--- 1/draft-ietf-ipwave-ipv6-over-80211ocb-09.txt 2017-10-12 06:13:14.545694444 -0700 +++ 2/draft-ietf-ipwave-ipv6-over-80211ocb-10.txt 2017-10-12 06:13:14.621696168 -0700 @@ -1,26 +1,26 @@ Network Working Group A. Petrescu Internet-Draft CEA, LIST Intended status: Standards Track N. Benamar -Expires: April 9, 2018 Moulay Ismail University +Expires: April 15, 2018 Moulay Ismail University J. Haerri Eurecom J. Lee Sangmyung University T. Ernst YoGoKo - October 6, 2017 + October 12, 2017 Transmission of IPv6 Packets over IEEE 802.11 Networks operating in mode Outside the Context of a Basic Service Set (IPv6-over-80211-OCB) - draft-ietf-ipwave-ipv6-over-80211ocb-09.txt + draft-ietf-ipwave-ipv6-over-80211ocb-10.txt Abstract In order to transmit IPv6 packets on IEEE 802.11 networks running outside the context of a basic service set (OCB, earlier "802.11p") there is a need to define a few parameters such as the supported Maximum Transmission Unit size on the 802.11-OCB link, the header format preceding the IPv6 header, the Type value within it, and others. This document describes these parameters for IPv6 and IEEE 802.11-OCB networks; it portrays the layering of IPv6 on 802.11-OCB @@ -35,76 +35,76 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on April 9, 2018. + This Internet-Draft will expire on April 15, 2018. Copyright Notice Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 4 + 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 5 4. IPv6 over 802.11-OCB . . . . . . . . . . . . . . . . . . . . 5 4.1. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 5 - 4.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 5 + 4.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 6 4.2.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 6 4.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 8 - 4.4. Address Mapping . . . . . . . . . . . . . . . . . . . . . 8 - 4.4.1. Address Mapping -- Unicast . . . . . . . . . . . . . 8 - 4.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 8 - 4.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 8 - 4.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 9 - 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 - 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 - 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 - 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 - 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 - 9.1. Normative References . . . . . . . . . . . . . . . . . . 11 - 9.2. Informative References . . . . . . . . . . . . . . . . . 14 + 4.4. Address Mapping . . . . . . . . . . . . . . . . . . . . . 9 + 4.4.1. Address Mapping -- Unicast . . . . . . . . . . . . . 9 + 4.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 9 + 4.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 9 + 4.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 10 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 + 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 11 + 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 + 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 + 9.1. Normative References . . . . . . . . . . . . . . . . . . 12 + 9.2. Informative References . . . . . . . . . . . . . . . . . 15 Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 16 - Appendix B. 802.11p . . . . . . . . . . . . . . . . . . . . . . 20 - Appendix C. Aspects introduced by the OCB mode to 802.11 . . . . 20 + Appendix B. 802.11p . . . . . . . . . . . . . . . . . . . . . . 22 + Appendix C. Aspects introduced by the OCB mode to 802.11 . . . . 22 Appendix D. Changes Needed on a software driver 802.11a to - become a 802.11-OCB driver . . . 25 - Appendix E. EPD . . . . . . . . . . . . . . . . . . . . . . . . 26 - Appendix F. Design Considerations . . . . . . . . . . . . . . . 26 - F.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 27 - F.2. Reliability Requirements . . . . . . . . . . . . . . . . 27 - F.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 28 - F.4. MAC Address Generation . . . . . . . . . . . . . . . . . 29 + become a 802.11-OCB driver . . . 27 + Appendix E. EtherType Protocol Discrimination (EPD) . . . . . . 28 + Appendix F. Design Considerations . . . . . . . . . . . . . . . 29 + F.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 29 + F.2. Reliability Requirements . . . . . . . . . . . . . . . . 29 + F.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 30 + F.4. MAC Address Generation . . . . . . . . . . . . . . . . . 31 - Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 29 - Appendix H. Implementation Status . . . . . . . . . . . . . . . 29 - H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 30 - H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 33 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 35 + Appendix G. IEEE 802.11 Messages Transmitted in OCB mode . . . . 31 + Appendix H. Implementation Status . . . . . . . . . . . . . . . 31 + H.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 32 + H.