idnits 2.17.1 draft-ietf-ipwave-ipv6-over-80211ocb-26.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The exact meaning of the all-uppercase expression 'MAY NOT' is not defined in RFC 2119. If it is intended as a requirements expression, it should be rewritten using one of the combinations defined in RFC 2119; otherwise it should not be all-uppercase. == The expression 'MAY NOT', while looking like RFC 2119 requirements text, is not defined in RFC 2119, and should not be used. Consider using 'MUST NOT' instead (if that is what you mean). Found 'MAY NOT' in this paragraph: A subnet is formed by the external 802.11-OCB interfaces of vehicles that are in close range (not by their in-vehicle interfaces). This subnet MUST use at least the link-local prefix fe80::/10 and the interfaces MUST be assigned IPv6 addresses of type link-local. This subnet MAY NOT have any other prefix than the link-local prefix. -- The document date (September 7, 2018) is 2059 days in the past. Is this intentional? -- Found something which looks like a code comment -- if you have code sections in the document, please surround them with '' and '' lines. Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) ** Obsolete normative reference: RFC 2818 (Obsoleted by RFC 9110) ** Downref: Normative reference to an Informational RFC: RFC 3753 ** Downref: Normative reference to an Informational RFC: RFC 5889 ** Obsolete normative reference: RFC 7042 (Obsoleted by RFC 9542) ** Downref: Normative reference to an Informational RFC: RFC 7721 Summary: 5 errors (**), 0 flaws (~~), 2 warnings (==), 3 comments (--). 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: March 11, 2019 Moulay Ismail University 6 J. Haerri 7 Eurecom 8 J. Lee 9 Sangmyung University 10 T. Ernst 11 YoGoKo 12 September 7, 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-26 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 March 11, 2019. 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 5.1. Privacy Considerations . . . . . . . . . . . . . . . . . 9 79 5.2. MAC Address Generation . . . . . . . . . . . . . . . . . 10 80 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 81 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 82 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 83 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 84 9.1. Normative References . . . . . . . . . . . . . . . . . . 11 85 9.2. Informative References . . . . . . . . . . . . . . . . . 14 86 Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 15 87 Appendix B. 802.11p . . . . . . . . . . . . . . . . . . . . . . 24 88 Appendix C. Aspects introduced by the OCB mode to 802.11 . . . . 24 89 Appendix D. Changes Needed on a software driver 802.11a to 90 become a 802.11-OCB driver . . . 28 91 Appendix E. EtherType Protocol Discrimination (EPD) . . . . . . 29 92 Appendix F. Design Considerations . . . . . . . . . . . . . . . 30 93 F.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 30 94 F.2. Reliability Requirements . . . . . . . . . . . . . . . . 31 95 F.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 31 96 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 32 97 Appendix H. Examples of Packet Formats . . . . . . . . . . . . . 32 98 H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 33 99 H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 36 100 Appendix I. Extra Terminology . . . . . . . . . . . . . . . . . 38 101 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 103 1. Introduction 105 This document describes the transmission of IPv6 packets on IEEE Std 106 802.11-OCB networks [IEEE-802.11-2016] (a.k.a "802.11p" see 107 Appendix B, Appendix C and Appendix D). This involves the layering 108 of IPv6 networking on top of the IEEE 802.11 MAC layer, with an LLC 109 layer. Compared to running IPv6 over the Ethernet MAC layer, there 110 is no modification expected to IEEE Std 802.11 MAC and Logical Link 111 sublayers: IPv6 works fine directly over 802.11-OCB too, with an LLC 112 layer. 114 The IPv6 network layer operates on 802.11-OCB in the same manner as 115 operating on Ethernet, but there are two kinds of exceptions: 117 o Exceptions due to different operation of IPv6 network layer on 118 802.11 than on Ethernet. To satisfy these exceptions, this 119 document describes an Ethernet Adaptation Layer between Ethernet 120 headers and 802.11 headers. The Ethernet Adaptation Layer is 121 described Section 4.2.1. The operation of IP on Ethernet is 122 described in [RFC1042], [RFC2464] and 123 [I-D.hinden-6man-rfc2464bis]. 125 o Exceptions due to the OCB nature of 802.11-OCB compared to 802.11. 126 This has impacts on security, privacy, subnet structure and 127 handover behaviour. For security and privacy recommendations see 128 Section 5 and Section 4.5. The subnet structure is described in 129 Section 4.6. The handover behaviour on OCB links is not described 130 in this document. 132 In the published literature, many documents describe aspects and 133 problems related to running IPv6 over 802.11-OCB: 134 [I-D.ietf-ipwave-vehicular-networking-survey]. 136 2. Terminology 138 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 139 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 140 document are to be interpreted as described in RFC 2119 [RFC2119]. 142 IP-OBU (Internet Protocol On-Board Unit): an IP-OBU is a computer 143 situated in a vehicle such as an automobile, bicycle, or similar. It 144 has at least one IP interface that runs in mode OCB of 802.11, and 145 that has an "OBU" transceiver. See the definition of the term "OBU" 146 in section Appendix I. 148 IP-RSU (IP Road-Side Unit): an IP-RSU is situated along the road. An 149 IP-RSU has at least two distinct IP-enabled interfaces; at least one 150 interface is operated in mode OCB of IEEE 802.11 and is IP-enabled. 151 An IP-RSU is similar to a Wireless Termination Point (WTP), as 152 defined in [RFC5415], or an Access Point (AP), as defined in IEEE 153 documents, or an Access Network Router (ANR) defined in [RFC3753], 154 with one key particularity: the wireless PHY/MAC layer of at least 155 one of its IP-enabled interfaces is configured to operate in 156 802.11-OCB mode. The IP-RSU communicates with the IP-OBU in the 157 vehicle over 802.11 wireless link operating in OCB mode. 159 OCB (outside the context of a basic service set - BSS): A mode of 160 operation in which a STA is not a member of a BSS and does not 161 utilize IEEE Std 802.11 authentication, association, or data 162 confidentiality. 164 802.11-OCB: mode specified in IEEE Std 802.11-2016 when the MIB 165 attribute dot11OCBActivited is true. Note: compliance with standards 166 and regulations set in different countries when using the 5.9GHz 167 frequency band is required. 169 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 171 The IEEE 802.11-OCB Networks are used for vehicular communications, 172 as 'Wireless Access in Vehicular Environments'. The IP communication 173 scenarios for these environments have been described in several 174 documents; in particular, we refer the reader to 175 [I-D.ietf-ipwave-vehicular-networking-survey], that lists some 176 scenarios and requirements for IP in Intelligent Transportation 177 Systems. 179 The link model is the following: STA --- 802.11-OCB --- STA. In 180 vehicular networks, STAs can be IP-RSUs and/or IP-OBUs. While 181 802.11-OCB is clearly specified, and the use of IPv6 over such link 182 is not radically new, the operating environment (vehicular networks) 183 brings in new perspectives. 185 The mechanisms for forming and terminating, discovering, peering and 186 mobility management for 802.11-OCB links are not described in this 187 document. 189 4. IPv6 over 802.11-OCB 191 4.1. Maximum Transmission Unit (MTU) 193 The default MTU for IP packets on 802.11-OCB MUST be 1500 octets. It 194 is the same value as IPv6 packets on Ethernet links, as specified in 195 [RFC2464]. This value of the MTU respects the recommendation that 196 every link on the Internet must have a minimum MTU of 1280 octets 197 (stated in [RFC8200], and the recommendations therein, especially 198 with respect to fragmentation). 200 4.2. Frame Format 202 IP packets MUST be transmitted over 802.11-OCB media as QoS Data 203 frames whose format is specified in IEEE Std 802.11. 205 The IPv6 packet transmitted on 802.11-OCB MUST be immediately 206 preceded by a Logical Link Control (LLC) header and an 802.11 header. 207 In the LLC header, and in accordance with the EtherType Protocol 208 Discrimination (EPD), the value of the Type field MUST be set to 209 0x86DD (IPv6). In the 802.11 header, the value of the Subtype sub- 210 field in the Frame Control field MUST be set to 8 (i.e. 'QoS Data'); 211 the value of the Traffic Identifier (TID) sub-field of the QoS 212 Control field of the 802.11 header MUST be set to binary 001 (i.e. 213 User Priority 'Background', QoS Access Category 'AC_BK'). 215 To simplify the Application Programming Interface (API) between the 216 operating system and the 802.11-OCB media, device drivers MAY 217 implement an Ethernet Adaptation Layer that translates Ethernet II 218 frames to the 802.11 format and vice versa. An Ethernet Adaptation 219 Layer is described in Section 4.2.1. 221 4.2.1. Ethernet Adaptation Layer 223 An 'adaptation' layer is inserted between a MAC layer and the 224 Networking layer. This is used to transform some parameters between 225 their form expected by the IP stack and the form provided by the MAC 226 layer. 