I have just tried again: if I submit just the xml then the web page
complains in red about title and draft name. If I submit both the xml
and the txt then it accepts it.
The complain in red is this:
Could not extract a valid draft revision from the upload. To fix this
in a text upload, please make sure that the full draft name including
revision number appears centered on its own line below the document
title on the first page. In an xml upload, please make sure that the
top-level <rfc/> element has a docName attribute which provides the
full draft name including revision number.
This is the xml excerpt that may cause issue?:
<rfc category="std"
docName="draft-ietf-ipwave-ipv6-over-80211ocb-24.txt"
ipr="trust200902">
Attached the full xml file for what it's worth.
Alex
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE rfc SYSTEM "rfc2629.dtd" []>
<?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?>
<?rfc strict="yes" ?>
<?rfc toc="yes"?>
<?rfc tocdepth="4"?>
<?rfc symrefs="yes"?>
<?rfc sortrefs="yes" ?>
<?rfc compact="yes" ?>
<?rfc subcompact="no" ?>
<?rfc iprnotified="no" ?>
<rfc category="std"
docName="draft-ietf-ipwave-ipv6-over-80211ocb-24.txt"
ipr="trust200902">
<!-- category values: std, bcp, info, exp, and historic ipr values:
trust200902, noModificationTrust200902,
noDerivativesTrust200902, or pre5378Trust200902 you can add the
attributes updates="NNNN" and obsoletes="NNNN" they will
automatically be output with "(if approved)" -->
<front>
<title abbrev="IPv6-over-80211-OCB">
Transmission of IPv6 Packets over IEEE 802.11 Networks operating
in mode Outside the Context of a Basic Service Set
(IPv6-over-80211-OCB)
</title>
<author initials='A.' surname="Petrescu" fullname='Alexandre Petrescu'>
<organization>CEA, LIST</organization>
<address>
<postal>
<street>
CEA Saclay
</street>
<city>
Gif-sur-Yvette
</city>
<region>
Ile-de-France
</region>
<code>
91190
</code>
<country>
France
</country>
</postal>
<phone>
+33169089223
</phone>
<email>
Alexandre.Petrescu@xxxxxx
</email>
</address>
</author>
<author initials='N.' surname="Benamar" fullname='Nabil Benamar'>
<organization>Moulay Ismail University</organization>
<address>
<postal>
<street>
</street>
<city>
</city>
<region>
</region>
<code>
</code>
<country>
Morocco
</country>
</postal>
<phone>
+212670832236
</phone>
<email>
n.benamar@xxxxxxxxxxxxx
</email>
</address>
</author>
<!-- <author initials='T.' surname="Leinmueller" fullname='Tim Leinmueller'> -->
<!-- <organization>DENSO INTERNATIONAL EUROPE</organization> -->
<!-- <address> -->
<!-- <postal> -->
<!-- <street> -->
<!-- </street> -->
<!-- <city> -->
<!-- </city> -->
<!-- <region> -->
<!-- </region> -->
<!-- <code> -->
<!-- </code> -->
<!-- <country> -->
<!-- Deutschland -->
<!-- </country> -->
<!-- </postal> -->
<!-- <phone> -->
<!-- </phone> -->
<!-- <email> -->
<!-- t.leinmueller@xxxxxxxxxxxxx -->
<!-- </email> -->
<!-- </address> -->
<!-- </author> -->
<author initials="J." surname="Haerri" fullname="Jerome Haerri">
<organization>Eurecom</organization>
<address>
<postal>
<street>
</street>
<city> Sophia-Antipolis
</city>
<region>
</region>
<code> 06904
</code>
<country>
France
</country>
</postal>
<phone>
+33493008134
</phone>
<email>
Jerome.Haerri@xxxxxxxxxx
</email>
</address>
</author>
<!-- <author fullname="Christian Huitema" initials="C." surname="Huitema"> -->
<!-- <organization>Private Octopus Inc.</organization> -->
<!-- <address> -->
<!-- <postal> -->
<!-- <street> </street> -->
<!-- <city>Friday Harbor</city> -->
<!-- <code>98250</code> -->
<!-- <region>WA</region> -->
<!-- <country>U.S.A.</country> -->
<!-- </postal> -->
<!-- <email>huitema@xxxxxxxxxxx</email> -->
<!-- </address> -->
<!-- </author> -->
<!-- <author fullname="Christian Huitema" initials="C." surname="Huitema"> -->
<!-- <organization>Microsoft</organization> -->
<!-- <address> -->
<!-- <postal> -->
<!-- <street> </street> -->
<!-- <city>Redmond</city> -->
<!-- <code>98052</code> -->
<!-- <region>WA</region> -->
<!-- <country>U.S.A.</country> -->
<!-- </postal> -->
<!-- <email>huitema@xxxxxxxxxxxxx</email> -->
<!-- </address> -->
<!-- </author> -->
<author fullname="Jong-Hyouk Lee" initials="J.-H." surname="Lee">
<organization>
Sangmyung University
</organization>
<address>
<postal>
<street>
31, Sangmyeongdae-gil, Dongnam-gu
</street>
<code>
31066
</code>
<city>
Cheonan
</city>
<country>
Republic of Korea
</country>
</postal>
<email>
jonghyouk@xxxxxxxxx
</email>
</address>
</author>
<author initials="T." surname="Ernst" fullname="Thierry Ernst">
<organization>YoGoKo</organization>
<address>
<postal>
<street>
</street>
<city>
</city>
<region>
</region>
<code>
</code>
<country>
France
</country>
</postal>
<phone>
</phone>
<email>
thierry.ernst@xxxxxxxxx
</email>
</address>
</author>
<!-- <author initials="T." surname="Li" fullname="Tony Li"> -->
<!-- <organization>Peloton Technology</organization> -->
<!-- <address> -->
<!-- <postal> -->
<!-- <street> -->
<!-- 1060 La Avenida St. -->
<!-- </street> -->
<!-- <city>Mountain View</city> -->
<!-- <region> -->
<!-- California -->
<!-- </region> -->
<!-- <code> -->
<!-- 94043 -->
<!-- </code> -->
<!-- <country> -->
<!-- United States -->
<!-- </country> -->
<!-- </postal> -->
<!-- <phone> -->
<!-- +16503957356 -->
<!-- </phone> -->
<!-- <email> -->
<!-- tony.li@xxxxxxx -->
<!-- </email> -->
<!-- </address> -->
<!-- </author> -->
<date year='2018'/>
<!-- Meta-data Declarations -->
<area>Internet</area>
<workgroup>Network Working Group</workgroup>
<!-- WG name at the upperleft corner of the doc, IETF is fine for
individual submissions. If this element is not present, the
default is "Network Working Group", which is used by the RFC
Editor as a nod to the history of the IETF. -->
<keyword>
IPv6 over 802.11p, OCB, IPv6 over 802.11-OCB
</keyword>
<!-- Keywords will be incorporated into HTML output files in a
meta tag but they have no effect on text or nroff output. If
you submit your draft to the RFC Editor, the keywords will be
used for the search engine. -->
<abstract>
<t>
In order to transmit IPv6 packets on IEEE 802.11 networks
running outside the context of a basic service set (OCB,
earlier "802.11p") there is a need to define a few parameters
such as the supported Maximum Transmission Unit size on the
802.11-OCB link, the header format preceding the IPv6 header,
the Type value within it, and others. This document describes
these parameters for IPv6 and IEEE 802.11-OCB networks; it
portrays the layering of IPv6 on 802.11-OCB similarly to other
known 802.11 and Ethernet layers - by using an Ethernet
Adaptation Layer.
</t>
</abstract>
</front>
<middle>
<section title="Introduction">
<t>
This document describes the transmission of IPv6 packets on
IEEE Std 802.11-OCB networks <xref target="IEEE-802.11-2016"/>
(a.k.a "802.11p" see <xref target='i802.11p'/>). This
involves the layering of IPv6 networking on top of the IEEE
802.11 MAC layer, with an LLC layer. Compared to running IPv6
over the Ethernet MAC layer, there is no modification expected
to IEEE Std 802.11 MAC and Logical Link sublayers: IPv6 works
fine directly over 802.11-OCB too, with an LLC layer.
</t>
<t>
The IPv6 network layer operates on 802.11-OCB in the same
manner as operating on Ethernet, but there are two kinds of
exceptions:
</t>
<t>
<list style='symbols'>
<t>
Exceptions due to different operation of IPv6 network
layer on 802.11 than on Ethernet. To satisfy these
exceptions, this document describes an Ethernet Adaptation
Layer between Ethernet headers and 802.11 headers. The
Ethernet Adaptation Layer is described <xref
target='eal'/>. The operation of IP on Ethernet is
described in <xref target='RFC1042'/>, <xref
target='RFC2464'/> and <xref
target='I-D.hinden-6man-rfc2464bis'/>.
