draft-ietf-ipwave-ipv6-over-80211ocb-04.txt   draft-ietf-ipwave-ipv6-over-80211ocb-05.txt 
Network Working Group A. Petrescu Network Working Group A. Petrescu
Internet-Draft CEA, LIST Internet-Draft CEA, LIST
Intended status: Standards Track N. Benamar Intended status: Standards Track N. Benamar
Expires: February 18, 2018 Moulay Ismail University Expires: March 14, 2018 Moulay Ismail University
J. Haerri J. Haerri
Eurecom Eurecom
C. Huitema C. Huitema
Private Octopus Inc.
J. Lee J. Lee
Sangmyung University Sangmyung University
T. Ernst T. Ernst
YoGoKo YoGoKo
T. Li T. Li
Peloton Technology Peloton Technology
August 17, 2017 September 10, 2017
Transmission of IPv6 Packets over IEEE 802.11 Networks in mode Outside Transmission of IPv6 Packets over IEEE 802.11 Networks operating in mode
the Context of a Basic Service Set (IPv6-over-80211ocb) Outside the Context of a Basic Service Set (IPv6-over-80211-OCB)
draft-ietf-ipwave-ipv6-over-80211ocb-04.txt draft-ietf-ipwave-ipv6-over-80211ocb-05.txt
Abstract Abstract
In order to transmit IPv6 packets on IEEE 802.11 networks run outside In order to transmit IPv6 packets on IEEE 802.11 networks run outside
the context of a basic service set (OCB, earlier "802.11p") there is the context of a basic service set (OCB, earlier "802.11p") there is
a need to define a few parameters such as the recommended Maximum a need to define a few parameters such as the supported Maximum
Transmission Unit size, the header format preceding the IPv6 header, Transmission Unit size on the 802.11-OCB link, the header format
the Type value within it, and others. This document describes these preceding the IPv6 header, the Type value within it, and others.
parameters for IPv6 and IEEE 802.11 OCB networks; it portrays the This document describes these parameters for IPv6 and IEEE 802.11-OCB
layering of IPv6 on 802.11 OCB similarly to other known 802.11 and networks; it portrays the layering of IPv6 on 802.11-OCB similarly to
Ethernet layers - by using an Ethernet Adaptation Layer. other known 802.11 and Ethernet layers - by using an Ethernet
Adaptation Layer.
In addition, the document attempts to list what is different in
802.11 OCB (802.11p) compared to more 'traditional' 802.11a/b/g/n
layers, layers over which IPv6 protocols operates without issues.
Most notably, the operation outside the context of a BSS (OCB) has
impact on IPv6 handover behaviour and on IPv6 security.
An example of an IPv6 packet captured while transmitted over an IEEE In addition, the document lists what is different in 802.11-OCB
802.11 OCB link (802.11p) is given. (802.11p) links compared to more 'traditional' 802.11a/b/g/n links,
where IPv6 protocols operate without issues. Most notably, the
operation outside the context of a BSS (OCB) has impact on IPv6
handover behaviour and on IPv6 security.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 18, 2018. This Internet-Draft will expire on March 14, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Communication Scenarios where IEEE 802.11 OCB Links are Used 6 3. Communication Scenarios where IEEE 802.11-OCB Links are Used 6
4. Aspects introduced by the OCB mode to 802.11 . . . . . . . . 6 4. Aspects introduced by the OCB mode to 802.11 . . . . . . . . 7
5. Layering of IPv6 over 802.11-OCB as over Ethernet . . . . . . 10 5. Layering of IPv6 over 802.11-OCB as over Ethernet . . . . . . 11
5.1. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 10 5.1. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 11
5.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 11 5.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 11
5.2.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 12 5.2.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 13
5.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 13 5.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 14
5.4. Address Mapping . . . . . . . . . . . . . . . . . . . . . 14 5.4. Address Mapping . . . . . . . . . . . . . . . . . . . . . 14
5.4.1. Address Mapping -- Unicast . . . . . . . . . . . . . 14 5.4.1. Address Mapping -- Unicast . . . . . . . . . . . . . 14
5.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 14 5.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 15
5.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 15 5.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 16
5.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 16 5.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 17
6. Example IPv6 Packet captured over a IEEE 802.11-OCB link . . 16 6. Security Considerations . . . . . . . . . . . . . . . . . . . 17
6.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 17 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
6.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 19 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 18
7. Security Considerations . . . . . . . . . . . . . . . . . . . 21 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 10.1. Normative References . . . . . . . . . . . . . . . . . . 19
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 10.2. Informative References . . . . . . . . . . . . . . . . . 21
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 23 Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 24
11.1. Normative References . . . . . . . . . . . . . . . . . . 23
11.2. Informative References . . . . . . . . . . . . . . . . . 24
Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 26
Appendix B. Changes Needed on a software driver 802.11a to Appendix B. Changes Needed on a software driver 802.11a to
become a 802.11-OCB driver . . . 28 become a 802.11-OCB driver . . . 27
Appendix C. Design Considerations . . . . . . . . . . . . . . . 30
C.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 30 Appendix C. Design Considerations . . . . . . . . . . . . . . . 28
C.2. Reliability Requirements . . . . . . . . . . . . . . . . 30 C.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 28
C.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 31 C.2. Reliability Requirements . . . . . . . . . . . . . . . . 29
C.4. MAC Address Generation . . . . . . . . . . . . . . . . . 32 C.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 30
Appendix D. IEEE 802.11 Messages Transmitted in OCB mode . . . . 32 C.4. MAC Address Generation . . . . . . . . . . . . . . . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 32 Appendix D. IEEE 802.11 Messages Transmitted in OCB mode . . . . 31
Appendix E. Implementation Status . . . . . . . . . . . . . . . 31
E.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 32
E.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 34
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 36
1. Introduction 1. Introduction
This document describes the transmission of IPv6 packets on IEEE Std This document describes the transmission of IPv6 packets on IEEE Std
802.11 OCB networks (earlier known as 802.11p). This involves the 802.11-OCB networks (earlier known as 802.11p) [IEEE-802.11-2012].
layering of IPv6 networking on top of the IEEE 802.11 MAC layer (with This involves the layering of IPv6 networking on top of the IEEE
an LLC layer). Compared to running IPv6 over the Ethernet MAC layer, 802.11 MAC layer (with an LLC layer). Compared to running IPv6 over
there is no modification required to the standards: IPv6 works fine the Ethernet MAC layer, there is no modification required to the
directly over 802.11 OCB too (with an LLC layer). standards: IPv6 works fine directly over 802.11-OCB too (with an LLC
layer).
The term "802.11p" is an earlier definition. As of year 2012, the The term "802.11p" is an earlier definition. As of year 2012, the
behaviour of "802.11p" networks has been rolled in the document IEEE behaviour of "802.11p" networks has been rolled in the document IEEE
Std 802.11-2012. In this document the term 802.11p disappears. Std 802.11-2012. In that document the term 802.11p disappears.
Instead, each 802.11p feature is conditioned by a flag in the Instead, each 802.11p feature is conditioned by a flag in the
Management Information Base. That flag is named "OCBActivated". Management Information Base. That flag is named "OCBActivated".
Whenever OCBActivated is set to true the feature it relates to Whenever OCBActivated is set to true the feature it relates to, or
represents an earlier 802.11p feature. For example, an 802.11 represents, an earlier 802.11p feature. For example, an 802.11
STAtion operating outside the context of a basic service set has the STAtion operating outside the context of a basic service set has the
OCBActivated flag set. Such a station, when it has the flag set, it OCBActivated flag set. Such a station, when it has the flag set,
uses a BSS identifier equal to ff:ff:ff:ff:ff:ff. uses a BSS identifier equal to ff:ff:ff:ff:ff:ff.
In the following text we use the term "802.11p" to mean 802.11-2012 The IPv6 network layer operates on 802.11-OCB in the same manner as
OCB.
The IPv6 network layer operates on 802.11 OCB in the same manner as
it operates on 802.11 WiFi, with a few particular exceptions. The it operates on 802.11 WiFi, with a few particular exceptions. The
IPv6 network layer operates on WiFi by involving an Ethernet IPv6 network layer operates on WiFi by involving an Ethernet
Adaptation Layer; this Ethernet Adaptation Layer maps 802.11 headers Adaptation Layer; this Ethernet Adaptation Layer maps 802.11 headers
to Ethernet II headers. The operation of IP on Ethernet is described to Ethernet II headers. The operation of IP on Ethernet is described
in [RFC1042] and [RFC2464]. The situation of IPv6 networking layer in [RFC1042], [RFC2464] and [I-D.hinden-6man-rfc2464bis]. The
on Ethernet Adaptation Layer is illustrated below: situation of IPv6 networking layer on Ethernet Adaptation Layer is
illustrated below:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 | | IPv6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ethernet Adaptation Layer | | Ethernet Adaptation Layer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 802.11 WiFi MAC | | 802.11 WiFi MAC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 802.11 WiFi PHY | | 802.11 WiFi PHY |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(in the above figure, a WiFi profile is represented; this is used (in the above figure, a WiFi profile is represented; this is used
also for OCB profile.) also for OCB profile.)
A more theoretical and detailed view of layer stacking, and A more theoretical and detailed view of layer stacking, and
interfaces between the IP layer and 802.11 OCB layers, is illustrated interfaces between the IP layer and 802.11-OCB layers, is illustrated
below. The IP layer operates on top of the EtherType Protocol below. The IP layer operates on top of the EtherType Protocol
Discrimination (EPD); this Discrimination layer is described in IEEE Discrimination (EPD); this Discrimination layer is described in IEEE
Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP Std 802.3-2012; the interface between IPv6 and EPD is the LLC_SAP
(Link Layer Control Service Accesss Point). (Link Layer Control Service Accesss Point).
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 | | IPv6 |
+-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+
{ LLC_SAP } 802.11 OCB { LLC_SAP } 802.11-OCB
+-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary +-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary
| EPD | | | | EPD | | |
| | MLME | | | | MLME | |
+-+-+-{ MAC_SAP }+-+-+-| MLME_SAP | +-+-+-{ MAC_SAP }+-+-+-| MLME_SAP |
| MAC Sublayer | | | 802.11 OCB | MAC Sublayer | | | 802.11-OCB
| and ch. coord. | | SME | Services | and ch. coord. | | SME | Services
+-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| |
| | PLME | | | | PLME | |
| PHY Layer | PLME_SAP | | PHY Layer | PLME_SAP |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
In addition to the description of interface between IP and MAC using In addition to the description of interface between IP and MAC using
"Ethernet Adaptation Layer" and "Ethernet Protocol Discrimination "Ethernet Adaptation Layer" and "Ethernet Protocol Discrimination
(EPD)" it is worth mentioning that SNAP [RFC1042] is used to carry (EPD)" it is worth mentioning that SNAP [RFC1042] is used to carry
the IPv6 Ethertype. the IPv6 Ethertype.
