idnits 2.17.1 draft-ietf-ipwave-ipv6-over-80211ocb-28.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 19, 2018) is 2046 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 23, 2019 Moulay Ismail University 6 J. Haerri 7 Eurecom 8 J. Lee 9 Sangmyung University 10 T. Ernst 11 YoGoKo 12 September 19, 2018 14 Transmission of IPv6 Packets over IEEE 802.11 Networks operating in mode 15 Outside the Context of a Basic Service Set (IPv6-over-80211-OCB) 16 draft-ietf-ipwave-ipv6-over-80211ocb-28 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 23, 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. Pseudonym Handling . . . . . . . . . . . . . . . . . . . 5 69 4.2. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 5 70 4.3. Frame Format . . . . . . . . . . . . . . . . . . . . . . 5 71 4.3.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 5 72 4.4. Link-Local Addresses . . . . . . . . . . . . . . . . . . 7 73 4.5. Address Mapping . . . . . . . . . . . . . . . . . . . . . 7 74 4.5.1. Address Mapping -- Unicast . . . . . . . . . . . . . 7 75 4.5.2. Address Mapping -- Multicast . . . . . . . . . . . . 7 76 4.6. Stateless Autoconfiguration . . . . . . . . . . . . . . . 7 77 4.7. Subnet Structure . . . . . . . . . . . . . . . . . . . . 8 78 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 79 5.1. Privacy Considerations . . . . . . . . . . . . . . . . . 10 80 5.2. MAC Address and Interface ID Generation . . . . . . . . . 10 81 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 82 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 11 83 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 84 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 85 9.1. Normative References . . . . . . . . . . . . . . . . . . 12 86 9.2. Informative References . . . . . . . . . . . . . . . . . 14 87 Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 16 88 Appendix B. 802.11p . . . . . . . . . . . . . . . . . . . . . . 25 89 Appendix C. Aspects introduced by the OCB mode to 802.11 . . . . 25 90 Appendix D. Changes Needed on a software driver 802.11a to 91 become a 802.11-OCB driver . . . 29 92 Appendix E. EtherType Protocol Discrimination (EPD) . . . . . . 30 93 Appendix F. Design Considerations . . . . . . . . . . . . . . . 31 94 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 31 95 Appendix H. Examples of Packet Formats . . . . . . . . . . . . . 32 96 H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 33 97 H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 35 98 Appendix I. Extra Terminology . . . . . . . . . . . . . . . . . 37 99 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38 101 1. Introduction 103 This document describes the transmission of IPv6 packets on IEEE Std 104 802.11-OCB networks [IEEE-802.11-2016] (a.k.a "802.11p" see 105 Appendix B, Appendix C and Appendix D). This involves the layering 106 of IPv6 networking on top of the IEEE 802.11 MAC layer, with an LLC 107 layer. Compared to running IPv6 over the Ethernet MAC layer, there 108 is no modification expected to IEEE Std 802.11 MAC and Logical Link 109 sublayers: IPv6 works fine directly over 802.11-OCB too, with an LLC 110 layer. 112 The IPv6 network layer operates on 802.11-OCB in the same manner as 113 operating on Ethernet, but there are two kinds of exceptions: 115 o Exceptions due to different operation of IPv6 network layer on 116 802.11 than on Ethernet. To satisfy these exceptions, this 117 document describes an Ethernet Adaptation Layer between Ethernet 118 headers and 802.11 headers. The Ethernet Adaptation Layer is 119 described Section 4.3.1. The operation of IP on Ethernet is 120 described in [RFC1042], [RFC2464] and 121 [I-D.hinden-6man-rfc2464bis]. 123 o Exceptions due to the OCB nature of 802.11-OCB compared to 802.11. 124 This has impacts on security, privacy, subnet structure and 125 handover behaviour. For security and privacy recommendations see 126 Section 5 and Section 4.6. The subnet structure is described in 127 Section 4.7. The handover behaviour on OCB links is not described 128 in this document. 130 The Security Considerations section describes security and privacy 131 aspects of 802.11-OCB. 133 In the published literature, many documents describe aspects and 134 problems related to running IPv6 over 802.11-OCB: 135 [I-D.ietf-ipwave-vehicular-networking-survey]. 137 2. Terminology 139 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 140 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 141 document are to be interpreted as described in RFC 2119 [RFC2119]. 143 IP-OBU (Internet Protocol On-Board Unit): an IP-OBU is a computer 144 situated in a vehicle such as an automobile, bicycle, or similar. It 145 has at least one IP interface that runs in mode OCB of 802.11, and 146 that has an "OBU" transceiver. See the definition of the term "OBU" 147 in section Appendix I. 149 IP-RSU (IP Road-Side Unit): an IP-RSU is situated along the road. It 150 has at least two distinct IP-enabled interfaces; the wireless PHY/MAC 151 layer of at least one of its IP-enabled interfaces is configured to 152 operate in 802.11-OCB mode. An IP-RSU communicates with the IP-OBU 153 in the vehicle over 802.11 wireless link operating in OCB mode. An 154 IP-RSU is similar to an Access Network Router (ANR) defined in 155 [RFC3753], and a Wireless Termination Point (WTP) defined in 156 [RFC5415]. 158 OCB (outside the context of a basic service set - BSS): A mode of 159 operation in which a STA is not a member of a BSS and does not 160 utilize IEEE Std 802.11 authentication, association, or data 161 confidentiality. 163 802.11-OCB: mode specified in IEEE Std 802.11-2016 when the MIB 164 attribute dot11OCBActivited is true. Note: compliance with standards 165 and regulations set in different countries when using the 5.9GHz 166 frequency band is required. 168 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 170 The IEEE 802.11-OCB Networks are used for vehicular communications, 171 as 'Wireless Access in Vehicular Environments'. The IP communication 172 scenarios for these environments have been described in several 173 documents; in particular, we refer the reader to 174 [I-D.ietf-ipwave-vehicular-networking-survey], that lists some 175 scenarios and requirements for IP in Intelligent Transportation 176 Systems. 178 The link model is the following: STA --- 802.11-OCB --- STA. In 179 vehicular networks, STAs can be IP-RSUs and/or IP-OBUs. While 180 802.11-OCB is clearly specified, and the use of IPv6 over such link 181 is not radically new, the operating environment (vehicular networks) 182 brings in new perspectives. 184 The mechanisms for forming and terminating, discovering, peering and 185 mobility management for 802.11-OCB links are not described in this 186 document. 188 4. IPv6 over 802.11-OCB 190 4.1. Pseudonym Handling 192 Pseudonym. 194 4.2. Maximum Transmission Unit (MTU) 196 The default MTU for IP packets on 802.11-OCB MUST be 1500 octets. It 197 is the same value as IPv6 packets on Ethernet links, as specified in 198 [RFC2464]. This value of the MTU respects the recommendation that 199 every link on the Internet must have a minimum MTU of 1280 octets 200 (stated in [RFC8200], and the recommendations therein, especially 201 with respect to fragmentation). 203 4.3. Frame Format 205 IP packets MUST be transmitted over 802.11-OCB media as QoS Data 206 frames whose format is specified in IEEE Std 802.11. 208 The IPv6 packet transmitted on 802.11-OCB MUST be immediately 209 preceded by a Logical Link Control (LLC) header and an 802.11 header. 210 In the LLC header, and in accordance with the EtherType Protocol 211 Discrimination (EPD), the value of the Type field MUST be set to 212 0x86DD (IPv6). In the 802.11 header, the value of the Subtype sub- 213 field in the Frame Control field MUST be set to 8 (i.e. 'QoS Data'); 214 the value of the Traffic Identifier (TID) sub-field of the QoS 215 Control field of the 802.11 header MUST be set to binary 001 (i.e. 216 User Priority 'Background', QoS Access Category 'AC_BK'). 218 To simplify the Application Programming Interface (API) between the 219 operating system and the 802.11-OCB media, device drivers MAY 220 implement an Ethernet Adaptation Layer that translates Ethernet II 221 frames to the 802.11 format and vice versa. An Ethernet Adaptation 222 Layer is described in Section 4.3.1. 224 4.3.1. Ethernet Adaptation Layer 226 An 'adaptation' layer is inserted between a MAC layer and the 227 Networking layer. This is used to transform some parameters between 228 their form expected by the IP stack and the form provided by the MAC 229 layer. 231 An Ethernet Adaptation Layer makes an 802.11 MAC look to IP 232 Networking layer as a more traditional Ethernet layer. At reception, 233 this layer takes as input the IEEE 802.11 header and the Logical-Link 234 Layer Control Header and produces an Ethernet II Header. At sending, 235 the reverse operation is performed. 237 The operation of the Ethernet Adaptation Layer is depicted by the 238 double arrow in Figure 1. 