</t>
<t>
Exceptions due to the OCB nature of 802.11-OCB compared to
802.11. This has impacts on security, privacy, subnet
structure and handover behaviour. For security and
privacy recommendations see <xref target='Security'/> and
<xref target='slaac'/>. The subnet structure is described
in <xref target='subnet-structure'/>. The handover
behaviour on OCB links is not described in this document.
</t>
</list>
</t>
<t>
In the published literature, many documents describe aspects
and problems related to running IPv6 over 802.11-OCB: <xref
target='I-D.ietf-ipwave-vehicular-networking-survey'/>.
</t>
</section>
<section title="Terminology"
anchor='terminology'>
<t>
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in
<xref target="RFC2119">RFC 2119</xref>.
</t>
<t>
IP-OBU (Internet Protocol On-Board Unit): an IP-OBU is a
computer situated in a vehicle such as an automobile, bicycle,
or similar. It has at least one IP interface that runs in
mode OCB of 802.11, and that has an "OBU" transceiver. See
the definition of the term "OBU" in section <xref
target='extra-terminology'/>.
</t>
<t>
IP-RSU (IP Road-Side Unit): an IP-RSU is situated along the
road. An IP-RSU has at least two distinct IP-enabled
interfaces; at least one interface is operated in mode OCB of
IEEE 802.11 and is IP-enabled. An IP-RSU is similar to a
Wireless Termination Point (WTP), as defined in <xref
target='RFC5415'/>, or an Access Point (AP), as defined in
IEEE documents, or an Access Network Router (ANR) defined in
<xref target="RFC3753"/>, with one key particularity: the
wireless PHY/MAC layer of at least one of its IP-enabled
interfaces is configured to operate in 802.11-OCB mode. The
IP-RSU communicates with the IP-OBU in the vehicle over 802.11
wireless link operating in OCB mode.
</t>
<t>
OCB (outside the context of a basic service set - BSS): A mode
of operation in which a STA is not a member of a BSS and does
not utilize IEEE Std 802.11 authentication, association, or
data confidentiality.
</t>
<t>
802.11-OCB: mode specified in IEEE Std 802.11-2016 when the
MIB attribute dot11OCBActivited is true. Note: compliance
with standards and regulations set in different countries when
using the 5.9GHz frequency band is required.
</t>
</section>
<section
title="Communication Scenarios where IEEE 802.11-OCB Links are Used"
>
<t>
The IEEE 802.11-OCB Networks are used for vehicular
communications, as 'Wireless Access in Vehicular
Environments'. The IP communication scenarios for these
environments have been described in several documents; in
particular, we refer the reader to <xref
target='I-D.ietf-ipwave-vehicular-networking-survey'/>, that
lists some scenarios and requirements for IP in Intelligent
Transportation Systems.
</t>
<t>
The link model is the following: STA --- 802.11-OCB --- STA.
In vehicular networks, STAs can be IP-RSUs and/or IP-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.
</t>
<t>
The mechanisms for forming and terminating, discovering,
peering and mobility management for 802.11-OCB links are not
described in this document.
</t>
</section>
<section
title="IPv6 over 802.11-OCB">
<t>
</t>
<section title="Maximum Transmission Unit (MTU)"
anchor="MTU">
<t>
The default MTU for IP packets on 802.11-OCB MUST be 1500
octets. It is the same value as IPv6 packets on Ethernet
links, as specified in <xref target="RFC2464"/>. This value
of the MTU respects the recommendation that every link on
the Internet must have a minimum MTU of 1280 octets (stated
in <xref target="RFC8200"/>, and the recommendations
therein, especially with respect to fragmentation).
</t>
</section>
<section title="Frame Format">
<t>
IP packets MUST be transmitted over 802.11-OCB media as QoS
Data frames whose format is specified in IEEE Std 802.11.
</t>
<t>
The IPv6 packet transmitted on 802.11-OCB MUST be
immediately preceded by a Logical Link Control (LLC) header
and an 802.11 header. In the LLC header, and in accordance
with the EtherType Protocol Discrimination (EPD), the value
of the Type field MUST be set to 0x86DD (IPv6). In the
802.11 header, the value of the Subtype sub-field in the
Frame Control field MUST be set to 8 (i.e. 'QoS Data'); the
value of the Traffic Identifier (TID) sub-field of the QoS
Control field of the 802.11 header MUST be set to binary 001
(i.e. User Priority 'Background', QoS Access Category
'AC_BK').
</t>
<t>
To simplify the Application Programming Interface (API)
between the operating system and the 802.11-OCB media,
device drivers MAY implement an Ethernet Adaptation Layer
that translates Ethernet II frames to the 802.11 format and
vice versa. An Ethernet Adaptation Layer is described in
<xref target='eal'/>.
</t>
<!-- <t> -->
<!-- <list style='hanging'> -->
<!-- <t hangText="1 0 0 0 0 1 1 0 1 1 0 1 1 1 0 1"> -->
<!-- <vspace/> -->
<!-- is the binary representation of the EtherType value -->
<!-- 0x86DD. -->
<!-- </t> -->
<!-- </list> -->
<!-- </t> -->
<section title='Ethernet Adaptation Layer'
anchor='eal'>
<t>
An 'adaptation' layer is inserted between a MAC layer and
the Networking layer. This is used to transform some
parameters between their form expected by the IP stack and
the form provided by the MAC layer.
</t>
<t>
An Ethernet Adaptation Layer makes an 802.11 MAC look to
IP Networking layer as a more traditional Ethernet layer.
At reception, this layer takes as input the IEEE 802.11
header and the Logical-Link Layer Control Header and
produces an Ethernet II Header. At sending, the reverse
operation is performed.
</t>
<t>
The operation of the Ethernet Adaptation Layer is depicted
by the double arrow in <xref target='fig:eal'/>.
</t>
<t>
<figure anchor="fig:eal"
title='Operation of the Ethernet Adaptation Layer'
align="center">
<artwork align="center">
<![CDATA[
+------------------+------------+-------------+---------+-----------+
| 802.11 header | LLC Header | IPv6 Header | Payload |.11 Trailer|
+------------------+------------+-------------+---------+-----------+
\ / \ /
--------------------------- --------
\---------------------------------------------/
^
|
802.11-to-Ethernet Adaptation Layer
|
v
+---------------------+-------------+---------+
| Ethernet II Header | IPv6 Header | Payload |
+---------------------+-------------+---------+
]]>
</artwork>
</figure>
</t>
<t>
The Receiver and Transmitter Address fields in the 802.11
header MUST contain the same values as the Destination and
the Source Address fields in the Ethernet II Header,
respectively. The value of the Type field in the LLC
Header MUST be the same as the value of the Type field in
the Ethernet II Header. That value MUST be set to 0x86DD
(IPv6).
</t>
<t>
The ".11 Trailer" contains solely a 4-byte Frame Check
Sequence.
</t>
<t>
The placement of IPv6 networking layer on Ethernet
Adaptation Layer is illustrated in <xref
target='fig:eal-layer'/>.
</t>
<t>
<figure anchor='fig:eal-layer'
title='Ethernet Adaptation Layer
stacked with other layers'
align="center">
<artwork align="center">
<![CDATA[
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ethernet Adaptation Layer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 802.11 MAC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 802.11 PHY |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
]]>
</artwork>
</figure>
</t>
<t>
(in the above figure, a 802.11 profile is represented;
this is used also for 802.11-OCB profile.)
</t>
</section>
</section>
<section title='Link-Local Addresses'>
<t>
The link-local address of an 802.11-OCB interface is formed
in the same manner as on an Ethernet interface. This manner
is described in section 5 of <xref target='RFC2464'/>.
Additionally, if stable identifiers are needed, it is
RECOMMENDED to follow the Recommendation on Stable IPv6
Interface Identifiers <xref target="RFC8064"/>.
Additionally, if semantically opaque Interface Identifiers
are needed, a potential method for generating semantically
opaque Interface Identifiers with IPv6 Stateless Address
Autoconfiguration is given in <xref target="RFC7217"/>.
</t>
</section>
<section title='Address Mapping'>
<t>
Unicast and multicast address mapping MUST follow the
procedures specified for Ethernet interfaces in sections 6
and 7 of <xref target='RFC2464'/>.
</t>
<section title='Address Mapping -- Unicast'>
<t>
The procedure for mapping IPv6 unicast addresses into
Ethernet link-layer addresses is described in <xref
target="RFC4861"/>.
</t>
</section>
<section title="Address Mapping -- Multicast">
<t>
The multicast address mapping is performed according to
the method specified in section 7 of <xref
target='RFC2464'/>. The meaning of the value "3333"
mentioned in that section 7 of <xref target='RFC2464'/> is
defined in section 2.3.1 of <xref target='RFC7042'/>.
</t>
<t>
Transmitting IPv6 packets to multicast destinations over
802.11 links proved to have some performance issues <xref
target='I-D.perkins-intarea-multicast-ieee802'/>. These
issues may be exacerbated in OCB mode. Solutions for
these problems should consider the OCB mode of operation.
