idnits 2.17.1 draft-ietf-ipwave-ipv6-over-80211ocb-29.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 20, 2018) is 2038 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 24, 2019 Moulay Ismail University 6 J. Haerri 7 Eurecom 8 J. Lee 9 Sangmyung University 10 T. Ernst 11 YoGoKo 12 September 20, 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-29 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 24, 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 . . . . . . . . . . . . . . . . . . . . 9 78 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 79 5.1. Privacy Considerations . . . . . . . . . . . . . . . . . 10 80 5.2. MAC Address and Interface ID Generation . . . . . . . . . 11 81 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 82 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 12 83 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 84 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 85 9.1. Normative References . . . . . . . . . . . . . . . . . . 13 86 9.2. Informative References . . . . . . . . . . . . . . . . . 15 87 Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 17 88 Appendix B. 802.11p . . . . . . . . . . . . . . . . . . . . . . 26 89 Appendix C. Aspects introduced by the OCB mode to 802.11 . . . . 26 90 Appendix D. Changes Needed on a software driver 802.11a to 91 become a 802.11-OCB driver . . . 30 92 Appendix E. EtherType Protocol Discrimination (EPD) . . . . . . 31 93 Appendix F. Design Considerations . . . . . . . . . . . . . . . 32 94 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 32 95 Appendix H. Examples of Packet Formats . . . . . . . . . . . . . 33 96 H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 34 97 H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 36 98 Appendix I. Extra Terminology . . . . . . . . . . . . . . . . . 38 99 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 101 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 Semantically opaque Interface Identifiers, instead of meaningful 347 Interface Identifiers derived from a valid and meaningful MAC address 348 ([RFC2464], section 4), MAY be needed in order to avoid certain 349 privacy risks. 351 A valid MAC address includes a unique identifier pointing to a 352 company together with its postal address, and a unique number within 353 that company MAC space (see the oui.txt file). The calculation 354 operation of the MAC address back from a given meaningful Interface 355 Identifier is straightforward ([RFC2464], section 4). The Interface 356 Identifier is part of an IPv6 address that is stored in IPv6 packets. 357 The IPv6 packets can be captured in the Internet easily. For these 358 reasons, an attacker may realize many attacks on privacy. One such 359 attack on 802.11-OCB is to capture, store and correlate Company ID 360 information of many cars in public areas (e.g. listen for Router 361 Advertisements, or other IPv6 application data packets, and record 362 the value of the source address in these packets). Further 363 correlation of this information with other data captured by other 364 means, or other visual information (car color, others) MAY constitute 365 privacy risks. 367 In order to avoid these risks, opaque Interface Identifiers MAY be 368 formed according to rules described in [RFC7217]. These opaque 369 Interface Identifiers are formed starting from identifiers different 370 than the MAC addresses, and from cryptographically strong material. 371 Thus, privacy sensitive information is absent from Interface IDs, and 372 it is impossible to calculate the initial value from which the 373 Interface ID was calculated. 375 Some applications that use IPv6 packets on 802.11-OCB links (among 376 other link types) may benefit from IPv6 addresses whose Interface 377 Identifiers don't change too often. It is RECOMMENDED to use the 378 mechanisms described in RFC 7217 to permit the use of Stable 379 Interface Identifiers that do not change within one subnet prefix. A 380 possible source for the Net-Iface Parameter is a virtual interface 381 name, or logical interface name, that is decided by a local 382 administrator. 384 The way Interface Identifiers are used MAY involve risks to privacy, 385 as described in Section 5.1. 387 4.7. Subnet Structure 389 A subnet is formed by the external 802.11-OCB interfaces of vehicles 390 that are in close range (not by their in-vehicle interfaces). This 391 subnet MUST use at least the link-local prefix fe80::/10 and the 392 interfaces MUST be assigned IPv6 addresses of type link-local. This 393 subnet MAY NOT have any other prefix than the link-local prefix. 395 The structure of this subnet is ephemeral, in that it is strongly 396 influenced by the mobility of vehicles: the 802.11 hidden node 397 effects appear; the 802.11 networks in OCB mode may be considered as 398 'ad-hoc' networks with an addressing model as described in [RFC5889]. 399 On another hand, the structure of the internal subnets in each car is 400 relatively stable. 402 As recommended in [RFC5889], when the timing requirements are very 403 strict (e.g. fast drive through IP-RSU coverage), no on-link subnet 404 prefix should be configured on an 802.11-OCB interface. In such 405 cases, the exclusive use of IPv6 link-local addresses is RECOMMENDED. 407 Additionally, even if the timing requirements are not very strict 408 (e.g. the moving subnet formed by two following vehicles is stable, a 409 fixed IP-RSU is absent), the subnet is disconnected from the Internet 410 (a default route is absent), and the addressing peers are equally 411 qualified (impossible to determine that some vehicle owns and 412 distributes addresses to others) the use of link-local addresses is 413 RECOMMENDED. 415 The Neighbor Discovery protocol (ND) [RFC4861] is used over 416 802.11-OCB links. 418 The operation of the Mobile IPv6 protocol over 802.11-OCB links is 419 different than on other links. The Movement Detection operation 420 (section 11.5.1 of [RFC6275]) can not rely on Neighbor Unreachability 421 Detection operation of the Neighbor Discovery protocol, for the 422 reason mentioned in the previous paragraph. Also, the 802.11-OCB 423 link layer is not a lower layer that can provide an indication that a 424 link layer handover has occured. The operation of the Mobile IPv6 425 protocol over 802.11-OCB is not specified in this document. 427 5. Security Considerations 429 Any security mechanism at the IP layer or above that may be carried 430 out for the general case of IPv6 may also be carried out for IPv6 431 operating over 802.11-OCB. 433 The OCB operation is stripped off of all existing 802.11 link-layer 434 security mechanisms. There is no encryption applied below the 435 network layer running on 802.11-OCB. At application layer, the IEEE 436 1609.2 document [IEEE-1609.2] does provide security services for 437 certain applications to use; application-layer mechanisms are out-of- 438 scope of this document. On another hand, a security mechanism 439 provided at networking layer, such as IPsec [RFC4301], may provide 440 data security protection to a wider range of applications. 442 802.11-OCB does not provide any cryptographic protection, because it 443 operates outside the context of a BSS (no Association Request/ 444 Response, no Challenge messages). Any attacker can therefore just 445 sit in the near range of vehicles, sniff the network (just set the 446 interface card's frequency to the proper range) and perform attacks 447 without needing to physically break any wall. Such a link is less 448 protected than commonly used links (wired link or protected 802.11). 450 The potential attack vectors are: MAC address spoofing, IP address 451 and session hijacking, and privacy violation Section 5.1. 