draft-ietf-ipwave-ipv6-over-80211ocb-01.txt   draft-ietf-ipwave-ipv6-over-80211ocb-02.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: August 24, 2017 Moulay Ismail University Expires: September 13, 2017 Moulay Ismail University
J. Haerri J. Haerri
Eurecom Eurecom
C. Huitema C. Huitema
J. Lee J. Lee
Sangmyung University Sangmyung University
T. Ernst T. Ernst
YoGoKo YoGoKo
T. Li T. Li
Peloton Technology Peloton Technology
February 20, 2017 March 12, 2017
Transmission of IPv6 Packets over IEEE 802.11 Networks in mode Outside Transmission of IPv6 Packets over IEEE 802.11 Networks in mode Outside
the Context of a Basic Service Set (IPv6-over-80211ocb) the Context of a Basic Service Set (IPv6-over-80211ocb)
draft-ietf-ipwave-ipv6-over-80211ocb-01.txt draft-ietf-ipwave-ipv6-over-80211ocb-02.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 recommended Maximum
Transmission Unit size, the header format preceding the IPv6 header, Transmission Unit size, the header format preceding the IPv6 header,
the Type value within it, and others. This document describes these the Type value within it, and others. This document describes these
parameters for IPv6 and IEEE 802.11 OCB networks; it portrays the parameters for IPv6 and IEEE 802.11 OCB networks; it portrays the
layering of IPv6 on 802.11 OCB similarly to other known 802.11 and layering of IPv6 on 802.11 OCB similarly to other known 802.11 and
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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 http://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 August 24, 2017. This Internet-Draft will expire on September 13, 2017.
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 (http://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
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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 . . . . . . . . . . . . . . . . . . . . . . . . . 5
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 . . . . . . . . 6
5. Layering of IPv6 over 802.11p as over Ethernet . . . . . . . 10 5. Layering of IPv6 over 802.11-OCB as over Ethernet . . . . . . 10
5.1. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 10 5.1. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . 10
5.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 10 5.2. Frame Format . . . . . . . . . . . . . . . . . . . . . . 10
5.2.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 11 5.2.1. Ethernet Adaptation Layer . . . . . . . . . . . . . . 11
5.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 13 5.3. Link-Local Addresses . . . . . . . . . . . . . . . . . . 13
5.4. Address Mapping . . . . . . . . . . . . . . . . . . . . . 13 5.4. Address Mapping . . . . . . . . . . . . . . . . . . . . . 13
5.4.1. Address Mapping -- Unicast . . . . . . . . . . . . . 13 5.4.1. Address Mapping -- Unicast . . . . . . . . . . . . . 13
5.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 13 5.4.2. Address Mapping -- Multicast . . . . . . . . . . . . 13
5.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 14 5.5. Stateless Autoconfiguration . . . . . . . . . . . . . . . 14
5.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 15 5.6. Subnet Structure . . . . . . . . . . . . . . . . . . . . 15
6. Example IPv6 Packet captured over a IEEE 802.11p link . . . . 15 6. Example IPv6 Packet captured over a IEEE 802.11-OCB link . . 15
6.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 15 6.1. Capture in Monitor Mode . . . . . . . . . . . . . . . . . 16
6.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 18 6.2. Capture in Normal Mode . . . . . . . . . . . . . . . . . 18
7. Security Considerations . . . . . . . . . . . . . . . . . . . 20 7. Security Considerations . . . . . . . . . . . . . . . . . . . 20
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 21 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 21
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 22
11.1. Normative References . . . . . . . . . . . . . . . . . . 22 11.1. Normative References . . . . . . . . . . . . . . . . . . 22
11.2. Informative References . . . . . . . . . . . . . . . . . 23 11.2. Informative References . . . . . . . . . . . . . . . . . 23
Appendix A. ChangeLog . . . . . . . . . . . . . . . . . . . . . 26 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 . . . 27 become a 802.11-OCB driver . . . 27
Appendix C. Design Considerations . . . . . . . . . . . . . . . 28 Appendix C. Design Considerations . . . . . . . . . . . . . . . 29
C.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 28 C.1. Vehicle ID . . . . . . . . . . . . . . . . . . . . . . . 29
C.2. Reliability Requirements . . . . . . . . . . . . . . . . 29 C.2. Reliability Requirements . . . . . . . . . . . . . . . . 29
C.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 29 C.3. Multiple interfaces . . . . . . . . . . . . . . . . . . . 30
C.4. MAC Address Generation . . . . . . . . . . . . . . . . . 30 C.4. MAC Address Generation . . . . . . . . . . . . . . . . . 31
Appendix D. IEEE 802.11 Messages Transmitted in OCB mode . . . . 31 Appendix D. IEEE 802.11 Messages Transmitted in OCB mode . . . . 31
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
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). This involves the
layering of IPv6 networking on top of the IEEE 802.11 MAC layer (with layering of IPv6 networking on top of the IEEE 802.11 MAC layer (with
an LLC layer). Compared to running IPv6 over the Ethernet MAC layer, an LLC layer). Compared to running IPv6 over the Ethernet MAC layer,
there is no modification required to the standards: IPv6 works fine there is no modification required to the standards: IPv6 works fine
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Std 802.11-2012. In this document the term 802.11p disappears. Std 802.11-2012. In this 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
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, it
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 In the following text we use the term "802.11p" to mean 802.11-2012
OCB, and vice-versa. OCB.