However, there may be some deployment considerations helping optimize However, there may be some deployment considerations helping optimize
the performances of running IPv6 over 802.11-OCB (e.g. in the case of the performances of running IPv6 over 802.11-OCB (e.g. in the case of
handovers between 802.11 OCB-enabled access routers, or the handovers between 802.11-OCB-enabled access routers, or the
consideration of using the IP security layer [RFC4301]). consideration of using the IP security architecture [RFC4301]).
There are currently no specifications for handover between OCB links There are currently no specifications for handover between OCB links
since these are currently specified as LLC-1 links (i.e. since these are currently specified as LLC-1 links (i.e.
connectionless). Any handovers must be performed above the Data Link connectionless). Any handovers must be performed above the Data Link
Layer. Also, while there is no encryption applied below the network Layer. To realize handovers between OCB links there is a need of
layer using 802.11p, 1609.2 [ieee1609.2] does provide security specific indicators to assist in the handover process. The
services for applications to use so that there can easily be data indicators may be IP Router Advertisements, or 802.11-OCB's Time
security over the air without invoking IPsec. Advertisements, or higher layer messages such as the 'Basic Safety
Message' (in the US), or the 'Cooperative Awareness Message' (in the
EU), or the 'WAVE Routing Advertisement'. However, this document
does not describe handover behaviour.
The OCB operation is stripping off all existing 802.11 link-layer
security mechanisms. There is no encryption applied below the
network layer running on 802.11-OCB. At application layer, the IEEE
1609.2 document [IEEE-1609.2] does provide security services for
certain applications to use. A security mechanism provided at
networking layer, such as IPsec [RFC4301], may provide data security
protection to a wider range of applications. See the section
Security Considerations of this document, Section 6
We briefly introduce the vehicular communication scenarios where IEEE We briefly introduce the vehicular communication scenarios where IEEE
802.11-OCB links are used. This is followed by a description of 802.11-OCB links are used. This is followed by a description of
differences in specification terms, between 802.11 OCB and differences in specification terms, between 802.11-OCB and
802.11a/b/g/n (and the same differences expressed in terms of 802.11a/b/g/n - we answer the question of what are the aspects
requirements to software implementation are listed in Appendix B.) introduced by OCB mode to 802.11; the same aspects, but expressed in
terms of requirements to implementation, are listed in Appendix B.)
The document then concentrates on the parameters of layering IP over The document then concentrates on the parameters of layering IP over
802.11 OCB as over Ethernet: value of MTU, the contents of Frame 802.11-OCB as over Ethernet: value of MTU, the Frame Format which
Format, the rules for forming Interface Identifiers, the mechanism includes a description of an Ethernet Adaptation Layer, the forming
for Address Mapping and for State-less Address Auto-configuration. of Link-Local Addresses the rules for forming Interface Identifiers
These are precisely the same as IPv6 over Ethernet [RFC2464]. for Stateless Autoconfiguration, the mechanisms for Address Mapping.
These are precisely the same as IPv6 over Ethernet [RFC2464]. A
reference is made to ad-hoc networking characteristics of the subnet
structure in OCB mode.
As an example, these characteristics of layering IPv6 straight over As an example, these characteristics of layering IPv6 straight over
LLC over 802.11 OCB MAC are illustrated by dissecting an IPv6 packet LLC over 802.11-OCB MAC are illustrated by dissecting an IPv6 packet
captured over a 802.11 OCB link; this is described in the section captured over a 802.11-OCB link; this is described in the section
Section 6. Appendix E.
A couple of points can be considered as different, although they are
not required in order to have a working implementation of IPv6-over-
802.11-OCB. These points are consequences of the OCB operation which
is particular to 802.11 OCB (Outside the Context of a BSS). First,
the handovers between OCB links need specific behaviour for IP Router
Advertisements, or otherwise 802.11 OCB's Time Advertisement, or of
higher layer messages such as the 'Basic Safety Message' (in the US)
or the 'Cooperative Awareness Message' (in the EU) or the 'WAVE
Routing Advertisement'; second, the IP security mechanisms are
necessary, since OCB means that 802.11 is stripped of all 802.11
link-layer security; a small additional security aspect which is
shared between 802.11 OCB and other 802.11 links is the privacy
concerns related to the address formation mechanisms.
In the published literature, many documents describe aspects related In the published literature, many documents describe aspects related
to running IPv6 over 802.11 OCB: to running IPv6 over 802.11-OCB:
[I-D.jeong-ipwave-vehicular-networking-survey]. [I-D.jeong-ipwave-vehicular-networking-survey].
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
RSU: Road Side Unit. A computer equipped with at least one IEEE OBU (On-Board Unit): contrary to an RSU, an OBU is almost always
802.11 interface operated in OCB mode. This definition applies to situated in a vehicle; it is a computer with at least two IP
this document. An RSU may be connected to the Internet, and may be interfaces; also, at least one IP interface runs in OCB mode of
equipped with additional wired or wireless network interfaces running 802.11. It may be an IP router.
IP. An RSU MAY be an IP Router.
OCB: outside the context of a basic service set (BSS): A mode of RSU (Road Side Unit): It is a Wireless Termination Point (WTP), as
defined in [RFC5415], or an Access Point (AP), or an Access Network
Router (ANR) defined in [RFC3753], with one key particularity: the
wireless PHY/MAC layer is configured to operate in 802.11-OCB mode.
The RSU communicates with the On board Unit (OBU) in the vehicle over
802.11 wireless link operating in OCB mode. An RSU 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.
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 operation in which a STA is not a member of a BSS and does not
utilize IEEE Std 802.11 authentication, association, or data utilize IEEE Std 802.11 authentication, association, or data
confidentiality. confidentiality.
802.11-OCB, or 802.11 OCB: text in document IEEE 802.11-2012 that is 802.11-OCB, or 802.11-OCB: text in document IEEE 802.11-2012 that is
flagged by "dot11OCBActivated". This means: IEEE 802.11e for quality flagged by "dot11OCBActivated". The text flagged "dot11OCBActivated"
of service; 802.11j-2004 for half-clocked operations; and (what was includes IEEE 802.11e for quality of service, 802.11j-2004 for half-
known earlier as) 802.11p for operation in the 5.9 GHz band and in clocked operations and (what was known earlier as) 802.11p for
mode OCB. operation in the 5.9 GHz band and in mode OCB.
3. Communication Scenarios where IEEE 802.11 OCB Links are Used 3. Communication Scenarios where IEEE 802.11-OCB Links are Used
The IEEE 802.11 OCB Networks are used for vehicular communications, The IEEE 802.11-OCB Networks are used for vehicular communications,
as 'Wireless Access in Vehicular Environments'. The IP communication as 'Wireless Access in Vehicular Environments'. The IP communication
scenarios for these environments have been described in several scenarios for these environments have been described in several
documents, among which we refer the reader to one recently updated documents, among which we refer the reader to one recently updated
[I-D.petrescu-its-scenarios-reqs], about scenarios and requirements [I-D.petrescu-its-scenarios-reqs], about scenarios and requirements
for IP in Intelligent Transportation Systems. for IP in Intelligent Transportation Systems.
The link model is the following: STA --- 802.11-OCB --- STA. In
vehicular networks, STAs can be RSUs and/or OBUs. 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
manage mobility is not given in this document.
4. Aspects introduced by the OCB mode to 802.11 4. Aspects introduced by the OCB mode to 802.11
In the IEEE 802.11 OCB mode, all nodes in the wireless range can In the IEEE 802.11-OCB mode, all nodes in the wireless range can
directly communicate with each other without authentication/ directly communicate with each other without involving authentication
association procedures. Briefly, the IEEE 802.11 OCB mode has the or association procedures. At link layer, it is necessary to set a
following properties: 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.
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 o The use by each node of a 'wildcard' BSSID (i.e., each bit of the
BSSID is set to 1) BSSID is set to 1)
o No IEEE 802.11 Beacon frames transmitted o No IEEE 802.11 Beacon frames are transmitted
o No authentication required o No authentication is required in order to be able to communicate
o No association needed o No association is needed in order to be able to communicate
o No encryption provided o No encryption is provided in order to be able to communicate
o Flag dot11OCBActivated set to true o Flag dot11OCBActivated is set to true
All the nodes in the radio communication range (OBU and RSU) receive
all the messages transmitted (OBU and RSU) 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 following message exchange diagram illustrates a comparison
between traditional 802.11 and 802.11 in OCB mode. The 'Data' between traditional 802.11 and 802.11 in OCB mode. The 'Data'
messages can be IP messages such as the messages used in Stateless or messages can be IP packets such as HTTP or others. Other 802.11
Stateful Address Auto-Configuration, or other IP messages. Other management and control frames (non IP) may be transmitted, as
802.11 management and control frames (non IP) may be transmitted, as
specified in the 802.11 standard. For information, the names of specified in the 802.11 standard. For information, the names of
these messages as currently specified by the 802.11 standard are these messages as currently specified by the 802.11 standard are
listed in Appendix D. listed in Appendix D.
STA AP STA1 STA2 STA AP STA1 STA2
| | | | | | | |
|<------ Beacon -------| |<------ Data -------->| |<------ Beacon -------| |<------ Data -------->|
| | | | | | | |
|---- Probe Req. ----->| |<------ Data -------->| |---- Probe Req. ----->| |<------ Data -------->|
|<--- Probe Res. ------| | | |<--- Probe Res. ------| | |
| | |<------ Data -------->| | | |<------ Data -------->|
|---- Auth Req. ------>| | | |---- Auth Req. ------>| | |
|<--- Auth Res. -------| |<------ Data -------->| |<--- Auth Res. -------| |<------ Data -------->|
| | | | | | | |
|---- Asso Req. ------>| |<------ Data -------->| |---- Asso Req. ------>| |<------ Data -------->|
|<--- Asso Res. -------| | | |<--- Asso Res. -------| | |
| | |<------ Data -------->| | | |<------ Data -------->|
|<------ Data -------->| | | |<------ Data -------->| | |
|<------ Data -------->| |<------ Data -------->| |<------ Data -------->| |<------ Data -------->|
(a) 802.11 Infrastructure mode (b) 802.11 OCB mode (a) 802.11 Infrastructure mode (b) 802.11-OCB mode
The link 802.11 OCB was specified in IEEE Std 802.11p (TM) -2010 The link 802.11-OCB was specified in IEEE Std 802.11p (TM) -2010
[ieee802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007, [IEEE-802.11p-2010] as an amendment to IEEE Std 802.11 (TM) -2007,
titled "Amendment 6: Wireless Access in Vehicular Environments". titled "Amendment 6: Wireless Access in Vehicular Environments".