</t>
</section>
</section>
<section title='Stateless Autoconfiguration'
anchor='slaac'>
<t>
The Interface Identifier for an 802.11-OCB interface is
formed using the same rules as the Interface Identifier for
an Ethernet interface; this is described in section 4 of
<xref target='RFC2464'/>. No changes are needed, but some
care must be taken when considering the use of the Stateless
Address Auto-Configuration procedure.
</t>
<t>
The bits in the interface identifier have no generic
meaning and the identifier should be treated as an opaque
value. The bits 'Universal' and 'Group' in the identifier
of an 802.11-OCB interface are significant, as this is an
IEEE link-layer address. The details of this significance
are described in <xref target="RFC7136"/>.
</t>
<t>
As with all Ethernet and 802.11 interface identifiers (<xref
target='RFC7721'/>), the identifier of an 802.11-OCB
interface may involve privacy, MAC address spoofing and IP
address hijacking risks. A vehicle embarking an OBU or an
IP-OBU whose egress interface is 802.11-OCB may expose itself
to eavesdropping and subsequent correlation of data; this
may reveal data considered private by the vehicle owner;
there is a risk of being tracked; see the privacy
considerations described in <xref
target="design-considerations"/>.
</t>
<t>
If stable Interface Identifiers are needed in order to form
IPv6 addresses on 802.11-OCB links, it is recommended to
follow the recommendation in <xref target='RFC8064'/>.
Additionally, if semantically opaque Interface Identifiers
are needed, a potential method for generating semantically
opaque Interface Identifiers with IPv6 Stateless Address
Autoconfiguration is given in <xref target="RFC7217"/>.
</t>
</section>
<section title='Subnet Structure' anchor='subnet-structure'>
<t>
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.
</t>
<t>
The 802.11 networks in OCB mode may be considered as
'ad-hoc' networks. The addressing model for such networks
is described in <xref target='RFC5889'/>.
</t>
<t>
The operation of the Neighbor Discovery protocol (ND) over
802.11-OCB links is different than over 802.11 links. In
OCB, the link layer does not ensure that all associated
members receive all messages, because there is no
association operation. The operation of ND over 802.11-OCB
is not specified in this document.
</t>
<t>
The operation of the Mobile IPv6 protocol over 802.11-OCB
links is different than on other links. The Movement
Detection operation (section 11.5.1 of <xref
target='RFC6275'/>) can not rely on Neighbor Unreachability
Detection operation of the Neighbor Discovery protocol, for
the reason mentioned in the previous paragraph. Also, the
802.11-OCB link layer is not a lower layer that can provide
an indication that a link layer handover has occured. The
operation of the Mobile IPv6 protocol over 802.11-OCB is not
specified in this document.
</t>
</section>
</section>
<section anchor="Security" title="Security Considerations">
<t>
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 operating over 802.11-OCB.
</t>
<t>
The OCB operation is stripped off of 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 <xref
target="IEEE-1609.2"/> does provide security services for
certain applications to use; application-layer mechanisms are
out-of-scope of this document. On another hand, a security
mechanism provided at networking layer, such as IPsec <xref
target="RFC4301"/>, may provide data security protection to a
wider range of applications.
</t>
<t>
802.11-OCB does not provide any cryptographic protection,
because it operates outside the context of a BSS (no
Association Request/Response, no Challenge messages). Any
attacker can therefore just sit in the near range of vehicles,
sniff the network (just set the interface card's frequency to
the proper range) and perform attacks without needing to
physically break any wall. Such a link is less protected than
commonly used links (wired link or protected 802.11).
</t>
<t>
The potential attack vectors are: MAC address spoofing, IP
address and session hijacking and privacy violation.
</t>
<t>
Within the IPsec Security Architecture <xref
target="RFC4301"/>, the IPsec AH and ESP headers <xref
target="RFC4302"/> and <xref target="RFC4303"/> respectively,
its multicast extensions <xref target="RFC5374"/>, HTTPS <xref
target="RFC2818"/> and SeND <xref target="RFC3971"/> protocols
can be used to protect communications. Further, the
assistance of proper Public Key Infrastructure (PKI) protocols
<xref target="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 <xref target="ETSI-sec-archi"/>.
</t>
<t>
As with all Ethernet and 802.11 interface identifiers, there
may exist privacy risks in the use of 802.11-OCB interface
identifiers. Moreover, in outdoors vehicular settings, the
privacy risks are more important than in indoors settings.
New risks are induced by the possibility of attacker sniffers
deployed along routes which listen for IP packets of vehicles
passing by. For this reason, in the 802.11-OCB deployments,
there is a strong necessity to use protection tools such as
dynamically changing MAC addresses. This may help mitigate
privacy risks to a certain level. On another hand, it may
have an impact in the way typical IPv6 address
auto-configuration is performed for vehicles (SLAAC would rely
on MAC addresses and would hence dynamically change the
affected IP address), in the way the IPv6 Privacy addresses
were used, and other effects.
</t>
</section>
<section anchor="IANA" title="IANA Considerations">
<t>
No request to IANA.
</t>
</section>
<section anchor="Contributors"
title="Contributors">
<t>
Christian Huitema, Tony Li.
</t>
<t>
Romain Kuntz contributed extensively about IPv6 handovers
between links running outside the context of a BSS (802.11-OCB
links).
</t>
<t>
Tim Leinmueller contributed the idea of the use of IPv6 over
802.11-OCB for distribution of certificates.
</t>
<t>
Marios Makassikis, Jose Santa Lozano, Albin Severinson and
Alexey Voronov provided significant feedback on the experience
of using IP messages over 802.11-OCB in initial trials.
</t>
<t>
Michelle Wetterwald contributed extensively the MTU
discussion, offered the ETSI ITS perspective, and reviewed
other parts of the document.
</t>
</section>
<section anchor="Acknowledgements"
title="Acknowledgements">
<t>
The authors would like to thank Witold Klaudel, Ryuji
Wakikawa, Emmanuel Baccelli, John Kenney, John Moring,
Francois Simon, Dan Romascanu, Konstantin Khait, Ralph Droms,
Richard 'Dick' Roy, Ray Hunter, Tom Kurihara, Michal Sojka,
Jan de Jongh, Suresh Krishnan, Dino Farinacci, Vincent Park,
Jaehoon Paul Jeong, Gloria Gwynne, Hans-Joachim Fischer, Russ
Housley, Rex Buddenberg, Erik Nordmark, Bob Moskowitz, Andrew
Dryden, Georg Mayer, Dorothy Stanley, Sandra Cespedes, Mariano
Falcitelli, Sri Gundavelli, Abdussalam Baryun, Margaret
Cullen, Erik Kline, Carlos Jesus Bernardos Cano, Ronald in 't
Velt, Katrin Sjoberg, Roland Bless, Russ Housley, Tijink
Jasja, Kevin Smith and William Whyte. Their valuable comments
clarified particular issues and generally helped to improve
the document.
</t>
<t>
Pierre Pfister, Rostislav Lisovy, and others, wrote 802.11-OCB
drivers for linux and described how.
</t>
<t>
For the multicast discussion, the authors would like to thank
Owen DeLong, Joe Touch, Jen Linkova, Erik Kline, Brian
Haberman and participants to discussions in network working
groups.
</t>
<t>
The authors would like to thank participants to the
Birds-of-a-Feather "Intelligent Transportation Systems"
meetings held at IETF in 2016.
</t>
</section>
</middle>
<!-- *****BACK MATTER ***** -->
<back>
<references title="Normative References">
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.1042";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2119";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2464";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2818";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.3753";
?>
<!-- <?rfc -->
<!-- include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.3963"; -->
<!-- ?> -->
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.3971";
?>
<?rfc
include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.4086";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4210";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4301";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4302";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4303";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4861";
?>
<!-- <?rfc -->
<!-- include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4429"; -->
<!-- ?> -->
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5374";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5415";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5889";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6275";
?>
<!-- <?rfc -->
<!-- include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6775"; -->
<!-- ?> -->
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7042";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7136";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7217";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7721";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8064";
?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8200";
?>
</references>
<references title="Informative References">
<reference anchor="IEEE-802.11p-2010" >
<front>
<title>
IEEE Std 802.11p (TM)-2010, IEEE Standard for Information
Technology - Telecommunications and information exchange
between systems - Local and metropolitan area networks -
Specific requirements, Part 11: Wireless LAN Medium Access
Control (MAC) and Physical Layer (PHY) Specifications,
Amendment 6: Wireless Access in Vehicular Environments;
document freely available at URL
http://standards.ieee.org/getieee802/download/802.11p-2010.pdf
retrieved on September 20th, 2013.
</title>
<author/>
<date/>
</front>
</reference>
<reference anchor="IEEE-1609.2">
<front>
<title>
IEEE SA - 1609.2-2016 - IEEE Standard for Wireless Access
in Vehicular Environments (WAVE) -- Security Services for
Applications and Management Messages. Example URL
http://ieeexplore.ieee.org/document/7426684/ accessed on
August 17th, 2017.