The IPv6 network layer operates on 802.11 OCB in the same manner as The IPv6 network layer operates on 802.11 OCB in the same manner as
it operates on 802.11 WiFi. The IPv6 network layer operates on WiFi it operates on 802.11 WiFi. The IPv6 network layer operates on WiFi
by involving an Ethernet Adaptation Layer; this Ethernet Adaptation by involving an Ethernet Adaptation Layer; this Ethernet Adaptation
Layer converts between 802.11 Headers and Ethernet II headers. The Layer converts between 802.11 Headers and Ethernet II headers. The
operation of IP on Ethernet is described in [RFC1042] and [RFC2464]. operation of IP on Ethernet is described in [RFC1042] and [RFC2464].
The situation of IPv6 networking layer on Ethernet Adaptation Layer The situation of IPv6 networking layer on Ethernet Adaptation Layer
is illustrated below: is illustrated below:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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+-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| | +-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| |
| | PLME | | | | PLME | |
| PHY Layer | PLME_SAP | | PHY Layer | PLME_SAP |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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). consideration of using the IP security layer).
There are currently no specifications for handover between OCB links
since these are currently specified as LLC-1 links (i.e.
connectionless). Any handovers must be performed above the Data Link
Layer. Also, while there is no encryption applied below the network
layer using 802.11p, 1609.2 does provide security services for
applications to use so that there can easily be data security over
the air without invoking IPsec.
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 (and the same differences expressed in terms of
requirements to software implementation are listed in Appendix B.) requirements to software 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: MTU, Frame Format, Interface Identifier, 802.11 OCB as over Ethernet: value of MTU, the contents of Frame
Address Mapping, State-less Address Auto-configuration. The values Format, the rules for forming Interface Identifiers, the mechanism
of these parameters are precisely the same as IPv6 over Ethernet for Address Mapping and for State-less Address Auto-configuration.
[RFC2464]: the recommended value of MTU to be 1500 octets, the Frame These are precisely the same as IPv6 over Ethernet [RFC2464].
Format containing the Type 0x86DD, the rules for forming an Interface
Identifier, the Address Mapping mechanism and the Stateless Address
Auto-Configuration.
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. Section 6.
A couple of points can be considered as different, although they are A couple of points can be considered as different, although they are
not required in order to have a working implementation of IPv6-over- not required in order to have a working implementation of IPv6-over-
802.11-OCB. These points are consequences of the OCB operation which 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, is particular to 802.11 OCB (Outside the Context of a BSS). First,
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RSU: Road Side Unit. An IP router equipped with, or connected to, at RSU: Road Side Unit. An IP router equipped with, or connected to, at
least one interface that is 802.11 and that is an interface that least one interface that is 802.11 and that is an interface that
operates in OCB mode. operates in OCB mode.
OCB: outside the context of a basic service set (BSS): A mode of 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: text in document IEEE 802.11-2012 that is flagged by 802.11-OCB, or 802.11 OCB: text in document IEEE 802.11-2012 that is
"dot11OCBActivated". This means: IEEE 802.11e for quality of flagged by "dot11OCBActivated". This means: IEEE 802.11e for quality
service; 802.11j-2004 for half-clocked operations; and 802.11p for of service; 802.11j-2004 for half-clocked operations; and (what was
operation in the 5.9 GHz band and in mode OCB. known earlier as) 802.11p for 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.
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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 messages such as the messages used in Stateless or
Stateful Address Auto-Configuration, or other IP messages. Other Stateful Address Auto-Configuration, or other IP messages. Other
802.11 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 -------->|
| | |<------ Data -------->| | | |<------ Data -------->|
|---- Probe Req. ----->| |<------ Data -------->| |---- Probe Req. ----->| |<------ Data -------->|
|<--- Probe Res. ------| |<------ Data -------->| |<--- Probe Res. ------| |<------ Data -------->|
| | |<------ Data -------->| | | |<------ Data -------->|
|---- Auth Req. ------>| |<------ Data -------->| |---- Auth Req. ------>| |<------ Data -------->|
|<--- Auth Res. -------| |<------ Data -------->| |<--- Auth Res. -------| |<------ Data -------->|
| | |<------ Data -------->| | | |<------ Data -------->|
|---- Asso Req. ------>| |<------ Data -------->| |---- Asso Req. ------>| |<------ Data -------->|
|<--- Asso Res. -------| |<------ Data -------->| |<--- Asso Res. -------| |<------ Data -------->|
| | |<------ Data -------->| | | |<------ Data -------->|
|------- Data -------->| |<------ Data -------->| |------- Data -------->| |<------ Data -------->|
|------- Data -------->| |<------ Data -------->| |------- Data -------->| |<------ Data -------->|
(a) Traditional IEEE 802.11 (b) IEEE 802.11 OCB mode (a) Traditional IEEE 802.11 (b) IEEE 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 the 802.11 specifications, [ieee802.11p-2010] as an amendment to the 802.11 specifications,
titled "Amendment 6: Wireless Access in Vehicular Environments". titled "Amendment 6: Wireless Access in Vehicular Environments".