Since then, this amendment has been included in IEEE 802.11(TM)-2012 Since then, this amendment has been included in IEEE 802.11(TM)-2012
[ieee802.11-2012], titled "IEEE Standard for Information technology-- [IEEE-802.11-2012], titled "IEEE Standard for Information
Telecommunications and information exchange between systems Local and technology--Telecommunications and information exchange between
metropolitan area networks--Specific requirements Part 11: Wireless systems Local and metropolitan area networks--Specific requirements
LAN Medium Access Control (MAC) and Physical Layer (PHY) Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer
Specifications"; the modifications are diffused throughout various (PHY) Specifications"; the modifications are diffused throughout
sections (e.g. the Time Advertisement message described in the various sections (e.g. the Time Advertisement message described in
earlier 802.11 (TM) p amendment is now described in section 'Frame the earlier 802.11 (TM) p amendment is now described in section
formats', and the operation outside the context of a BSS described in 'Frame formats', and the operation outside the context of a BSS
section 'MLME'). described in section 'MLME').
In document 802.11-2012, specifically anything referring In document 802.11-2012, specifically anything referring
"OCBActivated", or "outside the context of a basic service set" is "OCBActivated", or "outside the context of a basic service set" is
actually referring to the 802.11p aspects introduced to 802.11. Note actually referring to OCB aspects introduced to 802.11. Note that in
that in earlier 802.11p documents the term "OCBEnabled" was used earlier 802.11p documents the term "OCBEnabled" was used instead of
instead of te current "OCBActivated". the current "OCBActivated".
In order to delineate the aspects introduced by 802.11 OCB to 802.11, In order to delineate the aspects introduced by 802.11-OCB to 802.11,
we refer to the earlier [ieee802.11p-2010]. The amendment is we refer to the earlier [IEEE-802.11p-2010]. The amendment is
concerned with vehicular communications, where the wireless link is concerned with vehicular communications, where the wireless link is
similar to that of Wireless LAN (using a PHY layer specified by 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 802.11a/b/g/n), but which needs to cope with the high mobility factor
inherent in scenarios of communications between moving vehicles, and inherent in scenarios of communications between moving vehicles, and
between vehicles and fixed infrastructure deployed along roads. between vehicles and fixed infrastructure deployed along roads.
While 'p' is a letter just like 'a, b, g' and 'n' are, 'p' is 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 concerned more with MAC modifications, and a little with PHY
modifications; the others are mainly about PHY modifications. It is modifications; the others are mainly about PHY modifications. It is
possible in practice to combine a 'p' MAC with an 'a' PHY by 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. operating outside the context of a BSS with OFDM at 5.4GHz.
The 802.11 OCB links are specified to be compatible as much as 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 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 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 offers practically the same interface to IP as the WiFi and Ethernet
layers do (802.11a/b/g/n and 802.3). layers do (802.11a/b/g/n and 802.3). A packet sent by an OBU may be
received by one or multiple RSUs. 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 To support this similarity statement (IPv6 is layered on top of LLC
on top of 802.11 OCB similarly as on top of LLC on top of on top of 802.11-OCB, in the same way that IPv6 is layered on top of
802.11a/b/g/n, and as on top of LLC on top of 802.3) it is useful to LLC on top of 802.11a/b/g/n (for WLAN) or layered on top of LLC on
analyze the differences between 802.11 OCB and 802.11 specifications. top of 802.3 (for Ethernet)) it is useful to analyze the differences
Whereas the 802.11p amendment specifies relatively complex and between 802.11-OCB and 802.11 specifications. During this analysis,
numerous changes to the MAC layer (and very little to the PHY layer), we note that whereas 802.11-OCB lists relatively complex and numerous
we note there are only a few characteristics which may be important changes to the MAC layer (and very little to the PHY layer), there
for an implementation transmitting IPv6 packets on 802.11 OCB links. are only a few characteristics which may be important for an
implementation transmitting IPv6 packets on 802.11-OCB links.
In the list below, the only 802.11 OCB fundamental points which The most important 802.11-OCB point which influences the IPv6
influence IPv6 are the OCB operation and the 12Mbit/s maximum which functioning is the OCB characteristic; an additional, less direct
may be afforded by the IPv6 applications. influence, is the maximum bandwidth afforded by the PHY modulation/
demodulation methods and channel access specified by 802.11-OCB. The
maximum bandwidth possible in 802.11-OCB 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 o Operation Outside the Context of a BSS (OCB): the (earlier
802.11p) 802.11-OCB links are operated without a Basic Service Set 802.11p) 802.11-OCB links are operated without a Basic Service Set
(BSS). This means that the frames IEEE 802.11 Beacon, Association (BSS). This means that the frames IEEE 802.11 Beacon, Association
Request/Response, Authentication Request/Response, and similar, Request/Response, Authentication Request/Response, and similar,
are not used. The used identifier of BSS (BSSID) has a are not used. The used identifier of BSS (BSSID) has a
hexadecimal value always 0xffffffffffff (48 '1' bits, represented hexadecimal value always 0xffffffffffff (48 '1' bits, represented
as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' as MAC address ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard'
BSSID), as opposed to an arbitrary BSSID value set by BSSID), as opposed to an arbitrary BSSID value set by
administrator (e.g. 'My-Home-AccessPoint'). The OCB operation - administrator (e.g. 'My-Home-AccessPoint'). The OCB operation -
namely the lack of beacon-based scanning and lack of namely the lack of beacon-based scanning and lack of
authentication - has a potentially strong impact on the use of the authentication - should be taken into account when the Mobile IPv6
Mobile IPv6 protocol [RFC6275] and on the protocols for IP layer protocol [RFC6275] and the protocols for IP layer security
security [RFC4301]. [RFC4301] are used. The way these protocols adapt to OCB is not
described in this document.
o Timing Advertisement: is a new message defined in 802.11-OCB, 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 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 stations to inform other stations about the value of time. It is
similar to the time as delivered by a GNSS system (Galileo, GPS, similar to the time as delivered by a GNSS system (Galileo, GPS,
...) or by a cellular system. This message is optional for ...) or by a cellular system. This message is optional for
implementation. At the date of writing, an experienced reviewer implementation.
considers that currently no field testing has used this message.
Another implementor considers this feature implemented in an
initial manner. In the future, it is speculated that this message
may be useful for very simple devices which may not have their own
hardware source of time (Galileo, GPS, cellular network), or by
vehicular devices situated in areas not covered by such network
(in tunnels, underground, outdoors but shaded by foliage or
buildings, in remote areas, etc.)
o Frequency range: this is a characteristic of the PHY layer, with o Frequency range: this is a characteristic of the PHY layer, with
almost no impact to the interface between MAC and IP. However, it almost no impact to the interface between MAC and IP. However, it
is worth considering that the frequency range is regulated by a is worth considering that the frequency range is regulated by a
regional authority (ARCEP, ETSI, FCC, etc.); as part of the regional authority (ARCEP, ETSI, FCC, etc.); as part of the
regulation process, specific applications are associated with regulation process, specific applications are associated with
specific frequency ranges. In the case of 802.11-OCB, the specific frequency ranges. In the case of 802.11-OCB, the
regulator associates a set of frequency ranges, or slots within a regulator associates a set of frequency ranges, or slots within a
band, to the use of applications of vehicular communications, in a band, to the use of applications of vehicular communications, in a
band known as "5.9GHz". This band is "5.9GHz" which is different band known as "5.9GHz". The 5.9GHz band is different from the
from the bands "2.4GHz" or "5GHz" used by Wireless LAN. However, 2.4GHz and 5GHz bands used by Wireless LAN. However, as with
as with Wireless LAN, the operation of 802.11-OCB in "5.9GHz" Wireless LAN, the operation of 802.11-OCB in "5.9GHz" bands is
bands is exempt from owning a license in EU (in US the 5.9GHz is a exempt from owning a license in EU (in US the 5.9GHz is a licensed
licensed band of spectrum; for the the fixed infrastructure an band of spectrum; for the the fixed infrastructure an explicit FCC
explicit FCC autorization is required; for an onboard device a autorization is required; for an onboard device a 'licensed-by-
'licensed-by-rule' concept applies: rule certification conformity rule' concept applies: rule certification conformity is required);
is required); however technical conditions are different than however technical conditions are different than those of the bands
those of the bands "2.4GHz" or "5GHz". On one hand, the allowed "2.4GHz" or "5GHz". On one hand, the allowed power levels, and
power levels, and implicitly the maximum allowed distance between implicitly the maximum allowed distance between vehicles, is of
vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20 33dBm for 802.11-OCB (in Europe), compared to 20 dBm for Wireless
dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum LAN 802.11a/b/g/n; this leads to a maximum distance of
distance of approximately 1km, compared to approximately 50m. On approximately 1km, compared to approximately 50m. On the other
the other hand, specific conditions related to congestion hand, specific conditions related to congestion avoidance, jamming
avoidance, jamming avoidance, and radar detection are imposed on avoidance, and radar detection are imposed on the use of DSRC (in
the use of DSRC (in US) and on the use of frequencies for US) and on the use of frequencies for Intelligent Transportation
Intelligent Transportation Systems (in EU), compared to Wireless Systems (in EU), compared to Wireless LAN (802.11a/b/g/n).
LAN (802.11a/b/g/n).
o Prohibition of IPv6 on some channels relevant for IEEE 802.11-OCB, o Prohibition of IPv6 on some channels relevant for IEEE 802.11-OCB,
as opposed to IPv6 not being prohibited on any channel on which as opposed to IPv6 not being prohibited on any channel on which
802.11a/b/g/n runs: 802.11a/b/g/n runs:
* Some channels are reserved for safety communications; the IPv6 * Some channels are reserved for safety communications; the IPv6
packets should not be sent on these channels. packets should not be sent on these channels.
* At the time of writing, the prohibition is explicit at higher * At the time of writing, the prohibition is explicit at higher
layer protocols providing services to the application; these layer protocols providing services to the application; these
higher layer protocols are specified in IEEE 1609 documents. higher layer protocols are specified in IEEE 1609 documents,
i.e. the "WAVE" stack.