453 Within the IPsec Security Architecture [RFC4301], the IPsec AH and 454 ESP headers [RFC4302] and [RFC4303] respectively, its multicast 455 extensions [RFC5374], HTTPS [RFC2818] and SeND [RFC3971] protocols 456 can be used to protect communications. Further, the assistance of 457 proper Public Key Infrastructure (PKI) protocols [RFC4210] is 458 necessary to establish credentials. More IETF protocols are 459 available in the toolbox of the IP security protocol designer. 460 Certain ETSI protocols related to security protocols in Intelligent 461 Transportation Systems are described in [ETSI-sec-archi]. 463 5.1. Privacy Considerations 465 As with all Ethernet and 802.11 interface identifiers ([RFC7721]), 466 the identifier of an 802.11-OCB interface may involve privacy, MAC 467 address spoofing and IP address hijacking risks. A vehicle embarking 468 an IP-OBU whose egress interface is 802.11-OCB may expose itself to 469 eavesdropping and subsequent correlation of data; this may reveal 470 data considered private by the vehicle owner; there is a risk of 471 being tracked. In outdoors public environments, where vehicles 472 typically circulate, the privacy risks are more important than in 473 indoors settings. It is highly likely that attacker sniffers are 474 deployed along routes which listen for IEEE frames, including IP 475 packets, of vehicles passing by. For this reason, in the 802.11-OCB 476 deployments, there is a strong necessity to use protection tools such 477 as dynamically changing MAC addresses Section 5.2, semantically 478 opaque Interface Identifiers and stable Interface Identifiers 479 Section 4.6. This may help mitigate privacy risks to a certain 480 level. 482 5.2. MAC Address and Interface ID Generation 484 In 802.11-OCB networks, the MAC addresses MAY change during well 485 defined renumbering events. In the moment the MAC address is changed 486 on an 802.11-OCB interface all the Interface Identifiers of IPv6 487 addresses assigned to that interface MUST change. 489 The policy dictating when the MAC address is changed on the 490 802.11-OCB interface is to-be-determined. For more information on 491 the motivation of this policy please refer to the privacy discussion 492 in Appendix C. 494 A 'randomized' MAC address has the following characteristics: 496 o Bit "Local/Global" set to "locally admninistered". 498 o Bit "Unicast/Multicast" set to "Unicast". 500 o The 46 remaining bits are set to a random value, using a random 501 number generator that meets the requirements of [RFC4086]. 503 To meet the randomization requirements for the 46 remaining bits, a 504 hash function may be used. For example, the SHA256 hash function may 505 be used with input a 256 bit local secret, the 'nominal' MAC Address 506 of the interface, and a representation of the date and time of the 507 renumbering event. 509 A randomized Interface ID has the same characteristics of a 510 randomized MAC address, except the length in bits. A MAC address 511 SHOULD be of length 48 decimal. An Interface ID SHOULD be of length 512 64 decimal for all types of IPv6 addresses. In the particular case 513 of IPv6 link-local addresses, the length of the Interface ID MAY be 514 118 decimal. 516 6. IANA Considerations 518 No request to IANA. 520 7. Contributors 522 Christian Huitema, Tony Li. 524 Romain Kuntz contributed extensively about IPv6 handovers between 525 links running outside the context of a BSS (802.11-OCB links). 527 Tim Leinmueller contributed the idea of the use of IPv6 over 528 802.11-OCB for distribution of certificates. 530 Marios Makassikis, Jose Santa Lozano, Albin Severinson and Alexey 531 Voronov provided significant feedback on the experience of using IP 532 messages over 802.11-OCB in initial trials. 534 Michelle Wetterwald contributed extensively the MTU discussion, 535 offered the ETSI ITS perspective, and reviewed other parts of the 536 document. 538 8. Acknowledgements 540 The authors would like to thank Witold Klaudel, Ryuji Wakikawa, 541 Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan 542 Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray 543 Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan, 544 Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne, 545 Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark, 546 Bob Moskowitz, Andrew Dryden, Georg Mayer, Dorothy Stanley, Sandra 547 Cespedes, Mariano Falcitelli, Sri Gundavelli, Abdussalam Baryun, 548 Margaret Cullen, Erik Kline, Carlos Jesus Bernardos Cano, Ronald in 549 't Velt, Katrin Sjoberg, Roland Bless, Tijink Jasja, Kevin Smith, 550 Brian Carpenter, Julian Reschke, Mikael Abrahamsson and William 551 Whyte. Their valuable comments clarified particular issues and 552 generally helped to improve the document. 554 Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB 555 drivers for linux and described how. 557 For the multicast discussion, the authors would like to thank Owen 558 DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and 559 participants to discussions in network working groups. 561 The authors would like to thank participants to the Birds-of- 562 a-Feather "Intelligent Transportation Systems" meetings held at IETF 563 in 2016. 565 Human Rights Protocol Considerations review by Amelia Andersdotter. 567 9. References 569 9.1. Normative References 571 [RFC1042] Postel, J. and J. Reynolds, "Standard for the transmission 572 of IP datagrams over IEEE 802 networks", STD 43, RFC 1042, 573 DOI 10.17487/RFC1042, February 1988, 574 . 576 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 577 Requirement Levels", BCP 14, RFC 2119, 578 DOI 10.17487/RFC2119, March 1997, 579 . 581 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 582 Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, 583 . 585 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, 586 DOI 10.17487/RFC2818, May 2000, 587 . 589 [RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related 590 Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004, 591 . 593 [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, 594 "SEcure Neighbor Discovery (SEND)", RFC 3971, 595 DOI 10.17487/RFC3971, March 2005, 596 . 598 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 599 "Randomness Requirements for Security", BCP 106, RFC 4086, 600 DOI 10.17487/RFC4086, June 2005, 601 . 603 [RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast 604 Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005, 605 . 607 [RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen, 608 "Internet X.509 Public Key Infrastructure Certificate 609 Management Protocol (CMP)", RFC 4210, 610 DOI 10.17487/RFC4210, September 2005, 611 . 613 [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing 614 Architecture", RFC 4291, DOI 10.17487/RFC4291, February 615 2006, . 617 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 618 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 619 December 2005, . 621 [RFC4302] Kent, S., "IP Authentication Header", RFC 4302, 622 DOI 10.17487/RFC4302, December 2005, 623 . 625 [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", 626 RFC 4303, DOI 10.17487/RFC4303, December 2005, 627 . 629 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 630 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 631 DOI 10.17487/RFC4861, September 2007, 632 . 634 [RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast 635 Extensions to the Security Architecture for the Internet 636 Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008, 637 . 639 [RFC5415] Calhoun, P., Ed., Montemurro, M., Ed., and D. Stanley, 640 Ed., "Control And Provisioning of Wireless Access Points 641 (CAPWAP) Protocol Specification", RFC 5415, 642 DOI 10.17487/RFC5415, March 2009, 643 . 645 [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing 646 Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, 647 September 2010, . 649 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 650 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 651 2011, . 653 [RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and 654 IETF Protocol and Documentation Usage for IEEE 802 655 Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042, 656 October 2013, . 