228 An Ethernet Adaptation Layer makes an 802.11 MAC look to IP 229 Networking layer as a more traditional Ethernet layer. At reception, 230 this layer takes as input the IEEE 802.11 header and the Logical-Link 231 Layer Control Header and produces an Ethernet II Header. At sending, 232 the reverse operation is performed. 234 The operation of the Ethernet Adaptation Layer is depicted by the 235 double arrow in Figure 1. 237 +------------------+------------+-------------+---------+-----------+ 238 | 802.11 header | LLC Header | IPv6 Header | Payload |.11 Trailer| 239 +------------------+------------+-------------+---------+-----------+ 240 \ / \ / 241 --------------------------- -------- 242 \---------------------------------------------/ 243 ^ 244 | 245 802.11-to-Ethernet Adaptation Layer 246 | 247 v 248 +---------------------+-------------+---------+ 249 | Ethernet II Header | IPv6 Header | Payload | 250 +---------------------+-------------+---------+ 252 Figure 1: Operation of the Ethernet Adaptation Layer 254 The Receiver and Transmitter Address fields in the 802.11 header MUST 255 contain the same values as the Destination and the Source Address 256 fields in the Ethernet II Header, respectively. The value of the 257 Type field in the LLC Header MUST be the same as the value of the 258 Type field in the Ethernet II Header. That value MUST be set to 259 0x86DD (IPv6). 261 The ".11 Trailer" contains solely a 4-byte Frame Check Sequence. 263 The placement of IPv6 networking layer on Ethernet Adaptation Layer 264 is illustrated in Figure 2. 266 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 | IPv6 | 268 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 269 | Ethernet Adaptation Layer | 270 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 271 | 802.11 MAC | 272 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 273 | 802.11 PHY | 274 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 276 Figure 2: Ethernet Adaptation Layer stacked with other layers 278 (in the above figure, a 802.11 profile is represented; this is used 279 also for 802.11-OCB profile.) 281 4.3. Link-Local Addresses 283 There are several types of IPv6 addresses [RFC4291], [RFC4193], that 284 MAY be assigned to an 802.11-OCB interface. Among these types of 285 addresses only the IPv6 link-local addresses MAY be formed using an 286 EUI-64 identifier. 288 If the IPv6 link-local address is formed using an EUI-64 identifier, 289 then the mechanism of forming that address is the same mechanism as 290 used to form an IPv6 link-local address on Ethernet links. This 291 mechanism is described in section 5 of [RFC2464]. 293 4.4. Address Mapping 295 Unicast and multicast address mapping MUST follow the procedures 296 specified for Ethernet interfaces in sections 6 and 7 of [RFC2464]. 298 4.4.1. Address Mapping -- Unicast 300 The procedure for mapping IPv6 unicast addresses into Ethernet link- 301 layer addresses is described in [RFC4861]. 303 4.4.2. Address Mapping -- Multicast 305 The multicast address mapping is performed according to the method 306 specified in section 7 of [RFC2464]. The meaning of the value "3333" 307 mentioned in that section 7 of [RFC2464] is defined in section 2.3.1 308 of [RFC7042]. 310 Transmitting IPv6 packets to multicast destinations over 802.11 links 311 proved to have some performance issues 312 [I-D.perkins-intarea-multicast-ieee802]. These issues may be 313 exacerbated in OCB mode. Solutions for these problems should 314 consider the OCB mode of operation. 316 4.5. Stateless Autoconfiguration 318 There are several types of IPv6 addresses [RFC4291], [RFC4193], that 319 MAY be assigned to an 802.11-OCB interface. This section describes 320 the formation of Interface Identifiers for IPv6 addresses of type 321 'Global' or 'Unique Local'. For Interface Identifiers for IPv6 322 address of type 'Link-Local' see Section 4.3. 324 The Interface Identifier for an 802.11-OCB interface is formed using 325 the same rules as the Interface Identifier for an Ethernet interface; 326 the RECOMMENDED method for forming stable Interface Identifiers 327 (IIDs) is described in [RFC8064]. The method of forming IIDs 328 described in section 4 of [RFC2464] MAY be used during transition 329 time. 331 The bits in the Interface Identifier have no generic meaning and the 332 identifier should be treated as an opaque value. The bits 333 'Universal' and 'Group' in the identifier of an 802.11-OCB interface 334 are significant, as this is an IEEE link-layer address. The details 335 of this significance are described in [RFC7136]. If semantically 336 opaque Interface Identifiers are needed, a potential method for 337 generating semantically opaque Interface Identifiers with IPv6 338 Stateless Address Autoconfiguration is given in [RFC7217]. 340 The way Interface Identifiers are used MAY involve risks to privacy, 341 as described in Section 5.1. 343 4.6. Subnet Structure 345 A subnet is formed by the external 802.11-OCB interfaces of vehicles 346 that are in close range (not by their in-vehicle interfaces). This 347 subnet MUST use at least the link-local prefix fe80::/10 and the 348 interfaces MUST be assigned IPv6 addresses of type link-local. This 349 subnet MAY NOT have any other prefix than the link-local prefix. 351 The structure of this subnet is ephemeral, in that it is strongly 352 influenced by the mobility of vehicles: the 802.11 hidden node 353 effects appear; the 802.11 networks in OCB mode may be considered as 354 'ad-hoc' networks with an addressing model as described in [RFC5889]. 355 On another hand, the structure of the internal subnets in each car is 356 relatively stable. 358 As recommended in [RFC5889], when the timing requirements are very 359 strict (e.g. fast drive through IP-RSU coverage), no on-link subnet 360 prefix should be configured on an 802.11-OCB interface. In such 361 cases, the exclusive use of IPv6 link-local addresses is RECOMMENDED. 363 The Neighbor Discovery protocol (ND) [RFC4861] is used over 364 802.11-OCB links. 366 The operation of the Mobile IPv6 protocol over 802.11-OCB links is 367 different than on other links. The Movement Detection operation 368 (section 11.5.1 of [RFC6275]) can not rely on Neighbor Unreachability 369 Detection operation of the Neighbor Discovery protocol, for the 370 reason mentioned in the previous paragraph. Also, the 802.11-OCB 371 link layer is not a lower layer that can provide an indication that a 372 link layer handover has occured. The operation of the Mobile IPv6 373 protocol over 802.11-OCB is not specified in this document. 375 5. Security Considerations 377 Any security mechanism at the IP layer or above that may be carried 378 out for the general case of IPv6 may also be carried out for IPv6 379 operating over 802.11-OCB. 381 The OCB operation is stripped off of all existing 802.11 link-layer 382 security mechanisms. There is no encryption applied below the 383 network layer running on 802.11-OCB. At application layer, the IEEE 384 1609.2 document [IEEE-1609.2] does provide security services for 385 certain applications to use; application-layer mechanisms are out-of- 386 scope of this document. On another hand, a security mechanism 387 provided at networking layer, such as IPsec [RFC4301], may provide 388 data security protection to a wider range of applications. 390 802.11-OCB does not provide any cryptographic protection, because it 391 operates outside the context of a BSS (no Association Request/ 392 Response, no Challenge messages). Any attacker can therefore just 393 sit in the near range of vehicles, sniff the network (just set the 394 interface card's frequency to the proper range) and perform attacks 395 without needing to physically break any wall. Such a link is less 396 protected than commonly used links (wired link or protected 802.11). 398 The potential attack vectors are: MAC address spoofing, IP address 399 and session hijacking and privacy violation. 401 Within the IPsec Security Architecture [RFC4301], the IPsec AH and 402 ESP headers [RFC4302] and [RFC4303] respectively, its multicast 403 extensions [RFC5374], HTTPS [RFC2818] and SeND [RFC3971] protocols 404 can be used to protect communications. Further, the assistance of 405 proper Public Key Infrastructure (PKI) protocols [RFC4210] is 406 necessary to establish credentials. More IETF protocols are 407 available in the toolbox of the IP security protocol designer. 408 Certain ETSI protocols related to security protocols in Intelligent 409 Transportation Systems are described in [ETSI-sec-archi]. 411 5.1. Privacy Considerations 413 As with all Ethernet and 802.11 interface identifiers ([RFC7721]), 414 the identifier of an 802.11-OCB interface may involve privacy, MAC 415 address spoofing and IP address hijacking risks. A vehicle embarking 416 an IP-OBU whose egress interface is 802.11-OCB may expose itself to 417 eavesdropping and subsequent correlation of data; this may reveal 418 data considered private by the vehicle owner; there is a risk of 419 being tracked. In outdoors public environments, where vehicles 420 typically circulate, the privacy risks are more important than in 421 indoors settings. It is highly likely that attacker sniffers are 422 deployed along routes which listen for IEEE frames, including IP 423 packets, of vehicles passing by. For this reason, in the 802.11-OCB 424 deployments, there is a strong necessity to use protection tools such 425 as dynamically changing MAC addresses. This may help mitigate 426 privacy risks to a certain level. 