240 +------------------+------------+-------------+---------+-----------+ 241 | 802.11 header | LLC Header | IPv6 Header | Payload |.11 Trailer| 242 +------------------+------------+-------------+---------+-----------+ 243 \ / \ / 244 --------------------------- -------- 245 \---------------------------------------------/ 246 ^ 247 | 248 802.11-to-Ethernet Adaptation Layer 249 | 250 v 251 +---------------------+-------------+---------+ 252 | Ethernet II Header | IPv6 Header | Payload | 253 +---------------------+-------------+---------+ 255 Figure 1: Operation of the Ethernet Adaptation Layer 257 The Receiver and Transmitter Address fields in the 802.11 header MUST 258 contain the same values as the Destination and the Source Address 259 fields in the Ethernet II Header, respectively. The value of the 260 Type field in the LLC Header MUST be the same as the value of the 261 Type field in the Ethernet II Header. That value MUST be set to 262 0x86DD (IPv6). 264 The ".11 Trailer" contains solely a 4-byte Frame Check Sequence. 266 The placement of IPv6 networking layer on Ethernet Adaptation Layer 267 is illustrated in Figure 2. 269 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 270 | IPv6 | 271 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 272 | Ethernet Adaptation Layer | 273 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 274 | 802.11 MAC | 275 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 276 | 802.11 PHY | 277 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 279 Figure 2: Ethernet Adaptation Layer stacked with other layers 281 (in the above figure, a 802.11 profile is represented; this is used 282 also for 802.11-OCB profile.) 284 4.4. Link-Local Addresses 286 There are several types of IPv6 addresses [RFC4291], [RFC4193], that 287 MAY be assigned to an 802.11-OCB interface. Among these types of 288 addresses only the IPv6 link-local addresses MAY be formed using an 289 EUI-64 identifier. 291 If the IPv6 link-local address is formed using an EUI-64 identifier, 292 then the mechanism of forming that address is the same mechanism as 293 used to form an IPv6 link-local address on Ethernet links. This 294 mechanism is described in section 5 of [RFC2464]. 296 For privacy, the link-local address MAY be formed according to the 297 mechanisms described in Section 5.2. 299 4.5. Address Mapping 301 Unicast and multicast address mapping MUST follow the procedures 302 specified for Ethernet interfaces in sections 6 and 7 of [RFC2464]. 304 4.5.1. Address Mapping -- Unicast 306 The procedure for mapping IPv6 unicast addresses into Ethernet link- 307 layer addresses is described in [RFC4861]. 309 4.5.2. Address Mapping -- Multicast 311 The multicast address mapping is performed according to the method 312 specified in section 7 of [RFC2464]. The meaning of the value "3333" 313 mentioned in that section 7 of [RFC2464] is defined in section 2.3.1 314 of [RFC7042]. 316 Transmitting IPv6 packets to multicast destinations over 802.11 links 317 proved to have some performance issues 318 [I-D.perkins-intarea-multicast-ieee802]. These issues may be 319 exacerbated in OCB mode. Solutions for these problems should 320 consider the OCB mode of operation. 322 4.6. Stateless Autoconfiguration 324 There are several types of IPv6 addresses [RFC4291], [RFC4193], that 325 MAY be assigned to an 802.11-OCB interface. This section describes 326 the formation of Interface Identifiers for IPv6 addresses of type 327 'Global' or 'Unique Local'. For Interface Identifiers for IPv6 328 address of type 'Link-Local' see Section 4.4. 330 The Interface Identifier for an 802.11-OCB interface is formed using 331 the same rules as the Interface Identifier for an Ethernet interface; 332 the RECOMMENDED method for forming stable Interface Identifiers 333 (IIDs) is described in [RFC8064]. The method of forming IIDs 334 described in section 4 of [RFC2464] MAY be used during transition 335 time. 337 The bits in the Interface Identifier have no generic meaning and the 338 identifier should be treated as an opaque value. The bits 339 'Universal' and 'Group' in the identifier of an 802.11-OCB interface 340 are significant, as this is an IEEE link-layer address. The details 341 of this significance are described in [RFC7136]. If semantically 342 opaque Interface Identifiers are needed, a potential method for 343 generating semantically opaque Interface Identifiers with IPv6 344 Stateless Address Autoconfiguration is given in [RFC7217]. 346 The way Interface Identifiers are used MAY involve risks to privacy, 347 as described in Section 5.1. 349 4.7. Subnet Structure 351 A subnet is formed by the external 802.11-OCB interfaces of vehicles 352 that are in close range (not by their in-vehicle interfaces). This 353 subnet MUST use at least the link-local prefix fe80::/10 and the 354 interfaces MUST be assigned IPv6 addresses of type link-local. This 355 subnet MAY NOT have any other prefix than the link-local prefix. 357 The structure of this subnet is ephemeral, in that it is strongly 358 influenced by the mobility of vehicles: the 802.11 hidden node 359 effects appear; the 802.11 networks in OCB mode may be considered as 360 'ad-hoc' networks with an addressing model as described in [RFC5889]. 361 On another hand, the structure of the internal subnets in each car is 362 relatively stable. 364 As recommended in [RFC5889], when the timing requirements are very 365 strict (e.g. fast drive through IP-RSU coverage), no on-link subnet 366 prefix should be configured on an 802.11-OCB interface. In such 367 cases, the exclusive use of IPv6 link-local addresses is RECOMMENDED. 369 Additionally, even if the timing requirements are not very strict 370 (e.g. the moving subnet formed by two following vehicles is stable, a 371 fixed IP-RSU is absent), the subnet is disconnected from the Internet 372 (a default route is absent), and the addressing peers are equally 373 qualified (impossible to determine that some vehicle owns and 374 distributes addresses to others) the use of link-local addresses is 375 RECOMMENDED. 377 The Neighbor Discovery protocol (ND) [RFC4861] is used over 378 802.11-OCB links. 380 The operation of the Mobile IPv6 protocol over 802.11-OCB links is 381 different than on other links. The Movement Detection operation 382 (section 11.5.1 of [RFC6275]) can not rely on Neighbor Unreachability 383 Detection operation of the Neighbor Discovery protocol, for the 384 reason mentioned in the previous paragraph. Also, the 802.11-OCB 385 link layer is not a lower layer that can provide an indication that a 386 link layer handover has occured. The operation of the Mobile IPv6 387 protocol over 802.11-OCB is not specified in this document. 389 5. Security Considerations 391 Any security mechanism at the IP layer or above that may be carried 392 out for the general case of IPv6 may also be carried out for IPv6 393 operating over 802.11-OCB. 395 The OCB operation is stripped off of all existing 802.11 link-layer 396 security mechanisms. There is no encryption applied below the 397 network layer running on 802.11-OCB. At application layer, the IEEE 398 1609.2 document [IEEE-1609.2] does provide security services for 399 certain applications to use; application-layer mechanisms are out-of- 400 scope of this document. On another hand, a security mechanism 401 provided at networking layer, such as IPsec [RFC4301], may provide 402 data security protection to a wider range of applications. 404 802.11-OCB does not provide any cryptographic protection, because it 405 operates outside the context of a BSS (no Association Request/ 406 Response, no Challenge messages). Any attacker can therefore just 407 sit in the near range of vehicles, sniff the network (just set the 408 interface card's frequency to the proper range) and perform attacks 409 without needing to physically break any wall. Such a link is less 410 protected than commonly used links (wired link or protected 802.11). 412 The potential attack vectors are: MAC address spoofing, IP address 413 and session hijacking, and privacy violation Section 5.1. 415 Within the IPsec Security Architecture [RFC4301], the IPsec AH and 416 ESP headers [RFC4302] and [RFC4303] respectively, its multicast 417 extensions [RFC5374], HTTPS [RFC2818] and SeND [RFC3971] protocols 418 can be used to protect communications. Further, the assistance of 419 proper Public Key Infrastructure (PKI) protocols [RFC4210] is 420 necessary to establish credentials. More IETF protocols are 421 available in the toolbox of the IP security protocol designer. 422 Certain ETSI protocols related to security protocols in Intelligent 423 Transportation Systems are described in [ETSI-sec-archi]. 