* National or regional specifications and regulations specify the * National or regional specifications and regulations specify the
use of different channels; these regulations must be followed. use of different channels; these regulations must be followed.
o 'Half-rate' encoding: as the frequency range, this parameter is o 'Half-rate' encoding: as the frequency range, this parameter is
related to PHY, and thus has not much impact on the interface related to PHY, and thus has not much impact on the interface
between the IP layer and the MAC layer. between the IP layer and the MAC layer.
o In vehicular communications using 802.11-OCB links, there are o In vehicular communications using 802.11-OCB links, there are
strong privacy requirements with respect to addressing. While the strong privacy requirements with respect to addressing. While the
802.11-OCB standard does not specify anything in particular with 802.11-OCB standard does not specify anything in particular with
respect to MAC addresses, in these settings there exists a strong respect to MAC addresses, in these settings there exists a strong
need for dynamic change of these addresses (as opposed to the non- need for dynamic change of these addresses (as opposed to the non-
vehicular settings - real wall protection - where fixed MAC vehicular settings - real wall protection - where fixed MAC
addresses do not currently pose some privacy risks). This is addresses do not currently pose some privacy risks). This is
further described in section Section 7. A relevant function is further described in section Section 6. A relevant function is
described in IEEE 1609.3-2016 [ieee1609.3], clause 5.5.1 and IEEE described in IEEE 1609.3-2016 [IEEE-1609.3], clause 5.5.1 and IEEE
1609.4-2016 [ieee1609.4], clause 6.7. 1609.4-2016 [IEEE-1609.4], clause 6.7.
Other aspects particular to 802.11-OCB which are also particular to 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 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 the use of transmission of IPv6 packets on 802.11-OCB networks. The
subnet structure which may be assumed in 802.11-OCB networks is OCB subnet structure is described in section Section 5.6.
strongly influenced by the mobility of vehicles.
5. Layering of IPv6 over 802.11-OCB as over Ethernet 5. Layering of IPv6 over 802.11-OCB as over Ethernet
5.1. Maximum Transmission Unit (MTU) 5.1. Maximum Transmission Unit (MTU)
The default MTU for IP packets on 802.11-OCB is 1500 octets. It is The default MTU for IP packets on 802.11-OCB is 1500 octets. It is
the same value as IPv6 packets on Ethernet links, as specified in the same value as IPv6 packets on Ethernet links, as specified in
[RFC2464]. This value of the MTU respects the recommendation that [RFC2464]. This value of the MTU respects the recommendation that
every link in the Internet must have a minimum MTU of 1280 octets every link in the Internet must have a minimum MTU of 1280 octets
(stated in [RFC2460], and the recommendations therein, especially (stated in [RFC8200], and the recommendations therein, especially
with respect to fragmentation). If IPv6 packets of size larger than with respect to fragmentation). If IPv6 packets of size larger than
1500 bytes are sent on an 802.11-OCB interface card then the IP stack 1500 bytes are sent on an 802.11-OCB interface card then the IP stack
will fragment. In case there are IP fragments, the field "Sequence will fragment. In case there are IP fragments, the field "Sequence
number" of the 802.11 Data header containing the IP fragment field is number" of the 802.11 Data header containing the IP fragment field is
increased. increased.
Non-IP packets such as WAVE Short Message Protocol (WSMP) can be Non-IP packets such as WAVE Short Message Protocol (WSMP) can be
delivered on 802.11-OCB links. Specifications of these packets are delivered on 802.11-OCB links. Specifications of these packets are
out of scope of this document, and do not impose any limit on the MTU out of scope of this document, and do not impose any limit on the MTU
size, allowing an arbitrary number of 'containers'. Non-IP packets size, allowing an arbitrary number of 'containers'. Non-IP packets
such as ETSI 'geonet' packets have an MTU of 1492 bytes. such as ETSI GeoNetworking packets have an MTU of 1492 bytes. The
operation of IPv6 over GeoNetworking is specified at
The Equivalent Transmit Time on Channel is a concept that may be used [ETSI-IPv6-GeoNetworking].
as an alternative to the MTU concept. A rate of transmission may be
specified as well. The ETTC, rate and MTU may be in direct
relationship.
5.2. Frame Format 5.2. Frame Format
IP packets are transmitted over 802.11-OCB as standard Ethernet IP packets are transmitted over 802.11-OCB as standard Ethernet
packets. As with all 802.11 frames, an Ethernet adaptation layer is packets. As with all 802.11 frames, an Ethernet adaptation layer is
used with 802.11-OCB as well. This Ethernet Adaptation Layer used with 802.11-OCB as well. This Ethernet Adaptation Layer
performing 802.11-to-Ethernet is described in Section 5.2.1. The performing 802.11-to-Ethernet is described in Section 5.2.1. The
Ethernet Type code (EtherType) for IPv6 is 0x86DD (hexadecimal 86DD, Ethernet Type code (EtherType) for IPv6 is 0x86DD (hexadecimal 86DD,
or otherwise #86DD). or otherwise #86DD).
skipping to change at page 13, line 18 skipping to change at page 14, line 4
field in the Ethernet II Header. field in the Ethernet II Header.
The ".11 Trailer" contains solely a 4-byte Frame Check Sequence. The ".11 Trailer" contains solely a 4-byte Frame Check Sequence.
The Ethernet Adaptation Layer performs operations in relation to IP The Ethernet Adaptation Layer performs operations in relation to IP
fragmentation and MTU. One of these operations is briefly described fragmentation and MTU. One of these operations is briefly described
in section Section 5.1. in section Section 5.1.
In OCB mode, IPv6 packets can be transmitted either as "IEEE 802.11 In OCB mode, IPv6 packets can be transmitted either as "IEEE 802.11
Data" or alternatively as "IEEE 802.11 QoS Data", as illustrated in Data" or alternatively as "IEEE 802.11 QoS Data", as illustrated in
the following figure: the figure below. Some commercial OCB products use 802.11 Data, and
others 802.11 QoS data. In the future, both could be used.
+--------------------+-------------+-------------+---------+-----------+ +--------------------+-------------+-------------+---------+-----------+
| 802.11 Data Header | LLC Header | IPv6 Header | Payload |.11 Trailer| | 802.11 Data Header | LLC Header | IPv6 Header | Payload |.11 Trailer|
+--------------------+-------------+-------------+---------+-----------+ +--------------------+-------------+-------------+---------+-----------+
or or
+--------------------+-------------+-------------+---------+-----------+ +--------------------+-------------+-------------+---------+-----------+
| 802.11 QoS Data Hdr| LLC Header | IPv6 Header | Payload |.11 Trailer| | 802.11 QoS Data Hdr| LLC Header | IPv6 Header | Payload |.11 Trailer|
+--------------------+-------------+-------------+---------+-----------+ +--------------------+-------------+-------------+---------+-----------+
skipping to change at page 14, line 18 skipping to change at page 15, line 5
multicast address mapping format of Ethernet interfaces, as defined multicast address mapping format of Ethernet interfaces, as defined
by sections 6 and 7 of [RFC2464]. by sections 6 and 7 of [RFC2464].
5.4.1. Address Mapping -- Unicast 5.4.1. Address Mapping -- Unicast
The procedure for mapping IPv6 unicast addresses into Ethernet link- The procedure for mapping IPv6 unicast addresses into Ethernet link-
layer addresses is described in [RFC4861]. The Source/Target Link- layer addresses is described in [RFC4861]. The Source/Target Link-
layer Address option has the following form when the link-layer is layer Address option has the following form when the link-layer is
Ethernet. Ethernet.
0 1 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+- Ethernet -+ +- Ethernet -+
| | | |
+- Address -+ +- Address -+
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 15, line 17 skipping to change at page 16, line 5
"All_DHCP_Servers" IPv6 multicast address ff02::1:2, and in OSPF the "All_DHCP_Servers" IPv6 multicast address ff02::1:2, and in OSPF the
"All_SPF_Routers" IPv6 multicast address ff02::5, need to be mapped "All_SPF_Routers" IPv6 multicast address ff02::5, need to be mapped
on a multicast MAC address. on a multicast MAC address.
An IPv6 packet with a multicast destination address DST, consisting An IPv6 packet with a multicast destination address DST, consisting
of the sixteen octets DST[1] through DST[16], is transmitted to the of the sixteen octets DST[1] through DST[16], is transmitted to the
IEEE 802.11-OCB MAC multicast address whose first two octets are the IEEE 802.11-OCB MAC multicast address whose first two octets are the
value 0x3333 and whose last four octets are the last four octets of value 0x3333 and whose last four octets are the last four octets of
DST. DST.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 1 1 0 0 1 1|0 0 1 1 0 0 1 1| |0 0 1 1 0 0 1 1|0 0 1 1 0 0 1 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DST[13] | DST[14] | | DST[13] | DST[14] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DST[15] | DST[16] | | DST[15] | DST[16] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
A Group ID TBD of length 112bits may be requested from IANA; this A Group ID named TBD, of length 112bits is requested to IANA; this
Group ID signifies "All 80211OCB Interfaces Address". Only the least Group ID signifies "All 80211OCB Interfaces Address". Only the least
32 significant bits of this "All 80211OCB Interfaces Address" will be 32 significant bits of this "All 80211OCB Interfaces Address" will be
mapped to and from a MAC multicast address. mapped to and from a MAC multicast address.
Transmitting IPv6 packets to multicast destinations over 802.11 links Transmitting IPv6 packets to multicast destinations over 802.11 links
proved to have some performance issues proved to have some performance issues
[I-D.perkins-intarea-multicast-ieee802]. These issues may be [I-D.perkins-intarea-multicast-ieee802]. These issues may be
exacerbated in OCB mode. Solutions for these problems should exacerbated in OCB mode. Solutions for these problems should
consider the OCB mode of operation. consider the OCB mode of operation.
skipping to change at page 15, line 48 skipping to change at page 16, line 36
The Interface Identifier for an 802.11-OCB interface is formed using The Interface Identifier for an 802.11-OCB interface is formed using
the same rules as the Interface Identifier for an Ethernet interface; the same rules as the Interface Identifier for an Ethernet interface;
this is described in section 4 of [RFC2464]. No changes are needed, this is described in section 4 of [RFC2464]. No changes are needed,
but some care must be taken when considering the use of the SLAAC but some care must be taken when considering the use of the SLAAC
procedure. procedure.
The bits in the the interface identifier have no generic meaning and The bits in the the interface identifier have no generic meaning and
the identifier should be treated as an opaque value. The bits the identifier should be treated as an opaque value. The bits
'Universal' and 'Group' in the identifier of an 802.11-OCB interface 'Universal' and 'Group' in the identifier of an 802.11-OCB interface
are significant, as this is an IEEE link-layer address. The details are significant, as this is an IEEE link-layer address. The details
of this significance are described in [I-D.ietf-6man-ug]. of this significance are described in [RFC7136].