658 [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 659 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, 660 February 2014, . 662 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 663 Interface Identifiers with IPv6 Stateless Address 664 Autoconfiguration (SLAAC)", RFC 7217, 665 DOI 10.17487/RFC7217, April 2014, 666 . 668 [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy 669 Considerations for IPv6 Address Generation Mechanisms", 670 RFC 7721, DOI 10.17487/RFC7721, March 2016, 671 . 673 [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu, 674 "Recommendation on Stable IPv6 Interface Identifiers", 675 RFC 8064, DOI 10.17487/RFC8064, February 2017, 676 . 678 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 679 (IPv6) Specification", STD 86, RFC 8200, 680 DOI 10.17487/RFC8200, July 2017, 681 . 683 9.2. Informative References 685 [ETSI-sec-archi] 686 "ETSI TS 102 940 V1.2.1 (2016-11), ETSI Technical 687 Specification, Intelligent Transport Systems (ITS); 688 Security; ITS communications security architecture and 689 security management, November 2016. Downloaded on 690 September 9th, 2017, freely available from ETSI website at 691 URL http://www.etsi.org/deliver/ 692 etsi_ts/102900_102999/102940/01.02.01_60/ 693 ts_102940v010201p.pdf". 695 [I-D.hinden-6man-rfc2464bis] 696 Crawford, M. and R. Hinden, "Transmission of IPv6 Packets 697 over Ethernet Networks", draft-hinden-6man-rfc2464bis-02 698 (work in progress), March 2017. 700 [I-D.ietf-ipwave-vehicular-networking-survey] 701 Jeong, J., Cespedes, S., Benamar, N., Haerri, J., and M. 702 Wetterwald, "Survey on IP-based Vehicular Networking for 703 Intelligent Transportation Systems", draft-ietf-ipwave- 704 vehicular-networking-survey-00 (work in progress), July 705 2017. 707 [I-D.perkins-intarea-multicast-ieee802] 708 Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, 709 "Multicast Considerations over IEEE 802 Wireless Media", 710 draft-perkins-intarea-multicast-ieee802-03 (work in 711 progress), July 2017. 713 [IEEE-1609.2] 714 "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access 715 in Vehicular Environments (WAVE) -- Security Services for 716 Applications and Management Messages. Example URL 717 http://ieeexplore.ieee.org/document/7426684/ accessed on 718 August 17th, 2017.". 720 [IEEE-1609.3] 721 "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access 722 in Vehicular Environments (WAVE) -- Networking Services. 723 Example URL http://ieeexplore.ieee.org/document/7458115/ 724 accessed on August 17th, 2017.". 726 [IEEE-1609.4] 727 "IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access 728 in Vehicular Environments (WAVE) -- Multi-Channel 729 Operation. Example URL 730 http://ieeexplore.ieee.org/document/7435228/ accessed on 731 August 17th, 2017.". 733 [IEEE-802.11-2016] 734 "IEEE Standard 802.11-2016 - IEEE Standard for Information 735 Technology - Telecommunications and information exchange 736 between systems Local and metropolitan area networks - 737 Specific requirements - Part 11: Wireless LAN Medium 738 Access Control (MAC) and Physical Layer (PHY) 739 Specifications. Status - Active Standard. Description 740 retrieved freely on September 12th, 2017, at URL 741 https://standards.ieee.org/findstds/ 742 standard/802.11-2016.html". 744 [IEEE-802.11p-2010] 745 "IEEE Std 802.11p (TM)-2010, IEEE Standard for Information 746 Technology - Telecommunications and information exchange 747 between systems - Local and metropolitan area networks - 748 Specific requirements, Part 11: Wireless LAN Medium Access 749 Control (MAC) and Physical Layer (PHY) Specifications, 750 Amendment 6: Wireless Access in Vehicular Environments; 751 document freely available at URL 752 http://standards.ieee.org/getieee802/ 753 download/802.11p-2010.pdf retrieved on September 20th, 754 2013.". 756 Appendix A. ChangeLog 758 The changes are listed in reverse chronological order, most recent 759 changes appearing at the top of the list. 761 -29: 763 o 765 -28: 767 o Created a new section 'Pseudonym Handling'. 769 o removed the 'Vehicle ID' appendix. 771 o improved the address generation from random MAC address. 773 o shortened Term IP-RSU definition. 775 o removed refs to two detail Clauses in IEEE documents, kept just 776 these latter. 778 -27: part 1 of addressing Human Rights review from IRTF. Removed 779 appendices F.2 and F.3. Shortened definition of IP-RSU. Removed 780 reference to 1609.4. A few other small changes, see diff. 782 -26: moved text from SLAAC section and from Design Considerations 783 appendix about privacy into a new Privacy Condiderations subsection 784 of the Security section; reformulated the SLAAC and IID sections to 785 stress only LLs can use EUI-64; removed the "GeoIP" wireshark 786 explanation; reformulated SLAAC and LL sections; added brief mention 787 of need of use LLs; clarified text about MAC address changes; dropped 788 pseudonym discussion; changed title of section describing examples of 789 packet formats. 791 -25: added a reference to 'IEEE Management Information Base', instead 792 of just 'Management Information Base'; added ref to further 793 appendices in the introductory phrases; improved text for IID 794 formation for SLAAC, inserting recommendation for RFC8064 before 795 RFC2464. 797 From draft-ietf-ipwave-ipv6-over-80211ocb-23 to draft-ietf-ipwave- 798 ipv6-over-80211ocb-24 800 o Nit: wrote "IPWAVE Working Group" on the front page, instead of 801 "Network Working Group". 803 o Addressed the comments on 6MAN: replaced a sentence about ND 804 problem with "is used over 802.11-OCB". 806 From draft-ietf-ipwave-ipv6-over-80211ocb-22 to draft-ietf-ipwave- 807 ipv6-over-80211ocb-23 809 o No content modifications, but check the entire draft chain on 810 IPv6-only: xml2rfc, submission on tools.ietf.org and datatracker. 812 From draft-ietf-ipwave-ipv6-over-80211ocb-21 to draft-ietf-ipwave- 813 ipv6-over-80211ocb-22 815 o Corrected typo, use dash in "802.11-OCB" instead of space. 817 o Improved the Frame Format section: MUST use QoSData, specify the 818 values within; clarified the Ethernet Adaptation Layer text. 820 From draft-ietf-ipwave-ipv6-over-80211ocb-20 to draft-ietf-ipwave- 821 ipv6-over-80211ocb-21 823 o Corrected a few nits and added names in Acknowledgments section. 825 o Removed unused reference to old Internet Draft tsvwg about QoS. 827 From draft-ietf-ipwave-ipv6-over-80211ocb-19 to draft-ietf-ipwave- 828 ipv6-over-80211ocb-20 830 o Reduced the definition of term "802.11-OCB". 832 o Left out of this specification which 802.11 header to use to 833 transmit IP packets in OCB mode (QoS Data header, Data header, or 834 any other). 836 o Added 'MUST' use an Ethernet Adaptation Layer, instead of 'is 837 using' an Ethernet Adaptation Layer. 839 From draft-ietf-ipwave-ipv6-over-80211ocb-18 to draft-ietf-ipwave- 840 ipv6-over-80211ocb-19 842 o Removed the text about fragmentation. 844 o Removed the mentioning of WSMP and GeoNetworking. 846 o Removed the explanation of the binary representation of the 847 EtherType. 849 o Rendered normative the paragraph about unicast and multicast 850 address mapping. 852 o Removed paragraph about addressing model, subnet structure and 853 easiness of using LLs. 855 o Clarified the Type/Subtype field in the 802.11 Header. 857 o Used RECOMMENDED instead of recommended, for the stable interface 858 identifiers. 860 From draft-ietf-ipwave-ipv6-over-80211ocb-17 to draft-ietf-ipwave- 861 ipv6-over-80211ocb-18 863 o Improved the MTU and fragmentation paragraph. 865 From draft-ietf-ipwave-ipv6-over-80211ocb-16 to draft-ietf-ipwave- 866 ipv6-over-80211ocb-17 868 o Susbtituted "MUST be increased" to "is increased" in the MTU 869 section, about fragmentation. 871 From draft-ietf-ipwave-ipv6-over-80211ocb-15 to draft-ietf-ipwave- 872 ipv6-over-80211ocb-16 874 o Removed the definition of the 'WiFi' term and its occurences. 