425 5.1. Privacy Considerations 427 As with all Ethernet and 802.11 interface identifiers ([RFC7721]), 428 the identifier of an 802.11-OCB interface may involve privacy, MAC 429 address spoofing and IP address hijacking risks. A vehicle embarking 430 an IP-OBU whose egress interface is 802.11-OCB may expose itself to 431 eavesdropping and subsequent correlation of data; this may reveal 432 data considered private by the vehicle owner; there is a risk of 433 being tracked. In outdoors public environments, where vehicles 434 typically circulate, the privacy risks are more important than in 435 indoors settings. It is highly likely that attacker sniffers are 436 deployed along routes which listen for IEEE frames, including IP 437 packets, of vehicles passing by. For this reason, in the 802.11-OCB 438 deployments, there is a strong necessity to use protection tools such 439 as dynamically changing MAC addresses Section 5.2, semantically 440 opaque Interface Identifiers and stable Interface Identifiers 441 Section 4.6. This may help mitigate privacy risks to a certain 442 level. 444 5.2. MAC Address and Interface ID Generation 446 In 802.11-OCB networks, the MAC addresses MAY change during well 447 defined renumbering events. In the moment the MAC address is changed 448 on an 802.11-OCB interface all the Interface Identifiers of IPv6 449 addresses assigned to that interface MUST change. 451 The policy dictating when the MAC address is changed on the 452 802.11-OCB interface is to-be-determined. For more information on 453 the motivation of this policy please refer to the privacy discussion 454 in Appendix C. 456 A 'randomized' MAC address has the following characteristics: 458 o Bit "Local/Global" set to "locally admninistered". 460 o Bit "Unicast/Multicast" set to "Unicast". 462 o The 46 remaining bits are set to a random value, using a random 463 number generator that meets the requirements of [RFC4086]. 465 To meet the randomization requirements for the 46 remaining bits, a 466 hash function may be used. For example, the SHA256 hash function may 467 be used with input a 256 bit local secret, the 'nominal' MAC Address 468 of the interface, and a representation of the date and time of the 469 renumbering event. 471 A randomized Interface ID has the same characteristics of a 472 randomized MAC address, except the length in bits. A MAC address 473 SHOULD be of length 48 decimal. An Interface ID SHOULD be of length 474 64 decimal for all types of IPv6 addresses. In the particular case 475 of IPv6 link-local addresses, the length of the Interface ID MAY be 476 118 decimal. 478 6. IANA Considerations 480 No request to IANA. 482 7. Contributors 484 Christian Huitema, Tony Li. 486 Romain Kuntz contributed extensively about IPv6 handovers between 487 links running outside the context of a BSS (802.11-OCB links). 489 Tim Leinmueller contributed the idea of the use of IPv6 over 490 802.11-OCB for distribution of certificates. 492 Marios Makassikis, Jose Santa Lozano, Albin Severinson and Alexey 493 Voronov provided significant feedback on the experience of using IP 494 messages over 802.11-OCB in initial trials. 496 Michelle Wetterwald contributed extensively the MTU discussion, 497 offered the ETSI ITS perspective, and reviewed other parts of the 498 document. 500 8. Acknowledgements 502 The authors would like to thank Witold Klaudel, Ryuji Wakikawa, 503 Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan 504 Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray 505 Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan, 506 Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne, 507 Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark, 508 Bob Moskowitz, Andrew Dryden, Georg Mayer, Dorothy Stanley, Sandra 509 Cespedes, Mariano Falcitelli, Sri Gundavelli, Abdussalam Baryun, 510 Margaret Cullen, Erik Kline, Carlos Jesus Bernardos Cano, Ronald in 511 't Velt, Katrin Sjoberg, Roland Bless, Tijink Jasja, Kevin Smith, 512 Brian Carpenter, Julian Reschke, Mikael Abrahamsson and William 513 Whyte. Their valuable comments clarified particular issues and 514 generally helped to improve the document. 516 Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB 517 drivers for linux and described how. 519 For the multicast discussion, the authors would like to thank Owen 520 DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and 521 participants to discussions in network working groups. 523 The authors would like to thank participants to the Birds-of- 524 a-Feather "Intelligent Transportation Systems" meetings held at IETF 525 in 2016. 527 Human Rights Protocol Considerations review by Amelia Andersdotter. 529 9. References 531 9.1. Normative References 533 [RFC1042] Postel, J. and J. Reynolds, "Standard for the transmission 534 of IP datagrams over IEEE 802 networks", STD 43, RFC 1042, 535 DOI 10.17487/RFC1042, February 1988, 536 . 538 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 539 Requirement Levels", BCP 14, RFC 2119, 540 DOI 10.17487/RFC2119, March 1997, 541 . 543 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 544 Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, 545 . 547 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, 548 DOI 10.17487/RFC2818, May 2000, 549 . 551 [RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related 552 Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004, 553 . 555 [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, 556 "SEcure Neighbor Discovery (SEND)", RFC 3971, 557 DOI 10.17487/RFC3971, March 2005, 558 . 560 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 561 "Randomness Requirements for Security", BCP 106, RFC 4086, 562 DOI 10.17487/RFC4086, June 2005, 563 . 565 [RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast 566 Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005, 567 . 569 [RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen, 570 "Internet X.509 Public Key Infrastructure Certificate 571 Management Protocol (CMP)", RFC 4210, 572 DOI 10.17487/RFC4210, September 2005, 573 . 575 [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing 576 Architecture", RFC 4291, DOI 10.17487/RFC4291, February 577 2006, . 579 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 580 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 581 December 2005, . 583 [RFC4302] Kent, S., "IP Authentication Header", RFC 4302, 584 DOI 10.17487/RFC4302, December 2005, 585 . 587 [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", 588 RFC 4303, DOI 10.17487/RFC4303, December 2005, 589 . 591 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 592 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 593 DOI 10.17487/RFC4861, September 2007, 594 . 596 [RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast 597 Extensions to the Security Architecture for the Internet 598 Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008, 599 . 601 [RFC5415] Calhoun, P., Ed., Montemurro, M., Ed., and D. Stanley, 602 Ed., "Control And Provisioning of Wireless Access Points 603 (CAPWAP) Protocol Specification", RFC 5415, 604 DOI 10.17487/RFC5415, March 2009, 605 . 607 [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing 608 Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, 609 September 2010, . 611 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 612 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 613 2011, . 615 [RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and 616 IETF Protocol and Documentation Usage for IEEE 802 617 Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042, 618 October 2013, . 620 [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 621 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, 622 February 2014, . 624 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 625 Interface Identifiers with IPv6 Stateless Address 626 Autoconfiguration (SLAAC)", RFC 7217, 627 DOI 10.17487/RFC7217, April 2014, 628 . 630 [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy 631 Considerations for IPv6 Address Generation Mechanisms", 632 RFC 7721, DOI 10.17487/RFC7721, March 2016, 633 . 635 [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu, 636 "Recommendation on Stable IPv6 Interface Identifiers", 637 RFC 8064, DOI 10.17487/RFC8064, February 2017, 638 . 640 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 641 (IPv6) Specification", STD 86, RFC 8200, 642 DOI 10.17487/RFC8200, July 2017, 643 . 645 9.2. Informative References 647 [ETSI-sec-archi] 648 "ETSI TS 102 940 V1.2.1 (2016-11), ETSI Technical 649 Specification, Intelligent Transport Systems (ITS); 650 Security; ITS communications security architecture and 651 security management, November 2016. Downloaded on 652 September 9th, 2017, freely available from ETSI website at 653 URL http://www.etsi.org/deliver/ 654 etsi_ts/102900_102999/102940/01.02.01_60/ 655 ts_102940v010201p.pdf". 657 [I-D.hinden-6man-rfc2464bis] 658 Crawford, M. and R. Hinden, "Transmission of IPv6 Packets 659 over Ethernet Networks", draft-hinden-6man-rfc2464bis-02 660 (work in progress), March 2017. 662 [I-D.ietf-ipwave-vehicular-networking-survey] 663 Jeong, J., Cespedes, S., Benamar, N., Haerri, J., and M. 664 Wetterwald, "Survey on IP-based Vehicular Networking for 665 Intelligent Transportation Systems", draft-ietf-ipwave- 666 vehicular-networking-survey-00 (work in progress), July 667 2017. 669 [I-D.perkins-intarea-multicast-ieee802] 670 Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, 671 "Multicast Considerations over IEEE 802 Wireless Media", 672 draft-perkins-intarea-multicast-ieee802-03 (work in 673 progress), July 2017. 