Since then, these 802.11p amendments have been included in IEEE Since then, this amendment has been included in IEEE 802.11(TM)-2012
802.11(TM)-2012 [ieee802.11-2012], titled "IEEE Standard for [ieee802.11-2012], titled "IEEE Standard for Information technology--
Information technology--Telecommunications and information exchange Telecommunications and information exchange between systems Local and
between systems Local and metropolitan area networks--Specific metropolitan area networks--Specific requirements Part 11: Wireless
requirements Part 11: Wireless LAN Medium Access Control (MAC) and LAN Medium Access Control (MAC) and Physical Layer (PHY)
Physical Layer (PHY) Specifications"; the modifications are diffused Specifications"; the modifications are diffused throughout various
throughout various sections (e.g. 802.11p's Time Advertisement sections (e.g. the Time Advertisement message described in the
message is described in section 'Frame formats', and the operation earlier 802.11p ammendment is now described in section 'Frame
outside the context of a BSS described in section 'MLME'). formats', and the operation outside the context of a BSS 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 the 802.11p aspects introduced to 802.11. Note
in earlier 802.11p documents the term "OCBEnabled" was used instead. that in earlier 802.11p documents the term "OCBEnabled" was used
instead of te 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 [ieee802.11p-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
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analyze the differences between 802.11 OCB and 802.11 specifications. analyze the differences between 802.11 OCB and 802.11 specifications.
Whereas the 802.11p amendment specifies relatively complex and Whereas the 802.11p amendment specifies relatively complex and
numerous changes to the MAC layer (and very little to the PHY layer), numerous changes to the MAC layer (and very little to the PHY layer),
we note there are only a few characteristics which may be important we note there are only a few characteristics which may be important
for an implementation transmitting IPv6 packets on 802.11 OCB links. for an implementation transmitting IPv6 packets on 802.11 OCB links.
In the list below, the only 802.11 OCB fundamental points which In the list below, the only 802.11 OCB fundamental points which
influence IPv6 are the OCB operation and the 12Mbit/s maximum which influence IPv6 are the OCB operation and the 12Mbit/s maximum which
may be afforded by the IPv6 applications. may be afforded by the IPv6 applications.
o Operation Outside the Context of a BSS (OCB): the 802.11p links o Operation Outside the Context of a BSS (OCB): the (earlier
are operated without a Basic Service Set (BSS). This means that 802.11p) 802.11-OCB links are operated without a Basic Service Set
the messages Beacon, Association Request/Response, Authentication (BSS). This means that the messages Beacon, Association Request/
Request/Response, and similar, are not used. The used identifier Response, Authentication Request/Response, and similar, are not
of BSS (BSSID) has a hexadecimal value always ff:ff:ff:ff:ff:ff used. The used identifier of BSS (BSSID) has a hexadecimal value
(48 '1' bits, or the 'wildcard' BSSID), as opposed to an arbitrary always ff:ff:ff:ff:ff:ff (48 '1' bits, or the 'wildcard' BSSID),
BSSID value set by administrator (e.g. 'My-Home-AccessPoint'). as opposed to an arbitrary BSSID value set by administrator (e.g.
The OCB operation - namely the lack of beacon-based scanning and 'My-Home-AccessPoint'). The OCB operation - namely the lack of
lack of authentication - has a potentially strong impact on the beacon-based scanning and lack of authentication - has a
use of the Mobile IPv6 protocol and on the protocols for IP layer potentially strong impact on the use of the Mobile IPv6 protocol
security. and on the protocols for IP layer security.
o Timing Advertisement: is a new message defined in 802.11p, which o Timing Advertisement: is a new message defined in 802.11-OCB,
does not exist in 802.11a/b/g/n. This message is used by stations which does not exist in 802.11a/b/g/n. This message is used by
to inform other stations about the value of time. It is similar stations to inform other stations about the value of time. It is
to the time as delivered by a GNSS system (Galileo, GPS, ...) or similar to the time as delivered by a GNSS system (Galileo, GPS,
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. At the date of writing, an experienced reviewer
considers that currently no field testing has used this message. considers that currently no field testing has used this message.
Another implementor considers this feature implemented in an Another implementor considers this feature implemented in an
initial manner. In the future, it is speculated that this message initial manner. In the future, it is speculated that this message
may be useful for very simple devices which may not have their own may be useful for very simple devices which may not have their own
hardware source of time (Galileo, GPS, cellular network), or by hardware source of time (Galileo, GPS, cellular network), or by
vehicular devices situated in areas not covered by such network vehicular devices situated in areas not covered by such network
(in tunnels, underground, outdoors but shaded by foliage or (in tunnels, underground, outdoors but shaded by foliage or
buildings, in remote areas, etc.) 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 802.11p, the regulator specific frequency ranges. In the case of 802.11-OCB, the
associates a set of frequency ranges, or slots within a band, to regulator associates a set of frequency ranges, or slots within a
the use of applications of vehicular communications, in a band band, to the use of applications of vehicular communications, in a
known as "5.9GHz". This band is "5.9GHz" which is different from band known as "5.9GHz". This band is "5.9GHz" which is different
the bands "2.4GHz" or "5GHz" used by Wireless LAN. However, as from the bands "2.4GHz" or "5GHz" used by Wireless LAN. However,
with Wireless LAN, the operation of 802.11p in "5.9GHz" bands is as with Wireless LAN, the operation of 802.11-OCB in "5.9GHz"
exempt from owning a license in EU (in US the 5.9GHz is a licensed bands is exempt from owning a license in EU (in US the 5.9GHz is a
band of spectrum; for the the fixed infrastructure an explicit FCC licensed band of spectrum; for the the fixed infrastructure an
autorization is required; for an onboard device a 'licensed-by- explicit FCC autorization is required; for an onboard device a
rule' concept applies: rule certification conformity is required); 'licensed-by-rule' concept applies: rule certification conformity
however technical conditions are different than those of the bands is required); however technical conditions are different than
"2.4GHz" or "5GHz". On one hand, the allowed power levels, and those of the bands "2.4GHz" or "5GHz". On one hand, the allowed
implicitly the maximum allowed distance between vehicles, is of power levels, and implicitly the maximum allowed distance between
33dBm for 802.11p (in Europe), compared to 20 dBm for Wireless LAN vehicles, is of 33dBm for 802.11-OCB (in Europe), compared to 20
802.11a/b/g/n; this leads to a maximum distance of approximately dBm for Wireless LAN 802.11a/b/g/n; this leads to a maximum
1km, compared to approximately 50m. On the hand, specific distance of approximately 1km, compared to approximately 50m. On
conditions related to congestion avoidance, jamming avoidance, and the hand, specific conditions related to congestion avoidance,
radar detection are imposed on the use of DSRC (in US) and on the jamming avoidance, and radar detection are imposed on the use of
use of frequencies for Intelligent Transportation Systems (in EU), DSRC (in US) and on the use of frequencies for Intelligent
compared to Wireless LAN (802.11a/b/g/n). Transportation Systems (in EU), compared to Wireless LAN
(802.11a/b/g/n).