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 35 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37 1. Introduction This document describes the transmission of IPv6 packets on IEEE Std 802.11-OCB networks [IEEE-802.11-2016] (a.k.a "802.11p" see Appendix B). This involves the layering of IPv6 networking on top of the IEEE 802.11 MAC layer, with an LLC layer. Compared to running IPv6 over the Ethernet MAC layer, there is no modification expected to IEEE Std 802.11 MAC and Logical Link sublayers: IPv6 works fine directly over 802.11-OCB too, with an LLC layer. @@ -117,86 +117,94 @@ document describes an Ethernet Adaptation Layer between Ethernet headers and 802.11 headers. The Ethernet Adaptation Layer is described Section 4.2.1. The operation of IP on Ethernet is described in [RFC1042], [RFC2464] and [I-D.hinden-6man-rfc2464bis]. o Exceptions due to the OCB nature of 802.11-OCB compared to 802.11. This has impacts on security, privacy, subnet structure and handover behaviour. For security and privacy recommendations see Section 5 and Section 4.5. The subnet structure is described in - Section 4.6; a new Group ID is requested to be used in such - subnets, see section Section 6. The handover behaviour on OCB - links is not described in this document. + Section 4.6. The handover behaviour on OCB links is not described + in this document. In the published literature, many documents describe aspects and problems related to running IPv6 over 802.11-OCB: [I-D.ietf-ipwave-vehicular-networking-survey]. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. WiFi: Wireless Fidelity. OBRU (On-Board Router Unit): an OBRU is almost always situated in a - vehicle; it is a computer with at least two IP interfaces; at least - one IP interface runs in OCB mode of 802.11. It MAY be an IP Router. + vehicle; it is a computer with at least two IP real or virtual + interfaces; at least one IP interface runs in OCB mode of 802.11. It + MAY be an IP Router. + + OBU (On-Board Unit): term defined outside the IETF. RSRU (Road-Side Router Unit): an RSRU is almost always situated in a box fixed along the road. An RSRU has at least two distinct IP- enabled interfaces; at least one interface is operated in mode OCB of IEEE 802.11 and is IP-enabled. An RSRU is similar to a Wireless Termination Point (WTP), as defined in [RFC5415], or an Access Point (AP), as defined in IEEE documents, or an Access Network Router (ANR) defined in [RFC3753], with one key particularity: the wireless PHY/ MAC layer of at least one of its IP-enabled interfaces is configured - to operate in 802.11-OCB mode. The RSRU communicates with the On - board Unit (OBRU) in the vehicle over 802.11 wireless link operating - in OCB mode. An RSRU MAY be connected to the Internet, and MAY be an - IP Router. When it is connected to the Internet, the term V2I - (Vehicle to Internet) is relevant. + to operate in 802.11-OCB mode. The RSRU communicates with the OBRU + in the vehicle over 802.11 wireless link operating in OCB mode. An + RSRU MAY be connected to the Internet, and MAY be an IP Router. When + it is connected to the Internet, the term V2I (Vehicle to Internet) + is relevant. RSU (Road-Side Unit): an RSU operates in 802.11-OCB mode. A RSU broadcasts data to OBUs or exchanges data with OBUs in its communications zone. An RSU may provide channel assignments and operating instructions to OBUs in its communications zone, when required. The basic functional blocks of an RSU are: internal computer processing, permanent storage capability, an integrated GPS receiver for positioning and timing and an interface that supports both IPv4 and IPv6 connectivity, compliant with 802.3at. An OCB interface of an RSU MAY be IP-enabled simultaneously to being WAVE- enabled or GeoNetworking-enabled (MAY support simultaneously EtherTypes 0x86DD for IPv6 _and_ 0x88DC for WAVE and 0x8947 for - GeoNetworking). + GeoNetworking). The difference between RSU and RSRU is that an RSU + is likely to have one single OCB interface which is likely not IP + enabled, whereas an RSRU is likely to have one or more OCB interfaces + which are almost always IP-enabled; moreover, an RSRU does IP + forwarding, whereas an RSU does not. OCB (outside the context of a basic service set - BSS): A mode of operation in which a STA is not a member of a BSS and does not utilize IEEE Std 802.11 authentication, association, or data confidentiality. 802.11-OCB: mode specified in IEEE Std 802.11-2016 when the MIB attribute dot11OCBActivited is true. The OCB mode requires transmission of QoS data frames (IEEE Std 802.11e), half-clocked operation (IEEE Std 802.11j), and use of 5.9 GHz frequency band. + Nota: any implementation should comply with standards and regulations + set in the different countries for using that frequency band. 3. Communication Scenarios where IEEE 802.11-OCB Links are Used The IEEE 802.11-OCB Networks are used for vehicular communications, as 'Wireless Access in Vehicular Environments'. The IP communication scenarios for these environments have been described in several documents; in particular, we refer the reader to - - [I-D.petrescu-its-scenarios-reqs], about scenarios and requirements - for IP in Intelligent Transportation Systems. + [I-D.ietf-ipwave-vehicular-networking-survey], that lists some + scenarios and requirements for IP in Intelligent Transportation + Systems. The link model is the following: STA --- 802.11-OCB --- STA. In vehicular networks, STAs can be RSRUs and/or OBRUs. While 802.11-OCB is clearly specified, and the use of IPv6 over such link is not radically new, the operating environment (vehicular networks) brings in new perspectives. The 802.11-OCB links form and terminate; nodes connected to these links peer, and discover each other; the nodes are mobile. However, the precise description of how links discover each other, peer and @@ -247,86 +255,95 @@ Networking layer. This is used to transform some parameters between their form expected by the IP stack and the form provided by the MAC layer. An Ethernet Adaptation Layer makes an 802.11 MAC look to IP Networking layer as a more traditional Ethernet layer. At reception, this layer takes as input the IEEE 802.11 Data Header and the Logical-Link Layer Control Header and produces