675 [IEEE-1609.2] 676 "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access 677 in Vehicular Environments (WAVE) -- Security Services for 678 Applications and Management Messages. Example URL 679 http://ieeexplore.ieee.org/document/7426684/ accessed on 680 August 17th, 2017.". 682 [IEEE-1609.3] 683 "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access 684 in Vehicular Environments (WAVE) -- Networking Services. 685 Example URL http://ieeexplore.ieee.org/document/7458115/ 686 accessed on August 17th, 2017.". 688 [IEEE-1609.4] 689 "IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access 690 in Vehicular Environments (WAVE) -- Multi-Channel 691 Operation. Example URL 692 http://ieeexplore.ieee.org/document/7435228/ accessed on 693 August 17th, 2017.". 695 [IEEE-802.11-2016] 696 "IEEE Standard 802.11-2016 - IEEE Standard for Information 697 Technology - Telecommunications and information exchange 698 between systems Local and metropolitan area networks - 699 Specific requirements - Part 11: Wireless LAN Medium 700 Access Control (MAC) and Physical Layer (PHY) 701 Specifications. Status - Active Standard. Description 702 retrieved freely on September 12th, 2017, at URL 703 https://standards.ieee.org/findstds/ 704 standard/802.11-2016.html". 706 [IEEE-802.11p-2010] 707 "IEEE Std 802.11p (TM)-2010, IEEE Standard for Information 708 Technology - Telecommunications and information exchange 709 between systems - Local and metropolitan area networks - 710 Specific requirements, Part 11: Wireless LAN Medium Access 711 Control (MAC) and Physical Layer (PHY) Specifications, 712 Amendment 6: Wireless Access in Vehicular Environments; 713 document freely available at URL 714 http://standards.ieee.org/getieee802/ 715 download/802.11p-2010.pdf retrieved on September 20th, 716 2013.". 718 Appendix A. ChangeLog 720 The changes are listed in reverse chronological order, most recent 721 changes appearing at the top of the list. 723 -28: 725 o Created a new section 'Pseudonym Handling'. 727 o removed the 'Vehicle ID' appendix. 729 o improved the address generation from random MAC address. 731 o shortened Term IP-RSU definition. 733 o removed refs to two detail Clauses in IEEE documents, kept just 734 these latter. 736 -27: part 1 of addressing Human Rights review from IRTF. Removed 737 appendices F.2 and F.3. Shortened definition of IP-RSU. Removed 738 reference to 1609.4. A few other small changes, see diff. 740 -26: moved text from SLAAC section and from Design Considerations 741 appendix about privacy into a new Privacy Condiderations subsection 742 of the Security section; reformulated the SLAAC and IID sections to 743 stress only LLs can use EUI-64; removed the "GeoIP" wireshark 744 explanation; reformulated SLAAC and LL sections; added brief mention 745 of need of use LLs; clarified text about MAC address changes; dropped 746 pseudonym discussion; changed title of section describing examples of 747 packet formats. 749 -25: added a reference to 'IEEE Management Information Base', instead 750 of just 'Management Information Base'; added ref to further 751 appendices in the introductory phrases; improved text for IID 752 formation for SLAAC, inserting recommendation for RFC8064 before 753 RFC2464. 755 From draft-ietf-ipwave-ipv6-over-80211ocb-23 to draft-ietf-ipwave- 756 ipv6-over-80211ocb-24 758 o Nit: wrote "IPWAVE Working Group" on the front page, instead of 759 "Network Working Group". 761 o Addressed the comments on 6MAN: replaced a sentence about ND 762 problem with "is used over 802.11-OCB". 764 From draft-ietf-ipwave-ipv6-over-80211ocb-22 to draft-ietf-ipwave- 765 ipv6-over-80211ocb-23 767 o No content modifications, but check the entire draft chain on 768 IPv6-only: xml2rfc, submission on tools.ietf.org and datatracker. 770 From draft-ietf-ipwave-ipv6-over-80211ocb-21 to draft-ietf-ipwave- 771 ipv6-over-80211ocb-22 773 o Corrected typo, use dash in "802.11-OCB" instead of space. 775 o Improved the Frame Format section: MUST use QoSData, specify the 776 values within; clarified the Ethernet Adaptation Layer text. 778 From draft-ietf-ipwave-ipv6-over-80211ocb-20 to draft-ietf-ipwave- 779 ipv6-over-80211ocb-21 781 o Corrected a few nits and added names in Acknowledgments section. 783 o Removed unused reference to old Internet Draft tsvwg about QoS. 785 From draft-ietf-ipwave-ipv6-over-80211ocb-19 to draft-ietf-ipwave- 786 ipv6-over-80211ocb-20 788 o Reduced the definition of term "802.11-OCB". 790 o Left out of this specification which 802.11 header to use to 791 transmit IP packets in OCB mode (QoS Data header, Data header, or 792 any other). 794 o Added 'MUST' use an Ethernet Adaptation Layer, instead of 'is 795 using' an Ethernet Adaptation Layer. 797 From draft-ietf-ipwave-ipv6-over-80211ocb-18 to draft-ietf-ipwave- 798 ipv6-over-80211ocb-19 800 o Removed the text about fragmentation. 802 o Removed the mentioning of WSMP and GeoNetworking. 804 o Removed the explanation of the binary representation of the 805 EtherType. 807 o Rendered normative the paragraph about unicast and multicast 808 address mapping. 810 o Removed paragraph about addressing model, subnet structure and 811 easiness of using LLs. 813 o Clarified the Type/Subtype field in the 802.11 Header. 815 o Used RECOMMENDED instead of recommended, for the stable interface 816 identifiers. 818 From draft-ietf-ipwave-ipv6-over-80211ocb-17 to draft-ietf-ipwave- 819 ipv6-over-80211ocb-18 821 o Improved the MTU and fragmentation paragraph. 823 From draft-ietf-ipwave-ipv6-over-80211ocb-16 to draft-ietf-ipwave- 824 ipv6-over-80211ocb-17 826 o Susbtituted "MUST be increased" to "is increased" in the MTU 827 section, about fragmentation. 829 From draft-ietf-ipwave-ipv6-over-80211ocb-15 to draft-ietf-ipwave- 830 ipv6-over-80211ocb-16 832 o Removed the definition of the 'WiFi' term and its occurences. 833 Clarified a phrase that used it in Appendix C "Aspects introduced 834 by the OCB mode to 802.11". 836 o Added more normative words: MUST be 0x86DD, MUST fragment if size 837 larger than MTU, Sequence number in 802.11 Data header MUST be 838 increased. 840 From draft-ietf-ipwave-ipv6-over-80211ocb-14 to draft-ietf-ipwave- 841 ipv6-over-80211ocb-15 843 o Added normative term MUST in two places in section "Ethernet 844 Adaptation Layer". 846 From draft-ietf-ipwave-ipv6-over-80211ocb-13 to draft-ietf-ipwave- 847 ipv6-over-80211ocb-14 849 o Created a new Appendix titled "Extra Terminology" that contains 850 terms DSRC, DSRCS, OBU, RSU as defined outside IETF. Some of them 851 are used in the main Terminology section. 853 o Added two paragraphs explaining that ND and Mobile IPv6 have 854 problems working over 802.11-OCB, yet their adaptations is not 855 specified in this document. 857 From draft-ietf-ipwave-ipv6-over-80211ocb-12 to draft-ietf-ipwave- 858 ipv6-over-80211ocb-13 860 o Substituted "IP-OBU" for "OBRU", and "IP-RSU" for "RSRU" 861 throughout and improved OBU-related definitions in the Terminology 862 section. 864 From draft-ietf-ipwave-ipv6-over-80211ocb-11 to draft-ietf-ipwave- 865 ipv6-over-80211ocb-12 867 o Improved the appendix about "MAC Address Generation" by expressing 868 the technique to be an optional suggestion, not a mandatory 869 mechanism. 871 From draft-ietf-ipwave-ipv6-over-80211ocb-10 to draft-ietf-ipwave- 872 ipv6-over-80211ocb-11 874 o Shortened the paragraph on forming/terminating 802.11-OCB links. 876 o Moved the draft tsvwg-ieee-802-11 to Informative References. 878 From draft-ietf-ipwave-ipv6-over-80211ocb-09 to draft-ietf-ipwave- 879 ipv6-over-80211ocb-10 881 o Removed text requesting a new Group ID for multicast for OCB. 883 o Added a clarification of the meaning of value "3333" in the 884 section Address Mapping -- Multicast. 886 o Added note clarifying that in Europe the regional authority is not 887 ETSI, but "ECC/CEPT based on ENs from ETSI". 889 o Added note stating that the manner in which two STAtions set their 890 communication channel is not described in this document. 892 o Added a time qualifier to state that the "each node is represented 893 uniquely at a certain point in time." 895 o Removed text "This section may need to be moved" (the "Reliability 896 Requirements" section). This section stays there at this time. 898 o In the term definition "802.11-OCB" added a note stating that "any 899 implementation should comply with standards and regulations set in 900 the different countries for using that frequency band." 902 o In the RSU term definition, added a sentence explaining the 903 difference between RSU and RSRU: in terms of number of interfaces 904 and IP forwarding. 906 o Replaced "with at least two IP interfaces" with "with at least two 907 real or virtual IP interfaces". 909 o Added a term in the Terminology for "OBU". However the definition 910 is left empty, as this term is defined outside IETF. 912 o Added a clarification that it is an OBU or an OBRU in this phrase 913 "A vehicle embarking an OBU or an OBRU". 915 o Checked the entire document for a consistent use of terms OBU and 916 OBRU. 918 o Added note saying that "'p' is a letter identifying the 919 Ammendment". 