</title>
<author/>
<date/>
</front>
</reference>
<reference anchor="IEEE-1609.3">
<front>
<title>
IEEE SA - 1609.3-2016 - IEEE Standard for Wireless Access
in Vehicular Environments (WAVE) -- Networking Services.
Example URL http://ieeexplore.ieee.org/document/7458115/
accessed on August 17th, 2017.
</title>
<author/>
<date/>
</front>
</reference>
<reference anchor="IEEE-1609.4">
<front>
<title>
IEEE SA - 1609.4-2016 - IEEE Standard for Wireless Access
in Vehicular Environments (WAVE) -- Multi-Channel
Operation. Example URL
http://ieeexplore.ieee.org/document/7435228/ accessed on
August 17th, 2017.
</title>
<author/>
<date/>
</front>
</reference>
<reference anchor="IEEE-802.11-2016" >
<front>
<title>
IEEE Standard 802.11-2016 - IEEE Standard for Information
Technology - Telecommunications and information exchange
between systems Local and metropolitan area networks -
Specific requirements - Part 11: Wireless LAN Medium
Access Control (MAC) and Physical Layer (PHY)
Specifications. Status - Active Standard. Description
retrieved freely on September 12th, 2017, at URL
https://standards.ieee.org/findstds/standard/802.11-2016.html
</title>
<author/>
<date/>
</front>
</reference>
<reference anchor="ETSI-sec-archi">
<front>
<title>
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. Downloaded on
September 9th, 2017, freely available from ETSI website at
URL
http://www.etsi.org/deliver/etsi_ts/102900_102999/102940/01.02.01_60/ts_102940v010201p.pdf
</title>
<author/>
<date/>
</front>
</reference>
<!-- <reference anchor="fcc-cc" > -->
<!-- <front> -->
<!-- <title> -->
<!-- 'Report and Order, Before the Federal Communications -->
<!-- Commission Washington, D.C. 20554', FCC 03-324, Released -->
<!-- on February 10, 2004, document FCC-03-324A1.pdf, -->
<!-- document freely available at URL -->
<!-- http://www.its.dot.gov/exit/fcc_edocs.htm downloaded on -->
<!-- October 17th, 2013. -->
<!-- </title> -->
<!-- <author/> -->
<!-- <date/> -->
<!-- </front> -->
<!-- </reference> -->
<!-- <reference anchor="fcc-cc-172-184" > -->
<!-- <front> -->
<!-- <title> -->
<!-- 'Memorandum Opinion and Order, Before the Federal -->
<!-- Communications Commission Washington, D.C. 20554', FCC -->
<!-- 06-10, Released on July 26, 2006, document -->
<!-- FCC-06-110A1.pdf, document freely available at URL -->
<!-- http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-06-110A1.pdf -->
<!-- downloaded on June 5th, 2014. -->
<!-- </title> -->
<!-- <author/> -->
<!-- <date/> -->
<!-- </front> -->
<!-- </reference> -->
<!-- <reference anchor="etsi-302663-v1.2.1p-2013" > -->
<!-- <front> -->
<!-- <title> -->
<!-- Intelligent Transport Systems (ITS); Access layer -->
<!-- specification for Intelligent Transport Systems -->
<!-- operating in the 5 GHz frequency band, 2013-07, document -->
<!-- en_302663v010201p.pdf, document freely available at URL -->
<!-- http://www.etsi.org/deliver/etsi_en/302600_302699/302663/ -->
<!-- 01.02.01_60/en_302663v010201p.pdf downloaded on October -->
<!-- 17th, 2013. -->
<!-- </title> -->
<!-- <author/> -->
<!-- <date/> -->
<!-- </front> -->
<!-- </reference> -->
<!-- <reference anchor="etsi-draft-102492-2-v1.1.1-2006" > -->
<!-- <front> -->
<!-- <title> -->
<!-- Electromagnetic compatibility and Radio spectrum Matters -->
<!-- (ERM); Intelligent Transport Systems (ITS); Part 2: -->
<!-- Technical characteristics for pan European harmonized -->
<!-- communications equipment operating in the 5 GHz -->
<!-- frequency range intended for road safety and traffic -->
<!-- management, and for non-safety related ITS applications; -->
<!-- System Reference Document, Draft ETSI TR 102 492-2 -->
<!-- V1.1.1, 2006-07, document tr_10249202v010101p.pdf freely -->
<!-- available at URL -->
<!-- http://www.etsi.org/deliver/etsi_tr/102400_102499/ -->
<!-- 10249202/01.01.01_60/tr_10249202v010101p.pdf downloaded -->
<!-- on October 18th, 2013. -->
<!-- </title> -->
<!-- <author/> -->
<!-- <date/> -->
<!-- </front> -->
<!-- </reference> -->
<!-- <reference anchor="TS103097" > -->
<!-- <front> -->
<!-- <title> -->
<!-- Intelligent Transport Systems (ITS); Security; Security -->
<!-- header and certificate formats; document freely -->
<!-- available at URL -->
<!-- http://www.etsi.org/deliver/etsi_ts/103000_103099/103097/01.01.01_60/ts_103097v010101p.pdf -->
<!-- retrieved on July 08th, 2016. -->
<!-- </title> -->
<!-- <author/> -->
<!-- <date/> -->
<!-- </front> -->
<!-- </reference> -->
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-ipwave-vehicular-networking-survey";
?>
<!-- <?rfc -->
<!-- include="http://xml2rfc.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-tsvwg-ieee-802-11"; -->
<!-- ?> -->
<?rfc include="http://xml2rfc.ietf.org/public/rfc/bibxml3/reference.I-D.hinden-6man-rfc2464bis"; ?>
<?rfc
include="http://xml2rfc.ietf.org/public/rfc/bibxml3/reference.I-D.perkins-intarea-multicast-ieee802";
?>
</references>
<section anchor='changelog'
title='ChangeLog'>
<t>
The changes are listed in reverse chronological order, most
recent changes appearing at the top of the list.
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-22 to
draft-ietf-ipwave-ipv6-over-80211ocb-23
<list style='symbols'>
<t>
No content modifications, but check the entire draft chain
on IPv6-only: xml2rfc, submission on tools.ietf.org and
datatracker.
</t>
<t>
Improved the Frame Format section: MUST use QoSData,
specify the values within; clarified the Ethernet
Adaptation Layer text.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-21 to
draft-ietf-ipwave-ipv6-over-80211ocb-22
<list style='symbols'>
<t>
Corrected typo, use dash in "802.11-OCB" instead of space.
</t>
<t>
Improved the Frame Format section: MUST use QoSData,
specify the values within; clarified the Ethernet
Adaptation Layer text.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-20 to
draft-ietf-ipwave-ipv6-over-80211ocb-21
<list style='symbols'>
<t>
Corrected a few nits and added names in Acknowledgments
section.
</t>
<t>
Removed unused reference to old Internet Draft tsvwg about
QoS.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-19 to
draft-ietf-ipwave-ipv6-over-80211ocb-20
<list style='symbols'>
<t>
Reduced the definition of term "802.11-OCB".
</t>
<t>
Left out of this specification which 802.11 header to use
to transmit IP packets in OCB mode (QoS Data header, Data
header, or any other).
</t>
<t>
Added 'MUST' use an Ethernet Adaptation Layer, instead of
'is using' an Ethernet Adaptation Layer.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-18 to
draft-ietf-ipwave-ipv6-over-80211ocb-19
<list style='symbols'>
<t>
Removed the text about fragmentation.
</t>
<t>
Removed the mentioning of WSMP and GeoNetworking.
</t>
<t>
Removed the explanation of the binary representation of
the EtherType.
</t>
<t>
Rendered normative the paragraph about unicast and
multicast address mapping.
</t>
<t>
Removed paragraph about addressing model, subnet structure
and easiness of using LLs.
</t>
<t>
Clarified the Type/Subtype field in the 802.11 Header.
</t>
<t>
Used RECOMMENDED instead of recommended, for the stable
interface identifiers.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-17 to
draft-ietf-ipwave-ipv6-over-80211ocb-18
<list style='symbols'>
<t>
Improved the MTU and fragmentation paragraph.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-16 to
draft-ietf-ipwave-ipv6-over-80211ocb-17
<list style='symbols'>
<t>
Susbtituted "MUST be increased" to "is increased" in the
MTU section, about fragmentation.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-15 to
draft-ietf-ipwave-ipv6-over-80211ocb-16
<list style='symbols'>
<t>
Removed the definition of the 'WiFi' term and its
occurences. Clarified a phrase that used it in Appendix C
"Aspects introduced by the OCB mode to 802.11".
</t>
<t>
Added more normative words: MUST be 0x86DD, MUST fragment
if size larger than MTU, Sequence number in 802.11 Data
header MUST be increased.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-14 to
draft-ietf-ipwave-ipv6-over-80211ocb-15
<list style='symbols'>
<t>
Added normative term MUST in two places in section
"Ethernet Adaptation Layer".