428 5.2. MAC Address Generation 430 In 802.11-OCB networks, the MAC addresses MAY change during well 431 defined renumbering events. In the moment the MAC address is changed 432 on an 802.11-OCB interface all the Interface Identifiers of IPv6 433 addresses assigned to that interface MUST change. 435 The policy dictating when the MAC address is changed on the 436 802.11-OCB interface is to-be-determined. For more information on 437 the motivation of this policy please refer to the privacy discussion 438 in Appendix C. 440 A 'randomized' MAC address has the following characteristics: 442 o Bit "Local/Global" set to "locally admninistered". 444 o Bit "Unicast/Multicast" set to "Unicast". 446 o The 46 remaining bits are set to a random value, using a random 447 number generator that meets the requirements of [RFC4086]. 449 To meet the randomization requirements for the 46 remaining bits, a 450 hash function may be used. For example, the SHA256 hash function may 451 be used with input a 256 bit local secret, the "nominal" MAC Address 452 of the interface, and a representation of the date and time of the 453 renumbering event. 455 6. IANA Considerations 457 No request to IANA. 459 7. Contributors 461 Christian Huitema, Tony Li. 463 Romain Kuntz contributed extensively about IPv6 handovers between 464 links running outside the context of a BSS (802.11-OCB links). 466 Tim Leinmueller contributed the idea of the use of IPv6 over 467 802.11-OCB for distribution of certificates. 469 Marios Makassikis, Jose Santa Lozano, Albin Severinson and Alexey 470 Voronov provided significant feedback on the experience of using IP 471 messages over 802.11-OCB in initial trials. 473 Michelle Wetterwald contributed extensively the MTU discussion, 474 offered the ETSI ITS perspective, and reviewed other parts of the 475 document. 477 8. Acknowledgements 479 The authors would like to thank Witold Klaudel, Ryuji Wakikawa, 480 Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan 481 Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray 482 Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan, 483 Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne, 484 Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark, 485 Bob Moskowitz, Andrew Dryden, Georg Mayer, Dorothy Stanley, Sandra 486 Cespedes, Mariano Falcitelli, Sri Gundavelli, Abdussalam Baryun, 487 Margaret Cullen, Erik Kline, Carlos Jesus Bernardos Cano, Ronald in 488 't Velt, Katrin Sjoberg, Roland Bless, Tijink Jasja, Kevin Smith, 489 Brian Carpenter, Julian Reschke, Mikael Abrahamsson and William 490 Whyte. Their valuable comments clarified particular issues and 491 generally helped to improve the document. 493 Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB 494 drivers for linux and described how. 496 For the multicast discussion, the authors would like to thank Owen 497 DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and 498 participants to discussions in network working groups. 500 The authors would like to thank participants to the Birds-of- 501 a-Feather "Intelligent Transportation Systems" meetings held at IETF 502 in 2016. 504 9. References 506 9.1. Normative References 508 [RFC1042] Postel, J. and J. Reynolds, "Standard for the transmission 509 of IP datagrams over IEEE 802 networks", STD 43, RFC 1042, 510 DOI 10.17487/RFC1042, February 1988, 511 . 513 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 514 Requirement Levels", BCP 14, RFC 2119, 515 DOI 10.17487/RFC2119, March 1997, 516 . 518 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 519 Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, 520 . 522 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, 523 DOI 10.17487/RFC2818, May 2000, 524 . 526 [RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related 527 Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004, 528 . 530 [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, 531 "SEcure Neighbor Discovery (SEND)", RFC 3971, 532 DOI 10.17487/RFC3971, March 2005, 533 . 535 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 536 "Randomness Requirements for Security", BCP 106, RFC 4086, 537 DOI 10.17487/RFC4086, June 2005, 538 . 540 [RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast 541 Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005, 542 . 544 [RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen, 545 "Internet X.509 Public Key Infrastructure Certificate 546 Management Protocol (CMP)", RFC 4210, 547 DOI 10.17487/RFC4210, September 2005, 548 . 550 [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing 551 Architecture", RFC 4291, DOI 10.17487/RFC4291, February 552 2006, . 554 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 555 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 556 December 2005, . 558 [RFC4302] Kent, S., "IP Authentication Header", RFC 4302, 559 DOI 10.17487/RFC4302, December 2005, 560 . 562 [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", 563 RFC 4303, DOI 10.17487/RFC4303, December 2005, 564 . 566 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 567 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 568 DOI 10.17487/RFC4861, September 2007, 569 . 571 [RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast 572 Extensions to the Security Architecture for the Internet 573 Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008, 574 . 576 [RFC5415] Calhoun, P., Ed., Montemurro, M., Ed., and D. Stanley, 577 Ed., "Control And Provisioning of Wireless Access Points 578 (CAPWAP) Protocol Specification", RFC 5415, 579 DOI 10.17487/RFC5415, March 2009, 580 . 582 [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing 583 Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, 584 September 2010, . 586 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 587 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 588 2011, . 590 [RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and 591 IETF Protocol and Documentation Usage for IEEE 802 592 Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042, 593 October 2013, . 595 [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 596 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, 597 February 2014, . 599 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 600 Interface Identifiers with IPv6 Stateless Address 601 Autoconfiguration (SLAAC)", RFC 7217, 602 DOI 10.17487/RFC7217, April 2014, 603 . 605 [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy 606 Considerations for IPv6 Address Generation Mechanisms", 607 RFC 7721, DOI 10.17487/RFC7721, March 2016, 608 . 610 [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu, 611 "Recommendation on Stable IPv6 Interface Identifiers", 612 RFC 8064, DOI 10.17487/RFC8064, February 2017, 613 . 615 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 616 (IPv6) Specification", STD 86, RFC 8200, 617 DOI 10.17487/RFC8200, July 2017, 618 . 620 9.2. Informative References 622 [ETSI-sec-archi] 623 "ETSI TS 102 940 V1.2.1 (2016-11), ETSI Technical 624 Specification, Intelligent Transport Systems (ITS); 625 Security; ITS communications security architecture and 626 security management, November 2016. Downloaded on 627 September 9th, 2017, freely available from ETSI website at 628 URL http://www.etsi.org/deliver/ 629 etsi_ts/102900_102999/102940/01.02.01_60/ 630 ts_102940v010201p.pdf". 632 [I-D.hinden-6man-rfc2464bis] 633 Crawford, M. and R. Hinden, "Transmission of IPv6 Packets 634 over Ethernet Networks", draft-hinden-6man-rfc2464bis-02 635 (work in progress), March 2017. 637 [I-D.ietf-ipwave-vehicular-networking-survey] 638 Jeong, J., Cespedes, S., Benamar, N., Haerri, J., and M. 639 Wetterwald, "Survey on IP-based Vehicular Networking for 640 Intelligent Transportation Systems", draft-ietf-ipwave- 641 vehicular-networking-survey-00 (work in progress), July 642 2017. 644 [I-D.perkins-intarea-multicast-ieee802] 645 Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, 646 "Multicast Considerations over IEEE 802 Wireless Media", 647 draft-perkins-intarea-multicast-ieee802-03 (work in 648 progress), July 2017. 650 [IEEE-1609.2] 651 "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access 652 in Vehicular Environments (WAVE) -- Security Services for 653 Applications and Management Messages. Example URL 654 http://ieeexplore.ieee.org/document/7426684/ accessed on 655 August 17th, 2017.". 657 [IEEE-1609.3] 658 "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access 659 in Vehicular Environments (WAVE) -- Networking Services. 660 Example URL http://ieeexplore.ieee.org/document/7458115/ 661 accessed on August 17th, 2017.". 663 [IEEE-1609.4] 664 "IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access 665 in Vehicular Environments (WAVE) -- Multi-Channel 666 Operation. Example URL 667 http://ieeexplore.ieee.org/document/7435228/ accessed on 668 August 17th, 2017.". 670 [IEEE-802.11-2016] 671 "IEEE Standard 802.11-2016 - IEEE Standard for Information 672 Technology - Telecommunications and information exchange 673 between systems Local and metropolitan area networks - 674 Specific requirements - Part 11: Wireless LAN Medium 675 Access Control (MAC) and Physical Layer (PHY) 676 Specifications. Status - Active Standard. Description 677 retrieved freely on September 12th, 2017, at URL 678 https://standards.ieee.org/findstds/ 679 standard/802.11-2016.html". 