921 o Substituted lower case for capitals SHALL or MUST in the 922 Appendices. 924 o Added reference to RFC7042, helpful in the 3333 explanation. 925 Removed reference to individual submission draft-petrescu-its- 926 scenario-reqs and added reference to draft-ietf-ipwave-vehicular- 927 networking-survey. 929 o Added figure captions, figure numbers, and references to figure 930 numbers instead of 'below'. Replaced "section Section" with 931 "section" throughout. 933 o Minor typographical errors. 935 From draft-ietf-ipwave-ipv6-over-80211ocb-08 to draft-ietf-ipwave- 936 ipv6-over-80211ocb-09 938 o Significantly shortened the Address Mapping sections, by text 939 copied from RFC2464, and rather referring to it. 941 o Moved the EPD description to an Appendix on its own. 943 o Shortened the Introduction and the Abstract. 945 o Moved the tutorial section of OCB mode introduced to .11, into an 946 appendix. 948 o Removed the statement that suggests that for routing purposes a 949 prefix exchange mechanism could be needed. 951 o Removed refs to RFC3963, RFC4429 and RFC6775; these are about ND, 952 MIP/NEMO and oDAD; they were referred in the handover discussion 953 section, which is out. 955 o Updated a reference from individual submission to now a WG item in 956 IPWAVE: the survey document. 958 o Added term definition for WiFi. 960 o Updated the authorship and expanded the Contributors section. 962 o Corrected typographical errors. 964 From draft-ietf-ipwave-ipv6-over-80211ocb-07 to draft-ietf-ipwave- 965 ipv6-over-80211ocb-08 967 o Removed the per-channel IPv6 prohibition text. 969 o Corrected typographical errors. 971 From draft-ietf-ipwave-ipv6-over-80211ocb-06 to draft-ietf-ipwave- 972 ipv6-over-80211ocb-07 974 o Added new terms: OBRU and RSRU ('R' for Router). Refined the 975 existing terms RSU and OBU, which are no longer used throughout 976 the document. 978 o Improved definition of term "802.11-OCB". 980 o Clarified that OCB does not "strip" security, but that the 981 operation in OCB mode is "stripped off of all .11 security". 983 o Clarified that theoretical OCB bandwidth speed is 54mbits, but 984 that a commonly observed bandwidth in IP-over-OCB is 12mbit/s. 986 o Corrected typographical errors, and improved some phrasing. 988 From draft-ietf-ipwave-ipv6-over-80211ocb-05 to draft-ietf-ipwave- 989 ipv6-over-80211ocb-06 991 o Updated references of 802.11-OCB document from -2012 to the IEEE 992 802.11-2016. 994 o In the LL address section, and in SLAAC section, added references 995 to 7217 opaque IIDs and 8064 stable IIDs. 997 From draft-ietf-ipwave-ipv6-over-80211ocb-04 to draft-ietf-ipwave- 998 ipv6-over-80211ocb-05 999 o Lengthened the title and cleanded the abstract. 1001 o Added text suggesting LLs may be easy to use on OCB, rather than 1002 GUAs based on received prefix. 1004 o Added the risks of spoofing and hijacking. 1006 o Removed the text speculation on adoption of the TSA message. 1008 o Clarified that the ND protocol is used. 1010 o Clarified what it means "No association needed". 1012 o Added some text about how two STAs discover each other. 1014 o Added mention of external (OCB) and internal network (stable), in 1015 the subnet structure section. 1017 o Added phrase explaining that both .11 Data and .11 QoS Data 1018 headers are currently being used, and may be used in the future. 1020 o Moved the packet capture example into an Appendix Implementation 1021 Status. 1023 o Suggested moving the reliability requirements appendix out into 1024 another document. 1026 o Added a IANA Consiserations section, with content, requesting for 1027 a new multicast group "all OCB interfaces". 1029 o Added new OBU term, improved the RSU term definition, removed the 1030 ETTC term, replaced more occurences of 802.11p, 802.11-OCB with 1031 802.11-OCB. 1033 o References: 1035 * Added an informational reference to ETSI's IPv6-over- 1036 GeoNetworking. 1038 * Added more references to IETF and ETSI security protocols. 1040 * Updated some references from I-D to RFC, and from old RFC to 1041 new RFC numbers. 1043 * Added reference to multicast extensions to IPsec architecture 1044 RFC. 1046 * Added a reference to 2464-bis. 1048 * Removed FCC informative references, because not used. 1050 o Updated the affiliation of one author. 1052 o Reformulation of some phrases for better readability, and 1053 correction of typographical errors. 1055 From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave- 1056 ipv6-over-80211ocb-04 1058 o Removed a few informative references pointing to Dx draft IEEE 1059 1609 documents. 1061 o Removed outdated informative references to ETSI documents. 1063 o Added citations to IEEE 1609.2, .3 and .4-2016. 1065 o Minor textual issues. 1067 From draft-ietf-ipwave-ipv6-over-80211ocb-02 to draft-ietf-ipwave- 1068 ipv6-over-80211ocb-03 1070 o Keep the previous text on multiple addresses, so remove talk about 1071 MIP6, NEMOv6 and MCoA. 1073 o Clarified that a 'Beacon' is an IEEE 802.11 frame Beacon. 1075 o Clarified the figure showing Infrastructure mode and OCB mode side 1076 by side. 1078 o Added a reference to the IP Security Architecture RFC. 1080 o Detailed the IPv6-per-channel prohibition paragraph which reflects 1081 the discussion at the last IETF IPWAVE WG meeting. 1083 o Added section "Address Mapping -- Unicast". 1085 o Added the ".11 Trailer" to pictures of 802.11 frames. 1087 o Added text about SNAP carrying the Ethertype. 1089 o New RSU definition allowing for it be both a Router and not 1090 necessarily a Router some times. 1092 o Minor textual issues. 1094 From draft-ietf-ipwave-ipv6-over-80211ocb-01 to draft-ietf-ipwave- 1095 ipv6-over-80211ocb-02 1096 o Replaced almost all occurences of 802.11p with 802.11-OCB, leaving 1097 only when explanation of evolution was necessary. 1099 o Shortened by removing parameter details from a paragraph in the 1100 Introduction. 1102 o Moved a reference from Normative to Informative. 1104 o Added text in intro clarifying there is no handover spec at IEEE, 1105 and that 1609.2 does provide security services. 1107 o Named the contents the fields of the EthernetII header (including 1108 the Ethertype bitstring). 1110 o Improved relationship between two paragraphs describing the 1111 increase of the Sequence Number in 802.11 header upon IP 1112 fragmentation. 1114 o Added brief clarification of "tracking". 1116 From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave- 1117 ipv6-over-80211ocb-01 1119 o Introduced message exchange diagram illustrating differences 1120 between 802.11 and 802.11 in OCB mode. 1122 o Introduced an appendix listing for information the set of 802.11 1123 messages that may be transmitted in OCB mode. 1125 o Removed appendix sections "Privacy Requirements", "Authentication 1126 Requirements" and "Security Certificate Generation". 1128 o Removed appendix section "Non IP Communications". 1130 o Introductory phrase in the Security Considerations section. 1132 o Improved the definition of "OCB". 1134 o Introduced theoretical stacked layers about IPv6 and IEEE layers 1135 including EPD. 1137 o Removed the appendix describing the details of prohibiting IPv6 on 1138 certain channels relevant to 802.11-OCB. 1140 o Added a brief reference in the privacy text about a precise clause 1141 in IEEE 1609.3 and .4. 1143 o Clarified the definition of a Road Side Unit. 1145 o Removed the discussion about security of WSA (because is non-IP). 1147 o Removed mentioning of the GeoNetworking discussion. 1149 o Moved references to scientific articles to a separate 'overview' 1150 draft, and referred to it. 1152 Appendix B. 802.11p 1154 The term "802.11p" is an earlier definition. The behaviour of 1155 "802.11p" networks is rolled in the document IEEE Std 802.11-2016. 1156 In that document the term 802.11p disappears. Instead, each 802.11p 1157 feature is conditioned by the IEEE Management Information Base (MIB) 1158 attribute "OCBActivated" [IEEE-802.11-2016]. Whenever OCBActivated 1159 is set to true the IEEE Std 802.11-OCB state is activated. For 1160 example, an 802.11 STAtion operating outside the context of a basic 1161 service set has the OCBActivated flag set. Such a station, when it 1162 has the flag set, uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. 1164 Appendix C. Aspects introduced by the OCB mode to 802.11 1166 In the IEEE 802.11-OCB mode, all nodes in the wireless range can 1167 directly communicate with each other without involving authentication 1168 or association procedures. At link layer, it is necessary to set the 1169 same channel number (or frequency) on two stations that need to 1170 communicate with each other. The manner in which stations set their 1171 channel number is not specified in this document. Stations STA1 and 1172 STA2 can exchange IP packets if they are set on the same channel. At 1173 IP layer, they then discover each other by using the IPv6 Neighbor 1174 Discovery protocol. 