875 Clarified a phrase that used it in Appendix C "Aspects introduced 876 by the OCB mode to 802.11". 878 o Added more normative words: MUST be 0x86DD, MUST fragment if size 879 larger than MTU, Sequence number in 802.11 Data header MUST be 880 increased. 882 From draft-ietf-ipwave-ipv6-over-80211ocb-14 to draft-ietf-ipwave- 883 ipv6-over-80211ocb-15 885 o Added normative term MUST in two places in section "Ethernet 886 Adaptation Layer". 888 From draft-ietf-ipwave-ipv6-over-80211ocb-13 to draft-ietf-ipwave- 889 ipv6-over-80211ocb-14 891 o Created a new Appendix titled "Extra Terminology" that contains 892 terms DSRC, DSRCS, OBU, RSU as defined outside IETF. Some of them 893 are used in the main Terminology section. 895 o Added two paragraphs explaining that ND and Mobile IPv6 have 896 problems working over 802.11-OCB, yet their adaptations is not 897 specified in this document. 899 From draft-ietf-ipwave-ipv6-over-80211ocb-12 to draft-ietf-ipwave- 900 ipv6-over-80211ocb-13 902 o Substituted "IP-OBU" for "OBRU", and "IP-RSU" for "RSRU" 903 throughout and improved OBU-related definitions in the Terminology 904 section. 906 From draft-ietf-ipwave-ipv6-over-80211ocb-11 to draft-ietf-ipwave- 907 ipv6-over-80211ocb-12 909 o Improved the appendix about "MAC Address Generation" by expressing 910 the technique to be an optional suggestion, not a mandatory 911 mechanism. 913 From draft-ietf-ipwave-ipv6-over-80211ocb-10 to draft-ietf-ipwave- 914 ipv6-over-80211ocb-11 916 o Shortened the paragraph on forming/terminating 802.11-OCB links. 918 o Moved the draft tsvwg-ieee-802-11 to Informative References. 920 From draft-ietf-ipwave-ipv6-over-80211ocb-09 to draft-ietf-ipwave- 921 ipv6-over-80211ocb-10 923 o Removed text requesting a new Group ID for multicast for OCB. 925 o Added a clarification of the meaning of value "3333" in the 926 section Address Mapping -- Multicast. 928 o Added note clarifying that in Europe the regional authority is not 929 ETSI, but "ECC/CEPT based on ENs from ETSI". 931 o Added note stating that the manner in which two STAtions set their 932 communication channel is not described in this document. 934 o Added a time qualifier to state that the "each node is represented 935 uniquely at a certain point in time." 937 o Removed text "This section may need to be moved" (the "Reliability 938 Requirements" section). This section stays there at this time. 940 o In the term definition "802.11-OCB" added a note stating that "any 941 implementation should comply with standards and regulations set in 942 the different countries for using that frequency band." 944 o In the RSU term definition, added a sentence explaining the 945 difference between RSU and RSRU: in terms of number of interfaces 946 and IP forwarding. 948 o Replaced "with at least two IP interfaces" with "with at least two 949 real or virtual IP interfaces". 951 o Added a term in the Terminology for "OBU". However the definition 952 is left empty, as this term is defined outside IETF. 954 o Added a clarification that it is an OBU or an OBRU in this phrase 955 "A vehicle embarking an OBU or an OBRU". 957 o Checked the entire document for a consistent use of terms OBU and 958 OBRU. 960 o Added note saying that "'p' is a letter identifying the 961 Ammendment". 963 o Substituted lower case for capitals SHALL or MUST in the 964 Appendices. 966 o Added reference to RFC7042, helpful in the 3333 explanation. 967 Removed reference to individual submission draft-petrescu-its- 968 scenario-reqs and added reference to draft-ietf-ipwave-vehicular- 969 networking-survey. 971 o Added figure captions, figure numbers, and references to figure 972 numbers instead of 'below'. Replaced "section Section" with 973 "section" throughout. 975 o Minor typographical errors. 977 From draft-ietf-ipwave-ipv6-over-80211ocb-08 to draft-ietf-ipwave- 978 ipv6-over-80211ocb-09 980 o Significantly shortened the Address Mapping sections, by text 981 copied from RFC2464, and rather referring to it. 983 o Moved the EPD description to an Appendix on its own. 985 o Shortened the Introduction and the Abstract. 987 o Moved the tutorial section of OCB mode introduced to .11, into an 988 appendix. 990 o Removed the statement that suggests that for routing purposes a 991 prefix exchange mechanism could be needed. 993 o Removed refs to RFC3963, RFC4429 and RFC6775; these are about ND, 994 MIP/NEMO and oDAD; they were referred in the handover discussion 995 section, which is out. 997 o Updated a reference from individual submission to now a WG item in 998 IPWAVE: the survey document. 1000 o Added term definition for WiFi. 1002 o Updated the authorship and expanded the Contributors section. 1004 o Corrected typographical errors. 1006 From draft-ietf-ipwave-ipv6-over-80211ocb-07 to draft-ietf-ipwave- 1007 ipv6-over-80211ocb-08 1009 o Removed the per-channel IPv6 prohibition text. 1011 o Corrected typographical errors. 1013 From draft-ietf-ipwave-ipv6-over-80211ocb-06 to draft-ietf-ipwave- 1014 ipv6-over-80211ocb-07 1016 o Added new terms: OBRU and RSRU ('R' for Router). Refined the 1017 existing terms RSU and OBU, which are no longer used throughout 1018 the document. 1020 o Improved definition of term "802.11-OCB". 1022 o Clarified that OCB does not "strip" security, but that the 1023 operation in OCB mode is "stripped off of all .11 security". 1025 o Clarified that theoretical OCB bandwidth speed is 54mbits, but 1026 that a commonly observed bandwidth in IP-over-OCB is 12mbit/s. 1028 o Corrected typographical errors, and improved some phrasing. 1030 From draft-ietf-ipwave-ipv6-over-80211ocb-05 to draft-ietf-ipwave- 1031 ipv6-over-80211ocb-06 1033 o Updated references of 802.11-OCB document from -2012 to the IEEE 1034 802.11-2016. 1036 o In the LL address section, and in SLAAC section, added references 1037 to 7217 opaque IIDs and 8064 stable IIDs. 1039 From draft-ietf-ipwave-ipv6-over-80211ocb-04 to draft-ietf-ipwave- 1040 ipv6-over-80211ocb-05 1042 o Lengthened the title and cleanded the abstract. 1044 o Added text suggesting LLs may be easy to use on OCB, rather than 1045 GUAs based on received prefix. 1047 o Added the risks of spoofing and hijacking. 1049 o Removed the text speculation on adoption of the TSA message. 1051 o Clarified that the ND protocol is used. 1053 o Clarified what it means "No association needed". 1055 o Added some text about how two STAs discover each other. 1057 o Added mention of external (OCB) and internal network (stable), in 1058 the subnet structure section. 1060 o Added phrase explaining that both .11 Data and .11 QoS Data 1061 headers are currently being used, and may be used in the future. 1063 o Moved the packet capture example into an Appendix Implementation 1064 Status. 1066 o Suggested moving the reliability requirements appendix out into 1067 another document. 1069 o Added a IANA Consiserations section, with content, requesting for 1070 a new multicast group "all OCB interfaces". 1072 o Added new OBU term, improved the RSU term definition, removed the 1073 ETTC term, replaced more occurences of 802.11p, 802.11-OCB with 1074 802.11-OCB. 1076 o References: 1078 * Added an informational reference to ETSI's IPv6-over- 1079 GeoNetworking. 1081 * Added more references to IETF and ETSI security protocols. 1083 * Updated some references from I-D to RFC, and from old RFC to 1084 new RFC numbers. 1086 * Added reference to multicast extensions to IPsec architecture 1087 RFC. 1089 * Added a reference to 2464-bis. 1091 * Removed FCC informative references, because not used. 1093 o Updated the affiliation of one author. 1095 o Reformulation of some phrases for better readability, and 1096 correction of typographical errors. 1098 From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave- 1099 ipv6-over-80211ocb-04 1101 o Removed a few informative references pointing to Dx draft IEEE 1102 1609 documents. 