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-13 to
draft-ietf-ipwave-ipv6-over-80211ocb-14
<list style='symbols'>
<t>
Created a new Appendix titled "Extra Terminology" that
contains terms DSRC, DSRCS, OBU, RSU as defined outside
IETF. Some of them are used in the main Terminology
section.
</t>
<t>
Added two paragraphs explaining that ND and Mobile IPv6
have problems working over 802.11-OCB, yet their
adaptations is not specified in this document.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-12 to
draft-ietf-ipwave-ipv6-over-80211ocb-13
<list style='symbols'>
<t>
Substituted "IP-OBU" for "OBRU", and "IP-RSU" for "RSRU"
throughout and improved OBU-related definitions in the
Terminology section.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-11 to
draft-ietf-ipwave-ipv6-over-80211ocb-12
<list style='symbols'>
<t>
Improved the appendix about "MAC Address Generation" by
expressing the technique to be an optional suggestion, not
a mandatory mechanism.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-10 to
draft-ietf-ipwave-ipv6-over-80211ocb-11
<list style='symbols'>
<t>
Shortened the paragraph on forming/terminating 802.11-OCB
links.
</t>
<t>
Moved the draft tsvwg-ieee-802-11 to Informative
References.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-09 to
draft-ietf-ipwave-ipv6-over-80211ocb-10
<list style='symbols'>
<t>
Removed text requesting a new Group ID for multicast for
OCB.
</t>
<t>
Added a clarification of the meaning of value "3333" in
the section Address Mapping -- Multicast.
</t>
<t>
Added note clarifying that in Europe the regional
authority is not ETSI, but "ECC/CEPT based on ENs from
ETSI".
</t>
<t>
Added note stating that the manner in which two STAtions
set their communication channel is not described in this
document.
</t>
<t>
Added a time qualifier to state that the "each node is
represented uniquely at a certain point in time."
</t>
<t>
Removed text "This section may need to be moved" (the
"Reliability Requirements" section). This section stays
there at this time.
</t>
<t>
In the term definition "802.11-OCB" added a note stating
that "any implementation should comply with standards and
regulations set in the different countries for using that
frequency band."
</t>
<t>
In the RSU term definition, added a sentence explaining
the difference between RSU and RSRU: in terms of number of
interfaces and IP forwarding.
</t>
<t>
Replaced "with at least two IP interfaces" with "with at
least two real or virtual IP interfaces".
</t>
<t>
Added a term in the Terminology for "OBU". However the
definition is left empty, as this term is defined outside
IETF.
</t>
<t>
Added a clarification that it is an OBU or an OBRU in this
phrase "A vehicle embarking an OBU or an OBRU".
</t>
<t>
Checked the entire document for a consistent use of terms
OBU and OBRU.
</t>
<t>
Added note saying that "'p' is a letter identifying the
Ammendment".
</t>
<t>
Substituted lower case for capitals SHALL or MUST in the
Appendices.
</t>
<t>
Added reference to RFC7042, helpful in the 3333
explanation. Removed reference to individual submission
draft-petrescu-its-scenario-reqs and added reference to
draft-ietf-ipwave-vehicular-networking-survey.
</t>
<t>
Added figure captions, figure numbers, and references to
figure numbers instead of 'below'. Replaced "section
Section" with "section" throughout.
</t>
<t>
Minor typographical errors.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-08 to
draft-ietf-ipwave-ipv6-over-80211ocb-09
<list style='symbols'>
<t>
Significantly shortened the Address Mapping sections, by
text copied from RFC2464, and rather referring to it.
</t>
<t>
Moved the EPD description to an Appendix on its own.
</t>
<t>
Shortened the Introduction and the Abstract.
</t>
<t>
Moved the tutorial section of OCB mode introduced to .11,
into an appendix.
</t>
<t>
Removed the statement that suggests that for routing
purposes a prefix exchange mechanism could be needed.
</t>
<t>
Removed refs to RFC3963, RFC4429 and RFC6775; these are
about ND, MIP/NEMO and oDAD; they were referred in the
handover discussion section, which is out.
</t>
<t>
Updated a reference from individual submission to now a WG
item in IPWAVE: the survey document.
</t>
<t>
Added term definition for WiFi.
</t>
<t>
Updated the authorship and expanded the Contributors
section.
</t>
<t>
Corrected typographical errors.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-07 to
draft-ietf-ipwave-ipv6-over-80211ocb-08
<list style='symbols'>
<t>
Removed the per-channel IPv6 prohibition text.
</t>
<t>
Corrected typographical errors.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-06 to
draft-ietf-ipwave-ipv6-over-80211ocb-07
<list style='symbols'>
<t>
Added new terms: OBRU and RSRU ('R' for Router). Refined
the existing terms RSU and OBU, which are no longer used
throughout the document.
</t>
<t>
Improved definition of term "802.11-OCB".
</t>
<t>
Clarified that OCB does not "strip" security, but that the
operation in OCB mode is "stripped off of all .11
security".
</t>
<t>
Clarified that theoretical OCB bandwidth speed is 54mbits,
but that a commonly observed bandwidth in IP-over-OCB is
12mbit/s.
</t>
<t>
Corrected typographical errors, and improved some
phrasing.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-05 to
draft-ietf-ipwave-ipv6-over-80211ocb-06
<list style='symbols'>
<t>
Updated references of 802.11-OCB document from -2012 to
the IEEE 802.11-2016.
</t>
<t>
In the LL address section, and in SLAAC section, added
references to 7217 opaque IIDs and 8064 stable IIDs.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-04 to
draft-ietf-ipwave-ipv6-over-80211ocb-05
<list style='symbols'>
<t>
Lengthened the title and cleanded the abstract.
</t>
<t>
Added text suggesting LLs may be easy to use on OCB,
rather than GUAs based on received prefix.
</t>
<t>
Added the risks of spoofing and hijacking.
</t>
<t>
Removed the text speculation on adoption of the TSA
message.
</t>
<t>
Clarified that the ND protocol is used.
</t>
<t>
Clarified what it means "No association needed".
</t>
<t>
Added some text about how two STAs discover each other.
</t>
<t>
Added mention of external (OCB) and internal network
(stable), in the subnet structure section.
</t>
<t>
Added phrase explaining that both .11 Data and .11 QoS
Data headers are currently being used, and may be used in
the future.
</t>
<t>
Moved the packet capture example into an Appendix
Implementation Status.
</t>
<t>
Suggested moving the reliability requirements appendix out
into another document.
</t>
<t>
Added a IANA Consiserations section, with content,
requesting for a new multicast group "all OCB interfaces".
</t>
<t>
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.
</t>
<t>
References:
<list style='symbols'>
<t>
Added an informational reference to ETSI's
IPv6-over-GeoNetworking.
</t>
<t>
Added more references to IETF and ETSI security protocols.
</t>
<t>
Updated some references from I-D to RFC, and from old RFC
to new RFC numbers.
</t>
<t>
Added reference to multicast extensions to IPsec
architecture RFC.
</t>
<t>
Added a reference to 2464-bis.
</t>
<t>
Removed FCC informative references, because not used.
</t>
</list>
</t>
<t>
Updated the affiliation of one author.
</t>
<t>
Reformulation of some phrases for better readability, and
correction of typographical errors.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-03 to
draft-ietf-ipwave-ipv6-over-80211ocb-04
<list style='symbols'>
<t>
Removed a few informative references pointing to Dx draft
IEEE 1609 documents.
</t>
<t>
Removed outdated informative references to ETSI documents.
</t>
<t>
Added citations to IEEE 1609.2, .3 and .4-2016.
</t>
<t>
Minor textual issues.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-02 to
draft-ietf-ipwave-ipv6-over-80211ocb-03
<list style='symbols'>
<t>
Keep the previous text on multiple addresses, so remove
talk about MIP6, NEMOv6 and MCoA.
</t>
<t>
Clarified that a 'Beacon' is an IEEE 802.11 frame Beacon.
</t>
<t>
Clarified the figure showing Infrastructure mode and OCB
mode side by side.
</t>
<t>
Added a reference to the IP Security Architecture RFC.
</t>
<t>
Detailed the IPv6-per-channel prohibition paragraph which
reflects the discussion at the last IETF IPWAVE WG
meeting.
</t>
<t>
Added section "Address Mapping -- Unicast".
</t>
<t>
Added the ".11 Trailer" to pictures of 802.11 frames.
</t>
<t>
Added text about SNAP carrying the Ethertype.
</t>
<t>
New RSU definition allowing for it be both a Router and
not necessarily a Router some times.
</t>
<t>
Minor textual issues.
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-01 to
draft-ietf-ipwave-ipv6-over-80211ocb-02
<list style='symbols'>
<t>
Replaced almost all occurences of 802.11p with 802.11-OCB,
leaving only when explanation of evolution was necessary.