o Prohibition of IPv6 on some channels relevant for the PHY of IEEE o Prohibition of IPv6 on some channels relevant for the PHY of IEEE
802.11-OCB, as opposed to IPv6 not being prohibited on any channel 802.11-OCB, as opposed to IPv6 not being prohibited on any channel
on which 802.11a/b/g/n runs; at the time of writing, this on which 802.11a/b/g/n runs; at the time of writing, this
prohibition is explicit in IEEE 1609 documents. prohibition is explicit in IEEE 1609 documents.
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 802.11p links, there are strong o In vehicular communications using 802.11-OCB links, there are
privacy concerns with respect to addressing. While the 802.11p strong privacy concerns with respect to addressing. While the
standard does not specify anything in particular with respect to 802.11-OCB standard does not specify anything in particular with
MAC addresses, in these settings there exists a strong need for respect to MAC addresses, in these settings there exists a strong
dynamic change of these addresses (as opposed to the non-vehicular need for dynamic change of these addresses (as opposed to the non-
settings - real wall protection - where fixed MAC addresses do not vehicular settings - real wall protection - where fixed MAC
currently pose some privacy risks). This is further described in addresses do not currently pose some privacy risks). This is
section Section 7. A relevant function is described in IEEE further described in section Section 7. A relevant function is
1609.3, clause 5.5.1 and IEEE 1609.4, clause 6.7. described in IEEE 1609.3, clause 5.5.1 and IEEE 1609.4, clause
6.7.
Other aspects particular to 802.11p 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 802.11p networks. The the use of transmission of IPv6 packets on 802.11-OCB networks. The
subnet structure which may be assumed in 802.11p networks is strongly subnet structure which may be assumed in 802.11-OCB networks is
influenced by the mobility of vehicles. strongly influenced by the mobility of vehicles.
5. Layering of IPv6 over 802.11p 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 802.11p is 1500 octets. It is the The default MTU for IP packets on 802.11-OCB is 1500 octets. It is
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 [RFC2460], 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 then the IP stack will 1500 bytes are sent on an 802.11-OCB interface then the IP stack will
fragment. In case there are IP fragments, the field "Sequence 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
skipping to change at page 10, line 35 skipping to change at page 10, line 41
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 'geonet' packets have an MTU of 1492 bytes.
The Equivalent Transmit Time on Channel is a concept that may be used The Equivalent Transmit Time on Channel is a concept that may be used
as an alternative to the MTU concept. A rate of transmission may be 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 specified as well. The ETTC, rate and MTU may be in direct
relationship. relationship.
5.2. Frame Format 5.2. Frame Format
IP packets are transmitted over 802.11p as standard Ethernet packets. IP packets are transmitted over 802.11-OCB as standard Ethernet
As with all 802.11 frames, an Ethernet adaptation layer is used with packets. As with all 802.11 frames, an Ethernet adaptation layer is
802.11p as well. This Ethernet Adaptation Layer 802.11-to-Ethernet used with 802.11-OCB as well. This Ethernet Adaptation Layer
is described in Section 5.2.1. The Ethernet Type code (EtherType) performing 802.11-to-Ethernet is described in Section 5.2.1. The
for IPv6 is 0x86DD (hexadecimal 86DD, or otherwise #86DD). Ethernet Type code (EtherType) for IPv6 is 0x86DD (hexadecimal 86DD,
or otherwise #86DD).
The Frame format for transmitting IPv6 on 802.11p networks is the The Frame format for transmitting IPv6 on 802.11-OCB networks is the
same as transmitting IPv6 on Ethernet networks, and is described in same as transmitting IPv6 on Ethernet networks, and is described in
section 3 of [RFC2464]. The frame format for transmitting IPv6 section 3 of [RFC2464]. The frame format for transmitting IPv6
packets over Ethernet is illustrated below: packets over Ethernet is illustrated below:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination | | Destination |
+- -+ +- -+
| Ethernet | | Ethernet |
skipping to change at page 11, line 32 skipping to change at page 11, line 32
| IPv6 | | IPv6 |
+- -+ +- -+
| header | | header |
+- -+ +- -+
| and | | and |
+- -+ +- -+
/ payload ... / / payload ... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(Each tic mark represents one bit.) (Each tic mark represents one bit.)