681 [IEEE-802.11p-2010] 682 "IEEE Std 802.11p (TM)-2010, IEEE Standard for Information 683 Technology - Telecommunications and information exchange 684 between systems - Local and metropolitan area networks - 685 Specific requirements, Part 11: Wireless LAN Medium Access 686 Control (MAC) and Physical Layer (PHY) Specifications, 687 Amendment 6: Wireless Access in Vehicular Environments; 688 document freely available at URL 689 http://standards.ieee.org/getieee802/ 690 download/802.11p-2010.pdf retrieved on September 20th, 691 2013.". 693 Appendix A. ChangeLog 695 The changes are listed in reverse chronological order, most recent 696 changes appearing at the top of the list. 698 -26: moved text from SLAAC section and from Design Considerations 699 appendix about privacy into a new Privacy Condiderations subsection 700 of the Security section; reformulated the SLAAC and IID sections to 701 stress only LLs can use EUI-64; removed the "GeoIP" wireshark 702 explanation; reformulated SLAAC and LL sections; added brief mention 703 of need of use LLs; clarified text about MAC address changes; dropped 704 pseudonym discussion; changed title of section describing examples of 705 packet formats. 707 -25: added a reference to 'IEEE Management Information Base', instead 708 of just 'Management Information Base'; added ref to further 709 appendices in the introductory phrases; improved text for IID 710 formation for SLAAC, inserting recommendation for RFC8064 before 711 RFC2464. 713 From draft-ietf-ipwave-ipv6-over-80211ocb-23 to draft-ietf-ipwave- 714 ipv6-over-80211ocb-24 716 o Nit: wrote "IPWAVE Working Group" on the front page, instead of 717 "Network Working Group". 719 o Addressed the comments on 6MAN: replaced a sentence about ND 720 problem with "is used over 802.11-OCB". 722 From draft-ietf-ipwave-ipv6-over-80211ocb-22 to draft-ietf-ipwave- 723 ipv6-over-80211ocb-23 725 o No content modifications, but check the entire draft chain on 726 IPv6-only: xml2rfc, submission on tools.ietf.org and datatracker. 728 From draft-ietf-ipwave-ipv6-over-80211ocb-21 to draft-ietf-ipwave- 729 ipv6-over-80211ocb-22 731 o Corrected typo, use dash in "802.11-OCB" instead of space. 733 o Improved the Frame Format section: MUST use QoSData, specify the 734 values within; clarified the Ethernet Adaptation Layer text. 736 From draft-ietf-ipwave-ipv6-over-80211ocb-20 to draft-ietf-ipwave- 737 ipv6-over-80211ocb-21 739 o Corrected a few nits and added names in Acknowledgments section. 741 o Removed unused reference to old Internet Draft tsvwg about QoS. 743 From draft-ietf-ipwave-ipv6-over-80211ocb-19 to draft-ietf-ipwave- 744 ipv6-over-80211ocb-20 746 o Reduced the definition of term "802.11-OCB". 748 o Left out of this specification which 802.11 header to use to 749 transmit IP packets in OCB mode (QoS Data header, Data header, or 750 any other). 752 o Added 'MUST' use an Ethernet Adaptation Layer, instead of 'is 753 using' an Ethernet Adaptation Layer. 755 From draft-ietf-ipwave-ipv6-over-80211ocb-18 to draft-ietf-ipwave- 756 ipv6-over-80211ocb-19 757 o Removed the text about fragmentation. 759 o Removed the mentioning of WSMP and GeoNetworking. 761 o Removed the explanation of the binary representation of the 762 EtherType. 764 o Rendered normative the paragraph about unicast and multicast 765 address mapping. 767 o Removed paragraph about addressing model, subnet structure and 768 easiness of using LLs. 770 o Clarified the Type/Subtype field in the 802.11 Header. 772 o Used RECOMMENDED instead of recommended, for the stable interface 773 identifiers. 775 From draft-ietf-ipwave-ipv6-over-80211ocb-17 to draft-ietf-ipwave- 776 ipv6-over-80211ocb-18 778 o Improved the MTU and fragmentation paragraph. 780 From draft-ietf-ipwave-ipv6-over-80211ocb-16 to draft-ietf-ipwave- 781 ipv6-over-80211ocb-17 783 o Susbtituted "MUST be increased" to "is increased" in the MTU 784 section, about fragmentation. 786 From draft-ietf-ipwave-ipv6-over-80211ocb-15 to draft-ietf-ipwave- 787 ipv6-over-80211ocb-16 789 o Removed the definition of the 'WiFi' term and its occurences. 790 Clarified a phrase that used it in Appendix C "Aspects introduced 791 by the OCB mode to 802.11". 793 o Added more normative words: MUST be 0x86DD, MUST fragment if size 794 larger than MTU, Sequence number in 802.11 Data header MUST be 795 increased. 797 From draft-ietf-ipwave-ipv6-over-80211ocb-14 to draft-ietf-ipwave- 798 ipv6-over-80211ocb-15 800 o Added normative term MUST in two places in section "Ethernet 801 Adaptation Layer". 803 From draft-ietf-ipwave-ipv6-over-80211ocb-13 to draft-ietf-ipwave- 804 ipv6-over-80211ocb-14 805 o Created a new Appendix titled "Extra Terminology" that contains 806 terms DSRC, DSRCS, OBU, RSU as defined outside IETF. Some of them 807 are used in the main Terminology section. 809 o Added two paragraphs explaining that ND and Mobile IPv6 have 810 problems working over 802.11-OCB, yet their adaptations is not 811 specified in this document. 813 From draft-ietf-ipwave-ipv6-over-80211ocb-12 to draft-ietf-ipwave- 814 ipv6-over-80211ocb-13 816 o Substituted "IP-OBU" for "OBRU", and "IP-RSU" for "RSRU" 817 throughout and improved OBU-related definitions in the Terminology 818 section. 820 From draft-ietf-ipwave-ipv6-over-80211ocb-11 to draft-ietf-ipwave- 821 ipv6-over-80211ocb-12 823 o Improved the appendix about "MAC Address Generation" by expressing 824 the technique to be an optional suggestion, not a mandatory 825 mechanism. 827 From draft-ietf-ipwave-ipv6-over-80211ocb-10 to draft-ietf-ipwave- 828 ipv6-over-80211ocb-11 830 o Shortened the paragraph on forming/terminating 802.11-OCB links. 832 o Moved the draft tsvwg-ieee-802-11 to Informative References. 834 From draft-ietf-ipwave-ipv6-over-80211ocb-09 to draft-ietf-ipwave- 835 ipv6-over-80211ocb-10 837 o Removed text requesting a new Group ID for multicast for OCB. 839 o Added a clarification of the meaning of value "3333" in the 840 section Address Mapping -- Multicast. 842 o Added note clarifying that in Europe the regional authority is not 843 ETSI, but "ECC/CEPT based on ENs from ETSI". 845 o Added note stating that the manner in which two STAtions set their 846 communication channel is not described in this document. 848 o Added a time qualifier to state that the "each node is represented 849 uniquely at a certain point in time." 851 o Removed text "This section may need to be moved" (the "Reliability 852 Requirements" section). This section stays there at this time. 854 o In the term definition "802.11-OCB" added a note stating that "any 855 implementation should comply with standards and regulations set in 856 the different countries for using that frequency band." 858 o In the RSU term definition, added a sentence explaining the 859 difference between RSU and RSRU: in terms of number of interfaces 860 and IP forwarding. 862 o Replaced "with at least two IP interfaces" with "with at least two 863 real or virtual IP interfaces". 865 o Added a term in the Terminology for "OBU". However the definition 866 is left empty, as this term is defined outside IETF. 868 o Added a clarification that it is an OBU or an OBRU in this phrase 869 "A vehicle embarking an OBU or an OBRU". 871 o Checked the entire document for a consistent use of terms OBU and 872 OBRU. 874 o Added note saying that "'p' is a letter identifying the 875 Ammendment". 877 o Substituted lower case for capitals SHALL or MUST in the 878 Appendices. 880 o Added reference to RFC7042, helpful in the 3333 explanation. 881 Removed reference to individual submission draft-petrescu-its- 882 scenario-reqs and added reference to draft-ietf-ipwave-vehicular- 883 networking-survey. 885 o Added figure captions, figure numbers, and references to figure 886 numbers instead of 'below'. Replaced "section Section" with 887 "section" throughout. 889 o Minor typographical errors. 891 From draft-ietf-ipwave-ipv6-over-80211ocb-08 to draft-ietf-ipwave- 892 ipv6-over-80211ocb-09 894 o Significantly shortened the Address Mapping sections, by text 895 copied from RFC2464, and rather referring to it. 897 o Moved the EPD description to an Appendix on its own. 899 o Shortened the Introduction and the Abstract. 901 o Moved the tutorial section of OCB mode introduced to .11, into an 902 appendix. 904 o Removed the statement that suggests that for routing purposes a 905 prefix exchange mechanism could be needed. 907 o Removed refs to RFC3963, RFC4429 and RFC6775; these are about ND, 908 MIP/NEMO and oDAD; they were referred in the handover discussion 909 section, which is out. 911 o Updated a reference from individual submission to now a WG item in 912 IPWAVE: the survey document. 914 o Added term definition for WiFi. 916 o Updated the authorship and expanded the Contributors section. 918 o Corrected typographical errors. 920 From draft-ietf-ipwave-ipv6-over-80211ocb-07 to draft-ietf-ipwave- 921 ipv6-over-80211ocb-08 923 o Removed the per-channel IPv6 prohibition text. 925 o Corrected typographical errors. 927 From draft-ietf-ipwave-ipv6-over-80211ocb-06 to draft-ietf-ipwave- 928 ipv6-over-80211ocb-07 930 o Added new terms: OBRU and RSRU ('R' for Router). Refined the 931 existing terms RSU and OBU, which are no longer used throughout 932 the document. 934 o Improved definition of term "802.11-OCB". 936 o Clarified that OCB does not "strip" security, but that the 937 operation in OCB mode is "stripped off of all .11 security". 939 o Clarified that theoretical OCB bandwidth speed is 54mbits, but 940 that a commonly observed bandwidth in IP-over-OCB is 12mbit/s. 942 o Corrected typographical errors, and improved some phrasing. 944 From draft-ietf-ipwave-ipv6-over-80211ocb-05 to draft-ietf-ipwave- 945 ipv6-over-80211ocb-06 947 o Updated references of 802.11-OCB document from -2012 to the IEEE 948 802.11-2016. 