an Ethernet II Header. At sending, the reverse operation is performed. + The operation of the Ethernet Adaptation Layer is depicted by the + double arrow in Figure 1. + +--------------------+------------+-------------+---------+-----------+ | 802.11 Data Header | LLC Header | IPv6 Header | Payload |.11 Trailer| +--------------------+------------+-------------+---------+-----------+ \ / \ / ----------------------------- -------- \---------------------------------------------/ ^ | 802.11-to-Ethernet Adaptation Layer | v +---------------------+-------------+---------+ | Ethernet II Header | IPv6 Header | Payload | +---------------------+-------------+---------+ + Figure 1: Operation of the Ethernet Adaptation Layer + The Receiver and Transmitter Address fields in the 802.11 Data Header contain the same values as the Destination and the Source Address fields in the Ethernet II Header, respectively. The value of the Type field in the LLC Header is the same as the value of the Type field in the Ethernet II Header. The ".11 Trailer" contains solely a 4-byte Frame Check Sequence. Additionally, the Ethernet Adaptation Layer performs operations in relation to IP fragmentation and MTU. One of these operations is - briefly described in section Section 4.1. + briefly described in Section 4.1. In OCB mode, IPv6 packets MAY be transmitted either as "IEEE 802.11 Data" or alternatively as "IEEE 802.11 QoS Data", as illustrated in - the figure below. + Figure 2. +--------------------+-------------+-------------+---------+-----------+ | 802.11 Data Header | LLC Header | IPv6 Header | Payload |.11 Trailer| +--------------------+-------------+-------------+---------+-----------+ or +--------------------+-------------+-------------+---------+-----------+ | 802.11 QoS Data Hdr| LLC Header | IPv6 Header | Payload |.11 Trailer| +--------------------+-------------+-------------+---------+-----------+ + Figure 2: 802.11 Data Header or 802.11 QoS Data Header + The distinction between the two formats is given by the value of the field "Type/Subtype". The value of the field "Type/Subtype" in the 802.11 Data header is 0x0020. The value of the field "Type/Subtype" in the 802.11 QoS header is 0x0028. The mapping between qos-related fields in the IPv6 header (e.g. "Traffic Class", "Flow label") and fields in the "802.11 QoS Data Header" (e.g. "QoS Control") are not specified in this document. Guidance for a potential mapping is provided in [I-D.ietf-tsvwg-ieee-802-11], although it is not specific to OCB mode. The placement of IPv6 networking layer on Ethernet Adaptation Layer - is illustrated below: + is illustrated in Figure 3. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ethernet Adaptation Layer | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 802.11 WiFi MAC | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 802.11 WiFi PHY | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + Figure 3: Ethernet Adaptation Layer stacked with other layers + (in the above figure, a WiFi profile is represented; this is used also for OCB profile.) Other alternative views of layering are EtherType Protocol Discrimination (EPD), see Appendix E, and SNAP see [RFC1042]. 4.3. Link-Local Addresses The link-local address of an 802.11-OCB interface is formed in the same manner as on an Ethernet interface. This manner is described in @@ -343,24 +360,24 @@ multicast address mapping format of Ethernet interfaces, as defined by sections 6 and 7 of [RFC2464]. 4.4.1. Address Mapping -- Unicast The procedure for mapping IPv6 unicast addresses into Ethernet link- layer addresses is described in [RFC4861]. 4.4.2. Address Mapping -- Multicast - A Group ID named TBD, of length 112bits is requested to IANA; this - Group ID signifies "All 80211OCB Interfaces Address". Only the least - 32 significant bits of this "All 80211OCB Interfaces Address" will be - mapped to and from a MAC multicast address. + The multicast address mapping is performed according to the method + specified in section 7 of [RFC2464]. The meaning of the value "3333" + mentioned in that section 7 of [RFC2464] is defined in section 2.3.1 + of [RFC7042]. Transmitting IPv6 packets to multicast destinations over 802.11 links proved to have some performance issues [I-D.perkins-intarea-multicast-ieee802]. These issues may be exacerbated in OCB mode. Solutions for these problems should consider the OCB mode of operation. 4.5. Stateless Autoconfiguration The Interface Identifier for an 802.11-OCB interface is formed using @@ -371,21 +388,21 @@ The bits in the interface identifier have no generic meaning and the identifier should be treated as an opaque value. The bits 'Universal' and 'Group' in the identifier of an 802.11-OCB interface are significant, as this is an IEEE link-layer address. The details of this significance are described in [RFC7136]. As with all Ethernet and 802.11 interface identifiers ([RFC7721]), the identifier of an 802.11-OCB interface may involve privacy, MAC address spoofing and IP address hijacking risks. A vehicle embarking - an On-Board Unit whose egress interface is 802.11-OCB may expose + an OBU or an OBRU whose egress interface is 802.11-OCB may expose itself to eavesdropping and subsequent correlation of data; this may reveal data considered private by the vehicle owner; there is a risk of being tracked; see the privacy considerations described in Appendix F. If stable Interface Identifiers are needed in order to form IPv6 addresses on 802.11-OCB links, it is recommended to follow the recommendation in [RFC8064]. Additionally, if semantically opaque Interface Identifiers are needed, a potential method for generating semantically opaque Interface Identifiers with IPv6 Stateless Address @@ -456,22 +473,21 @@ 802.11-OCB deployments, there is a strong necessity to use protection tools such as dynamically changing MAC addresses. This may help mitigate privacy risks to a certain level. On another hand, it may have an impact in the way typical IPv6 address auto-configuration is performed for vehicles (SLAAC would rely on MAC addresses amd would hence dynamically change the affected IP address), in the way the IPv6 Privacy addresses were used, and other effects. 