</t>
<t>
Shortened by removing parameter details from a paragraph
in the Introduction.
</t>
<t>
Moved a reference from Normative to Informative.
</t>
<t>
Added text in intro clarifying there is no handover spec
at IEEE, and that 1609.2 does provide security services.
</t>
<t>
Named the contents the fields of the EthernetII header
(including the Ethertype bitstring).
</t>
<t>
Improved relationship between two paragraphs describing
the increase of the Sequence Number in 802.11 header upon
IP fragmentation.
</t>
<t>
Added brief clarification of "tracking".
</t>
</list>
</t>
<t>
From draft-ietf-ipwave-ipv6-over-80211ocb-00 to
draft-ietf-ipwave-ipv6-over-80211ocb-01
<list style='symbols'>
<t>
Introduced message exchange diagram illustrating
differences between 802.11 and 802.11 in OCB mode.
</t>
<t>
Introduced an appendix listing for information the set of
802.11 messages that may be transmitted in OCB mode.
</t>
<t>
Removed appendix sections "Privacy Requirements",
"Authentication Requirements" and "Security Certificate
Generation".
</t>
<t>
Removed appendix section "Non IP Communications".
</t>
<t>
Introductory phrase in the Security Considerations
section.
</t>
<t>
Improved the definition of "OCB".
</t>
<t>
Introduced theoretical stacked layers about IPv6 and IEEE
layers including EPD.
</t>
<t>
Removed the appendix describing the details of prohibiting
IPv6 on certain channels relevant to 802.11-OCB.
</t>
<t>
Added a brief reference in the privacy text about a
precise clause in IEEE 1609.3 and .4.
</t>
<t>
Clarified the definition of a Road Side Unit.
</t>
<t>
Removed the discussion about security of WSA (because is
non-IP).
</t>
<t>
Removed mentioning of the GeoNetworking discussion.
</t>
<t>
Moved references to scientific articles to a separate
'overview' draft, and referred to it.
</t>
</list>
</t>
</section>
<section title= "802.11p" anchor='i802.11p'>
<t>
The term "802.11p" is an earlier definition. The behaviour of
"802.11p" networks is rolled in the document IEEE Std
802.11-2016. In that document the term 802.11p disappears.
Instead, each 802.11p feature is conditioned by the Management
Information Base (MIB) attribute "OCBActivated". Whenever
OCBActivated is set to true the IEEE Std 802.11-OCB state is
activated. For example, an 802.11 STAtion operating outside
the context of a basic service set has the OCBActivated flag
set. Such a station, when it has the flag set, uses a BSS
identifier equal to ff:ff:ff:ff:ff:ff.
</t>
</section>
<section title="Aspects introduced by the OCB mode to 802.11">
<t>
In the IEEE 802.11-OCB mode, all nodes in the wireless range
can directly communicate with each other without involving
authentication or association procedures. At link layer, it
is necessary to set the same channel number (or frequency) on
two stations that need to communicate with each other. The
manner in which stations set their channel number is not
specified in this document. Stations STA1 and STA2 can
exchange IP packets if they are set on the same channel. At
IP layer, they then discover each other by using the IPv6
Neighbor Discovery protocol.
</t>
<t>
Briefly, the IEEE 802.11-OCB mode has the following
properties:
<list style="symbols">
<t>
The use by each node of a 'wildcard' BSSID (i.e., each bit
of the BSSID is set to 1)
</t>
<t> No IEEE 802.11 Beacon frames are transmitted </t>
<t> No authentication is required in order to be able to communicate</t>
<t> No association is needed in order to be able to communicate</t>
<t> No encryption is provided in order to be able to communicate</t>
<t> Flag dot11OCBActivated is set to true </t>
</list>
All the nodes in the radio communication range (IP-OBU and IP-RSU)
receive all the messages transmitted (IP-OBU and IP-RSU) within the
radio communications range. The eventual conflict(s) are
resolved by the MAC CDMA function.
</t>
<t>
The message exchange diagram in <xref target='fig:mess-exch'/>
illustrates a comparison between traditional 802.11 and 802.11
in OCB mode. The 'Data' messages can be IP packets such as
HTTP or others. Other 802.11 management and control frames
(non IP) may be transmitted, as specified in the 802.11
standard. For information, the names of these messages as
currently specified by the 802.11 standard are listed in <xref
target="OCB-messages"/>.
</t>
<t>
<figure title='Difference between messages exchanged
on 802.11 (left) and 802.11-OCB (right)'
anchor='fig:mess-exch'
align="center">
<artwork align="center">
<![CDATA[
STA AP STA1 STA2
| | | |
|<------ Beacon -------| |<------ Data -------->|
| | | |
|---- Probe Req. ----->| |<------ Data -------->|
|<--- Probe Res. ------| | |
| | |<------ Data -------->|
|---- Auth Req. ------>| | |
|<--- Auth Res. -------| |<------ Data -------->|
| | | |
|---- Asso Req. ------>| |<------ Data -------->|
|<--- Asso Res. -------| | |
| | |<------ Data -------->|
|<------ Data -------->| | |
|<------ Data -------->| |<------ Data -------->|
(i) 802.11 Infrastructure mode (ii) 802.11-OCB mode
]]>
</artwork>
</figure>
</t>
<t>
The interface 802.11-OCB was specified in IEEE Std 802.11p
(TM) -2010 <xref target="IEEE-802.11p-2010"/> as an amendment
to IEEE Std 802.11 (TM) -2007, titled "Amendment 6: Wireless
Access in Vehicular Environments". Since then, this amendment
has been integrated in IEEE 802.11(TM) -2012 and -2016 <xref
target="IEEE-802.11-2016"/>.
</t>
<t>
In document 802.11-2016, anything qualified specifically as
"OCBActivated", or "outside the context of a basic service"
set to be true, then it is actually referring to OCB aspects
introduced to 802.11.
</t>
<t>
In order to delineate the aspects introduced by 802.11-OCB to
802.11, we refer to the earlier <xref
target="IEEE-802.11p-2010"/>. The amendment is concerned with
vehicular communications, where the wireless link is similar
to that of Wireless LAN (using a PHY layer specified by
802.11a/b/g/n), but which needs to cope with the high mobility
factor inherent in scenarios of communications between moving
vehicles, and between vehicles and fixed infrastructure
deployed along roads. While 'p' is a letter identifying the
Ammendment, just like 'a, b, g' and 'n' are, 'p' is concerned
more with MAC modifications, and a little with PHY
modifications; the others are mainly about PHY modifications.
It is possible in practice to combine a 'p' MAC with an 'a'
PHY by operating outside the context of a BSS with OFDM at
5.4GHz and 5.9GHz.
</t>
<t>
The 802.11-OCB links are specified to be compatible as much as
possible with the behaviour of 802.11a/b/g/n and future
generation IEEE WLAN links. From the IP perspective, an
802.11-OCB MAC layer offers practically the same interface to
IP as the 802.11a/b/g/n and 802.3. A packet sent by an IP-OBU
may be received by one or multiple IP-RSUs. The link-layer
resolution is performed by using the IPv6 Neighbor Discovery
protocol.
</t>
<t>
To support this similarity statement (IPv6 is layered on top
of LLC on top of 802.11-OCB, in the same way that IPv6 is
layered on top of LLC on top of 802.11a/b/g/n (for WLAN) or
layered on top of LLC on top of 802.3 (for Ethernet)) it is
useful to analyze the differences between 802.11-OCB and
802.11 specifications. During this analysis, we note that
whereas 802.11-OCB lists relatively complex and numerous
changes to the MAC layer (and very little to the PHY layer),
there are only a few characteristics which may be important
for an implementation transmitting IPv6 packets on 802.11-OCB
links.
</t>
<t>
The most important 802.11-OCB point which influences the IPv6
functioning is the OCB characteristic; an additional, less
direct influence, is the maximum bandwidth afforded by the PHY
modulation/demodulation methods and channel access specified
by 802.11-OCB. The maximum bandwidth theoretically possible
in 802.11-OCB is 54 Mbit/s (when using, for example, the
following parameters: 20 MHz channel; modulation 64-QAM;
coding rate R is 3/4); in practice of IP-over-802.11-OCB a
commonly observed figure is 12Mbit/s; this bandwidth allows
the operation of a wide range of protocols relying on IPv6.
</t>
<t>
<list style='symbols'>
<t>
Operation Outside the Context of a BSS (OCB): the (earlier
802.11p) 802.11-OCB links are operated without a Basic
Service Set (BSS). This means that the frames IEEE 802.11
Beacon, Association Request/Response, Authentication
Request/Response, and similar, are not used. The used
identifier of BSS (BSSID) has a hexadecimal value always
0xffffffffffff (48 '1' bits, represented as MAC address
ff:ff:ff:ff:ff:ff, or otherwise the 'wildcard' BSSID), as
opposed to an arbitrary BSSID value set by administrator
(e.g. 'My-Home-AccessPoint'). The OCB operation - namely
the lack of beacon-based scanning and lack of
authentication - should be taken into account when the
Mobile IPv6 protocol <xref target='RFC6275'/> and the
protocols for IP layer security <xref target='RFC4301'/>
are used. The way these protocols adapt to OCB is not
described in this document.