1176 Briefly, the IEEE 802.11-OCB mode has the following properties: 1178 o The use by each node of a 'wildcard' BSSID (i.e., each bit of the 1179 BSSID is set to 1) 1181 o No IEEE 802.11 Beacon frames are transmitted 1183 o No authentication is required in order to be able to communicate 1185 o No association is needed in order to be able to communicate 1187 o No encryption is provided in order to be able to communicate 1189 o Flag dot11OCBActivated is set to true 1191 All the nodes in the radio communication range (IP-OBU and IP-RSU) 1192 receive all the messages transmitted (IP-OBU and IP-RSU) within the 1193 radio communications range. The eventual conflict(s) are resolved by 1194 the MAC CDMA function. 1196 The message exchange diagram in Figure 3 illustrates a comparison 1197 between traditional 802.11 and 802.11 in OCB mode. The 'Data' 1198 messages can be IP packets such as HTTP or others. Other 802.11 1199 management and control frames (non IP) may be transmitted, as 1200 specified in the 802.11 standard. For information, the names of 1201 these messages as currently specified by the 802.11 standard are 1202 listed in Appendix G. 1204 STA AP STA1 STA2 1205 | | | | 1206 |<------ Beacon -------| |<------ Data -------->| 1207 | | | | 1208 |---- Probe Req. ----->| |<------ Data -------->| 1209 |<--- Probe Res. ------| | | 1210 | | |<------ Data -------->| 1211 |---- Auth Req. ------>| | | 1212 |<--- Auth Res. -------| |<------ Data -------->| 1213 | | | | 1214 |---- Asso Req. ------>| |<------ Data -------->| 1215 |<--- Asso Res. -------| | | 1216 | | |<------ Data -------->| 1217 |<------ Data -------->| | | 1218 |<------ Data -------->| |<------ Data -------->| 1220 (i) 802.11 Infrastructure mode (ii) 802.11-OCB mode 1222 Figure 3: Difference between messages exchanged on 802.11 (left) and 1223 802.11-OCB (right) 1225 The interface 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010 1226 [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, 1227 titled "Amendment 6: Wireless Access in Vehicular Environments". 1228 Since then, this amendment has been integrated in IEEE 802.11(TM) 1229 -2012 and -2016 [IEEE-802.11-2016]. 1231 In document 802.11-2016, anything qualified specifically as 1232 "OCBActivated", or "outside the context of a basic service" set to be 1233 true, then it is actually referring to OCB aspects introduced to 1234 802.11. 1236 In order to delineate the aspects introduced by 802.11-OCB to 802.11, 1237 we refer to the earlier [IEEE-802.11p-2010]. The amendment is 1238 concerned with vehicular communications, where the wireless link is 1239 similar to that of Wireless LAN (using a PHY layer specified by 1240 802.11a/b/g/n), but which needs to cope with the high mobility factor 1241 inherent in scenarios of communications between moving vehicles, and 1242 between vehicles and fixed infrastructure deployed along roads. 1243 While 'p' is a letter identifying the Ammendment, just like 'a, b, g' 1244 and 'n' are, 'p' is concerned more with MAC modifications, and a 1245 little with PHY modifications; the others are mainly about PHY 1246 modifications. It is possible in practice to combine a 'p' MAC with 1247 an 'a' PHY by operating outside the context of a BSS with OFDM at 1248 5.4GHz and 5.9GHz. 1250 The 802.11-OCB links are specified to be compatible as much as 1251 possible with the behaviour of 802.11a/b/g/n and future generation 1252 IEEE WLAN links. From the IP perspective, an 802.11-OCB MAC layer 1253 offers practically the same interface to IP as the 802.11a/b/g/n and 1254 802.3. A packet sent by an IP-OBU may be received by one or multiple 1255 IP-RSUs. The link-layer resolution is performed by using the IPv6 1256 Neighbor Discovery protocol. 1258 To support this similarity statement (IPv6 is layered on top of LLC 1259 on top of 802.11-OCB, in the same way that IPv6 is layered on top of 1260 LLC on top of 802.11a/b/g/n (for WLAN) or layered on top of LLC on 1261 top of 802.3 (for Ethernet)) it is useful to analyze the differences 1262 between 802.11-OCB and 802.11 specifications. During this analysis, 1263 we note that whereas 802.11-OCB lists relatively complex and numerous 1264 changes to the MAC layer (and very little to the PHY layer), there 1265 are only a few characteristics which may be important for an 1266 implementation transmitting IPv6 packets on 802.11-OCB links. 1268 The most important 802.11-OCB point which influences the IPv6 1269 functioning is the OCB characteristic; an additional, less direct 1270 influence, is the maximum bandwidth afforded by the PHY modulation/ 1271 demodulation methods and channel access specified by 802.11-OCB. The 1272 maximum bandwidth theoretically possible in 802.11-OCB is 54 Mbit/s 1273 (when using, for example, the following parameters: 20 MHz channel; 1274 modulation 64-QAM; coding rate R is 3/4); in practice of IP-over- 1275 802.11-OCB a commonly observed figure is 12Mbit/s; this bandwidth 1276 allows the operation of a wide range of protocols relying on IPv6. 1278 o Operation Outside the Context of a BSS (OCB): the (earlier 1279 802.11p) 802.11-OCB links are operated without a Basic Service Set 1280 (BSS). This means that the frames IEEE 802.11 Beacon, Association 1281 Request/Response, Authentication Request/Response, and similar, 1282 are not used. The used identifier of BSS (BSSID) has a 1283 hexadecimal value always 0xffffffffffff (48 '1' bits, represented 1284 as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' 1285 BSSID), as opposed to an arbitrary BSSID value set by 1286 administrator (e.g. 'My-Home-AccessPoint'). The OCB operation - 1287 namely the lack of beacon-based scanning and lack of 1288 authentication - should be taken into account when the Mobile IPv6 1289 protocol [RFC6275] and the protocols for IP layer security 1290 [RFC4301] are used. The way these protocols adapt to OCB is not 1291 described in this document. 1293 o Timing Advertisement: is a new message defined in 802.11-OCB, 1294 which does not exist in 802.11a/b/g/n. This message is used by 1295 stations to inform other stations about the value of time. It is 1296 similar to the time as delivered by a GNSS system (Galileo, GPS, 1297 ...) or by a cellular system. This message is optional for 1298 implementation. 1300 o Frequency range: this is a characteristic of the PHY layer, with 1301 almost no impact on the interface between MAC and IP. However, it 1302 is worth considering that the frequency range is regulated by a 1303 regional authority (ARCEP, ECC/CEPT based on ENs from ETSI, FCC, 1304 etc.); as part of the regulation process, specific applications 1305 are associated with specific frequency ranges. In the case of 1306 802.11-OCB, the regulator associates a set of frequency ranges, or 1307 slots within a band, to the use of applications of vehicular 1308 communications, in a band known as "5.9GHz". The 5.9GHz band is 1309 different from the 2.4GHz and 5GHz bands used by Wireless LAN. 1310 However, as with Wireless LAN, the operation of 802.11-OCB in 1311 "5.9GHz" bands is exempt from owning a license in EU (in US the 1312 5.9GHz is a licensed band of spectrum; for the fixed 1313 infrastructure an explicit FCC authorization is required; for an 1314 on-board device a 'licensed-by-rule' concept applies: rule 1315 certification conformity is required.) Technical conditions are 1316 different than those of the bands "2.4GHz" or "5GHz". The allowed 1317 power levels, and implicitly the maximum allowed distance between 1318 vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20 1319 dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum 1320 distance of approximately 1km, compared to approximately 50m. 1321 Additionally, specific conditions related to congestion avoidance, 1322 jamming avoidance, and radar detection are imposed on the use of 1323 DSRC (in US) and on the use of frequencies for Intelligent 1324 Transportation Systems (in EU), compared to Wireless LAN 1325 (802.11a/b/g/n). 1327 o 'Half-rate' encoding: as the frequency range, this parameter is 1328 related to PHY, and thus has not much impact on the interface 1329 between the IP layer and the MAC layer. 1331 o In vehicular communications using 802.11-OCB links, there are 1332 strong privacy requirements with respect to addressing. While the 1333 802.11-OCB standard does not specify anything in particular with 1334 respect to MAC addresses, in these settings there exists a strong 1335 need for dynamic change of these addresses (as opposed to the non- 1336 vehicular settings - real wall protection - where fixed MAC 1337 addresses do not currently pose some privacy risks). This is 1338 further described in Section 5. A relevant function is described 1339 in documents IEEE 1609.3-2016 [IEEE-1609.3] and IEEE 1609.4-2016 1340 [IEEE-1609.4]. 1342 Appendix D. Changes Needed on a software driver 802.11a to become a 1343 802.11-OCB driver 1345 The 802.11p amendment modifies both the 802.11 stack's physical and 1346 MAC layers but all the induced modifications can be quite easily 1347 obtained by modifying an existing 802.11a ad-hoc stack. 