6. IANA Considerations - A Group ID named TBD, of length 112bits is requested to IANA; this - Group ID signifies "All 80211OCB Interfaces Address". + No request to IANA. 7. Contributors Christian Huitema, Tony Li. Romain Kuntz contributed extensively about IPv6 handovers between links running outside the context of a BSS (802.11-OCB links). Tim Leinmueller contributed the idea of the use of IPv6 over 802.11-OCB for distribution of certificates. @@ -497,21 +513,21 @@ Margaret Cullen and William Whyte. Their valuable comments clarified particular issues and generally helped to improve the document. Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB drivers for linux and described how. For the multicast discussion, the authors would like to thank Owen DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and participants to discussions in network working groups. - The authours would like to thank participants to the Birds-of- + The authors would like to thank participants to the Birds-of- a-Feather "Intelligent Transportation Systems" meetings held at IETF in 2016. 9. References 9.1. Normative References [I-D.ietf-tsvwg-ieee-802-11] Szigeti, T., Henry, J., and F. Baker, "Diffserv to IEEE 802.11 Mapping", draft-ietf-tsvwg-ieee-802-11-09 (work in @@ -584,20 +600,25 @@ . [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, September 2010, . [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 2011, . + [RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and + IETF Protocol and Documentation Usage for IEEE 802 + Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042, + October 2013, . + [RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, February 2014, . [RFC7217] Gont, F., "A Method for Generating Semantically Opaque Interface Identifiers with IPv6 Stateless Address Autoconfiguration (SLAAC)", RFC 7217, DOI 10.17487/RFC7217, April 2014, . @@ -626,21 +647,21 @@ Geonetworking Protocols. Downloaded on September 9th, 2017, freely available from ETSI website at URL http://www.etsi.org/deliver/ etsi_en/302600_302699/30263601/01.02.01_60/ en_30263601v010201p.pdf". [ETSI-sec-archi] "ETSI TS 102 940 V1.2.1 (2016-11), ETSI Technical Specification, Intelligent Transport Systems (ITS); Security; ITS communications security architecture and - security management, November 2016. Dowloaded on + security management, November 2016. Downloaded on September 9th, 2017, freely available from ETSI website at URL http://www.etsi.org/deliver/ etsi_ts/102900_102999/102940/01.02.01_60/ ts_102940v010201p.pdf". [I-D.hinden-6man-rfc2464bis] Crawford, M. and R. Hinden, "Transmission of IPv6 Packets over Ethernet Networks", draft-hinden-6man-rfc2464bis-02 (work in progress), March 2017. @@ -650,26 +671,20 @@ Intelligent Transportation Systems", draft-ietf-ipwave- vehicular-networking-survey-00 (work in progress), July 2017. [I-D.perkins-intarea-multicast-ieee802] Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, "Multicast Considerations over IEEE 802 Wireless Media", draft-perkins-intarea-multicast-ieee802-03 (work in progress), July 2017. - [I-D.petrescu-its-scenarios-reqs] - Petrescu, A., Janneteau, C., Boc, M., and W. Klaudel, - "Scenarios and Requirements for IP in Intelligent - Transportation Systems", draft-petrescu-its-scenarios- - reqs-03 (work in progress), October 2013. - [IEEE-1609.2] "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access in Vehicular Environments (WAVE) -- Security Services for Applications and Management Messages. Example URL http://ieeexplore.ieee.org/document/7426684/ accessed on August 17th, 2017.". [IEEE-1609.3] "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access in Vehicular Environments (WAVE) -- Networking Services. @@ -704,20 +719,77 @@ document freely available at URL http://standards.ieee.org/getieee802/ download/802.11p-2010.pdf retrieved on September 20th, 2013.". Appendix A. ChangeLog The changes are listed in reverse chronological order, most recent changes appearing at the top of the list. + From draft-ietf-ipwave-ipv6-over-80211ocb-09 to draft-ietf-ipwave- + ipv6-over-80211ocb-10 + + o Removed text requesting a new Group ID for multicast for OCB. + + o Added a clarification of the meaning of value "3333" in the + section Address Mapping -- Multicast. + + o Added note clarifying that in Europe the regional authority is not + ETSI, but "ECC/CEPT based on ENs from ETSI". + + o Added note stating that the manner in which two STAtions set their + communication channel is not described in this document. + + o Added a time qualifier to state that the "each node is represented + uniquely at a certain point in time." + + o Removed text "This section may need to be moved" (the "Reliability + Requirements" section). This section stays there at this time. + + o In the term definition "802.11-OCB" added a note stating that "any + implementation should comply with standards and regulations set in + the different countries for using that frequency band." + + o In the RSU term definition, added a sentence explaining the + difference