1104 o Removed outdated informative references to ETSI documents. 1106 o Added citations to IEEE 1609.2, .3 and .4-2016. 1108 o Minor textual issues. 1110 From draft-ietf-ipwave-ipv6-over-80211ocb-02 to draft-ietf-ipwave- 1111 ipv6-over-80211ocb-03 1113 o Keep the previous text on multiple addresses, so remove talk about 1114 MIP6, NEMOv6 and MCoA. 1116 o Clarified that a 'Beacon' is an IEEE 802.11 frame Beacon. 1118 o Clarified the figure showing Infrastructure mode and OCB mode side 1119 by side. 1121 o Added a reference to the IP Security Architecture RFC. 1123 o Detailed the IPv6-per-channel prohibition paragraph which reflects 1124 the discussion at the last IETF IPWAVE WG meeting. 1126 o Added section "Address Mapping -- Unicast". 1128 o Added the ".11 Trailer" to pictures of 802.11 frames. 1130 o Added text about SNAP carrying the Ethertype. 1132 o New RSU definition allowing for it be both a Router and not 1133 necessarily a Router some times. 1135 o Minor textual issues. 1137 From draft-ietf-ipwave-ipv6-over-80211ocb-01 to draft-ietf-ipwave- 1138 ipv6-over-80211ocb-02 1139 o Replaced almost all occurences of 802.11p with 802.11-OCB, leaving 1140 only when explanation of evolution was necessary. 1142 o Shortened by removing parameter details from a paragraph in the 1143 Introduction. 1145 o Moved a reference from Normative to Informative. 1147 o Added text in intro clarifying there is no handover spec at IEEE, 1148 and that 1609.2 does provide security services. 1150 o Named the contents the fields of the EthernetII header (including 1151 the Ethertype bitstring). 1153 o Improved relationship between two paragraphs describing the 1154 increase of the Sequence Number in 802.11 header upon IP 1155 fragmentation. 1157 o Added brief clarification of "tracking". 1159 From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave- 1160 ipv6-over-80211ocb-01 1162 o Introduced message exchange diagram illustrating differences 1163 between 802.11 and 802.11 in OCB mode. 1165 o Introduced an appendix listing for information the set of 802.11 1166 messages that may be transmitted in OCB mode. 1168 o Removed appendix sections "Privacy Requirements", "Authentication 1169 Requirements" and "Security Certificate Generation". 1171 o Removed appendix section "Non IP Communications". 1173 o Introductory phrase in the Security Considerations section. 1175 o Improved the definition of "OCB". 1177 o Introduced theoretical stacked layers about IPv6 and IEEE layers 1178 including EPD. 1180 o Removed the appendix describing the details of prohibiting IPv6 on 1181 certain channels relevant to 802.11-OCB. 1183 o Added a brief reference in the privacy text about a precise clause 1184 in IEEE 1609.3 and .4. 1186 o Clarified the definition of a Road Side Unit. 1188 o Removed the discussion about security of WSA (because is non-IP). 1190 o Removed mentioning of the GeoNetworking discussion. 1192 o Moved references to scientific articles to a separate 'overview' 1193 draft, and referred to it. 1195 Appendix B. 802.11p 1197 The term "802.11p" is an earlier definition. The behaviour of 1198 "802.11p" networks is rolled in the document IEEE Std 802.11-2016. 1199 In that document the term 802.11p disappears. Instead, each 802.11p 1200 feature is conditioned by the IEEE Management Information Base (MIB) 1201 attribute "OCBActivated" [IEEE-802.11-2016]. Whenever OCBActivated 1202 is set to true the IEEE Std 802.11-OCB state is activated. For 1203 example, an 802.11 STAtion operating outside the context of a basic 1204 service set has the OCBActivated flag set. Such a station, when it 1205 has the flag set, uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. 1207 Appendix C. Aspects introduced by the OCB mode to 802.11 1209 In the IEEE 802.11-OCB mode, all nodes in the wireless range can 1210 directly communicate with each other without involving authentication 1211 or association procedures. At link layer, it is necessary to set the 1212 same channel number (or frequency) on two stations that need to 1213 communicate with each other. The manner in which stations set their 1214 channel number is not specified in this document. Stations STA1 and 1215 STA2 can exchange IP packets if they are set on the same channel. At 1216 IP layer, they then discover each other by using the IPv6 Neighbor 1217 Discovery protocol. 1219 Briefly, the IEEE 802.11-OCB mode has the following properties: 1221 o The use by each node of a 'wildcard' BSSID (i.e., each bit of the 1222 BSSID is set to 1) 1224 o No IEEE 802.11 Beacon frames are transmitted 1226 o No authentication is required in order to be able to communicate 1228 o No association is needed in order to be able to communicate 1230 o No encryption is provided in order to be able to communicate 1232 o Flag dot11OCBActivated is set to true 1234 All the nodes in the radio communication range (IP-OBU and IP-RSU) 1235 receive all the messages transmitted (IP-OBU and IP-RSU) within the 1236 radio communications range. The eventual conflict(s) are resolved by 1237 the MAC CDMA function. 1239 The message exchange diagram in Figure 3 illustrates a comparison 1240 between traditional 802.11 and 802.11 in OCB mode. The 'Data' 1241 messages can be IP packets such as HTTP or others. Other 802.11 1242 management and control frames (non IP) may be transmitted, as 1243 specified in the 802.11 standard. For information, the names of 1244 these messages as currently specified by the 802.11 standard are 1245 listed in Appendix G. 1247 STA AP STA1 STA2 1248 | | | | 1249 |<------ Beacon -------| |<------ Data -------->| 1250 | | | | 1251 |---- Probe Req. ----->| |<------ Data -------->| 1252 |<--- Probe Res. ------| | | 1253 | | |<------ Data -------->| 1254 |---- Auth Req. ------>| | | 1255 |<--- Auth Res. -------| |<------ Data -------->| 1256 | | | | 1257 |---- Asso Req. ------>| |<------ Data -------->| 1258 |<--- Asso Res. -------| | | 1259 | | |<------ Data -------->| 1260 |<------ Data -------->| | | 1261 |<------ Data -------->| |<------ Data -------->| 1263 (i) 802.11 Infrastructure mode (ii) 802.11-OCB mode 1265 Figure 3: Difference between messages exchanged on 802.11 (left) and 1266 802.11-OCB (right) 1268 The interface 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010 1269 [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, 1270 titled "Amendment 6: Wireless Access in Vehicular Environments". 1271 Since then, this amendment has been integrated in IEEE 802.11(TM) 1272 -2012 and -2016 [IEEE-802.11-2016]. 1274 In document 802.11-2016, anything qualified specifically as 1275 "OCBActivated", or "outside the context of a basic service" set to be 1276 true, then it is actually referring to OCB aspects introduced to 1277 802.11. 1279 In order to delineate the aspects introduced by 802.11-OCB to 802.11, 1280 we refer to the earlier [IEEE-802.11p-2010]. The amendment is 1281 concerned with vehicular communications, where the wireless link is 1282 similar to that of Wireless LAN (using a PHY layer specified by 1283 802.11a/b/g/n), but which needs to cope with the high mobility factor 1284 inherent in scenarios of communications between moving vehicles, and 1285 between vehicles and fixed infrastructure deployed along roads. 1286 While 'p' is a letter identifying the Ammendment, just like 'a, b, g' 1287 and 'n' are, 'p' is concerned more with MAC modifications, and a 1288 little with PHY modifications; the others are mainly about PHY 1289 modifications. It is possible in practice to combine a 'p' MAC with 1290 an 'a' PHY by operating outside the context of a BSS with OFDM at 1291 5.4GHz and 5.9GHz. 1293 The 802.11-OCB links are specified to be compatible as much as 1294 possible with the behaviour of 802.11a/b/g/n and future generation 1295 IEEE WLAN links. From the IP perspective, an 802.11-OCB MAC layer 1296 offers practically the same interface to IP as the 802.11a/b/g/n and 1297 802.3. A packet sent by an IP-OBU may be received by one or multiple 1298 IP-RSUs. The link-layer resolution is performed by using the IPv6 1299 Neighbor Discovery protocol. 