Ethernet II Fields:
o Destination Ethernet Address: the MAC destination address.
o Source Ethernet Address: the MAC source address.
o "1 0 0 0 0 1 1 0 1 1 0 1 1 1 0 1": binary representation of the
EtherType value 0x86DD.
o IPv6 header and payload: the IPv6 packet containing IPv6 header
and payload.
5.2.1. Ethernet Adaptation Layer 5.2.1. Ethernet Adaptation Layer
In general, an 'adaptation' layer is inserted between a MAC layer and In general, an 'adaptation' layer is inserted between a MAC layer and
the Networking layer. This is used to transform some parameters the Networking layer. This is used to transform some parameters
between their form expected by the IP stack and the form provided by between their form expected by the IP stack and the form provided by
the MAC layer. For example, an 802.15.4 adaptation layer may perform the MAC layer. For example, an 802.15.4 adaptation layer may perform
fragmentation and reassembly operations on a MAC whose maximum Packet fragmentation and reassembly operations on a MAC whose maximum Packet
Data Unit size is smaller than the minimum MTU recognized by the IPv6 Data Unit size is smaller than the minimum MTU recognized by the IPv6
Networking layer. Other examples involve link-layer address Networking layer. Other examples involve link-layer address
transformation, packet header insertion/removal, and so on. transformation, packet header insertion/removal, and so on.
An Ethernet Adaptation Layer makes an 802.11 MAC look to IP An Ethernet Adaptation Layer makes an 802.11 MAC look to IP
Networking layer as a more traditional Ethernet layer. At reception, Networking layer as a more traditional Ethernet layer. At reception,
this layer takes as input the IEEE 802.11 Data Header and the this layer takes as input the IEEE 802.11 Data Header and the
Logical-Link Layer Control Header and produces an Ethernet II Header. Logical-Link Layer Control Header and produces an Ethernet II Header.
At sending, the reverse operation is performed. At sending, the reverse operation is performed.
+--------------------+-------------+-------------+---------+ +--------------------+-------------+-------------+---------+
| 802.11 Data Header | LLC Header | IPv6 Header | Payload | | 802.11 Data Header | LLC Header | IPv6 Header | Payload |
+--------------------+-------------+-------------+---------+ +--------------------+-------------+-------------+---------+
^ ^
| |
802.11-to-Ethernet Adaptation Layer 802.11-to-Ethernet Adaptation Layer
| |
v v
+---------------------+-------------+---------+ +---------------------+-------------+---------+
| Ethernet II Header | IPv6 Header | Payload | | Ethernet II Header | IPv6 Header | Payload |
+---------------------+-------------+---------+ +---------------------+-------------+---------+
The Receiver and Transmitter Address fields in the 802.11 Data Header The Receiver and Transmitter Address fields in the 802.11 Data Header
contain the same values as the Destination and the Source Address contain the same values as the Destination and the Source Address
fields in the Ethernet II Header, respectively. The value of the fields in the Ethernet II Header, respectively. The value of the
Type field in the LLC Header is the same as the value of the Type Type field in the LLC Header is the same as the value of the Type
field in the Ethernet II Header. field in the Ethernet II Header.
When the MTU value is smaller than the size of the IP packet to be The Ethernet Adaptation Layer performs operations in relation to IP
sent, the IP layer fragments the packet into multiple IP fragments. fragmentation and MTU. One of these operations is briefly described
During this operation, the "Sequence number" field of the 802.11 Data in section Section 5.1.
Header is increased.
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 following figure:
+--------------------+-------------+-------------+---------+ +--------------------+-------------+-------------+---------+
| 802.11 Data Header | LLC Header | IPv6 Header | Payload | | 802.11 Data Header | LLC Header | IPv6 Header | Payload |
+--------------------+-------------+-------------+---------+ +--------------------+-------------+-------------+---------+
or or
+--------------------+-------------+-------------+---------+ +--------------------+-------------+-------------+---------+
| 802.11 QoS Data Hdr| LLC Header | IPv6 Header | Payload | | 802.11 QoS Data Hdr| LLC Header | IPv6 Header | Payload |
+--------------------+-------------+-------------+---------+ +--------------------+-------------+-------------+---------+
The distinction between the two formats is given by the value of the The distinction between the two formats is given by the value of the
field "Type/Subtype". The value of the field "Type/Subtype" in the field "Type/Subtype". The value of the field "Type/Subtype" in the
802.11 Data header is 0x0020. The value of the field "Type/Subtype" 802.11 Data header is 0x0020. The value of the field "Type/Subtype"
in the 802.11 QoS header is 0x0028. in the 802.11 QoS header is 0x0028.
The mapping between qos-related fields in the IPv6 header (e.g. The mapping between qos-related fields in the IPv6 header (e.g.
"Traffic Class", "Flow label") and fields in the "802.11 QoS Data "Traffic Class", "Flow label") and fields in the "802.11 QoS Data
Header" (e.g. "QoS Control") are not specified in this document. Header" (e.g. "QoS Control") are not specified in this document.