between RSU and RSRU: in terms of number of interfaces + and IP forwarding. + + o Replaced "with at least two IP interfaces" with "with at least two + real or virtual IP interfaces". + + o Added a term in the Terminology for "OBU". However the definition + is left empty, as this term is defined outside IETF. + + o Added a clarification that it is an OBU or an OBRU in this phrase + "A vehicle embarking an OBU or an OBRU". + + o Checked the entire document for a consistent use of terms OBU and + OBRU. + + o Added note saying that "'p' is a letter identifying the + Ammendment". + + o Substituted lower case for capitals SHALL or MUST in the + Appendices. + + o Added reference to RFC7042, helpful in the 3333 explanation. + Removed reference to individual submission draft-petrescu-its- + scenario-reqs and added reference to draft-ietf-ipwave-vehicular- + networking-survey. + + o Added figure captions, figure numbers, and references to figure + numbers instead of 'below'. Replaced "section Section" with + "section" throughout. + + o Minor typographical errors. + From draft-ietf-ipwave-ipv6-over-80211ocb-08 to draft-ietf-ipwave- ipv6-over-80211ocb-09 o Significantly shortened the Address Mapping sections, by text copied from RFC2464, and rather referring to it. o Moved the EPD description to an Appendix on its own. o Shortened the Introduction and the Abstract. @@ -941,23 +1013,25 @@ STAtion operating outside the context of a basic service set has the OCBActivated flag set. Such a station, when it has the flag set, uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. Appendix C. Aspects introduced by the OCB mode to 802.11 In the IEEE 802.11-OCB mode, all nodes in the wireless range can directly communicate with each other without involving authentication or association procedures. At link layer, it is necessary to set the same channel number (or frequency) on two stations that need to - communicate with each other. Stations STA1 and STA2 can exchange IP - packets if they are set on the same channel. At IP layer, they then - discover each other by using the IPv6 Neighbor Discovery protocol. + communicate with each other. The manner in which stations set their + channel number is not specified in this document. Stations STA1 and + STA2 can exchange IP packets if they are set on the same channel. At + IP layer, they then discover each other by using the IPv6 Neighbor + Discovery protocol. Briefly, the IEEE 802.11-OCB mode has the following properties: o The use by each node of a 'wildcard' BSSID (i.e., each bit of the BSSID is set to 1) o No IEEE 802.11 Beacon frames are transmitted o No authentication is required in order to be able to communicate @@ -965,21 +1039,21 @@ o No encryption is provided in order to be able to communicate o Flag dot11OCBActivated is set to true All the nodes in the radio communication range (OBRU and RSRU) receive all the messages transmitted (OBRU and RSRU) within the radio communications range. The eventual conflict(s) are resolved by the MAC CDMA function. - The following message exchange diagram illustrates a comparison + The message exchange diagram in Figure 4 illustrates a comparison between traditional 802.11 and 802.11 in OCB mode. The 'Data' messages can be IP packets such as HTTP or others. Other 802.11 management and control frames (non IP) may be transmitted, as specified in the 802.11 standard. For information, the names of these messages as currently specified by the 802.11 standard are listed in Appendix G. STA AP STA1 STA2 | | | | |<------ Beacon -------| |<------ Data -------->| @@ -989,46 +1063,49 @@ | | |<------ Data -------->| |---- Auth Req. ------>| | | |<--- Auth Res. -------| |<------ Data -------->| | | | | |---- Asso Req. ------>| |<------ Data -------->| |<--- Asso Res. -------| | | | | |<------ Data -------->| |<------ Data -------->| | | |<------ Data -------->| |<------ Data -------->| - (a) 802.11 Infrastructure mode (b) 802.11-OCB mode + (i) 802.11 Infrastructure mode (ii) 802.11-OCB mode + + Figure 4: Difference between messages exchanged on 802.11 (left) and + 802.11-OCB (right) The interface 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010 [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, titled "Amendment 6: Wireless Access in Vehicular Environments". - Since then, this amendment has been included in IEEE 802.11(TM) -2012 - and -2016 [IEEE-802.11-2016]. + Since then, this amendment has been integrated in IEEE 802.11(TM) + -2012 and -2016 [IEEE-802.11-2016]. In document 802.11-2016, anything qualified specifically as "OCBActivated", or "outside the context of a basic service" set to be true, then it is actually referring to OCB aspects introduced to 802.11. In order to delineate the aspects introduced by 802.11-OCB to 802.11, we refer to the earlier [IEEE-802.11p-2010]. The amendment is concerned with vehicular communications, where the wireless link is similar to that of Wireless LAN (using a PHY layer specified by 802.11a/b/g/n), but which needs to cope with the high mobility factor inherent in scenarios of communications between moving vehicles, and between vehicles and fixed infrastructure deployed along roads. - While 'p' is a letter just like 'a, b, g' and 'n' are, 'p' is - concerned more with MAC modifications, and a little with PHY - modifications; the others are mainly about PHY modifications. It is - possible in practice to combine a 'p' MAC with an 'a' PHY by - operating outside the context of a BSS with OFDM at 5.4GHz and - 5.9GHz. + While 'p' is a letter identifying the Ammendment, just like 'a, b, g' + and 'n' are, 'p' is concerned more