778 Email: Jerome.Haerri@eurecom.fr 1780 Jong-Hyouk Lee 1781 Sangmyung University 1782 31, Sangmyeongdae-gil, Dongnam-gu 1783 Cheonan 31066 1784 Republic of Korea 1786 Email: jonghyouk@smu.ac.kr 1788 Thierry Ernst 1789 YoGoKo 1790 France 1792 Email: thierry.ernst@yogoko.fr