As with all Ethernet and 802.11 interface identifiers ([RFC7721]), As with all Ethernet and 802.11 interface identifiers ([RFC7721]),
the identifier of an 802.11-OCB interface may involve privacy risks. the identifier of an 802.11-OCB interface may involve privacy, MAC
A vehicle embarking an On-Board Unit whose egress interface is address spoofing and IP address hijacking risks. A vehicle embarking
802.11-OCB may expose itself to eavesdropping and subsequent an On-Board Unit whose egress interface is 802.11-OCB may expose
correlation of data; this may reveal data considered private by the itself to eavesdropping and subsequent correlation of data; this may
vehicle owner; there is a risk of being tracked; see the privacy reveal data considered private by the vehicle owner; there is a risk
considerations described in Appendix C. of being tracked; see the privacy considerations described in
Appendix C.
If stable Interface Identifiers are needed in order to form IPv6 If stable Interface Identifiers are needed in order to form IPv6
addresses on 802.11-OCB links, it is recommended to follow the addresses on 802.11-OCB links, it is recommended to follow the
recommendation in [I-D.ietf-6man-default-iids]. recommendation in [RFC8064].
5.6. Subnet Structure 5.6. Subnet Structure
A subnet is formed by the external 802.11-OCB interfaces of vehicles
that are in close range (not their on-board interfaces). This
ephemeral subnet structure is strongly influenced by the mobility of
vehicles: the 802.11 hidden node effects appear. On another hand,
the structure of the internal subnets in each car is relatively
stable.
For routing purposes, a prefix exchange mechanism could be needed
between neighboring vehicles.
The 802.11 networks in OCB mode may be considered as 'ad-hoc' The 802.11 networks in OCB mode may be considered as 'ad-hoc'
networks. The addressing model for such networks is described in networks. The addressing model for such networks is described in
[RFC5889]. [RFC5889].
6. Example IPv6 Packet captured over a IEEE 802.11-OCB link An addressing model involves several types of addresses, like
Globally-unique Addresses (GUA), Link-Local Addresses (LL) and Unique
We remind that a main goal of this document is to make the case that Local Addresses (ULA). The subnet structure in 'ad-hoc' networks may
IPv6 works fine over 802.11-OCB networks. Consequently, this section have characteristics that lead to difficulty of using GUAs derived
is an illustration of this concept and thus can help the implementer from a received prefix, but the LL addresses may be easier to use
when it comes to running IPv6 over IEEE 802.11-OCB. By way of since the prefix is constant.
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 | |
---| Router |--------------------------------| Host |
| | | |
+--------+ +-------+
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.
6.1. Capture in Monitor Mode
The IPv6 RA packet captured in monitor mode is illustrated below.
The radio tap header provides more flexibility for reporting the
characteristics of frames. The Radiotap Header is prepended by this
particular stack and operating system on the Host machine to the RA
packet received from the network (the Radiotap Header is not present
on the air). The implementation-dependent Radiotap Header is useful
for piggybacking PHY information from the chip's registers as data in
a packet understandable by userland applications using Socket
interfaces (the PHY interface can be, for example: power levels, data
rate, ratio of signal to noise).
The packet present on the air is formed by IEEE 802.11 Data Header,
Logical Link Control Header, IPv6 Base Header and ICMPv6 Header.
Radiotap Header v0
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Header Revision| Header Pad | Header length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Present flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Rate | Pad |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IEEE 802.11 Data Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type/Subtype and Frame Ctrl | Duration |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receiver Address...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Receiver Address | Transmitter Address...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Transmitter Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BSS Id...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... BSS Id | Frag Number and Seq Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Logical-Link Control Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DSAP |I| SSAP |C| Control field | Org. code...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Organizational Code | Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv6 Base Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Traffic Class | Flow Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Length | Next Header | Hop Limit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Source Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Destination Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Router Advertisement
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cur Hop Limit |M|O| Reserved | Router Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reachable Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Retrans Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Options ...
+-+-+-+-+-+-+-+-+-+-+-+-
The value of the Data Rate field in the Radiotap header is set to 6
Mb/s. This indicates the rate at which this RA was received.
The value of the Transmitter address in the IEEE 802.11 Data Header
is set to a 48bit value. The value of the destination address is
33:33:00:00:00:1 (all-nodes multicast address). The value of the BSS
Id field is ff:ff:ff:ff:ff:ff, which is recognized by the network
protocol analyzer as being "broadcast". The Fragment number and
sequence number fields are together set to 0x90C6.
The value of the Organization Code field in the Logical-Link Control
Header is set to 0x0, recognized as "Encapsulated Ethernet". The
value of the Type field is 0x86DD (hexadecimal 86DD, or otherwise
#86DD), recognized as "IPv6".
A Router Advertisement is periodically sent by the router to
multicast group address ff02::1. It is an icmp packet type 134. The
IPv6 Neighbor Discovery's Router Advertisement message contains an
8-bit field reserved for single-bit flags, as described in [RFC4861].
The IPv6 header contains the link local address of the router
(source) configured via EUI-64 algorithm, and destination address set
to ff02::1. Recent versions of network protocol analyzers (e.g.
Wireshark) provide additional informations for an IP address, if a
geolocalization database is present. In this example, the
geolocalization database is absent, and the "GeoIP" information is
set to unknown for both source and destination addresses (although
the IPv6 source and destination addresses are set to useful values).
This "GeoIP" can be a useful information to look up the city,
country, AS number, and other information for an IP address.
The Ethernet Type field in the logical-link control header is set to
0x86dd which indicates that the frame transports an IPv6 packet. In
the IEEE 802.11 data, the destination address is 33:33:00:00:00:01
which is he corresponding multicast MAC address. The BSS id is a
broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link
duration between vehicles and the roadside infrastructure, there is
no need in IEEE 802.11-OCB to wait for the completion of association
and authentication procedures before exchanging data. IEEE
802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s)
and may start communicating as soon as they arrive on the
communication channel.
6.2. Capture in Normal Mode
The same IPv6 Router Advertisement packet described above (monitor
mode) is captured on the Host, in the Normal mode, and depicted
below.
Ethernet II Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...Destination | Source...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv6 Base Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Traffic Class | Flow Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Length | Next Header | Hop Limit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Source Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Destination Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Router Advertisement
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cur Hop Limit |M|O| Reserved | Router Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reachable Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Retrans Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Options ...
+-+-+-+-+-+-+-+-+-+-+-+-
One notices that the Radiotap Header is not prepended, and that the
IEEE 802.11 Data Header and the Logical-Link Control Headers are not
present. On another hand, a new header named Ethernet II Header is
present.
The Destination and Source addresses in the Ethernet II header
contain the same values as the fields Receiver Address and
Transmitter Address present in the IEEE 802.11 Data Header in the
"monitor" mode capture.
The value of the Type field in the Ethernet II header is 0x86DD
(recognized as "IPv6"); this value is the same value as the value of
the field Type in the Logical-Link Control Header in the "monitor"
mode capture.
The knowledgeable experimenter will no doubt notice the similarity of
this Ethernet II Header with a capture in normal mode on a pure
Ethernet cable interface.
It may be interpreted that an Adaptation layer is inserted in a pure
IEEE 802.11 MAC packets in the air, before delivering to the
applications. In detail, this adaptation layer may consist in
elimination of the Radiotap, 802.11 and LLC headers and insertion of
the Ethernet II header. In this way, it can be stated that IPv6 runs
naturally straight over LLC over the 802.11-OCB MAC layer, as shown
by the use of the Type 0x86DD, and assuming an adaptation layer
(adapting 802.11 LLC/MAC to Ethernet II header).
7. Security Considerations 6. Security Considerations
Any security mechanism at the IP layer or above that may be carried Any security mechanism at the IP layer or above that may be carried
out for the general case of IPv6 may also be carried out for IPv6 out for the general case of IPv6 may also be carried out for IPv6
operating over 802.11-OCB. operating over 802.11-OCB.
802.11-OCB does not provide any cryptographic protection, because it 802.11-OCB does not provide any cryptographic protection, because it
operates outside the context of a BSS (no Association Request/ operates outside the context of a BSS (no Association Request/
Response, no Challenge messages). Any attacker can therefore just Response, no Challenge messages). Any attacker can therefore just
sit in the near range of vehicles, sniff the network (just set the sit in the near range of vehicles, sniff the network (just set the
interface card's frequency to the proper range) and perform attacks interface card's frequency to the proper range) and perform attacks
without needing to physically break any wall. Such a link is way without needing to physically break any wall. Such a link is less
less protected than commonly used links (wired link or protected protected than commonly used links (wired link or protected 802.11).
802.11).
At the IP layer, IPsec can be used to protect unicast communications, The potential attack vectors are: MAC address spoofing, IP address
and SeND can be used for multicast communications. If no protection and session hijacking and privacy violation.
is used by the IP layer, upper layers should be protected.
Otherwise, the end-user or system should be warned about the risks Within the IPsec Security Architecture [RFC4301], the IPsec AH and
they run. ESP headers [RFC4302] and [RFC4303] respectively, its multicast
extensions [RFC5374], HTTPS [RFC2818] and SeND [RFC3971] protocols
can be used to protect communications. Further, the assistance of
proper Public Key Infrastructure (PKI) protocols [RFC4210] is
necessary to establish credentials. More IETF protocols are
available in the toolbox of the IP security protocol designer.
Certain ETSI protocols related to security protocols in Intelligent
Transportation Systems are described in [ETSI-sec-archi].
As with all Ethernet and 802.11 interface identifiers, there may As with all Ethernet and 802.11 interface identifiers, there may
exist privacy risks in the use of 802.11-OCB interface identifiers. exist privacy risks in the use of 802.11-OCB interface identifiers.
Moreover, in outdoors vehicular settings, the privacy risks are more Moreover, in outdoors vehicular settings, the privacy risks are more
important than in indoors settings. New risks are induced by the important than in indoors settings. New risks are induced by the
possibility of attacker sniffers deployed along routes which listen possibility of attacker sniffers deployed along routes which listen
for IP packets of vehicles passing by. For this reason, in the for IP packets of vehicles passing by. For this reason, in the
802.11-OCB deployments, there is a strong necessity to use protection 802.11-OCB deployments, there is a strong necessity to use protection
tools such as dynamically changing MAC addresses. This may help tools such as dynamically changing MAC addresses. This may help
mitigate privacy risks to a certain level. On another hand, it may mitigate privacy risks to a certain level. On another hand, it may
have an impact in the way typical IPv6 address auto-configuration is have an impact in the way typical IPv6 address auto-configuration is
performed for vehicles (SLAAC would rely on MAC addresses amd would performed for vehicles (SLAAC would rely on MAC addresses amd would
hence dynamically change the affected IP address), in the way the hence dynamically change the affected IP address), in the way the
IPv6 Privacy addresses were used, and other effects. IPv6 Privacy addresses were used, and other effects.