with MAC modifications, and a + little with PHY modifications; the others are mainly about PHY + modifications. It is possible in practice to combine a 'p' MAC with + an 'a' PHY by operating outside the context of a BSS with OFDM at + 5.4GHz and 5.9GHz. The 802.11-OCB links are specified to be compatible as much as possible with the behaviour of 802.11a/b/g/n and future generation IEEE WLAN links. From the IP perspective, an 802.11-OCB MAC layer offers practically the same interface to IP as the WiFi and Ethernet layers do (802.11a/b/g/n and 802.3). A packet sent by an OBRU may be received by one or multiple RSRUs. The link-layer resolution is performed by using the IPv6 Neighbor Discovery protocol. To support this similarity statement (IPv6 is layered on top of LLC @@ -1040,21 +1117,21 @@ changes to the MAC layer (and very little to the PHY layer), there are only a few characteristics which may be important for an implementation transmitting IPv6 packets on 802.11-OCB links. The most important 802.11-OCB point which influences the IPv6 functioning is the OCB characteristic; an additional, less direct influence, is the maximum bandwidth afforded by the PHY modulation/ demodulation methods and channel access specified by 802.11-OCB. The maximum bandwidth theoretically possible in 802.11-OCB is 54 Mbit/s (when using, for example, the following parameters: 20 MHz channel; - modulation 64-QAM; codint rate R is 3/4); in practice of IP-over- + modulation 64-QAM; coding rate R is 3/4); in practice of IP-over- 802.11-OCB a commonly observed figure is 12Mbit/s; this bandwidth allows the operation of a wide range of protocols relying on IPv6. o Operation Outside the Context of a BSS (OCB): the (earlier 802.11p) 802.11-OCB links are operated without a Basic Service Set (BSS). This means that the frames IEEE 802.11 Beacon, Association Request/Response, Authentication Request/Response, and similar, are not used. The used identifier of BSS (BSSID) has a hexadecimal value always 0xffffffffffff (48 '1' bits, represented as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' @@ -1069,62 +1146,63 @@ o Timing Advertisement: is a new message defined in 802.11-OCB, which does not exist in 802.11a/b/g/n. This message is used by stations to inform other stations about the value of time. It is similar to the time as delivered by a GNSS system (Galileo, GPS, ...) or by a cellular system. This message is optional for implementation. o Frequency range: this is a characteristic of the PHY layer, with almost no impact on the interface between MAC and IP. However, it is worth considering that the frequency range is regulated by a - regional authority (ARCEP, ETSI, FCC, etc.); as part of the - regulation process, specific applications are associated with - specific frequency ranges. In the case of 802.11-OCB, the - regulator associates a set of frequency ranges, or slots within a - band, to the use of applications of vehicular communications, in a - band known as "5.9GHz". The 5.9GHz band is different from the - 2.4GHz and 5GHz bands used by Wireless LAN. However, as with - Wireless LAN, the operation of 802.11-OCB in "5.9GHz" bands is - exempt from owning a license in EU (in US the 5.9GHz is a licensed - band of spectrum; for the fixed infrastructure an explicit FCC - autorization is required; for an onboard device a 'licensed-by- - rule' concept applies: rule certification conformity is required); - however technical conditions are different than those of the bands - "2.4GHz" or "5GHz". On one hand, the allowed power levels, and - implicitly the maximum allowed distance between vehicles, is of - 33dBm for 802.11-OCB (in Europe), compared to 20 dBm for Wireless - LAN 802.11a/b/g/n; this leads to a maximum distance of - approximately 1km, compared to approximately 50m. On the other - hand, specific conditions related to congestion avoidance, jamming - avoidance, and radar detection are imposed on the use of DSRC (in - US) and on the use of frequencies for Intelligent Transportation - Systems (in EU), compared to Wireless LAN (802.11a/b/g/n). + regional authority (ARCEP, ECC/CEPT based on ENs from ETSI, FCC, + etc.); as part of the regulation process, specific applications + are associated with specific frequency ranges. In the case of + 802.11-OCB, the regulator associates a set of frequency ranges, or + slots within a band, to the use of applications of vehicular + communications, in a band known as "5.9GHz". The 5.9GHz band is + different from the 2.4GHz and 5GHz bands used by Wireless LAN. + However, as with Wireless LAN, the operation of 802.11-OCB in + "5.9GHz" bands is exempt from owning a license in EU (in US the + 5.9GHz is a licensed band of spectrum; for the fixed + infrastructure an explicit FCC authorization is required; for an + on-board device a 'licensed-by-rule' concept applies: rule + certification conformity is required.) Technical conditions are + different than those of the bands "2.4GHz" or "5GHz". The allowed + power levels, and implicitly the maximum allowed distance between + vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20 + dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum + distance of approximately 1km, compared to approximately 50m. + Additionally, specific conditions related to congestion avoidance, + jamming avoidance, and radar detection are imposed on the use of + DSRC (in US) and on the use of frequencies for Intelligent + Transportation Systems (in EU), compared to Wireless LAN + (802.11a/b/g/n). o 'Half-rate' encoding: as the frequency range, this parameter is related to PHY, and thus has not much impact on