Guidance for a potential mapping is provided in Guidance for a potential mapping is provided in
[I-D.ietf-tsvwg-ieee-802-11], although it is not specific to OCB [I-D.ietf-tsvwg-ieee-802-11], although it is not specific to OCB
mode. mode.
5.3. Link-Local Addresses 5.3. Link-Local Addresses
The link-local address of an 802.11p interface is formed in the same The link-local address of an 802.11-OCB interface is formed in the
manner as on an Ethernet interface. This manner is described in same manner as on an Ethernet interface. This manner is described in
section 5 of [RFC2464]. section 5 of [RFC2464].
5.4. Address Mapping 5.4. Address Mapping
For unicast as for multicast, there is no change from the unicast and For unicast as for multicast, there is no change from the unicast and
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-
layer addresses is described in
5.4.2. Address Mapping -- Multicast 5.4.2. Address Mapping -- Multicast
IPv6 protocols often make use of IPv6 multicast addresses in the IPv6 protocols often make use of IPv6 multicast addresses in the
destination field of IPv6 headers. For example, an ICMPv6 link- destination field of IPv6 headers. For example, an ICMPv6 link-
scoped Neighbor Advertisement is sent to the IPv6 address ff02::1 scoped Neighbor Advertisement is sent to the IPv6 address ff02::1
denoted "all-nodes" address. When transmitting these packets on denoted "all-nodes" address. When transmitting these packets on
802.11-OCB links it is necessary to map the IPv6 address to a MAC 802.11-OCB links it is necessary to map the IPv6 address to a MAC
address. address.
The same mapping requirement applies to the link-scoped multicast The same mapping requirement applies to the link-scoped multicast
skipping to change at page 14, line 5 skipping to change at page 14, line 17
"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 TBD of length 112bits may be requested from 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.
5.5. Stateless Autoconfiguration 5.5. Stateless Autoconfiguration
The Interface Identifier for an 802.11p interface is formed using the The Interface Identifier for an 802.11-OCB interface is formed using
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 802.11p interface are 'Universal' and 'Group' in the identifier of an 802.11-OCB interface
significant, as this is a IEEE link-layer address. The details of are significant, as this is an IEEE link-layer address. The details
this significance are described in [I-D.ietf-6man-ug]. of this significance are described in [I-D.ietf-6man-ug].
As with all Ethernet and 802.11 interface identifiers ([RFC7721]), As with all Ethernet and 802.11 interface identifiers ([RFC7721]),
the identifier of an 802.11p interface may involve privacy risks. A the identifier of an 802.11-OCB interface may involve privacy risks.
vehicle embarking an On-Board Unit whose egress interface is 802.11p A vehicle embarking an On-Board Unit whose egress interface is
may expose itself to eavesdropping and subsequent correlation of 802.11-OCB may expose itself to eavesdropping and subsequent
data; this may reveal data considered private by the vehicle owner. correlation of data; this may reveal data considered private by the
vehicle owner; there is a risk fo 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 [I-D.ietf-6man-default-iids].
5.6. Subnet Structure 5.6. Subnet Structure
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 802.11p link 6. Example IPv6 Packet captured over a IEEE 802.11-OCB link
We remind that a main goal of this document is to make the case that We remind that a main goal of this document is to make the case that
IPv6 works fine over 802.11p networks. Consequently, this section is IPv6 works fine over 802.11-OCB networks. Consequently, this section
an illustration of this concept and thus can help the implementer is an illustration of this concept and thus can help the implementer
when it comes to running IPv6 over IEEE 802.11p. By way of example when it comes to running IPv6 over IEEE 802.11-OCB. By way of
we show that there is no modification in the headers when transmitted example we show that there is no modification in the headers when
over 802.11p networks - they are transmitted like any other 802.11 transmitted over 802.11-OCB networks - they are transmitted like any
and Ethernet packets. other 802.11 and Ethernet packets.
We describe an experiment of capturing an IPv6 packet on an 802.11p We describe an experiment of capturing an IPv6 packet on an
link. In this experiment, the packet is an IPv6 Router 802.11-OCB link. In this experiment, the packet is an IPv6 Router
Advertisement. This packet is emitted by a Router on its 802.11p Advertisement. This packet is emitted by a Router on its 802.11-OCB
interface. The packet is captured on the Host, using a network interface. The packet is captured on the Host, using a network
protocol analyzer (e.g. Wireshark); the capture is performed in two protocol analyzer (e.g. Wireshark); the capture is performed in two
different modes: direct mode and 'monitor' mode. The topology used different modes: direct mode and 'monitor' mode. The topology used
during the capture is depicted below. during the capture is depicted below.
+--------+ +-------+ +--------+ +-------+
| | 802.11-OCB Link | | | | 802.11-OCB Link | |
---| Router |--------------------------------| Host | ---| Router |--------------------------------| Host |
| | | | | | | |
+--------+ +-------+ +--------+ +-------+
During several capture operations running from a few moments to During several capture operations running from a few moments to
several hours, no message relevant to the BSSID contexts were several hours, no message relevant to the BSSID contexts were
captured (no Association Request/Response, Authentication Req/Resp, captured (no Association Request/Response, Authentication Req/Resp,
Beacon). This shows that the operation of 802.11p is outside the Beacon). This shows that the operation of 802.11-OCB is outside the
context of a BSSID. context of a BSSID.