1349 Conditions for a 802.11a hardware to be 802.11-OCB compliant: 1351 o The PHY entity shall be an orthogonal frequency division 1352 multiplexing (OFDM) system. It must support the frequency bands 1353 on which the regulator recommends the use of ITS communications, 1354 for example using IEEE 802.11-OCB layer, in France: 5875MHz to 1355 5925MHz. 1357 o The OFDM system must provide a "half-clocked" operation using 10 1358 MHz channel spacings. 1360 o The chip transmit spectrum mask must be compliant to the "Transmit 1361 spectrum mask" from the IEEE 802.11p amendment (but experimental 1362 environments tolerate otherwise). 1364 o The chip should be able to transmit up to 44.8 dBm when used by 1365 the US government in the United States, and up to 33 dBm in 1366 Europe; other regional conditions apply. 1368 Changes needed on the network stack in OCB mode: 1370 o Physical layer: 1372 * The chip must use the Orthogonal Frequency Multiple Access 1373 (OFDM) encoding mode. 1375 * The chip must be set in half-mode rate mode (the internal clock 1376 frequency is divided by two). 1378 * The chip must use dedicated channels and should allow the use 1379 of higher emission powers. This may require modifications to 1380 the local computer file that describes regulatory domains 1381 rules, if used by the kernel to enforce local specific 1382 restrictions. Such modifications to the local computer file 1383 must respect the location-specific regulatory rules. 1385 MAC layer: 1387 * All management frames (beacons, join, leave, and others) 1388 emission and reception must be disabled except for frames of 1389 subtype Action and Timing Advertisement (defined below). 1391 * No encryption key or method must be used. 1393 * Packet emission and reception must be performed as in ad-hoc 1394 mode, using the wildcard BSSID (ff:ff:ff:ff:ff:ff). 1396 * The functions related to joining a BSS (Association Request/ 1397 Response) and for authentication (Authentication Request/Reply, 1398 Challenge) are not called. 1400 * The beacon interval is always set to 0 (zero). 1402 * Timing Advertisement frames, defined in the amendment, should 1403 be supported. The upper layer should be able to trigger such 1404 frames emission and to retrieve information contained in 1405 received Timing Advertisements. 1407 Appendix E. EtherType Protocol Discrimination (EPD) 1409 A more theoretical and detailed view of layer stacking, and 1410 interfaces between the IP layer and 802.11-OCB layers, is illustrated 1411 in Figure 4. The IP layer operates on top of the EtherType Protocol 1412 Discrimination (EPD); this Discrimination layer is described in IEEE 1413 Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP 1414 (Link Layer Control Service Access Point). 1416 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1417 | IPv6 | 1418 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ 1419 { LLC_SAP } 802.11-OCB 1420 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary 1421 | EPD | | | 1422 | | MLME | | 1423 +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | 1424 | MAC Sublayer | | | 802.11-OCB 1425 | and ch. coord. | | SME | Services 1426 +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | 1427 | | PLME | | 1428 | PHY Layer | PLME_SAP | 1429 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1431 Figure 4: EtherType Protocol Discrimination 1433 Appendix F. Design Considerations 1435 The networks defined by 802.11-OCB are in many ways similar to other 1436 networks of the 802.11 family. In theory, the encapsulation of IPv6 1437 over 802.11-OCB could be very similar to the operation of IPv6 over 1438 other networks of the 802.11 family. However, the high mobility, 1439 strong link asymmetry and very short connection makes the 802.11-OCB 1440 link significantly different from other 802.11 networks. Also, the 1441 automotive applications have specific requirements for reliability, 1442 security and privacy, which further add to the particularity of the 1443 802.11-OCB link. 1445 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode 1447 For information, at the time of writing, this is the list of IEEE 1448 802.11 messages that may be transmitted in OCB mode, i.e. when 1449 dot11OCBActivated is true in a STA: 1451 o The STA may send management frames of subtype Action and, if the 1452 STA maintains a TSF Timer, subtype Timing Advertisement; 1454 o The STA may send control frames, except those of subtype PS-Poll, 1455 CF-End, and CF-End plus CFAck; 1457 o The STA may send data frames of subtype Data, Null, QoS Data, and 1458 QoS Null. 1460 Appendix H. Examples of Packet Formats 1462 This section describes an example of an IPv6 Packet captured over a 1463 IEEE 802.11-OCB link. 1465 By way of example we show that there is no modification in the 1466 headers when transmitted over 802.11-OCB networks - they are 1467 transmitted like any other 802.11 and Ethernet packets. 1469 We describe an experiment of capturing an IPv6 packet on an 1470 802.11-OCB link. In topology depicted in Figure 5, the packet is an 1471 IPv6 Router Advertisement. This packet is emitted by a Router on its 1472 802.11-OCB interface. The packet is captured on the Host, using a 1473 network protocol analyzer (e.g. Wireshark); the capture is performed 1474 in two different modes: direct mode and 'monitor' mode. The topology 1475 used during the capture is depicted below. 1477 The packet is captured on the Host. The Host is an IP-OBU containing 1478 an 802.11 interface in format PCI express (an ITRI product). The 1479 kernel runs the ath5k software driver with modifications for OCB 1480 mode. The capture tool is Wireshark. The file format for save and 1481 analyze is 'pcap'. The packet is generated by the Router. The 1482 Router is an IP-RSU (ITRI product). 1484 +--------+ +-------+ 1485 | | 802.11-OCB Link | | 1486 ---| Router |--------------------------------| Host | 1487 | | | | 1488 +--------+ +-------+ 1490 Figure 5: Topology for capturing IP packets on 802.11-OCB 1492 During several capture operations running from a few moments to 1493 several hours, no message relevant to the BSSID contexts were 1494 captured (no Association Request/Response, Authentication Req/Resp, 1495 Beacon). This shows that the operation of 802.11-OCB is outside the 1496 context of a BSSID. 1498 Overall, the captured message is identical with a capture of an IPv6 1499 packet emitted on a 802.11b interface. The contents are precisely 1500 similar. 1502 H.1. Capture in Monitor Mode 1504 The IPv6 RA packet captured in monitor mode is illustrated below. 1505 The radio tap header provides more flexibility for reporting the 1506 characteristics of frames. The Radiotap Header is prepended by this 1507 particular stack and operating system on the Host machine to the RA 1508 packet received from the network (the Radiotap Header is not present 1509 on the air). The implementation-dependent Radiotap Header is useful 1510 for piggybacking PHY information from the chip's registers as data in 1511 a packet understandable by userland applications using Socket 1512 interfaces (the PHY interface can be, for example: power levels, data 1513 rate, ratio of signal to noise). 1515 The packet present on the air is formed by IEEE 802.11 Data Header, 1516 Logical Link Control Header, IPv6 Base Header and ICMPv6 Header. 1518 Radiotap Header v0 1519 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1520 |Header Revision| Header Pad | Header length | 1521 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1522 | Present flags | 1523 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1524 | Data Rate | Pad | 1525 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1527 IEEE 802.11 Data Header 1528 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1529 | Type/Subtype and Frame Ctrl | Duration | 1530 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1531 | Receiver Address... 1532 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1533 ... Receiver Address | Transmitter Address... 1534 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1535 ... Transmitter Address | 1536 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1537 | BSS Id... 1538 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1539 ... BSS Id | Frag Number and Seq Number | 1540 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1542 Logical-Link Control Header 1543 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1544 | DSAP |I| SSAP |C| Control field | Org. code... 1545 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1546 ... Organizational Code | Type | 1547 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1548 IPv6 Base Header 1549 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1550 |Version| Traffic Class | Flow Label | 1551 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1552 | Payload Length | Next Header | Hop Limit | 1553 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1554 | | 1555 + + 1556 | | 1557 + Source Address + 1558 | | 1559 + + 1560 | | 1561 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1562 | | 1563 + + 1564 | | 1565 + Destination Address + 1566 | | 1567 + + 1568 | | 1569 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1571 Router Advertisement 1572 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1573 | Type | Code | Checksum | 1574 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1575 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1576 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1577 | Reachable Time | 1578 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1579 | Retrans Timer | 1580 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1581 | Options ... 