1301 To support this similarity statement (IPv6 is layered on top of LLC 1302 on top of 802.11-OCB, in the same way that IPv6 is layered on top of 1303 LLC on top of 802.11a/b/g/n (for WLAN) or layered on top of LLC on 1304 top of 802.3 (for Ethernet)) it is useful to analyze the differences 1305 between 802.11-OCB and 802.11 specifications. During this analysis, 1306 we note that whereas 802.11-OCB lists relatively complex and numerous 1307 changes to the MAC layer (and very little to the PHY layer), there 1308 are only a few characteristics which may be important for an 1309 implementation transmitting IPv6 packets on 802.11-OCB links. 1311 The most important 802.11-OCB point which influences the IPv6 1312 functioning is the OCB characteristic; an additional, less direct 1313 influence, is the maximum bandwidth afforded by the PHY modulation/ 1314 demodulation methods and channel access specified by 802.11-OCB. The 1315 maximum bandwidth theoretically possible in 802.11-OCB is 54 Mbit/s 1316 (when using, for example, the following parameters: 20 MHz channel; 1317 modulation 64-QAM; coding rate R is 3/4); in practice of IP-over- 1318 802.11-OCB a commonly observed figure is 12Mbit/s; this bandwidth 1319 allows the operation of a wide range of protocols relying on IPv6. 1321 o Operation Outside the Context of a BSS (OCB): the (earlier 1322 802.11p) 802.11-OCB links are operated without a Basic Service Set 1323 (BSS). This means that the frames IEEE 802.11 Beacon, Association 1324 Request/Response, Authentication Request/Response, and similar, 1325 are not used. The used identifier of BSS (BSSID) has a 1326 hexadecimal value always 0xffffffffffff (48 '1' bits, represented 1327 as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' 1328 BSSID), as opposed to an arbitrary BSSID value set by 1329 administrator (e.g. 'My-Home-AccessPoint'). The OCB operation - 1330 namely the lack of beacon-based scanning and lack of 1331 authentication - should be taken into account when the Mobile IPv6 1332 protocol [RFC6275] and the protocols for IP layer security 1333 [RFC4301] are used. The way these protocols adapt to OCB is not 1334 described in this document. 1336 o Timing Advertisement: is a new message defined in 802.11-OCB, 1337 which does not exist in 802.11a/b/g/n. This message is used by 1338 stations to inform other stations about the value of time. It is 1339 similar to the time as delivered by a GNSS system (Galileo, GPS, 1340 ...) or by a cellular system. This message is optional for 1341 implementation. 1343 o Frequency range: this is a characteristic of the PHY layer, with 1344 almost no impact on the interface between MAC and IP. However, it 1345 is worth considering that the frequency range is regulated by a 1346 regional authority (ARCEP, ECC/CEPT based on ENs from ETSI, FCC, 1347 etc.); as part of the regulation process, specific applications 1348 are associated with specific frequency ranges. In the case of 1349 802.11-OCB, the regulator associates a set of frequency ranges, or 1350 slots within a band, to the use of applications of vehicular 1351 communications, in a band known as "5.9GHz". The 5.9GHz band is 1352 different from the 2.4GHz and 5GHz bands used by Wireless LAN. 1353 However, as with Wireless LAN, the operation of 802.11-OCB in 1354 "5.9GHz" bands is exempt from owning a license in EU (in US the 1355 5.9GHz is a licensed band of spectrum; for the fixed 1356 infrastructure an explicit FCC authorization is required; for an 1357 on-board device a 'licensed-by-rule' concept applies: rule 1358 certification conformity is required.) Technical conditions are 1359 different than those of the bands "2.4GHz" or "5GHz". The allowed 1360 power levels, and implicitly the maximum allowed distance between 1361 vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20 1362 dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum 1363 distance of approximately 1km, compared to approximately 50m. 1364 Additionally, specific conditions related to congestion avoidance, 1365 jamming avoidance, and radar detection are imposed on the use of 1366 DSRC (in US) and on the use of frequencies for Intelligent 1367 Transportation Systems (in EU), compared to Wireless LAN 1368 (802.11a/b/g/n). 1370 o 'Half-rate' encoding: as the frequency range, this parameter is 1371 related to PHY, and thus has not much impact on the interface 1372 between the IP layer and the MAC layer. 1374 o In vehicular communications using 802.11-OCB links, there are 1375 strong privacy requirements with respect to addressing. While the 1376 802.11-OCB standard does not specify anything in particular with 1377 respect to MAC addresses, in these settings there exists a strong 1378 need for dynamic change of these addresses (as opposed to the non- 1379 vehicular settings - real wall protection - where fixed MAC 1380 addresses do not currently pose some privacy risks). This is 1381 further described in Section 5. A relevant function is described 1382 in documents IEEE 1609.3-2016 [IEEE-1609.3] and IEEE 1609.4-2016 1383 [IEEE-1609.4]. 1385 Appendix D. Changes Needed on a software driver 802.11a to become a 1386 802.11-OCB driver 1388 The 802.11p amendment modifies both the 802.11 stack's physical and 1389 MAC layers but all the induced modifications can be quite easily 1390 obtained by modifying an existing 802.11a ad-hoc stack. 1392 Conditions for a 802.11a hardware to be 802.11-OCB compliant: 1394 o The PHY entity shall be an orthogonal frequency division 1395 multiplexing (OFDM) system. It must support the frequency bands 1396 on which the regulator recommends the use of ITS communications, 1397 for example using IEEE 802.11-OCB layer, in France: 5875MHz to 1398 5925MHz. 1400 o The OFDM system must provide a "half-clocked" operation using 10 1401 MHz channel spacings. 1403 o The chip transmit spectrum mask must be compliant to the "Transmit 1404 spectrum mask" from the IEEE 802.11p amendment (but experimental 1405 environments tolerate otherwise). 1407 o The chip should be able to transmit up to 44.8 dBm when used by 1408 the US government in the United States, and up to 33 dBm in 1409 Europe; other regional conditions apply. 1411 Changes needed on the network stack in OCB mode: 1413 o Physical layer: 1415 * The chip must use the Orthogonal Frequency Multiple Access 1416 (OFDM) encoding mode. 1418 * The chip must be set in half-mode rate mode (the internal clock 1419 frequency is divided by two). 1421 * The chip must use dedicated channels and should allow the use 1422 of higher emission powers. This may require modifications to 1423 the local computer file that describes regulatory domains 1424 rules, if used by the kernel to enforce local specific 1425 restrictions. Such modifications to the local computer file 1426 must respect the location-specific regulatory rules. 1428 MAC layer: 1430 * All management frames (beacons, join, leave, and others) 1431 emission and reception must be disabled except for frames of 1432 subtype Action and Timing Advertisement (defined below). 1434 * No encryption key or method must be used. 1436 * Packet emission and reception must be performed as in ad-hoc 1437 mode, using the wildcard BSSID (ff:ff:ff:ff:ff:ff). 1439 * The functions related to joining a BSS (Association Request/ 1440 Response) and for authentication (Authentication Request/Reply, 1441 Challenge) are not called. 1443 * The beacon interval is always set to 0 (zero). 1445 * Timing Advertisement frames, defined in the amendment, should 1446 be supported. The upper layer should be able to trigger such 1447 frames emission and to retrieve information contained in 1448 received Timing Advertisements. 