950 o In the LL address section, and in SLAAC section, added references 951 to 7217 opaque IIDs and 8064 stable IIDs. 953 From draft-ietf-ipwave-ipv6-over-80211ocb-04 to draft-ietf-ipwave- 954 ipv6-over-80211ocb-05 956 o Lengthened the title and cleanded the abstract. 958 o Added text suggesting LLs may be easy to use on OCB, rather than 959 GUAs based on received prefix. 961 o Added the risks of spoofing and hijacking. 963 o Removed the text speculation on adoption of the TSA message. 965 o Clarified that the ND protocol is used. 967 o Clarified what it means "No association needed". 969 o Added some text about how two STAs discover each other. 971 o Added mention of external (OCB) and internal network (stable), in 972 the subnet structure section. 974 o Added phrase explaining that both .11 Data and .11 QoS Data 975 headers are currently being used, and may be used in the future. 977 o Moved the packet capture example into an Appendix Implementation 978 Status. 980 o Suggested moving the reliability requirements appendix out into 981 another document. 983 o Added a IANA Consiserations section, with content, requesting for 984 a new multicast group "all OCB interfaces". 986 o Added new OBU term, improved the RSU term definition, removed the 987 ETTC term, replaced more occurences of 802.11p, 802.11-OCB with 988 802.11-OCB. 990 o References: 992 * Added an informational reference to ETSI's IPv6-over- 993 GeoNetworking. 995 * Added more references to IETF and ETSI security protocols. 997 * Updated some references from I-D to RFC, and from old RFC to 998 new RFC numbers. 1000 * Added reference to multicast extensions to IPsec architecture 1001 RFC. 1003 * Added a reference to 2464-bis. 1005 * Removed FCC informative references, because not used. 1007 o Updated the affiliation of one author. 1009 o Reformulation of some phrases for better readability, and 1010 correction of typographical errors. 1012 From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave- 1013 ipv6-over-80211ocb-04 1015 o Removed a few informative references pointing to Dx draft IEEE 1016 1609 documents. 1018 o Removed outdated informative references to ETSI documents. 1020 o Added citations to IEEE 1609.2, .3 and .4-2016. 1022 o Minor textual issues. 1024 From draft-ietf-ipwave-ipv6-over-80211ocb-02 to draft-ietf-ipwave- 1025 ipv6-over-80211ocb-03 1027 o Keep the previous text on multiple addresses, so remove talk about 1028 MIP6, NEMOv6 and MCoA. 1030 o Clarified that a 'Beacon' is an IEEE 802.11 frame Beacon. 1032 o Clarified the figure showing Infrastructure mode and OCB mode side 1033 by side. 1035 o Added a reference to the IP Security Architecture RFC. 1037 o Detailed the IPv6-per-channel prohibition paragraph which reflects 1038 the discussion at the last IETF IPWAVE WG meeting. 1040 o Added section "Address Mapping -- Unicast". 1042 o Added the ".11 Trailer" to pictures of 802.11 frames. 1044 o Added text about SNAP carrying the Ethertype. 1046 o New RSU definition allowing for it be both a Router and not 1047 necessarily a Router some times. 1049 o Minor textual issues. 1051 From draft-ietf-ipwave-ipv6-over-80211ocb-01 to draft-ietf-ipwave- 1052 ipv6-over-80211ocb-02 1054 o Replaced almost all occurences of 802.11p with 802.11-OCB, leaving 1055 only when explanation of evolution was necessary. 1057 o Shortened by removing parameter details from a paragraph in the 1058 Introduction. 1060 o Moved a reference from Normative to Informative. 1062 o Added text in intro clarifying there is no handover spec at IEEE, 1063 and that 1609.2 does provide security services. 1065 o Named the contents the fields of the EthernetII header (including 1066 the Ethertype bitstring). 1068 o Improved relationship between two paragraphs describing the 1069 increase of the Sequence Number in 802.11 header upon IP 1070 fragmentation. 1072 o Added brief clarification of "tracking". 1074 From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave- 1075 ipv6-over-80211ocb-01 1077 o Introduced message exchange diagram illustrating differences 1078 between 802.11 and 802.11 in OCB mode. 1080 o Introduced an appendix listing for information the set of 802.11 1081 messages that may be transmitted in OCB mode. 1083 o Removed appendix sections "Privacy Requirements", "Authentication 1084 Requirements" and "Security Certificate Generation". 1086 o Removed appendix section "Non IP Communications". 1088 o Introductory phrase in the Security Considerations section. 1090 o Improved the definition of "OCB". 1092 o Introduced theoretical stacked layers about IPv6 and IEEE layers 1093 including EPD. 1095 o Removed the appendix describing the details of prohibiting IPv6 on 1096 certain channels relevant to 802.11-OCB. 1098 o Added a brief reference in the privacy text about a precise clause 1099 in IEEE 1609.3 and .4. 1101 o Clarified the definition of a Road Side Unit. 1103 o Removed the discussion about security of WSA (because is non-IP). 1105 o Removed mentioning of the GeoNetworking discussion. 1107 o Moved references to scientific articles to a separate 'overview' 1108 draft, and referred to it. 1110 Appendix B. 802.11p 1112 The term "802.11p" is an earlier definition. The behaviour of 1113 "802.11p" networks is rolled in the document IEEE Std 802.11-2016. 1114 In that document the term 802.11p disappears. Instead, each 802.11p 1115 feature is conditioned by the IEEE Management Information Base (MIB) 1116 attribute "OCBActivated" [IEEE-802.11-2016]. Whenever OCBActivated 1117 is set to true the IEEE Std 802.11-OCB state is activated. For 1118 example, an 802.11 STAtion operating outside the context of a basic 1119 service set has the OCBActivated flag set. Such a station, when it 1120 has the flag set, uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. 1122 Appendix C. Aspects introduced by the OCB mode to 802.11 1124 In the IEEE 802.11-OCB mode, all nodes in the wireless range can 1125 directly communicate with each other without involving authentication 1126 or association procedures. At link layer, it is necessary to set the 1127 same channel number (or frequency) on two stations that need to 1128 communicate with each other. The manner in which stations set their 1129 channel number is not specified in this document. Stations STA1 and 1130 STA2 can exchange IP packets if they are set on the same channel. At 1131 IP layer, they then discover each other by using the IPv6 Neighbor 1132 Discovery protocol. 1134 Briefly, the IEEE 802.11-OCB mode has the following properties: 1136 o The use by each node of a 'wildcard' BSSID (i.e., each bit of the 1137 BSSID is set to 1) 1139 o No IEEE 802.11 Beacon frames are transmitted 1141 o No authentication is required in order to be able to communicate 1142 o No association is needed in order to be able to communicate 1144 o No encryption is provided in order to be able to communicate 1146 o Flag dot11OCBActivated is set to true 1148 All the nodes in the radio communication range (IP-OBU and IP-RSU) 1149 receive all the messages transmitted (IP-OBU and IP-RSU) within the 1150 radio communications range. The eventual conflict(s) are resolved by 1151 the MAC CDMA function. 1153 The message exchange diagram in Figure 3 illustrates a comparison 1154 between traditional 802.11 and 802.11 in OCB mode. The 'Data' 1155 messages can be IP packets such as HTTP or others. Other 802.11 1156 management and control frames (non IP) may be transmitted, as 1157 specified in the 802.11 standard. For information, the names of 1158 these messages as currently specified by the 802.11 standard are 1159 listed in Appendix G. 1161 STA AP STA1 STA2 1162 | | | | 1163 |<------ Beacon -------| |<------ Data -------->| 1164 | | | | 1165 |---- Probe Req. ----->| |<------ Data -------->| 1166 |<--- Probe Res. ------| | | 1167 | | |<------ Data -------->| 1168 |---- Auth Req. ------>| | | 1169 |<--- Auth Res. -------| |<------ Data -------->| 1170 | | | | 1171 |---- Asso Req. ------>| |<------ Data -------->| 1172 |<--- Asso Res. -------| | | 1173 | | |<------ Data -------->| 1174 |<------ Data -------->| | | 1175 |<------ Data -------->| |<------ Data -------->| 1177 (i) 802.11 Infrastructure mode (ii) 802.11-OCB mode 1179 Figure 3: Difference between messages exchanged on 802.11 (left) and 1180 802.11-OCB (right) 1182 The interface 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010 1183 [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, 1184 titled "Amendment 6: Wireless Access in Vehicular Environments". 1185 Since then, this amendment has been integrated in IEEE 802.11(TM) 1186 -2012 and -2016 [IEEE-802.11-2016]. 1188 In document 802.11-2016, anything qualified specifically as 1189 "OCBActivated", or "outside the context of a basic service" set to be 1190 true, then it is actually referring to OCB aspects introduced to 1191 802.11. 1193 In order to delineate the aspects introduced by 802.11-OCB to 802.11, 1194 we refer to the earlier [IEEE-802.11p-2010]. The amendment is 1195 concerned with vehicular communications, where the wireless link is 1196 similar to that of Wireless LAN (using a PHY layer specified by 1197 802.11a/b/g/n), but which needs to cope with the high mobility factor 1198 inherent in scenarios of communications between moving vehicles, and 1199 between vehicles and fixed infrastructure deployed along roads. 