1582 +-+-+-+-+-+-+-+-+-+-+-+- 1584 The value of the Data Rate field in the Radiotap header is set to 6 1585 Mb/s. This indicates the rate at which this RA was received. 1587 The value of the Transmitter address in the IEEE 802.11 Data Header 1588 is set to a 48bit value. The value of the destination address is 1589 33:33:00:00:00:1 (all-nodes multicast address). The value of the BSS 1590 Id field is ff:ff:ff:ff:ff:ff, which is recognized by the network 1591 protocol analyzer as being "broadcast". The Fragment number and 1592 sequence number fields are together set to 0x90C6. 1594 The value of the Organization Code field in the Logical-Link Control 1595 Header is set to 0x0, recognized as "Encapsulated Ethernet". The 1596 value of the Type field is 0x86DD (hexadecimal 86DD, or otherwise 1597 #86DD), recognized as "IPv6". 1599 A Router Advertisement is periodically sent by the router to 1600 multicast group address ff02::1. It is an icmp packet type 134. The 1601 IPv6 Neighbor Discovery's Router Advertisement message contains an 1602 8-bit field reserved for single-bit flags, as described in [RFC4861]. 1604 The IPv6 header contains the link local address of the router 1605 (source) configured via EUI-64 algorithm, and destination address set 1606 to ff02::1. 1608 The Ethernet Type field in the logical-link control header is set to 1609 0x86dd which indicates that the frame transports an IPv6 packet. In 1610 the IEEE 802.11 data, the destination address is 33:33:00:00:00:01 1611 which is the corresponding multicast MAC address. The BSS id is a 1612 broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link 1613 duration between vehicles and the roadside infrastructure, there is 1614 no need in IEEE 802.11-OCB to wait for the completion of association 1615 and authentication procedures before exchanging data. IEEE 1616 802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s) 1617 and may start communicating as soon as they arrive on the 1618 communication channel. 1620 H.2. Capture in Normal Mode 1622 The same IPv6 Router Advertisement packet described above (monitor 1623 mode) is captured on the Host, in the Normal mode, and depicted 1624 below. 1626 Ethernet II Header 1627 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1628 | Destination... 1629 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1630 ...Destination | Source... 1631 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1632 ...Source | 1633 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1634 | Type | 1635 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1637 IPv6 Base Header 1638 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1639 |Version| Traffic Class | Flow Label | 1640 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1641 | Payload Length | Next Header | Hop Limit | 1642 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1643 | | 1644 + + 1645 | | 1646 + Source Address + 1647 | | 1648 + + 1649 | | 1650 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1651 | | 1652 + + 1653 | | 1654 + Destination Address + 1655 | | 1656 + + 1657 | | 1658 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1660 Router Advertisement 1661 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1662 | Type | Code | Checksum | 1663 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1664 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1665 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1666 | Reachable Time | 1667 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1668 | Retrans Timer | 1669 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1670 | Options ... 1671 +-+-+-+-+-+-+-+-+-+-+-+- 1673 One notices that the Radiotap Header, the IEEE 802.11 Data Header and 1674 the Logical-Link Control Headers are not present. On the other hand, 1675 a new header named Ethernet II Header is present. 1677 The Destination and Source addresses in the Ethernet II header 1678 contain the same values as the fields Receiver Address and 1679 Transmitter Address present in the IEEE 802.11 Data Header in the 1680 "monitor" mode capture. 1682 The value of the Type field in the Ethernet II header is 0x86DD 1683 (recognized as "IPv6"); this value is the same value as the value of 1684 the field Type in the Logical-Link Control Header in the "monitor" 1685 mode capture. 1687 The knowledgeable experimenter will no doubt notice the similarity of 1688 this Ethernet II Header with a capture in normal mode on a pure 1689 Ethernet cable interface. 1691 An Adaptation layer is inserted on top of a pure IEEE 802.11 MAC 1692 layer, in order to adapt packets, before delivering the payload data 1693 to the applications. It adapts 802.11 LLC/MAC headers to Ethernet II 1694 headers. In further detail, this adaptation consists in the 1695 elimination of the Radiotap, 802.11 and LLC headers, and in the 1696 insertion of the Ethernet II header. In this way, IPv6 runs straight 1697 over LLC over the 802.11-OCB MAC layer; this is further confirmed by 1698 the use of the unique Type 0x86DD. 1700 Appendix I. Extra Terminology 1702 The following terms are defined outside the IETF. They are used to 1703 define the main terms in the main terminology section Section 2. 1705 DSRC (Dedicated Short Range Communication): a term defined outside 1706 the IETF. The US Federal Communications Commission (FCC) Dedicated 1707 Short Range Communication (DSRC) is defined in the Code of Federal 1708 Regulations (CFR) 47, Parts 90 and 95. This Code is referred in the 1709 definitions below. At the time of the writing of this Internet 1710 Draft, the last update of this Code was dated October 1st, 2010. 1712 DSRCS (Dedicated Short-Range Communications Services): a term defined 1713 outside the IETF. The use of radio techniques to transfer data over 1714 short distances between roadside and mobile units, between mobile 1715 units, and between portable and mobile units to perform operations 1716 related to the improvement of traffic flow, traffic safety, and other 1717 intelligent transportation service applications in a variety of 1718 environments. DSRCS systems may also transmit status and 1719 instructional messages related to the units involve. [Ref. 47 CFR 1720 90.7 - Definitions] 1721 OBU (On-Board Unit): a term defined outside the IETF. An On-Board 1722 Unit is a DSRCS transceiver that is normally mounted in or on a 1723 vehicle, or which in some instances may be a portable unit. An OBU 1724 can be operational while a vehicle or person is either mobile or 1725 stationary. The OBUs receive and contend for time to transmit on one 1726 or more radio frequency (RF) channels. Except where specifically 1727 excluded, OBU operation is permitted wherever vehicle operation or 1728 human passage is permitted. The OBUs mounted in vehicles are 1729 licensed by rule under part 95 of the respective chapter and 1730 communicate with Roadside Units (RSUs) and other OBUs. Portable OBUs 1731 are also licensed by rule under part 95 of the respective chapter. 1732 OBU operations in the Unlicensed National Information Infrastructure 1733 (UNII) Bands follow the rules in those bands. - [CFR 90.7 - 1734 Definitions]. 1736 RSU (Road-Side Unit): a term defined outside of IETF. A Roadside 1737 Unit is a DSRC transceiver that is mounted along a road or pedestrian 1738 passageway. An RSU may also be mounted on a vehicle or is hand 1739 carried, but it may only operate when the vehicle or hand- carried 1740 unit is stationary. Furthermore, an RSU operating under the 1741 respectgive part is restricted to the location where it is licensed 1742 to operate. However, portable or hand-held RSUs are permitted to 1743 operate where they do not interfere with a site-licensed operation. 1744 A RSU broadcasts data to OBUs or exchanges data with OBUs in its 1745 communications zone. An RSU also provides channel assignments and 1746 operating instructions to OBUs in its communications zone, when 1747 required. - [CFR 90.7 - Definitions]. 1749 Authors' Addresses 1751 Alexandre Petrescu 1752 CEA, LIST 1753 CEA Saclay 1754 Gif-sur-Yvette , Ile-de-France 91190 1755 France 1757 Phone: +33169089223 1758 Email: Alexandre.Petrescu@cea.fr 1760 Nabil Benamar 1761 Moulay Ismail University 1762 Morocco 1764 Phone: +212670832236 1765 Email: n.benamar@est.umi.ac.ma 1766 Jerome Haerri 1767 Eurecom 1768 Sophia-Antipolis 06904 1769 France 1771 Phone: +33493008134 1772 Email: Jerome.Haerri@eurecom.fr 1774 Jong-Hyouk Lee 1775 Sangmyung University 1776 31, Sangmyeongdae-gil, Dongnam-gu 1777 Cheonan 31066 1778 Republic of Korea 1780 Email: jonghyouk@smu.ac.kr 1782 Thierry Ernst 1783 YoGoKo 1784 France 1786 Email: thierry.ernst@yogoko.fr