8. IANA Considerations 7. IANA Considerations
9. Contributors A Group ID named TBD, of length 112bits is requested to IANA; this
Group ID signifies "All 80211OCB Interfaces Address".
8. Contributors
Romain Kuntz contributed extensively about IPv6 handovers between Romain Kuntz contributed extensively about IPv6 handovers between
links running outside the context of a BSS (802.11-OCB links). links running outside the context of a BSS (802.11-OCB links).
Tim Leinmueller contributed the idea of the use of IPv6 over Tim Leinmueller contributed the idea of the use of IPv6 over
802.11-OCB for distribution of certificates. 802.11-OCB for distribution of certificates.
Marios Makassikis, Jose Santa Lozano, Albin Severinson and Alexey Marios Makassikis, Jose Santa Lozano, Albin Severinson and Alexey
Voronov provided significant feedback on the experience of using IP Voronov provided significant feedback on the experience of using IP
messages over 802.11-OCB in initial trials. messages over 802.11-OCB in initial trials.
Michelle Wetterwald contributed extensively the MTU discussion, Michelle Wetterwald contributed extensively the MTU discussion,
offered the ETSI ITS perspective, and reviewed other parts of the offered the ETSI ITS perspective, and reviewed other parts of the
document. document.
10. Acknowledgements 9. Acknowledgements
The authors would like to thank Witold Klaudel, Ryuji Wakikawa, The authors would like to thank Witold Klaudel, Ryuji Wakikawa,
Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan Emmanuel Baccelli, John Kenney, John Moring, Francois Simon, Dan
Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray Romascanu, Konstantin Khait, Ralph Droms, Richard 'Dick' Roy, Ray
Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan, Hunter, Tom Kurihara, Michal Sojka, Jan de Jongh, Suresh Krishnan,
Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne, Dino Farinacci, Vincent Park, Jaehoon Paul Jeong, Gloria Gwynne,
Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark, Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, Erik Nordmark,
Bob Moskowitz, Andrew (Dryden?), Georg Mayer, Dorothy Stanley and Bob Moskowitz, Andrew (Dryden?), Georg Mayer, Dorothy Stanley, Sandra
William Whyte. Their valuable comments clarified certain issues and Cespedes, Mariano Falcitelli, Sri Gundavelli and William Whyte.
generally helped to improve the document.
Their valuable comments clarified particular issues and generally
helped to improve the document.
Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB
drivers for linux and described how. drivers for linux and described how.
For the multicast discussion, the authors would like to thank Owen For the multicast discussion, the authors would like to thank Owen
DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian Haberman and
participants to discussions in network working groups. participants to discussions in network working groups.
The authours would like to thank participants to the Birds-of- The authours would like to thank participants to the Birds-of-
a-Feather "Intelligent Transportation Systems" meetings held at IETF a-Feather "Intelligent Transportation Systems" meetings held at IETF
in 2016. in 2016.
11. References 10. References
11.1. Normative References
[I-D.ietf-6man-default-iids]
Gont, F., Cooper, A., Thaler, D., and S. LIU,
"Recommendation on Stable IPv6 Interface Identifiers",
draft-ietf-6man-default-iids-16 (work in progress),
September 2016.
[I-D.ietf-6man-ug] 10.1. Normative References
Carpenter, B. and S. Jiang, "Significance of IPv6
Interface Identifiers", draft-ietf-6man-ug-06 (work in
progress), December 2013.
[I-D.ietf-tsvwg-ieee-802-11] [I-D.ietf-tsvwg-ieee-802-11]
Szigeti, T., Henry, J., and F. Baker, "Diffserv to IEEE Szigeti, T., Henry, J., and F. Baker, "Diffserv to IEEE
802.11 Mapping", draft-ietf-tsvwg-ieee-802-11-06 (work in 802.11 Mapping", draft-ietf-tsvwg-ieee-802-11-07 (work in
progress), August 2017. progress), September 2017.
[RFC1042] Postel, J. and J. Reynolds, "Standard for the transmission [RFC1042] Postel, J. and J. Reynolds, "Standard for the transmission
of IP datagrams over IEEE 802 networks", STD 43, RFC 1042, of IP datagrams over IEEE 802 networks", STD 43, RFC 1042,
DOI 10.17487/RFC1042, February 1988, <https://www.rfc- DOI 10.17487/RFC1042, February 1988,
editor.org/info/rfc1042>. <https://www.rfc-editor.org/info/rfc1042>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, <https://www.rfc- DOI 10.17487/RFC2119, March 1997,
editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460,
December 1998, <https://www.rfc-editor.org/info/rfc2460>.
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet
Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998,
<https://www.rfc-editor.org/info/rfc2464>. <https://www.rfc-editor.org/info/rfc2464>.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,
DOI 10.17487/RFC2818, May 2000,
<https://www.rfc-editor.org/info/rfc2818>.
[RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related
Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004,
<https://www.rfc-editor.org/info/rfc3753>.
[RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P.
Thubert, "Network Mobility (NEMO) Basic Support Protocol", Thubert, "Network Mobility (NEMO) Basic Support Protocol",
RFC 3963, DOI 10.17487/RFC3963, January 2005, RFC 3963, DOI 10.17487/RFC3963, January 2005,
<https://www.rfc-editor.org/info/rfc3963>. <https://www.rfc-editor.org/info/rfc3963>.
[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,
"SEcure Neighbor Discovery (SEND)", RFC 3971,
DOI 10.17487/RFC3971, March 2005,
<https://www.rfc-editor.org/info/rfc3971>.
[RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker,
"Randomness Requirements for Security", BCP 106, RFC 4086, "Randomness Requirements for Security", BCP 106, RFC 4086,
DOI 10.17487/RFC4086, June 2005, <https://www.rfc- DOI 10.17487/RFC4086, June 2005,
editor.org/info/rfc4086>. <https://www.rfc-editor.org/info/rfc4086>.
[RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen,
"Internet X.509 Public Key Infrastructure Certificate
Management Protocol (CMP)", RFC 4210,
DOI 10.17487/RFC4210, September 2005,
<https://www.rfc-editor.org/info/rfc4210>.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the [RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <https://www.rfc-editor.org/info/rfc4301>. December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[RFC4302] Kent, S., "IP Authentication Header", RFC 4302,
DOI 10.17487/RFC4302, December 2005,
<https://www.rfc-editor.org/info/rfc4302>.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005,
<https://www.rfc-editor.org/info/rfc4303>.
[RFC4429] Moore, N., "Optimistic Duplicate Address Detection (DAD) [RFC4429] Moore, N., "Optimistic Duplicate Address Detection (DAD)
for IPv6", RFC 4429, DOI 10.17487/RFC4429, April 2006, for IPv6", RFC 4429, DOI 10.17487/RFC4429, April 2006,
<https://www.rfc-editor.org/info/rfc4429>. <https://www.rfc-editor.org/info/rfc4429>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007, <https://www.rfc- DOI 10.17487/RFC4861, September 2007,
editor.org/info/rfc4861>. <https://www.rfc-editor.org/info/rfc4861>.
[RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast
Extensions to the Security Architecture for the Internet
Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008,
<https://www.rfc-editor.org/info/rfc5374>.
[RFC5415] Calhoun, P., Ed., Montemurro, M., Ed., and D. Stanley,
Ed., "Control And Provisioning of Wireless Access Points
(CAPWAP) Protocol Specification", RFC 5415,
DOI 10.17487/RFC5415, March 2009,
<https://www.rfc-editor.org/info/rfc5415>.
[RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing
Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889,
September 2010, <https://www.rfc-editor.org/info/rfc5889>. September 2010, <https://www.rfc-editor.org/info/rfc5889>.
[RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July
2011, <https://www.rfc-editor.org/info/rfc6275>. 2011, <https://www.rfc-editor.org/info/rfc6275>.
[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C. [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
Bormann, "Neighbor Discovery Optimization for IPv6 over Bormann, "Neighbor Discovery Optimization for IPv6 over
Low-Power Wireless Personal Area Networks (6LoWPANs)", Low-Power Wireless Personal Area Networks (6LoWPANs)",
RFC 6775, DOI 10.17487/RFC6775, November 2012, RFC 6775, DOI 10.17487/RFC6775, November 2012,
<https://www.rfc-editor.org/info/rfc6775>. <https://www.rfc-editor.org/info/rfc6775>.
[RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6
Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136,
February 2014, <https://www.rfc-editor.org/info/rfc7136>.
[RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy
Considerations for IPv6 Address Generation Mechanisms", Considerations for IPv6 Address Generation Mechanisms",
RFC 7721, DOI 10.17487/RFC7721, March 2016, RFC 7721, DOI 10.17487/RFC7721, March 2016,
<https://www.rfc-editor.org/info/rfc7721>. <https://www.rfc-editor.org/info/rfc7721>.
11.2. Informative References [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu,
"Recommendation on Stable IPv6 Interface Identifiers",
RFC 8064, DOI 10.17487/RFC8064, February 2017,
<https://www.rfc-editor.org/info/rfc8064>.
[fcc-cc] "'Report and Order, Before the Federal Communications [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
Commission Washington, D.C. 20554', FCC 03-324, Released (IPv6) Specification", STD 86, RFC 8200,
on February 10, 2004, document FCC-03-324A1.pdf, document DOI 10.17487/RFC8200, July 2017,
freely available at URL <https://www.rfc-editor.org/info/rfc8200>.
http://www.its.dot.gov/exit/fcc_edocs.htm downloaded on
October 17th, 2013.".
[fcc-cc-172-184] 10.2. Informative References
"'Memorandum Opinion and Order, Before the Federal
Communications Commission Washington, D.C. 20554', FCC [ETSI-IPv6-GeoNetworking]
06-10, Released on July 26, 2006, document FCC- "ETSI EN 302 636-6-1 v1.2.1 (2014-05), ETSI, European
06-110A1.pdf, document freely available at URL Standard, Intelligent Transportation Systems (ITS);
http://hraunfoss.fcc.gov/edocs_public/attachmatch/ Vehicular Communications; Geonetworking; Part 6: Internet
FCC-06-110A1.pdf downloaded on June 5th, 2014.". Integration; Sub-part 1: Transmission of IPv6 Packets over
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
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.