1450 Appendix E. EtherType Protocol Discrimination (EPD) 1452 A more theoretical and detailed view of layer stacking, and 1453 interfaces between the IP layer and 802.11-OCB layers, is illustrated 1454 in Figure 4. The IP layer operates on top of the EtherType Protocol 1455 Discrimination (EPD); this Discrimination layer is described in IEEE 1456 Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP 1457 (Link Layer Control Service Access Point). 1459 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1460 | IPv6 | 1461 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ 1462 { LLC_SAP } 802.11-OCB 1463 +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary 1464 | EPD | | | 1465 | | MLME | | 1466 +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | 1467 | MAC Sublayer | | | 802.11-OCB 1468 | and ch. coord. | | SME | Services 1469 +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | 1470 | | PLME | | 1471 | PHY Layer | PLME_SAP | 1472 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1474 Figure 4: EtherType Protocol Discrimination 1476 Appendix F. Design Considerations 1478 The networks defined by 802.11-OCB are in many ways similar to other 1479 networks of the 802.11 family. In theory, the encapsulation of IPv6 1480 over 802.11-OCB could be very similar to the operation of IPv6 over 1481 other networks of the 802.11 family. However, the high mobility, 1482 strong link asymmetry and very short connection makes the 802.11-OCB 1483 link significantly different from other 802.11 networks. Also, the 1484 automotive applications have specific requirements for reliability, 1485 security and privacy, which further add to the particularity of the 1486 802.11-OCB link. 1488 Appendix G. IEEE 802.11 Messages Transmitted in OCB mode 1490 For information, at the time of writing, this is the list of IEEE 1491 802.11 messages that may be transmitted in OCB mode, i.e. when 1492 dot11OCBActivated is true in a STA: 1494 o The STA may send management frames of subtype Action and, if the 1495 STA maintains a TSF Timer, subtype Timing Advertisement; 1497 o The STA may send control frames, except those of subtype PS-Poll, 1498 CF-End, and CF-End plus CFAck; 1500 o The STA may send data frames of subtype Data, Null, QoS Data, and 1501 QoS Null. 1503 Appendix H. Examples of Packet Formats 1505 This section describes an example of an IPv6 Packet captured over a 1506 IEEE 802.11-OCB link. 1508 By way of example we show that there is no modification in the 1509 headers when transmitted over 802.11-OCB networks - they are 1510 transmitted like any other 802.11 and Ethernet packets. 1512 We describe an experiment of capturing an IPv6 packet on an 1513 802.11-OCB link. In topology depicted in Figure 5, the packet is an 1514 IPv6 Router Advertisement. This packet is emitted by a Router on its 1515 802.11-OCB interface. The packet is captured on the Host, using a 1516 network protocol analyzer (e.g. Wireshark); the capture is performed 1517 in two different modes: direct mode and 'monitor' mode. The topology 1518 used during the capture is depicted below. 1520 The packet is captured on the Host. The Host is an IP-OBU containing 1521 an 802.11 interface in format PCI express (an ITRI product). The 1522 kernel runs the ath5k software driver with modifications for OCB 1523 mode. The capture tool is Wireshark. The file format for save and 1524 analyze is 'pcap'. The packet is generated by the Router. The 1525 Router is an IP-RSU (ITRI product). 1527 +--------+ +-------+ 1528 | | 802.11-OCB Link | | 1529 ---| Router |--------------------------------| Host | 1530 | | | | 1531 +--------+ +-------+ 1533 Figure 5: Topology for capturing IP packets on 802.11-OCB 1535 During several capture operations running from a few moments to 1536 several hours, no message relevant to the BSSID contexts were 1537 captured (no Association Request/Response, Authentication Req/Resp, 1538 Beacon). This shows that the operation of 802.11-OCB is outside the 1539 context of a BSSID. 1541 Overall, the captured message is identical with a capture of an IPv6 1542 packet emitted on a 802.11b interface. The contents are precisely 1543 similar. 1545 H.1. Capture in Monitor Mode 1547 The IPv6 RA packet captured in monitor mode is illustrated below. 1548 The radio tap header provides more flexibility for reporting the 1549 characteristics of frames. The Radiotap Header is prepended by this 1550 particular stack and operating system on the Host machine to the RA 1551 packet received from the network (the Radiotap Header is not present 1552 on the air). The implementation-dependent Radiotap Header is useful 1553 for piggybacking PHY information from the chip's registers as data in 1554 a packet understandable by userland applications using Socket 1555 interfaces (the PHY interface can be, for example: power levels, data 1556 rate, ratio of signal to noise). 1558 The packet present on the air is formed by IEEE 802.11 Data Header, 1559 Logical Link Control Header, IPv6 Base Header and ICMPv6 Header. 1561 Radiotap Header v0 1562 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1563 |Header Revision| Header Pad | Header length | 1564 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1565 | Present flags | 1566 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1567 | Data Rate | Pad | 1568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1570 IEEE 802.11 Data Header 1571 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1572 | Type/Subtype and Frame Ctrl | Duration | 1573 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1574 | Receiver Address... 1575 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1576 ... Receiver Address | Transmitter Address... 1577 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1578 ... Transmitter Address | 1579 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1580 | BSS Id... 1581 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1582 ... BSS Id | Frag Number and Seq Number | 1583 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1585 Logical-Link Control Header 1586 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1587 | DSAP |I| SSAP |C| Control field | Org. code... 1588 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1589 ... Organizational Code | Type | 1590 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1591 IPv6 Base Header 1592 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1593 |Version| Traffic Class | Flow Label | 1594 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1595 | Payload Length | Next Header | Hop Limit | 1596 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1597 | | 1598 + + 1599 | | 1600 + Source Address + 1601 | | 1602 + + 1603 | | 1604 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1605 | | 1606 + + 1607 | | 1608 + Destination Address + 1609 | | 1610 + + 1611 | | 1612 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1614 Router Advertisement 1615 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1616 | Type | Code | Checksum | 1617 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1618 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1619 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1620 | Reachable Time | 1621 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1622 | Retrans Timer | 1623 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1624 | Options ... 1625 +-+-+-+-+-+-+-+-+-+-+-+- 1627 The value of the Data Rate field in the Radiotap header is set to 6 1628 Mb/s. This indicates the rate at which this RA was received. 1630 The value of the Transmitter address in the IEEE 802.11 Data Header 1631 is set to a 48bit value. The value of the destination address is 1632 33:33:00:00:00:1 (all-nodes multicast address). The value of the BSS 1633 Id field is ff:ff:ff:ff:ff:ff, which is recognized by the network 1634 protocol analyzer as being "broadcast". The Fragment number and 1635 sequence number fields are together set to 0x90C6. 1637 The value of the Organization Code field in the Logical-Link Control 1638 Header is set to 0x0, recognized as "Encapsulated Ethernet". The 1639 value of the Type field is 0x86DD (hexadecimal 86DD, or otherwise 1640 #86DD), recognized as "IPv6". 