1200 While 'p' is a letter identifying the Ammendment, just like 'a, b, g' 1201 and 'n' are, 'p' is concerned more with MAC modifications, and a 1202 little with PHY modifications; the others are mainly about PHY 1203 modifications. It is possible in practice to combine a 'p' MAC with 1204 an 'a' PHY by operating outside the context of a BSS with OFDM at 1205 5.4GHz and 5.9GHz. 1207 The 802.11-OCB links are specified to be compatible as much as 1208 possible with the behaviour of 802.11a/b/g/n and future generation 1209 IEEE WLAN links. From the IP perspective, an 802.11-OCB MAC layer 1210 offers practically the same interface to IP as the 802.11a/b/g/n and 1211 802.3. A packet sent by an IP-OBU may be received by one or multiple 1212 IP-RSUs. The link-layer resolution is performed by using the IPv6 1213 Neighbor Discovery protocol. 1215 To support this similarity statement (IPv6 is layered on top of LLC 1216 on top of 802.11-OCB, in the same way that IPv6 is layered on top of 1217 LLC on top of 802.11a/b/g/n (for WLAN) or layered on top of LLC on 1218 top of 802.3 (for Ethernet)) it is useful to analyze the differences 1219 between 802.11-OCB and 802.11 specifications. During this analysis, 1220 we note that whereas 802.11-OCB lists relatively complex and numerous 1221 changes to the MAC layer (and very little to the PHY layer), there 1222 are only a few characteristics which may be important for an 1223 implementation transmitting IPv6 packets on 802.11-OCB links. 1225 The most important 802.11-OCB point which influences the IPv6 1226 functioning is the OCB characteristic; an additional, less direct 1227 influence, is the maximum bandwidth afforded by the PHY modulation/ 1228 demodulation methods and channel access specified by 802.11-OCB. The 1229 maximum bandwidth theoretically possible in 802.11-OCB is 54 Mbit/s 1230 (when using, for example, the following parameters: 20 MHz channel; 1231 modulation 64-QAM; coding rate R is 3/4); in practice of IP-over- 1232 802.11-OCB a commonly observed figure is 12Mbit/s; this bandwidth 1233 allows the operation of a wide range of protocols relying on IPv6. 1235 o Operation Outside the Context of a BSS (OCB): the (earlier 1236 802.11p) 802.11-OCB links are operated without a Basic Service Set 1237 (BSS). This means that the frames IEEE 802.11 Beacon, Association 1238 Request/Response, Authentication Request/Response, and similar, 1239 are not used. The used identifier of BSS (BSSID) has a 1240 hexadecimal value always 0xffffffffffff (48 '1' bits, represented 1241 as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' 1242 BSSID), as opposed to an arbitrary BSSID value set by 1243 administrator (e.g. 'My-Home-AccessPoint'). The OCB operation - 1244 namely the lack of beacon-based scanning and lack of 1245 authentication - should be taken into account when the Mobile IPv6 1246 protocol [RFC6275] and the protocols for IP layer security 1247 [RFC4301] are used. The way these protocols adapt to OCB is not 1248 described in this document. 1250 o Timing Advertisement: is a new message defined in 802.11-OCB, 1251 which does not exist in 802.11a/b/g/n. This message is used by 1252 stations to inform other stations about the value of time. It is 1253 similar to the time as delivered by a GNSS system (Galileo, GPS, 1254 ...) or by a cellular system. This message is optional for 1255 implementation. 1257 o Frequency range: this is a characteristic of the PHY layer, with 1258 almost no impact on the interface between MAC and IP. However, it 1259 is worth considering that the frequency range is regulated by a 1260 regional authority (ARCEP, ECC/CEPT based on ENs from ETSI, FCC, 1261 etc.); as part of the regulation process, specific applications 1262 are associated with specific frequency ranges. In the case of 1263 802.11-OCB, the regulator associates a set of frequency ranges, or 1264 slots within a band, to the use of applications of vehicular 1265 communications, in a band known as "5.9GHz". The 5.9GHz band is 1266 different from the 2.4GHz and 5GHz bands used by Wireless LAN. 1267 However, as with Wireless LAN, the operation of 802.11-OCB in 1268 "5.9GHz" bands is exempt from owning a license in EU (in US the 1269 5.9GHz is a licensed band of spectrum; for the fixed 1270 infrastructure an explicit FCC authorization is required; for an 1271 on-board device a 'licensed-by-rule' concept applies: rule 1272 certification conformity is required.) Technical conditions are 1273 different than those of the bands "2.4GHz" or "5GHz". The allowed 1274 power levels, and implicitly the maximum allowed distance between 1275 vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20 1276 dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum 1277 distance of approximately 1km, compared to approximately 50m. 1278 Additionally, specific conditions related to congestion avoidance, 1279 jamming avoidance, and radar detection are imposed on the use of 1280 DSRC (in US) and on the use of frequencies for Intelligent 1281 Transportation Systems (in EU), compared to Wireless LAN 1282 (802.11a/b/g/n). 1284 o 'Half-rate' encoding: as the frequency range, this parameter is 1285 related to PHY, and thus has not much impact on the interface 1286 between the IP layer and the MAC layer. 1288 o In vehicular communications using 802.11-OCB links, there are 1289 strong privacy requirements with respect to addressing. While the 1290 802.11-OCB standard does not specify anything in particular with 1291 respect to MAC addresses, in these settings there exists a strong 1292 need for dynamic change of these addresses (as opposed to the non- 1293 vehicular settings - real wall protection - where fixed MAC 1294 addresses do not currently pose some privacy risks). This is 1295 further described in Section 5. A relevant function is described 1296 in IEEE 1609.3-2016 [IEEE-1609.3], clause 5.5.1 and IEEE 1297 1609.4-2016 [IEEE-1609.4], clause 6.7. 1299 Appendix D. Changes Needed on a software driver 802.11a to become a 1300 802.11-OCB driver 1302 The 802.11p amendment modifies both the 802.11 stack's physical and 1303 MAC layers but all the induced modifications can be quite easily 1304 obtained by modifying an existing 802.11a ad-hoc stack. 1306 Conditions for a 802.11a hardware to be 802.11-OCB compliant: 1308 o The PHY entity shall be an orthogonal frequency division 1309 multiplexing (OFDM) system. It must support the frequency bands 1310 on which the regulator recommends the use of ITS communications, 1311 for example using IEEE 802.11-OCB layer, in France: 5875MHz to 1312 5925MHz. 1314 o The OFDM system must provide a "half-clocked" operation using 10 1315 MHz channel spacings. 1317 o The chip transmit spectrum mask must be compliant to the "Transmit 1318 spectrum mask" from the IEEE 802.11p amendment (but experimental 1319 environments tolerate otherwise). 1321 o The chip should be able to transmit up to 44.8 dBm when used by 1322 the US government in the United States, and up to 33 dBm in 1323 Europe; other regional conditions apply. 1325 Changes needed on the network stack in OCB mode: 1327 o Physical layer: 1329 * The chip must use the Orthogonal Frequency Multiple Access 1330 (OFDM) encoding mode. 1332 * The chip must be set in half-mode rate mode (the internal clock 1333 frequency is divided by two). 1335 * The chip must use dedicated channels and should allow the use 1336 of higher emission powers. This may require modifications to 1337 the local computer file that describes regulatory domains 1338 rules, if used by the kernel to enforce local specific 1339 restrictions. Such modifications to the local computer file 1340 must respect the location-specific regulatory rules. 1342 MAC layer: 1344 * All management frames (beacons, join, leave, and others) 1345 emission and reception must be disabled except for frames of 1346 subtype Action and Timing Advertisement (defined below). 1348 * No encryption key or method must be used. 1350 * Packet emission and reception must be performed as in ad-hoc 1351 mode, using the wildcard BSSID (ff:ff:ff:ff:ff:ff). 1353 * The functions related to joining a BSS (Association Request/ 1354 Response) and for authentication (Authentication Request/Reply, 1355 Challenge) are not called. 1357 * The beacon interval is always set to 0 (zero). 1359 * Timing Advertisement frames, defined in the amendment, should 1360 be supported. The upper layer should be able to trigger such 1361 frames emission and to retrieve information contained in 1362 received Timing Advertisements. 1364 Appendix E. EtherType Protocol Discrimination (EPD) 1366 A more theoretical and detailed view of layer stacking, and 1367 interfaces between the IP layer and 802.11-OCB layers, is illustrated 1368 in Figure 4. The IP layer operates on top of the EtherType Protocol 1369 Discrimination (EPD); this Discrimination layer is described in IEEE 1370 Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP 1371 (Link Layer Control Service Access Point). 