[I-D.jeong-ipwave-vehicular-networking-survey] [I-D.jeong-ipwave-vehicular-networking-survey]
Jeong, J., Cespedes, S., Benamar, N., Haerri, J., and M. Jeong, J., Cespedes, S., Benamar, N., Haerri, J., and M.
Wetterwald, "Survey on IP-based Vehicular Networking for Wetterwald, "Survey on IP-based Vehicular Networking for
Intelligent Transportation Systems", draft-jeong-ipwave- Intelligent Transportation Systems", draft-jeong-ipwave-
vehicular-networking-survey-03 (work in progress), June vehicular-networking-survey-03 (work in progress), June
2017. 2017.
[I-D.perkins-intarea-multicast-ieee802] [I-D.perkins-intarea-multicast-ieee802]
Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, Perkins, C., Stanley, D., Kumari, W., and J. Zuniga,
"Multicast Considerations over IEEE 802 Wireless Media", "Multicast Considerations over IEEE 802 Wireless Media",
draft-perkins-intarea-multicast-ieee802-03 (work in draft-perkins-intarea-multicast-ieee802-03 (work in
progress), July 2017. progress), July 2017.
[I-D.petrescu-its-scenarios-reqs] [I-D.petrescu-its-scenarios-reqs]
Petrescu, A., Janneteau, C., Boc, M., and W. Klaudel, Petrescu, A., Janneteau, C., Boc, M., and W. Klaudel,
"Scenarios and Requirements for IP in Intelligent "Scenarios and Requirements for IP in Intelligent
Transportation Systems", draft-petrescu-its-scenarios- Transportation Systems", draft-petrescu-its-scenarios-
reqs-03 (work in progress), October 2013. reqs-03 (work in progress), October 2013.
[ieee1609.2] [IEEE-1609.2]
"IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access "IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access
in Vehicular Environments (WAVE) -- Security Services for in Vehicular Environments (WAVE) -- Security Services for
Applications and Management Messages. Example URL Applications and Management Messages. Example URL
http://ieeexplore.ieee.org/document/7426684/ accessed on http://ieeexplore.ieee.org/document/7426684/ accessed on
August 17th, 2017.". August 17th, 2017.".
[ieee1609.3] [IEEE-1609.3]
"IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access "IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access
in Vehicular Environments (WAVE) -- Networking Services. in Vehicular Environments (WAVE) -- Networking Services.
Example URL http://ieeexplore.ieee.org/document/7458115/ Example URL http://ieeexplore.ieee.org/document/7458115/
accessed on August 17th, 2017.". accessed on August 17th, 2017.".
[ieee1609.4] [IEEE-1609.4]
"IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access "IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access
in Vehicular Environments (WAVE) -- Multi-Channel in Vehicular Environments (WAVE) -- Multi-Channel
Operation. Example URL Operation. Example URL
http://ieeexplore.ieee.org/document/7435228/ accessed on http://ieeexplore.ieee.org/document/7435228/ accessed on
August 17th, 2017.". August 17th, 2017.".
[ieee802.11-2012] [IEEE-802.11-2012]
"802.11-2012 - IEEE Standard for Information technology-- "802.11-2012 - IEEE Standard for Information technology--
Telecommunications and information exchange between Telecommunications and information exchange between
systems Local and metropolitan area networks--Specific systems Local and metropolitan area networks--Specific
requirements Part 11: Wireless LAN Medium Access Control requirements Part 11: Wireless LAN Medium Access Control
(MAC) and Physical Layer (PHY) Specifications. Downloaded (MAC) and Physical Layer (PHY) Specifications. Downloaded
on October 17th, 2013, from IEEE Standards, document on October 17th, 2013, from IEEE Standards, document
freely available at URL freely available at URL
http://standards.ieee.org/findstds/ http://standards.ieee.org/findstds/
standard/802.11-2012.html retrieved on October 17th, standard/802.11-2012.html retrieved on October 17th,
2013.". 2013.".
[ieee802.11p-2010] [IEEE-802.11p-2010]
"IEEE Std 802.11p (TM)-2010, IEEE Standard for Information "IEEE Std 802.11p (TM)-2010, IEEE Standard for Information
Technology - Telecommunications and information exchange Technology - Telecommunications and information exchange
between systems - Local and metropolitan area networks - between systems - Local and metropolitan area networks -
Specific requirements, Part 11: Wireless LAN Medium Access Specific requirements, Part 11: Wireless LAN Medium Access
Control (MAC) and Physical Layer (PHY) Specifications, Control (MAC) and Physical Layer (PHY) Specifications,
Amendment 6: Wireless Access in Vehicular Environments; Amendment 6: Wireless Access in Vehicular Environments;
document freely available at URL document freely available at URL
http://standards.ieee.org/getieee802/ http://standards.ieee.org/getieee802/
download/802.11p-2010.pdf retrieved on September 20th, download/802.11p-2010.pdf retrieved on September 20th,
2013.". 2013.".
Appendix A. ChangeLog Appendix A. ChangeLog
The changes are listed in reverse chronological order, most recent The changes are listed in reverse chronological order, most recent
changes appearing at the top of the list. changes appearing at the top of the list.
From draft-ietf-ipwave-ipv6-over-80211ocb-04 to draft-ietf-ipwave-
ipv6-over-80211ocb-05
o Lengthened the title and cleanded the abstract.
o Added text suggesting LLs may be easy to use on OCB, rather than
GUAs based on received prefix.
o Added the risks of spoofing and hijacking.
o Removed the text speculation on adoption of the TSA message.
o Clarified that the ND protocol is used.
o Clarified what it means "No association needed".
o Added some text about how two STAs discover each other.
o Added mention of external (OCB) and internal network (stable), in
the subnet structure section.
o Added phrase explaining that both .11 Data and .11 QoS Data
headers are currently being used, and may be used in the future.
o Moved the packet capture example into an Appendix Implementation
Status.
o Suggested moving the reliability requirements appendix out into
another document.
o Added a IANA Consiserations section, with content, requesting for
a new multicast group "all OCB interfaces".
o Added new OBU term, improved the RSU term definition, removed the
ETTC term, replaced more occurences of 802.11p, 802.11 OCB with
802.11-OCB.
o References:
* Added an informational reference to ETSI's IPv6-over-
GeoNetworking.
* Added more references to IETF and ETSI security protocols.
* Updated some references from I-D to RFC, and from old RFC to
new RFC numbers.
* Added reference to multicast extensions to IPsec architecture
RFC.
* Added a reference to 2464-bis.
* Removed FCC informative references, because not used.
o Updated the affiliation of one author.
o Reformulation of some phrases for better readability, and
correction of typographical errors.
From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave- From draft-ietf-ipwave-ipv6-over-80211ocb-03 to draft-ietf-ipwave-
ipv6-over-80211ocb-04 ipv6-over-80211ocb-04
o Removed a few informative references pointing to Dx draft IEEE o Removed a few informative references pointing to Dx draft IEEE
1609 documents. 1609 documents.
o Removed outdated informative references to ETSI documents. o Removed outdated informative references to ETSI documents.
o Added citations to IEEE 1609.2, .3 and .4-2016. o Added citations to IEEE 1609.2, .3 and .4-2016.
skipping to change at page 30, line 16 skipping to change at page 28, line 39
be supported. The upper layer should be able to trigger such be supported. The upper layer should be able to trigger such
frames emission and to retrieve information contained in frames emission and to retrieve information contained in
received Timing Advertisements. received Timing Advertisements.
Appendix C. Design Considerations Appendix C. Design Considerations
The networks defined by 802.11-OCB are in many ways similar to other 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 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 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, other networks of the 802.11 family. However, the high mobility,
strong link asymetry and very short connection makes the 802.11-OCB strong link asymmetry and very short connection makes the 802.11-OCB
link significantly different from other 802.11 networks. Also, the link significantly different from other 802.11 networks. Also, the
automotive applications have specific requirements for reliability, automotive applications have specific requirements for reliability,
security and privacy, which further add to the particularity of the security and privacy, which further add to the particularity of the
802.11-OCB link. 802.11-OCB link.
C.1. Vehicle ID C.1. Vehicle ID
Automotive networks require the unique representation of each of In automotive networks it is required that each node is represented
their node. Accordingly, a vehicle must be identified by at least uniquely. Accordingly, a vehicle must be identified by at least one
one unique identifier. The current specification at ETSI and at IEEE unique identifier. The current specification at ETSI and at IEEE
1609 identifies a vehicle by its MAC address uniquely obtained from 1609 identifies a vehicle by its MAC address, which is obtained from
the 802.11-OCB NIC. the 802.11-OCB Network Interface Card (NIC).
A MAC address uniquely obtained from a IEEE 802.11-OCB NIC In case multiple 802.11-OCB NICs are present in one car, implicitely
implicitely generates multiple vehicle IDs in case of multiple multiple vehicle IDs will be generated. Additionally, some software
802.11-OCB NICs. A mechanims to uniquely identify a vehicle generates a random MAC address each time the computer boots; this
irrespectively to the different NICs and/or technologies is required. constitutes an additional difficulty.
A mechanim to uniquely identify a vehicle irrespectively to the
multiplicity of NICs, or frequent MAC address generation, is
necessary.
C.2. Reliability Requirements C.2. Reliability Requirements
This section may need to be moved out into a separate requirements
document.
The dynamically changing topology, short connectivity, mobile The dynamically changing topology, short connectivity, mobile
transmitter and receivers, different antenna heights, and many-to- transmitter and receivers, different antenna heights, and many-to-
many communication types, make IEEE 802.11-OCB links significantly many communication types, make IEEE 802.11-OCB links significantly
different from other IEEE 802.11 links. Any IPv6 mechanism operating different from other IEEE 802.11 links. Any IPv6 mechanism operating
on IEEE 802.11-OCB link MUST support strong link asymetry, spatio- on IEEE 802.11-OCB link MUST support strong link asymmetry, spatio-
temporal link quality, fast address resolution and transmission. temporal link quality, fast address resolution and transmission.
IEEE 802.11-OCB strongly differs from other 802.11 systems to operate 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 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 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 Basic Service Set management. In particular, IEEE 802.11-OCB SHALL
NOT use beacons. Any IPv6 mechanism requiring L2 services from IEEE NOT use beacons. Any IPv6 mechanism requiring L2 services from IEEE
802.11 beacons MUST support an alternative service. 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
skipping to change at page 31, line 18 skipping to change at page 29, line 46
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 implement an distributed mechanism to authenticate transmitters and
receivers without the support of a DHCP server. receivers without the support of a DHCP server.