the interface between the IP layer and the MAC layer. o In vehicular communications using 802.11-OCB links, there are strong privacy requirements with respect to addressing. While the 802.11-OCB standard does not specify anything in particular with respect to MAC addresses, in these settings there exists a strong need for dynamic change of these addresses (as opposed to the non- vehicular settings - real wall protection - where fixed MAC addresses do not currently pose some privacy risks). This is - further described in section Section 5. A relevant function is - described in IEEE 1609.3-2016 [IEEE-1609.3], clause 5.5.1 and IEEE + further described in Section 5. A relevant function is described + in IEEE 1609.3-2016 [IEEE-1609.3], clause 5.5.1 and IEEE 1609.4-2016 [IEEE-1609.4], clause 6.7. Other aspects particular to 802.11-OCB, which are also particular to 802.11 (e.g. the 'hidden node' operation), may have an influence on the use of transmission of IPv6 packets on 802.11-OCB networks. The - OCB subnet structure is described in section Section 4.6. + OCB subnet structure is described in Section 4.6. Appendix D. Changes Needed on a software driver 802.11a to become a 802.11-OCB driver The 802.11p amendment modifies both the 802.11 stack's physical and MAC layers but all the induced modifications can be quite easily obtained by modifying an existing 802.11a ad-hoc stack. Conditions for a 802.11a hardware to be 802.11-OCB compliant: @@ -1177,111 +1255,111 @@ Response) and for authentication (Authentication Request/Reply, Challenge) are not called. * The beacon interval is always set to 0 (zero). * Timing Advertisement frames, defined in the amendment, should be supported. The upper layer should be able to trigger such frames emission and to retrieve information contained in received Timing Advertisements. -Appendix E. EPD +Appendix E. EtherType Protocol Discrimination (EPD) A more theoretical and detailed view of layer stacking, and interfaces between the IP layer and 802.11-OCB layers, is illustrated - below. The IP layer operates on top of the EtherType Protocol + in Figure 5. The IP layer operates on top of the EtherType Protocol Discrimination (EPD); this Discrimination layer is described in IEEE Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP (Link Layer Control Service Access Point). +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 | +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ { LLC_SAP } 802.11-OCB +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary | EPD | | | | | MLME | | +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | | MAC Sublayer | | | 802.11-OCB | and ch. coord. | | SME | Services +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | | | PLME | | | PHY Layer | PLME_SAP | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + Figure 5: EtherType Protocol Discrimination + Appendix F. Design Considerations The networks defined by 802.11-OCB are in many ways similar to other networks of the 802.11 family. In theory, the encapsulation of IPv6 over 802.11-OCB could be very similar to the operation of IPv6 over other networks of the 802.11 family. However, the high mobility, strong link asymmetry and very short connection makes the 802.11-OCB link significantly different from other 802.11 networks. Also, the automotive applications have specific requirements for reliability, security and privacy, which further add to the particularity of the 802.11-OCB link. F.1. Vehicle ID In automotive networks it is required that each node is represented - uniquely. Accordingly, a vehicle must be identified by at least one - unique identifier. The current specification at ETSI and at IEEE - 1609 identifies a vehicle by its MAC address, which is obtained from - the 802.11-OCB Network Interface Card (NIC). + uniquely at a certain point in time. Accordingly, a vehicle must be + identified by at least one unique identifier. The current + specification at ETSI and at IEEE 1609 identifies a vehicle by its + MAC address, which is obtained from the 802.11-OCB Network Interface + Card (NIC). In case multiple 802.11-OCB NICs are present in one car, implicitely multiple vehicle IDs will be generated. Additionally, some software generates a random MAC address each time the computer boots; this constitutes an additional difficulty. A mechanim to uniquely identify a vehicle irrespectively to the multiplicity of NICs, or frequent MAC address generation, is necessary. F.2. Reliability Requirements - This section may need to be moved out into a separate requirements - document. - The dynamically changing topology, short connectivity, mobile transmitter and receivers, different antenna heights, and many-to- many communication types, make IEEE 802.11-OCB links significantly different from other IEEE 802.11 links. Any IPv6 mechanism operating - on IEEE 802.11-OCB link MUST support strong link asymmetry, spatio- + on IEEE 802.11-OCB link must support strong link asymmetry, spatio- temporal link quality, fast address resolution and transmission. IEEE 802.11-OCB strongly differs from other 802.11 systems to operate outside of the context of a Basic Service Set. This means in practice that IEEE 802.11-OCB does not rely on a Base Station for all - Basic Service Set management. In particular, IEEE 802.11-OCB SHALL - NOT use beacons. Any IPv6 mechanism requiring L2 services from IEEE - 802.11 beacons MUST support an alternative service. + Basic Service Set management. In particular, IEEE 802.11-OCB shall + not use beacons. Any IPv6 mechanism requiring L2 services from IEEE + 802.11 beacons must support an alternative