1642 A Router Advertisement is periodically sent by the router to 1643 multicast group address ff02::1. It is an icmp packet type 134. The 1644 IPv6 Neighbor Discovery's Router Advertisement message contains an 1645 8-bit field reserved for single-bit flags, as described in [RFC4861]. 1647 The IPv6 header contains the link local address of the router 1648 (source) configured via EUI-64 algorithm, and destination address set 1649 to ff02::1. 1651 The Ethernet Type field in the logical-link control header is set to 1652 0x86dd which indicates that the frame transports an IPv6 packet. In 1653 the IEEE 802.11 data, the destination address is 33:33:00:00:00:01 1654 which is the corresponding multicast MAC address. The BSS id is a 1655 broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link 1656 duration between vehicles and the roadside infrastructure, there is 1657 no need in IEEE 802.11-OCB to wait for the completion of association 1658 and authentication procedures before exchanging data. IEEE 1659 802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s) 1660 and may start communicating as soon as they arrive on the 1661 communication channel. 1663 H.2. Capture in Normal Mode 1665 The same IPv6 Router Advertisement packet described above (monitor 1666 mode) is captured on the Host, in the Normal mode, and depicted 1667 below. 1669 Ethernet II Header 1670 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1671 | Destination... 1672 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1673 ...Destination | Source... 1674 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1675 ...Source | 1676 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1677 | Type | 1678 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1680 IPv6 Base Header 1681 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1682 |Version| Traffic Class | Flow Label | 1683 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1684 | Payload Length | Next Header | Hop Limit | 1685 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1686 | | 1687 + + 1688 | | 1689 + Source Address + 1690 | | 1691 + + 1692 | | 1693 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1694 | | 1695 + + 1696 | | 1697 + Destination Address + 1698 | | 1699 + + 1700 | | 1701 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1703 Router Advertisement 1704 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1705 | Type | Code | Checksum | 1706 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1707 | Cur Hop Limit |M|O| Reserved | Router Lifetime | 1708 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1709 | Reachable Time | 1710 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1711 | Retrans Timer | 1712 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1713 | Options ... 1714 +-+-+-+-+-+-+-+-+-+-+-+- 1716 One notices that the Radiotap Header, the IEEE 802.11 Data Header and 1717 the Logical-Link Control Headers are not present. On the other hand, 1718 a new header named Ethernet II Header is present. 1720 The Destination and Source addresses in the Ethernet II header 1721 contain the same values as the fields Receiver Address and 1722 Transmitter Address present in the IEEE 802.11 Data Header in the 1723 "monitor" mode capture. 1725 The value of the Type field in the Ethernet II header is 0x86DD 1726 (recognized as "IPv6"); this value is the same value as the value of 1727 the field Type in the Logical-Link Control Header in the "monitor" 1728 mode capture. 1730 The knowledgeable experimenter will no doubt notice the similarity of 1731 this Ethernet II Header with a capture in normal mode on a pure 1732 Ethernet cable interface. 1734 An Adaptation layer is inserted on top of a pure IEEE 802.11 MAC 1735 layer, in order to adapt packets, before delivering the payload data 1736 to the applications. It adapts 802.11 LLC/MAC headers to Ethernet II 1737 headers. In further detail, this adaptation consists in the 1738 elimination of the Radiotap, 802.11 and LLC headers, and in the 1739 insertion of the Ethernet II header. In this way, IPv6 runs straight 1740 over LLC over the 802.11-OCB MAC layer; this is further confirmed by 1741 the use of the unique Type 0x86DD. 1743 Appendix I. Extra Terminology 1745 The following terms are defined outside the IETF. They are used to 1746 define the main terms in the main terminology section Section 2. 1748 DSRC (Dedicated Short Range Communication): a term defined outside 1749 the IETF. The US Federal Communications Commission (FCC) Dedicated 1750 Short Range Communication (DSRC) is defined in the Code of Federal 1751 Regulations (CFR) 47, Parts 90 and 95. This Code is referred in the 1752 definitions below. At the time of the writing of this Internet 1753 Draft, the last update of this Code was dated October 1st, 2010. 1755 DSRCS (Dedicated Short-Range Communications Services): a term defined 1756 outside the IETF. The use of radio techniques to transfer data over 1757 short distances between roadside and mobile units, between mobile 1758 units, and between portable and mobile units to perform operations 1759 related to the improvement of traffic flow, traffic safety, and other 1760 intelligent transportation service applications in a variety of 1761 environments. DSRCS systems may also transmit status and 1762 instructional messages related to the units involve. [Ref. 47 CFR 1763 90.7 - Definitions] 1764 OBU (On-Board Unit): a term defined outside the IETF. An On-Board 1765 Unit is a DSRCS transceiver that is normally mounted in or on a 1766 vehicle, or which in some instances may be a portable unit. An OBU 1767 can be operational while a vehicle or person is either mobile or 1768 stationary. The OBUs receive and contend for time to transmit on one 1769 or more radio frequency (RF) channels. Except where specifically 1770 excluded, OBU operation is permitted wherever vehicle operation or 1771 human passage is permitted. The OBUs mounted in vehicles are 1772 licensed by rule under part 95 of the respective chapter and 1773 communicate with Roadside Units (RSUs) and other OBUs. Portable OBUs 1774 are also licensed by rule under part 95 of the respective chapter. 1775 OBU operations in the Unlicensed National Information Infrastructure 1776 (UNII) Bands follow the rules in those bands. - [CFR 90.7 - 1777 Definitions]. 1779 RSU (Road-Side Unit): a term defined outside of IETF. A Roadside 1780 Unit is a DSRC transceiver that is mounted along a road or pedestrian 1781 passageway. An RSU may also be mounted on a vehicle or is hand 1782 carried, but it may only operate when the vehicle or hand- carried 1783 unit is stationary. Furthermore, an RSU operating under the 1784 respectgive part is restricted to the location where it is licensed 1785 to operate. However, portable or hand-held RSUs are permitted to 1786 operate where they do not interfere with a site-licensed operation. 1787 A RSU broadcasts data to OBUs or exchanges data with OBUs in its 1788 communications zone. An RSU also provides channel assignments and 1789 operating instructions to OBUs in its communications zone, when 1790 required. - [CFR 90.7 - Definitions]. 1792 Authors' Addresses 1794 Alexandre Petrescu 1795 CEA, LIST 1796 CEA Saclay 1797 Gif-sur-Yvette , Ile-de-France 91190 1798 France 1800 Phone: +33169089223 1801 Email: Alexandre.Petrescu@cea.fr 1803 Nabil Benamar 1804 Moulay Ismail University 1805 Morocco 1807 Phone: +212670832236 1808 Email: n.benamar@est.umi.ac.ma 1809 Jerome Haerri 1810 Eurecom 1811 Sophia-Antipolis 06904 1812 France 1814 Phone: +33493008134 1815 Email: Jerome.Haerri@eurecom.fr 1817 Jong-Hyouk Lee 1818 Sangmyung University 1819 31, Sangmyeongdae-gil, Dongnam-gu 1820 Cheonan 31066 1821 Republic of Korea 1823 Email: jonghyouk@smu.ac.kr 1825 Thierry Ernst 1826 YoGoKo 1827 France 1829 Email: thierry.ernst@yogoko.fr