</t>
<t>
Timing Advertisement: is a new message defined in
802.11-OCB, which does not exist in 802.11a/b/g/n. This
message is used by stations to inform other stations about
the value of time. It is similar to the time as delivered
by a GNSS system (Galileo, GPS, ...) or by a cellular
system. This message is optional for implementation.
</t>
<t>
Frequency range: this is a characteristic of the PHY
layer, with almost no impact on the interface between MAC
and IP. However, it is worth considering that the
frequency range is regulated by a regional authority
(ARCEP, ECC/CEPT based on ENs from ETSI, FCC, etc.); as
part of the regulation process, specific applications are
associated with specific frequency ranges. In the case of
802.11-OCB, the regulator associates a set of frequency
ranges, or slots within a band, to the use of applications
of vehicular communications, in a band known as "5.9GHz".
The 5.9GHz band is different from the 2.4GHz and 5GHz
bands used by Wireless LAN. However, as with Wireless
LAN, the operation of 802.11-OCB in "5.9GHz" bands is
exempt from owning a license in EU (in US the 5.9GHz is a
licensed band of spectrum; for the fixed infrastructure an
explicit FCC authorization is required; for an on-board
device a 'licensed-by-rule' concept applies: rule
certification conformity is required.) Technical
conditions are different than those of the bands "2.4GHz"
or "5GHz". The allowed power levels, and implicitly the
maximum allowed distance between vehicles, is of 33dBm for
802.11-OCB (in Europe), compared to 20 dBm for Wireless
LAN 802.11a/b/g/n; this leads to a maximum distance of
approximately 1km, compared to approximately 50m.
Additionally, specific conditions related to congestion
avoidance, jamming avoidance, and radar detection are
imposed on the use of DSRC (in US) and on the use of
frequencies for Intelligent Transportation Systems (in
EU), compared to Wireless LAN (802.11a/b/g/n).
</t>
<t>
'Half-rate' encoding: as the frequency range, this
parameter is related to PHY, and thus has not much
impact on the interface between the IP layer and the
MAC layer.
</t>
<t>
In vehicular communications using 802.11-OCB links, there
are strong privacy requirements with respect to
addressing. While the 802.11-OCB standard does not
specify anything in particular with respect to MAC
addresses, in these settings there exists a strong need
for dynamic change of these addresses (as opposed to the
non-vehicular settings - real wall protection - where
fixed MAC addresses do not currently pose some privacy
risks). This is further described in <xref
target="Security"/>. A relevant function is described in
IEEE 1609.3-2016 <xref target="IEEE-1609.3"/>, clause
5.5.1 and IEEE 1609.4-2016 <xref target="IEEE-1609.4"/>,
clause 6.7.
</t>
</list>
Other aspects particular to 802.11-OCB, which are also
particular to 802.11 (e.g. the 'hidden node' operation), may
have an influence on the use of transmission of IPv6 packets
on 802.11-OCB networks. The OCB subnet structure is described
in <xref target="subnet-structure"/>.
</t>
</section>
<section title="Changes Needed on a software driver 802.11a to become a
802.11-OCB driver"
anchor="software-changes">
<t>
The 802.11p amendment modifies both the 802.11 stack's
physical and MAC layers but all the induced modifications
can be quite easily obtained by modifying an existing
802.11a ad-hoc stack.
</t>
<t>
Conditions for a 802.11a hardware to be 802.11-OCB compliant:
<list style='symbols'>
<t>
The PHY entity shall be an orthogonal frequency division
multiplexing (OFDM) system. It must support the frequency
bands on which the regulator recommends the use of ITS
communications, for example using IEEE 802.11-OCB layer,
in France: 5875MHz to 5925MHz.
</t>
<t>
The OFDM system must provide a "half-clocked" operation
using 10 MHz channel spacings.
</t>
<t>
The chip transmit spectrum mask must be compliant to the
"Transmit spectrum mask" from the IEEE 802.11p amendment
(but experimental environments tolerate otherwise).
</t>
<t>
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 Europe; other regional conditions apply.
</t>
</list>
</t>
<t>
Changes needed on the network stack in OCB mode:
<list style='symbols'>
<t>
Physical layer:
<list style='symbols'>
<t>
The chip must use the Orthogonal Frequency Multiple
Access (OFDM) encoding mode.
</t>
<t>
The chip must be set in half-mode rate mode (the
internal clock frequency is divided by two).
</t>
<t>
The chip must use dedicated channels and should allow
the use of higher emission powers. This may require
modifications to the local computer file that
describes regulatory domains rules, if used by the
kernel to enforce local specific restrictions. Such
modifications to the local computer file must respect
the location-specific regulatory rules.
</t>
</list>
MAC layer:
<list style='symbols'>
<t>
All management frames (beacons, join, leave, and
others) emission and reception must be disabled
except for frames of subtype Action and Timing
Advertisement (defined below).
</t>
<t>
No encryption key or method must be used.
</t>
<t>
Packet emission and reception must be performed as in
ad-hoc mode, using the wildcard BSSID
(ff:ff:ff:ff:ff:ff).
</t>
<t>
The functions related to joining a BSS (Association
Request/Response) and for authentication
(Authentication Request/Reply, Challenge) are not
called.
</t>
<t>
The beacon interval is always set to 0 (zero).
</t>
<t>
Timing Advertisement frames, defined in the
amendment, should be supported. The upper layer
should be able to trigger such frames emission and to
retrieve information contained in received Timing
Advertisements.
</t>
</list>
</t>
</list>
</t>
</section>
<section title='EtherType Protocol Discrimination (EPD)'
anchor='epd'>
<t>
A more theoretical and detailed view of layer stacking, and
interfaces between the IP layer and 802.11-OCB layers, is
illustrated in <xref target='fig:epd'/>. The IP layer
operates on top of the EtherType Protocol Discrimination
(EPD); this Discrimination layer is described in IEEE Std
802.3-2012; the interface between IPv6 and EPD is the LLC_SAP
(Link Layer Control Service Access Point).
</t>
<t>
<figure align="center"
title='EtherType Protocol Discrimination'
anchor='fig:epd'>
<artwork align="center">
<![CDATA[
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 |
+-+-+-+-+-+-{ }+-+-+-+-+-+-+-+
{ LLC_SAP } 802.11-OCB
+-+-+-+-+-+-{ }+-+-+-+-+-+-+-+ Boundary
| EPD | | |
| | MLME | |
+-+-+-{ MAC_SAP }+-+-+-| MLME_SAP |
| MAC Sublayer | | | 802.11-OCB
| and ch. coord. | | SME | Services
+-+-+-{ PHY_SAP }+-+-+-+-+-+-+-| |
| | PLME | |
| PHY Layer | PLME_SAP |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
]]>
</artwork>
</figure>
</t>
</section>
<section title="Design Considerations"
anchor="design-considerations">
<t>
The networks defined by 802.11-OCB are in many ways similar to
other networks of the 802.11 family. In theory, the
encapsulation of IPv6 over 802.11-OCB could be very similar to
the operation of IPv6 over other networks of the 802.11
family. However, the high mobility, strong link asymmetry and
very short connection makes the 802.11-OCB link significantly
different from other 802.11 networks. Also, the automotive
applications have specific requirements for reliability,
security and privacy, which further add to the particularity
of the 802.11-OCB link.
</t>
<section title="Vehicle ID" anchor="VID" >
<t>
In automotive networks it is required that each node is
represented uniquely at a certain point in time.
Accordingly, a vehicle must be identified by at least one
unique identifier. The current specification at ETSI and at
IEEE 1609 identifies a vehicle by its MAC address, which is
obtained from the 802.11-OCB Network Interface Card (NIC).
</t>
<t>
In case multiple 802.11-OCB NICs are present in one car,
implicitely multiple vehicle IDs will be generated.
Additionally, some software generates a random MAC address
each time the computer boots; this constitutes an additional
difficulty.
</t>
<t>
A mechanim to uniquely identify a vehicle irrespectively to
the multiplicity of NICs, or frequent MAC address
generation, is necessary.
</t>
</section>
<section title="Reliability Requirements" anchor="link" >
<t>
The dynamically changing topology, short connectivity,
mobile transmitter and receivers, different antenna heights,
and many-to-many communication types, make IEEE 802.11-OCB
links significantly different from other IEEE 802.11 links.
Any IPv6 mechanism operating on IEEE 802.11-OCB link must
support strong link asymmetry, spatio-temporal link quality,
fast address resolution and transmission.
</t>
<t>
IEEE 802.11-OCB strongly differs from other 802.11 systems
to operate outside of the context of a Basic Service Set.