Overall, the captured message is identical with a capture of an IPv6 Overall, the captured message is identical with a capture of an IPv6
packet emitted on a 802.11b interface. The contents are precisely packet emitted on a 802.11b interface. The contents are precisely
similar. similar.
6.1. Capture in Monitor Mode 6.1. Capture in Monitor Mode
The IPv6 RA packet captured in monitor mode is illustrated below. The IPv6 RA packet captured in monitor mode is illustrated below.
The radio tap header provides more flexibility for reporting the The radio tap header provides more flexibility for reporting the
skipping to change at page 18, line 27 skipping to change at page 18, line 39
the IPv6 source and destination addresses are set to useful values). the IPv6 source and destination addresses are set to useful values).
This "GeoIP" can be a useful information to look up the city, This "GeoIP" can be a useful information to look up the city,
country, AS number, and other information for an IP address. country, AS number, and other information for an IP address.
The Ethernet Type field in the logical-link control header is set to The Ethernet Type field in the logical-link control header is set to
0x86dd which indicates that the frame transports an IPv6 packet. In 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 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 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 broadcast address of ff:ff:ff:ff:ff:ff. Due to the short link
duration between vehicles and the roadside infrastructure, there is duration between vehicles and the roadside infrastructure, there is
no need in IEEE 802.11p to wait for the completion of association and no need in IEEE 802.11-OCB to wait for the completion of association
authentication procedures before exchanging data. IEEE 802.11p and authentication procedures before exchanging data. IEEE
enabled nodes use the wildcard BSSID (a value of all 1s) and may 802.11-OCB enabled nodes use the wildcard BSSID (a value of all 1s)
start communicating as soon as they arrive on the communication and may start communicating as soon as they arrive on the
channel. communication channel.
6.2. Capture in Normal Mode 6.2. Capture in Normal Mode
The same IPv6 Router Advertisement packet described above (monitor The same IPv6 Router Advertisement packet described above (monitor
mode) is captured on the Host, in the Normal mode, and depicted mode) is captured on the Host, in the Normal mode, and depicted
below. below.
Ethernet II Header Ethernet II Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination... | Destination...
skipping to change at page 20, line 29 skipping to change at page 20, line 29
The knowledgeable experimenter will no doubt notice the similarity of The knowledgeable experimenter will no doubt notice the similarity of
this Ethernet II Header with a capture in normal mode on a pure this Ethernet II Header with a capture in normal mode on a pure
Ethernet cable interface. Ethernet cable interface.
It may be interpreted that an Adaptation layer is inserted in a pure 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 IEEE 802.11 MAC packets in the air, before delivering to the
applications. In detail, this adaptation layer may consist in applications. In detail, this adaptation layer may consist in
elimination of the Radiotap, 802.11 and LLC headers and insertion of 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 the Ethernet II header. In this way, it can be stated that IPv6 runs
naturally straight over LLC over the 802.11p MAC layer, as shown by naturally straight over LLC over the 802.11-OCB MAC layer, as shown
the use of the Type 0x86DD, and assuming an adaptation layer by the use of the Type 0x86DD, and assuming an adaptation layer
(adapting 802.11 LLC/MAC to Ethernet II header). (adapting 802.11 LLC/MAC to Ethernet II header).
7. Security Considerations 7. 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.
802.11p 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 way
less protected than commonly used links (wired link or protected less 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, At the IP layer, IPsec can be used to protect unicast communications,
and SeND can be used for multicast communications. If no protection and SeND can be used for multicast communications. If no protection
is used by the IP layer, upper layers should be protected. is used by the IP layer, upper layers should be protected.
Otherwise, the end-user or system should be warned about the risks Otherwise, the end-user or system should be warned about the risks
they run. they run.
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 802.11p interface identifiers. exist privacy risks in the use of 802.11-OCB interface identifiers.
However, 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
802.11p 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 8. IANA Considerations
9. Contributors 9. 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 (802.11p 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,
offering the ETSI ITS perspective, as well as other parts of the offeried the ETSI ITS perspective, and reviewed other parts of the
document. document.
10. Acknowledgements 10. 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, and William Hans-Joachim Fischer, Russ Housley, Rex Buddenberg, and William
skipping to change at page 22, line 33 skipping to change at page 22, line 33
[I-D.ietf-6man-ug] [I-D.ietf-6man-ug]
Carpenter, B. and S. Jiang, "Significance of IPv6 Carpenter, B. and S. Jiang, "Significance of IPv6
Interface Identifiers", draft-ietf-6man-ug-06 (work in Interface Identifiers", draft-ietf-6man-ug-06 (work in
progress), December 2013. progress), December 2013.
[I-D.ietf-tsvwg-ieee-802-11] [I-D.ietf-tsvwg-ieee-802-11]
Szigeti, T. and F. Baker, "DiffServ to IEEE 802.11 Szigeti, T. and F. Baker, "DiffServ to IEEE 802.11
Mapping", draft-ietf-tsvwg-ieee-802-11-01 (work in Mapping", draft-ietf-tsvwg-ieee-802-11-01 (work in
progress), November 2016. progress), November 2016.
[I-D.jeong-ipwave-vehicular-networking-survey]
Jeong, J., Cespedes, S., Benamar, N., and J. Haerri,
"Survey on IP-based Vehicular Networking for Intelligent
Transportation Systems", draft-jeong-ipwave-vehicular-
networking-survey-00 (work in progress), October 2016.