1373 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1374 | IPv6 | 1375 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ 1376 { LLC_SAP } 802.11-OCB 1377 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary 1378 | EPD | | | 1379 | | MLME | | 1380 +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | 1381 | MAC Sublayer | | | 802.11-OCB 1382 | and ch. coord. | | SME | Services 1383 +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | 1384 | | PLME | | 1385 | PHY Layer | PLME_SAP | 1386 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1388 Figure 4: EtherType Protocol Discrimination 1390 Appendix F. Design Considerations 1392 The networks defined by 802.11-OCB are in many ways similar to other 1393 networks of the 802.11 family. In theory, the encapsulation of IPv6 1394 over 802.11-OCB could be very similar to the operation of IPv6 over 1395 other networks of the 802.11 family. However, the high mobility, 1396 strong link asymmetry and very short connection makes the 802.11-OCB 1397 link significantly different from other 802.11 networks. Also, the 1398 automotive applications have specific requirements for reliability, 1399 security and privacy, which further add to the particularity of the 1400 802.11-OCB link. 1402 F.1. Vehicle ID 1404 In automotive networks it is required that each node is represented 1405 uniquely at a certain point in time. Accordingly, a vehicle must be 1406 identified by at least one unique identifier. The current 1407 specification at ETSI and at IEEE 1609 identifies a vehicle by its 1408 MAC address, which is obtained from the 802.11-OCB Network Interface 1409 Card (NIC). 1411 In case multiple 802.11-OCB NICs are present in one car, implicitely 1412 multiple vehicle IDs will be generated. Additionally, some software 1413 generates a random MAC address each time the computer boots; this 1414 constitutes an additional difficulty. 1416 A mechanim to uniquely identify a vehicle irrespectively to the 1417 multiplicity of NICs, or frequent MAC address generation, is 1418 necessary. 1420 F.2. Reliability Requirements 1422 The dynamically changing topology, short connectivity, mobile 1423 transmitter and receivers, different antenna heights, and many-to- 1424 many communication types, make IEEE 802.11-OCB links significantly 1425 different from other IEEE 802.11 links. Any IPv6 mechanism operating 1426 on IEEE 802.11-OCB link must support strong link asymmetry, spatio- 1427 temporal link quality, fast address resolution and transmission. 1429 IEEE 802.11-OCB strongly differs from other 802.11 systems to operate 1430 outside of the context of a Basic Service Set. This means in 1431 practice that IEEE 802.11-OCB does not rely on a Base Station for all 1432 Basic Service Set management. In particular, IEEE 802.11-OCB shall 1433 not use beacons. Any IPv6 mechanism requiring L2 services from IEEE 1434 802.11 beacons must support an alternative service. 1436 Channel scanning being disabled, IPv6 over IEEE 802.11-OCB must 1437 implement a mechanism for transmitter and receiver to converge to a 1438 common channel. 1440 Authentication not being possible, IPv6 over IEEE 802.11-OCB must 1441 implement an distributed mechanism to authenticate transmitters and 1442 receivers without the support of a DHCP server. 1444 Time synchronization not being available, IPv6 over IEEE 802.11-OCB 1445 must implement a higher layer mechanism for time synchronization 1446 between transmitters and receivers without the support of a NTP 1447 server. 1449 The IEEE 802.11-OCB link being asymmetric, IPv6 over IEEE 802.11-OCB 1450 must disable management mechanisms requesting acknowledgements or 1451 replies. 1453 The IEEE 802.11-OCB link having a short duration time, IPv6 over IEEE 1454 802.11-OCB should implement fast IPv6 mobility management mechanisms. 1456 F.3. Multiple interfaces 1458 There are considerations for 2 or more IEEE 802.11-OCB interface 1459 cards per vehicle. For each vehicle taking part in road traffic, one 1460 IEEE 802.11-OCB interface card could be fully allocated for Non IP 1461 safety-critical communication. Any other IEEE 802.11-OCB may be used 1462 for other type of traffic. 1464 The mode of operation of these other wireless interfaces is not 1465 clearly defined yet. One possibility is to consider each card as an 1466 independent network interface, with a specific MAC Address and a set 1467 of IPv6 addresses. Another possibility is to consider the set of 1468 these wireless interfaces as a single network interface (not 1469 including the IEEE 802.11-OCB interface used by Non IP safety 1470 critical communications). This will require specific logic to 1471 ensure, for example, that packets meant for a vehicle in front are 1472 actually sent by the radio in the front, or that multiple copies of 1473 the same packet received by multiple interfaces are treated as a 1474 single packet. Treating each wireless interface as a separate 1475 network interface pushes such issues to the application layer. 1477 Certain privacy requirements imply that if these multiple interfaces 1478 are represented by many network interface, a single renumbering event 1479 shall cause renumbering of all these interfaces. If one MAC changed 1480 and another stayed constant, external observers would be able to 1481 correlate old and new values, and the privacy benefits of 1482 randomization would be lost. 1484 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode 1486 For information, at the time of writing, this is the list of IEEE 1487 802.11 messages that may be transmitted in OCB mode, i.e. when 1488 dot11OCBActivated is true in a STA: 1490 o The STA may send management frames of subtype Action and, if the 1491 STA maintains a TSF Timer, subtype Timing Advertisement; 1493 o The STA may send control frames, except those of subtype PS-Poll, 1494 CF-End, and CF-End plus CFAck; 1496 o The STA may send data frames of subtype Data, Null, QoS Data, and 1497 QoS Null. 1499 Appendix H. Examples of Packet Formats 1501 This section describes an example of an IPv6 Packet captured over a 1502 IEEE 802.11-OCB link. 1504 By way of example we show that there is no modification in the 1505 headers when transmitted over 802.11-OCB networks - they are 1506 transmitted like any other 802.11 and Ethernet packets. 1508 We describe an experiment of capturing an IPv6 packet on an 1509 802.11-OCB link. In topology depicted in Figure 5, the packet is an 1510 IPv6 Router Advertisement. This packet is emitted by a Router on its 1511 802.11-OCB interface. The packet is captured on the Host, using a 1512 network protocol analyzer (e.g. Wireshark); the capture is performed 1513 in two different modes: direct mode and 'monitor' mode. The topology 1514 used during the capture is depicted below. 1516 The packet is captured on the Host. The Host is an IP-OBU containing 1517 an 802.11 interface in format PCI express (an ITRI product). The 1518 kernel runs the ath5k software driver with modifications for OCB 1519 mode. The capture tool is Wireshark. The file format for save and 1520 analyze is 'pcap'. The packet is generated by the Router. The 1521 Router is an IP-RSU (ITRI product). 1523 +--------+ +-------+ 1524 | | 802.11-OCB Link | | 1525 ---| Router |--------------------------------| Host | 1526 | | | | 1527 +--------+ +-------+ 1529 Figure 5: Topology for capturing IP packets on 802.11-OCB 1531 During several capture operations running from a few moments to 1532 several hours, no message relevant to the BSSID contexts were 1533 captured (no Association Request/Response, Authentication Req/Resp, 1534 Beacon). This shows that the operation of 802.11-OCB is outside the 1535 context of a BSSID. 1537 Overall, the captured message is identical with a capture of an IPv6 1538 packet emitted on a 802.11b interface. The contents are precisely 1539 similar. 1541 H.1. Capture in Monitor Mode 1543 The IPv6 RA packet captured in monitor mode is illustrated below. 1544 The radio tap header provides more flexibility for reporting the 1545 characteristics of frames. The Radiotap Header is prepended by this 1546 particular stack and operating system on the Host machine to the RA 1547 packet received from the network (the Radiotap Header is not present 1548 on the air). The implementation-dependent Radiotap Header is useful 1549 for piggybacking PHY information from the chip's registers as data in 1550 a packet understandable by userland applications using Socket 1551 interfaces (the PHY interface can be, for example: power levels, data 1552 rate, ratio of signal to noise). 1554 The packet present on the air is formed by IEEE 802.11 Data Header, 1555 Logical Link Control Header, IPv6 Base Header and ICMPv6 Header. 1557 Radiotap Header v0 1558 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1559 |Header Revision| Header Pad | Header length | 1560 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1561 | Present flags | 1562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1563 | Data Rate | Pad | 1564 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1566 IEEE 802.11 Data Header 1567 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1568 | Type/Subtype and Frame Ctrl | Duration | 1569 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1570 | Receiver Address... 1571 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1572 ... Receiver Address | Transmitter Address... 