Time synchronization not being available, IPv6 over IEEE 802.11-OCB 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 between transmitters and receivers without the support of a NTP
server. server.
The IEEE 802.11-OCB link being asymetic, IPv6 over IEEE 802.11-OCB 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. replies.
The IEEE 802.11-OCB link having a short duration time, IPv6 over IEEE The IEEE 802.11-OCB link having a short duration time, IPv6 over IEEE
802.11-OCB MUST implement fast IPv6 mobility management mechanisms. 802.11-OCB SHOULD implement fast IPv6 mobility management mechanisms.
C.3. Multiple interfaces C.3. Multiple interfaces
There are considerations for 2 or more IEEE 802.11-OCB interface There are considerations for 2 or more IEEE 802.11-OCB interface
cards per vehicle. For each vehicle taking part in road traffic, one 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 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 safety-critical communication. Any other IEEE 802.11-OCB may be used
for other type of traffic. for other type of traffic.
The mode of operation of these other wireless interfaces is not The mode of operation of these other wireless interfaces is not
skipping to change at page 31, line 46 skipping to change at page 30, line 26
of IPv6 addresses. Another possibility is to consider the set of of IPv6 addresses. Another possibility is to consider the set of
these wireless interfaces as a single network interface (not these wireless interfaces as a single network interface (not
including the IEEE 802.11-OCB interface used by Non IP safety including the IEEE 802.11-OCB interface used by Non IP safety
critical communications). This will require specific logic to critical communications). This will require specific logic to
ensure, for example, that packets meant for a vehicle in front are 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 actually sent by the radio in the front, or that multiple copies of
the same packet received by multiple interfaces are treated as a the same packet received by multiple interfaces are treated as a
single packet. Treating each wireless interface as a separate single packet. Treating each wireless interface as a separate
network interface pushes such issues to the application layer. network interface pushes such issues to the application layer.
The privacy requirements of [] imply that if these multiple Certain privacy requirements imply that if these multiple interfaces
interfaces are represented by many network interface, a single are represented by many network interface, a single renumbering event
renumbering event SHALL cause renumbering of all these interfaces. SHALL cause renumbering of all these interfaces. If one MAC changed
If one MAC changed and another stayed constant, external observers and another stayed constant, external observers would be able to
would be able to correlate old and new values, and the privacy correlate old and new values, and the privacy benefits of
benefits of randomization would be lost. randomization would be lost.
The privacy requirements of Non IP safety-critical communications The privacy requirements of Non IP safety-critical communications
imply that if a change of pseudonyme occurs, renumbering of all other imply that if a change of pseudonyme occurs, renumbering of all other
interfaces SHALL also occur. interfaces SHALL also occur.
C.4. MAC Address Generation C.4. MAC Address Generation
When designing the IPv6 over 802.11-OCB address mapping, we will When designing the IPv6 over 802.11-OCB address mapping, we will
assume that the MAC Addresses will change during well defined assume that the MAC Addresses will change during well defined
"renumbering events". The 48 bits randomized MAC addresses will have "renumbering events". The 48 bits randomized MAC addresses will have
skipping to change at page 32, line 44 skipping to change at page 31, line 23
o The STA may send management frames of subtype Action and, if the o The STA may send management frames of subtype Action and, if the
STA maintains a TSF Timer, subtype Timing Advertisement; STA maintains a TSF Timer, subtype Timing Advertisement;
o The STA may send control frames, except those of subtype PS-Poll, o The STA may send control frames, except those of subtype PS-Poll,
CF-End, and CF-End plus CFAck; CF-End, and CF-End plus CFAck;
o The STA may send data frames of subtype Data, Null, QoS Data, and o The STA may send data frames of subtype Data, Null, QoS Data, and
QoS Null. QoS Null.
Appendix E. Implementation Status
This section describese 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 | |
---| Router |--------------------------------| Host |
| | | |
+--------+ +-------+
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.
E.1. Capture in Monitor Mode
The IPv6 RA packet captured in monitor mode is illustrated below.
The radio tap header provides more flexibility for reporting the
characteristics of frames. The Radiotap Header is prepended by this
particular stack and operating system on the Host machine to the RA
packet received from the network (the Radiotap Header is not present
on the air). The implementation-dependent Radiotap Header is useful
for piggybacking PHY information from the chip's registers as data in
a packet understandable by userland applications using Socket
interfaces (the PHY interface can be, for example: power levels, data
rate, ratio of signal to noise).
The packet present on the air is formed by IEEE 802.11 Data Header,
Logical Link Control Header, IPv6 Base Header and ICMPv6 Header.
Radiotap Header v0
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Header Revision| Header Pad | Header length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Present flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Rate | Pad |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IEEE 802.11 Data Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type/Subtype and Frame Ctrl | Duration |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receiver Address...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Receiver Address | Transmitter Address...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Transmitter Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BSS Id...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... BSS Id | Frag Number and Seq Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Logical-Link Control Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DSAP |I| SSAP |C| Control field | Org. code...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Organizational Code | Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv6 Base Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Traffic Class | Flow Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Length | Next Header | Hop Limit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Source Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Destination Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Router Advertisement
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cur Hop Limit |M|O| Reserved | Router Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reachable Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Retrans Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Options ...
+-+-+-+-+-+-+-+-+-+-+-+-
The value of the Data Rate field in the Radiotap header is set to 6
Mb/s. This indicates the rate at which this RA was received.
The value of the Transmitter address in the IEEE 802.11 Data Header
is set to a 48bit value. The value of the destination address is
33:33:00:00:00:1 (all-nodes multicast address). The value of the BSS
Id field is ff:ff:ff:ff:ff:ff, which is recognized by the network
protocol analyzer as being "broadcast". The Fragment number and
sequence number fields are together set to 0x90C6.
The value of the Organization Code field in the Logical-Link Control
Header is set to 0x0, recognized as "Encapsulated Ethernet". The
value of the Type field is 0x86DD (hexadecimal 86DD, or otherwise
#86DD), recognized as "IPv6".
A Router Advertisement is periodically sent by the router to
multicast group address ff02::1. It is an icmp packet type 134. The
IPv6 Neighbor Discovery's Router Advertisement message contains an
8-bit field reserved for single-bit flags, as described in [RFC4861].
The IPv6 header contains the link local address of the router
(source) configured via EUI-64 algorithm, and destination address set
to ff02::1. Recent versions of network protocol analyzers (e.g.
Wireshark) provide additional informations for an IP address, if a
geolocalization database is present. In this example, the
geolocalization database is absent, and the "GeoIP" information is
set to unknown for both source and destination addresses (although
the IPv6 source and destination addresses are set to useful values).
This "GeoIP" can be a useful information to look up the city,
country, AS number, and other information for an IP address.
The Ethernet Type field in the logical-link control header is set to
0x86dd which indicates that the frame transports an IPv6 packet. In
the IEEE 802.11 data, the destination address is 33:33:00:00:00:01
which is the corresponding multicast MAC address. The BSS id is a
broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link
duration between vehicles and the roadside infrastructure, there is
no need in IEEE 802.11-OCB to wait for the completion of association
and authentication procedures before exchanging data. IEEE
802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s)
and may start communicating as soon as they arrive on the
communication channel.
E.2. Capture in Normal Mode
The same IPv6 Router Advertisement packet described above (monitor
mode) is captured on the Host, in the Normal mode, and depicted
below.
Ethernet II Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...Destination | Source...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv6 Base Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Traffic Class | Flow Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Length | Next Header | Hop Limit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Source Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Destination Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Router Advertisement
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cur Hop Limit |M|O| Reserved | Router Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reachable Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Retrans Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Options ...
+-+-+-+-+-+-+-+-+-+-+-+-
One notices that the Radiotap Header, the IEEE 802.11 Data Header and
the Logical-Link Control Headers are not present. On the other hand,
a new header named Ethernet II Header is present.
The Destination and Source addresses in the Ethernet II header
contain the same values as the fields Receiver Address and
Transmitter Address present in the IEEE 802.11 Data Header in the
"monitor" mode capture.
The value of the Type field in the Ethernet II header is 0x86DD
(recognized as "IPv6"); this value is the same value as the value of
the field Type in the Logical-Link Control Header in the "monitor"
mode capture.
The knowledgeable experimenter will no doubt notice the similarity of
this Ethernet II Header with a capture in normal mode on a pure
Ethernet cable interface.
An Adaptation layer is inserted on top of a pure IEEE 802.11 MAC
layer, in order to adapt packets, before delivering the payload data
to the applications. It adapts 802.11 LLC/MAC headers to Ethernet II
headers. In further detail, this adaptation consists in the
elimination of the Radiotap, 802.11 and LLC headers, and in the
insertion of the Ethernet II header. In this way, IPv6 runs straight
over LLC over the 802.11-OCB MAC layer; this is further confirmed by
the use of the unique Type 0x86DD.
Authors' Addresses Authors' Addresses
Alexandre Petrescu Alexandre Petrescu
CEA, LIST CEA, LIST
CEA Saclay CEA Saclay
Gif-sur-Yvette , Ile-de-France 91190 Gif-sur-Yvette , Ile-de-France 91190
France France
Phone: +33169089223 Phone: +33169089223
Email: Alexandre.Petrescu@cea.fr Email: Alexandre.Petrescu@cea.fr
Nabil Benamar Nabil Benamar
skipping to change at page 33, line 19 skipping to change at page 37, line 4
Phone: +33169089223 Phone: +33169089223
Email: Alexandre.Petrescu@cea.fr Email: Alexandre.Petrescu@cea.fr
Nabil Benamar Nabil Benamar
Moulay Ismail University Moulay Ismail University
Morocco Morocco
Phone: +212670832236 Phone: +212670832236
Email: benamar73@gmail.com Email: benamar73@gmail.com
Jerome Haerri Jerome Haerri
Eurecom Eurecom
Sophia-Antipolis 06904 Sophia-Antipolis 06904
France France
Phone: +33493008134 Phone: +33493008134
Email: Jerome.Haerri@eurecom.fr Email: Jerome.Haerri@eurecom.fr
Christian Huitema Christian Huitema
Private Octopus Inc.
Friday Harbor, WA 98250 Friday Harbor, WA 98250
U.S.A. U.S.A.
Email: huitema@huitema.net Email: huitema@huitema.net
Jong-Hyouk Lee Jong-Hyouk Lee
Sangmyung University Sangmyung University
31, Sangmyeongdae-gil, Dongnam-gu 31, Sangmyeongdae-gil, Dongnam-gu
Cheonan 31066 Cheonan 31066
Republic of Korea Republic of Korea
 End of changes. 108 change blocks. 
540 lines changed or deleted 707 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/