[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, DOI 10.17487/RFC1042, February 1988,
<http://www.rfc-editor.org/info/rfc1042>. <http://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, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
skipping to change at page 24, line 33 skipping to change at page 24, line 33
October 17th, 2013.". October 17th, 2013.".
[fcc-cc-172-184] [fcc-cc-172-184]
"'Memorandum Opinion and Order, Before the Federal "'Memorandum Opinion and Order, Before the Federal
Communications Commission Washington, D.C. 20554', FCC Communications Commission Washington, D.C. 20554', FCC
06-10, Released on July 26, 2006, document FCC- 06-10, Released on July 26, 2006, document FCC-
06-110A1.pdf, document freely available at URL 06-110A1.pdf, document freely available at URL
http://hraunfoss.fcc.gov/edocs_public/attachmatch/ http://hraunfoss.fcc.gov/edocs_public/attachmatch/
FCC-06-110A1.pdf downloaded on June 5th, 2014.". FCC-06-110A1.pdf downloaded on June 5th, 2014.".
[I-D.jeong-ipwave-vehicular-networking-survey]
Jeong, J., Cespedes, S., Benamar, N., and J. Haerri,
"Survey on IP-based Vehicular Networking for Intelligent
Transportation Systems", draft-jeong-ipwave-vehicular-
networking-survey-00 (work in progress), October 2016.
[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-ieee802-01 (work in draft-perkins-intarea-multicast-ieee802-01 (work in
progress), September 2016. progress), September 2016.
[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-
skipping to change at page 26, line 25 skipping to change at page 26, line 33
header and certificate formats; document freely available header and certificate formats; document freely available
at URL http://www.etsi.org/deliver/ at URL http://www.etsi.org/deliver/
etsi_ts/103000_103099/103097/01.01.01_60/ etsi_ts/103000_103099/103097/01.01.01_60/
ts_103097v010101p.pdf retrieved on July 08th, 2016.". ts_103097v010101p.pdf retrieved on July 08th, 2016.".
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-01 to draft-ietf-ipwave-
ipv6-over-80211ocb-02
o Replaced almost all occurences of 802.11p with 802.11-OCB, leaving
only when explanation of evolution was necessary.
o Shortened by removing parameter details from a paragraph in the
Introduction.
o Moved a reference from Normative to Informative.
o Added text in intro clarifying there is no handover spec at IEEE,
and that 1609.2 does provide security services.
o Named the contents the fields of the EthernetII header (including
the Ethertype bitstring).
o Improved relationship between two paragraphs describing the
increase of the Sequence Number in 802.11 header upon IP
fragmentation.
o Added brief clarification of "tracking".
From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave- From draft-ietf-ipwave-ipv6-over-80211ocb-00 to draft-ietf-ipwave-
ipv6-over-80211ocb-01 ipv6-over-80211ocb-01
o Introduced message exchange diagram illustrating differences o Introduced message exchange diagram illustrating differences
between 802.11 and 802.11 in OCB mode. between 802.11 and 802.11 in OCB mode.
o Introduced an appendix listing for information the set of 802.11 o Introduced an appendix listing for information the set of 802.11
messages that may be transmitted in OCB mode. messages that may be transmitted in OCB mode.
o Removed appendix sections "Privacy Requirements", "Authentication o Removed appendix sections "Privacy Requirements", "Authentication
skipping to change at page 27, line 19 skipping to change at page 27, line 50
o Moved references to scientific articles to a separate 'overview' o Moved references to scientific articles to a separate 'overview'
draft, and referred to it. draft, and referred to it.
Appendix B. Changes Needed on a software driver 802.11a to become a Appendix B. Changes Needed on a software driver 802.11a to become a
802.11-OCB driver 802.11-OCB driver
The 802.11p amendment modifies both the 802.11 stack's physical and The 802.11p amendment modifies both the 802.11 stack's physical and
MAC layers but all the induced modifications can be quite easily MAC layers but all the induced modifications can be quite easily
obtained by modifying an existing 802.11a ad-hoc stack. obtained by modifying an existing 802.11a ad-hoc stack.
Conditions for a 802.11a hardware to be 802.11p compliant: Conditions for a 802.11a hardware to be 802.11-OCB compliant:
o The chip must support the frequency bands on which the regulator o The chip must support the frequency bands on which the regulator
recommends the use of ITS communications, for example using IEEE recommends the use of ITS communications, for example using IEEE
802.11p layer, in France: 5875MHz to 5925MHz. 802.11-OCB layer, in France: 5875MHz to 5925MHz.
o The chip must support the half-rate mode (the internal clock o The chip must support the half-rate mode (the internal clock
should be able to be divided by two). should be able to be divided by two).
o The chip transmit spectrum mask must be compliant to the "Transmit o The chip transmit spectrum mask must be compliant to the "Transmit
spectrum mask" from the IEEE 802.11p amendment (but experimental spectrum mask" from the IEEE 802.11p amendment (but experimental
environments tolerate otherwise). environments tolerate otherwise).
o The chip should be able to transmit up to 44.8 dBm when used by o The chip should be able to transmit up to 44.8 dBm when used by
the US government in the United States, and up to 33 dBm in the US government in the United States, and up to 33 dBm in
 End of changes. 56 change blocks. 
184 lines changed or deleted 234 lines changed or added

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