This means in practice that IEEE 802.11-OCB does not rely on
a Base Station for all Basic Service Set management. In
particular, IEEE 802.11-OCB shall not use beacons. Any IPv6
mechanism requiring L2 services from IEEE 802.11 beacons
must support an alternative service.
</t>
<t>
Channel scanning being disabled, IPv6 over IEEE 802.11-OCB
must implement a mechanism for transmitter and receiver to
converge to a common channel.
</t>
<t>
Authentication not being possible, IPv6 over IEEE 802.11-OCB
must implement an distributed mechanism to authenticate
transmitters and receivers without the support of a DHCP
server.
</t>
<t>
Time synchronization not being available, IPv6 over IEEE
802.11-OCB must implement a higher layer mechanism for time
synchronization between transmitters and receivers without
the support of a NTP server.
</t>
<t>
The IEEE 802.11-OCB link being asymmetric, IPv6 over IEEE
802.11-OCB must disable management mechanisms requesting
acknowledgements or replies.
</t>
<t>
The IEEE 802.11-OCB link having a short duration time, IPv6
over IEEE 802.11-OCB should implement fast IPv6 mobility
management mechanisms.
</t>
</section>
<section title="Multiple interfaces" >
<t>
There are considerations for 2 or more IEEE 802.11-OCB
interface cards per vehicle. For each vehicle taking part in
road traffic, one IEEE 802.11-OCB interface card could be
fully allocated for Non IP safety-critical communication.
Any other IEEE 802.11-OCB may be used for other type of
traffic.
</t>
<t>
The mode of operation of these other wireless interfaces is
not clearly defined yet. One possibility is to consider each
card as an independent network interface, with a specific
MAC Address and a set of IPv6 addresses. Another
possibility is to consider the set of these wireless
interfaces as a single network interface (not including the
IEEE 802.11-OCB interface used by Non IP safety critical
communications). This will require specific logic to ensure,
for example, that packets meant for a vehicle in front are
actually sent by the radio in the front, or that multiple
copies of the same packet received by multiple interfaces
are treated as a single packet. Treating each wireless
interface as a separate network interface pushes such issues
to the application layer.
</t>
<t>
Certain privacy requirements imply that if these multiple
interfaces are represented by many network interface, a
single renumbering event shall cause renumbering of all
these interfaces. If one MAC changed and another stayed
constant, external observers would be able to correlate old
and new values, and the privacy benefits of randomization
would be lost.
</t>
<t>
The privacy requirements of Non IP safety-critical
communications imply that if a change of pseudonyme occurs,
renumbering of all other interfaces shall also occur.
</t>
</section>
<section title="MAC Address Generation" >
<t>
In 802.11-OCB networks, the MAC addresses may change during
well defined renumbering events. A 'randomized' MAC address
has the following characteristics:
</t>
<t>
<list style="symbols" >
<t>
Bit "Local/Global" set to "locally admninistered".
</t>
<t>
Bit "Unicast/Multicast" set to "Unicast".
</t>
<t>
The 46 remaining bits are set to a random value, using a
random number generator that meets the requirements of
<xref target="RFC4086" />.
</t>
</list>
</t>
<t>
To meet the randomization requirements for the 46 remaining
bits, a hash function may be used. For example, the SHA256
hash function may be used with input a 256 bit local secret,
the "nominal" MAC Address of the interface, and a
representation of the date and time of the renumbering
event.
</t>
</section>
</section>
<section title='IEEE 802.11 Messages Transmitted in OCB mode'
anchor="OCB-messages">
<t>
For information, at the time of writing, this is the list of
IEEE 802.11 messages that may be transmitted in OCB mode,
i.e. when dot11OCBActivated is true in a STA:
<list style='symbols'>
<t>
The STA may send management frames of subtype Action and,
if the STA maintains a TSF Timer, subtype Timing
Advertisement;
</t>
<t>
The STA may send control frames, except those of subtype
PS-Poll, CF-End, and CF-End plus CFAck;
</t>
<t>
The STA may send data frames of subtype Data, Null, QoS
Data, and QoS Null.
</t>
</list>
</t>
</section>
<section title='Implementation Status'
anchor="impl-status">
<t>
This section describes an example of an IPv6 Packet captured
over a IEEE 802.11-OCB link.
</t>
<t>
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.
</t>
<t>
We describe an experiment of capturing an IPv6 packet on an
802.11-OCB link. In topology depicted in <xref
target='topo'/>, 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.
</t>
<t>
The packet is captured on the Host. The Host is an IP-OBU
containing an 802.11 interface in format PCI express (an ITRI
product). The kernel runs the ath5k software driver with
modifications for OCB mode. The capture tool is Wireshark.
The file format for save and analyze is 'pcap'. The packet is
generated by the Router. The Router is an IP-RSU (ITRI
product).
</t>
<t>
<figure align="center"
title='Topology for capturing IP packets on 802.11-OCB'
anchor='topo'>
<artwork align="center">
<![CDATA[
+--------+ +-------+
| | 802.11-OCB Link | |
---| Router |--------------------------------| Host |
| | | |
+--------+ +-------+
]]>
</artwork>
</figure>
</t>
<t>
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.
</t>
<t>
Overall, the captured message is identical with a capture of
an IPv6 packet emitted on a 802.11b interface. The contents
are precisely similar.
</t>
<section title="Capture in Monitor Mode">
<t>
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).
</t>
<t>
The packet present on the air is formed by IEEE 802.11 Data
Header, Logical Link Control Header, IPv6 Base Header and
ICMPv6 Header.
</t>
<t>
<figure align="center">
<artwork align="center">
<![CDATA[
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 ...
+-+-+-+-+-+-+-+-+-+-+-+-
]]>
</artwork>
</figure>
</t>
<t>
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.
</t>
<t>
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.
</t>
<t>
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".
</t>
<t>
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 <xref target="RFC4861"/>.
</t>
<t>
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.
</t>
<t>
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.
</t>
</section>
<section title="Capture in Normal Mode">
<t>
The same IPv6 Router Advertisement packet described above
(monitor mode) is captured on the Host, in the Normal mode,
and depicted below.
</t>
<t>
<figure align="center">
<artwork align="center">
<![CDATA[
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 ...
+-+-+-+-+-+-+-+-+-+-+-+-
]]>
</artwork>
</figure>
</t>
<t>
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.
</t>
<t>
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.
</t>
<t>
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.
</t>
<t>
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.
</t>
<t>
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.
</t>
</section>
</section>
<section title='Extra Terminology'
anchor='extra-terminology'>
<t>
The following terms are defined outside the IETF. They are
used to define the main terms in the main terminology section
<xref target='terminology'/>.
</t>
<t>
DSRC (Dedicated Short Range Communication): a term defined
outside the IETF. The US Federal Communications Commission
(FCC) Dedicated Short Range Communication (DSRC) is defined in
the Code of Federal Regulations (CFR) 47, Parts 90 and 95.
This Code is referred in the definitions below. At the time
of the writing of this Internet Draft, the last update of this
Code was dated October 1st, 2010.
</t>
<t>
DSRCS (Dedicated Short-Range Communications Services): a term
defined outside the IETF. The use of radio techniques to
transfer data over short distances between roadside and mobile
units, between mobile units, and between portable and mobile
units to perform operations related to the improvement of
traffic flow, traffic safety, and other intelligent
transportation service applications in a variety of
environments. DSRCS systems may also transmit status and
instructional messages related to the units involve. [Ref. 47
CFR 90.7 - Definitions]
</t>
<t>
OBU (On-Board Unit): a term defined outside the IETF. An
On-Board Unit is a DSRCS transceiver that is normally mounted
in or on a vehicle, or which in some instances may be a
portable unit. An OBU can be operational while a vehicle or
person is either mobile or stationary. The OBUs receive and
contend for time to transmit on one or more radio frequency
(RF) channels. Except where specifically excluded, OBU
operation is permitted wherever vehicle operation or human
passage is permitted. The OBUs mounted in vehicles are
licensed by rule under part 95 of the respective chapter and
communicate with Roadside Units (RSUs) and other OBUs.
Portable OBUs are also licensed by rule under part 95 of the
respective chapter. OBU operations in the Unlicensed National
Information Infrastructure (UNII) Bands follow the rules in
those bands. - [CFR 90.7 - Definitions].
</t>
<t>
RSU (Road-Side Unit): a term defined outside of IETF. A
Roadside Unit is a DSRC transceiver that is mounted along a
road or pedestrian passageway. An RSU may also be mounted on
a vehicle or is hand carried, but it may only operate when the
vehicle or hand- carried unit is stationary. Furthermore, an
RSU operating under the respectgive part is restricted to the
location where it is licensed to operate. However, portable
or hand-held RSUs are permitted to operate where they do not
interfere with a site-licensed operation. A RSU broadcasts
data to OBUs or exchanges data with OBUs in its communications
zone. An RSU also provides channel assignments and operating
instructions to OBUs in its communications zone, when
required. - [CFR 90.7 - Definitions].
</t>
</section>
</back>
</rfc>