service. - Channel scanning being disabled, IPv6 over IEEE 802.11-OCB MUST + Channel scanning being disabled, IPv6 over IEEE 802.11-OCB must implement a mechanism for transmitter and receiver to converge to a common channel. - Authentication not being possible, IPv6 over IEEE 802.11-OCB MUST + Authentication not being possible, IPv6 over IEEE 802.11-OCB must implement an distributed mechanism to authenticate transmitters and receivers without the support of a DHCP server. Time synchronization not being available, IPv6 over IEEE 802.11-OCB - MUST implement a higher layer mechanism for time synchronization + must implement a higher layer mechanism for time synchronization between transmitters and receivers without the support of a NTP server. The IEEE 802.11-OCB link being asymmetric, IPv6 over IEEE 802.11-OCB - MUST disable management mechanisms requesting acknowledgements or + must disable management mechanisms requesting acknowledgements or replies. The IEEE 802.11-OCB link having a short duration time, IPv6 over IEEE - 802.11-OCB SHOULD implement fast IPv6 mobility management mechanisms. + 802.11-OCB should implement fast IPv6 mobility management mechanisms. F.3. Multiple interfaces There are considerations for 2 or more IEEE 802.11-OCB interface cards per vehicle. For each vehicle taking part in road traffic, one IEEE 802.11-OCB interface card could be fully allocated for Non IP safety-critical communication. Any other IEEE 802.11-OCB may be used for other type of traffic. The mode of operation of these other wireless interfaces is not @@ -1292,35 +1370,35 @@ including the IEEE 802.11-OCB interface used by Non IP safety critical communications). This will require specific logic to ensure, for example, that packets meant for a vehicle in front are actually sent by the radio in the front, or that multiple copies of the same packet received by multiple interfaces are treated as a single packet. Treating each wireless interface as a separate network interface pushes such issues to the application layer. Certain privacy requirements imply that if these multiple interfaces are represented by many network interface, a single renumbering event - SHALL cause renumbering of all these interfaces. If one MAC changed + shall cause renumbering of all these interfaces. If one MAC changed and another stayed constant, external observers would be able to correlate old and new values, and the privacy benefits of randomization would be lost. The privacy requirements of Non IP safety-critical communications imply that if a change of pseudonyme occurs, renumbering of all other - interfaces SHALL also occur. + interfaces shall also occur. F.4. MAC Address Generation - When designing the IPv6 over 802.11-OCB address mapping, we will - assume that the MAC Addresses will change during well defined - "renumbering events". The 48 bits randomized MAC addresses will have - the following characteristics: + When designing the IPv6 over 802.11-OCB address mapping, we assume + that the MAC Addresses change during well defined "renumbering + events". The 48 bits randomized MAC addresses will have the + following characteristics: o Bit "Local/Global" set to "locally admninistered". o Bit "Unicast/Multicast" set to "Unicast". o 46 remaining bits set to a random value, using a random number generator that meets the requirements of [RFC4086]. The way to meet the randomization requirements is to retain 46 bits from the output of a strong hash function, such as SHA256, taking as @@ -1346,33 +1424,35 @@ Appendix H. Implementation Status This section describes an example of an IPv6 Packet captured over a IEEE 802.11-OCB link. By way of example we show that there is no modification in the headers when transmitted over 802.11-OCB networks - they are transmitted like any other 802.11 and Ethernet packets. We describe an experiment of capturing an IPv6 packet on an - 802.11-OCB link. In this experiment, the packet is an IPv6 Router - Advertisement. This packet is emitted by a Router on its 802.11-OCB - interface. The packet is captured on the Host, using a network - protocol analyzer (e.g. Wireshark); the capture is performed in two - different modes: direct mode and 'monitor' mode. The topology used - during the capture is depicted below. + 802.11-OCB link. In topology depicted in Figure 6, the packet is an + IPv6 Router Advertisement. This packet is emitted by a Router on its + 802.11-OCB interface. The packet is captured on the Host, using a + network protocol analyzer (e.g. Wireshark); the capture is performed + in two different modes: direct mode and 'monitor' mode. The topology + used during the capture is depicted below. +--------+ +-------+ | | 802.11-OCB Link | | ---| Router |--------------------------------| Host | | | | | +--------+ +-------+ + Figure 6: Topology for capturing IP packets on 802.11-OCB + During several capture operations running from a few moments to several hours, no message relevant to the BSSID contexts were captured (no Association Request/Response, Authentication Req/Resp, Beacon). This shows that the operation of 802.11-OCB is outside the context of a BSSID. Overall, the captured message is identical with a capture of an IPv6 packet emitted on a 802.11b interface. The contents are precisely similar. @@ -1590,21 +1671,21 @@ France Phone: +33169089223 Email: Alexandre.Petrescu@cea.fr Nabil Benamar Moulay Ismail University Morocco Phone: +212670832236 - Email: benamar73@gmail.com + Email: n.benamar@est.umi.ac.ma Jerome Haerri Eurecom Sophia-Antipolis 06904 France Phone: +33493008134 Email: Jerome.Haerri@eurecom.fr Jong-Hyouk Lee Sangmyung University