1573 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1574 ... Transmitter Address | 1575 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1576 | BSS Id... 1577 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1578 ... BSS Id | Frag Number and Seq Number | 1579 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1581 Logical-Link Control Header 1582 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1583 | DSAP |I| SSAP |C| Control field | Org. code... 1584 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1585 ... Organizational Code | Type | 1586 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1588 IPv6 Base Header 1589 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1590 |Version| Traffic Class | Flow Label | 1591 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1592 | Payload Length | Next Header | Hop Limit | 1593 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1594 | | 1595 + + 1596 | | 1597 + Source Address + 1598 | | 1599 + + 1600 | | 1601 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1602 | | 1603 + + 1604 | | 1605 + Destination Address + 1606 | | 1607 + + 1608 | | 1609 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1611 Router Advertisement 1612 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1613 | Type | Code | Checksum | 1614 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1615 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1616 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1617 | Reachable Time | 1618 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1619 | Retrans Timer | 1620 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1621 | Options ... 1622 +-+-+-+-+-+-+-+-+-+-+-+- 1624 The value of the Data Rate field in the Radiotap header is set to 6 1625 Mb/s. This indicates the rate at which this RA was received. 1627 The value of the Transmitter address in the IEEE 802.11 Data Header 1628 is set to a 48bit value. The value of the destination address is 1629 33:33:00:00:00:1 (all-nodes multicast address). The value of the BSS 1630 Id field is ff:ff:ff:ff:ff:ff, which is recognized by the network 1631 protocol analyzer as being "broadcast". The Fragment number and 1632 sequence number fields are together set to 0x90C6. 1634 The value of the Organization Code field in the Logical-Link Control 1635 Header is set to 0x0, recognized as "Encapsulated Ethernet". The 1636 value of the Type field is 0x86DD (hexadecimal 86DD, or otherwise 1637 #86DD), recognized as "IPv6". 1639 A Router Advertisement is periodically sent by the router to 1640 multicast group address ff02::1. It is an icmp packet type 134. The 1641 IPv6 Neighbor Discovery's Router Advertisement message contains an 1642 8-bit field reserved for single-bit flags, as described in [RFC4861]. 1644 The IPv6 header contains the link local address of the router 1645 (source) configured via EUI-64 algorithm, and destination address set 1646 to ff02::1. 1648 The Ethernet Type field in the logical-link control header is set to 1649 0x86dd which indicates that the frame transports an IPv6 packet. In 1650 the IEEE 802.11 data, the destination address is 33:33:00:00:00:01 1651 which is the corresponding multicast MAC address. The BSS id is a 1652 broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link 1653 duration between vehicles and the roadside infrastructure, there is 1654 no need in IEEE 802.11-OCB to wait for the completion of association 1655 and authentication procedures before exchanging data. IEEE 1656 802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s) 1657 and may start communicating as soon as they arrive on the 1658 communication channel. 1660 H.2. Capture in Normal Mode 1662 The same IPv6 Router Advertisement packet described above (monitor 1663 mode) is captured on the Host, in the Normal mode, and depicted 1664 below. 1666 Ethernet II Header 1667 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1668 | Destination... 1669 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1670 ...Destination | Source... 1671 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1672 ...Source | 1673 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1674 | Type | 1675 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1677 IPv6 Base Header 1678 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1679 |Version| Traffic Class | Flow Label | 1680 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1681 | Payload Length | Next Header | Hop Limit | 1682 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1683 | | 1684 + + 1685 | | 1686 + Source Address + 1687 | | 1688 + + 1689 | | 1690 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1691 | | 1692 + + 1693 | | 1694 + Destination Address + 1695 | | 1696 + + 1697 | | 1698 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1700 Router Advertisement 1701 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1702 | Type | Code | Checksum | 1703 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1704 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1705 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1706 | Reachable Time | 1707 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1708 | Retrans Timer | 1709 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1710 | Options ... 1711 +-+-+-+-+-+-+-+-+-+-+-+- 1713 One notices that the Radiotap Header, the IEEE 802.11 Data Header and 1714 the Logical-Link Control Headers are not present. On the other hand, 1715 a new header named Ethernet II Header is present. 1717 The Destination and Source addresses in the Ethernet II header 1718 contain the same values as the fields Receiver Address and 1719 Transmitter Address present in the IEEE 802.11 Data Header in the 1720 "monitor" mode capture. 1722 The value of the Type field in the Ethernet II header is 0x86DD 1723 (recognized as "IPv6"); this value is the same value as the value of 1724 the field Type in the Logical-Link Control Header in the "monitor" 1725 mode capture. 1727 The knowledgeable experimenter will no doubt notice the similarity of 1728 this Ethernet II Header with a capture in normal mode on a pure 1729 Ethernet cable interface. 1731 An Adaptation layer is inserted on top of a pure IEEE 802.11 MAC 1732 layer, in order to adapt packets, before delivering the payload data 1733 to the applications. It adapts 802.11 LLC/MAC headers to Ethernet II 1734 headers. In further detail, this adaptation consists in the 1735 elimination of the Radiotap, 802.11 and LLC headers, and in the 1736 insertion of the Ethernet II header. In this way, IPv6 runs straight 1737 over LLC over the 802.11-OCB MAC layer; this is further confirmed by 1738 the use of the unique Type 0x86DD. 1740 Appendix I. Extra Terminology 1742 The following terms are defined outside the IETF. They are used to 1743 define the main terms in the main terminology section Section 2. 1745 DSRC (Dedicated Short Range Communication): a term defined outside 1746 the IETF. The US Federal Communications Commission (FCC) Dedicated 1747 Short Range Communication (DSRC) is defined in the Code of Federal 1748 Regulations (CFR) 47, Parts 90 and 95. This Code is referred in the 1749 definitions below. At the time of the writing of this Internet 1750 Draft, the last update of this Code was dated October 1st, 2010. 1752 DSRCS (Dedicated Short-Range Communications Services): a term defined 1753 outside the IETF. The use of radio techniques to transfer data over 1754 short distances between roadside and mobile units, between mobile 1755 units, and between portable and mobile units to perform operations 1756 related to the improvement of traffic flow, traffic safety, and other 1757 intelligent transportation service applications in a variety of 1758 environments. DSRCS systems may also transmit status and 1759 instructional messages related to the units involve. [Ref. 47 CFR 1760 90.7 - Definitions] 1761 OBU (On-Board Unit): a term defined outside the IETF. An On-Board 1762 Unit is a DSRCS transceiver that is normally mounted in or on a 1763 vehicle, or which in some instances may be a portable unit. An OBU 1764 can be operational while a vehicle or person is either mobile or 1765 stationary. The OBUs receive and contend for time to transmit on one 1766 or more radio frequency (RF) channels. Except where specifically 1767 excluded, OBU operation is permitted wherever vehicle operation or 1768 human passage is permitted. The OBUs mounted in vehicles are 1769 licensed by rule under part 95 of the respective chapter and 1770 communicate with Roadside Units (RSUs) and other OBUs. Portable OBUs 1771 are also licensed by rule under part 95 of the respective chapter. 1772 OBU operations in the Unlicensed National Information Infrastructure 1773 (UNII) Bands follow the rules in those bands. - [CFR 90.7 - 1774 Definitions]. 1776 RSU (Road-Side Unit): a term defined outside of IETF. A Roadside 1777 Unit is a DSRC transceiver that is mounted along a road or pedestrian 1778 passageway. An RSU may also be mounted on a vehicle or is hand 1779 carried, but it may only operate when the vehicle or hand- carried 1780 unit is stationary. Furthermore, an RSU operating under the 1781 respectgive part is restricted to the location where it is licensed 1782 to operate. However, portable or hand-held RSUs are permitted to 1783 operate where they do not interfere with a site-licensed operation. 1784 A RSU broadcasts data to OBUs or exchanges data with OBUs in its 1785 communications zone. An RSU also provides channel assignments and 1786 operating instructions to OBUs in its communications zone, when 1787 required. - [CFR 90.7 - Definitions]. 1789 Authors' Addresses 1791 Alexandre Petrescu 1792 CEA, LIST 1793 CEA Saclay 1794 Gif-sur-Yvette , Ile-de-France 91190 1795 France 1797 Phone: +33169089223 1798 Email: Alexandre.Petrescu@cea.fr 1800 Nabil Benamar 1801 Moulay Ismail University 1802 Morocco 1804 Phone: +212670832236 1805 Email: n.benamar@est.umi.ac.ma 1806 Jerome Haerri 1807 Eurecom 1808 Sophia-Antipolis 06904 1809 France 1811 Phone: +33493008134 1812 Email: Jerome.Haerri@eurecom.fr 1814 Jong-Hyouk Lee 1815 Sangmyung University 1816 31, Sangmyeongdae-gil, Dongnam-gu 1817 Cheonan 31066 1818 Republic of Korea 1820 Email: jonghyouk@smu.ac.kr 1822 Thierry Ernst 1823 YoGoKo 1824 France 1826 Email: thierry.ernst@yogoko.fr