Network Working Group S. Krishnan, Ed.
Internet-Draft Ericsson Research
Expires: April 9, 2007 N. Montavont
LSIIT - University Louis Pasteur
E. Njedjou
France Telecom
S. Veerepalli
Qualcomm
A. Yegin, Ed.
Samsung AIT
October 6, 2006
Link-layer Event Notifications for Detecting Network Attachments
draft-ietf-dna-link-information-04
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Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
Certain network access technologies are capable of providing various
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link-layer status information to IP. Link-layer event notifications
can help IP expeditiously detect configuration changes. This
document provides a non-exhaustive catalogue of information available
from well-known access technologies.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements notation . . . . . . . . . . . . . . . . . . 4
2. Link-Layer Event Notifications . . . . . . . . . . . . . . . . 5
2.1. GPRS/3GPP . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2. cdma2000/3GPP2 . . . . . . . . . . . . . . . . . . . . . . 8
2.3. IEEE 802.11/WiFi . . . . . . . . . . . . . . . . . . . . . 8
2.4. IEEE 802.3 CSMA/CD . . . . . . . . . . . . . . . . . . . . 10
2.4.1. Link Integrity Tests in 802.3 Networks . . . . . . . . 10
2.4.2. IEEE 802.1D Bridging and Its Effects on Link-layer
Event Notifications . . . . . . . . . . . . . . . . . 11
2.4.3. 802.1AB Link-Layer Discovery Protocol . . . . . . . . 13
2.4.4. Summary . . . . . . . . . . . . . . . . . . . . . . . 13
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
4. Security Considerations . . . . . . . . . . . . . . . . . . . 15
5. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 16
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.1. Normative References . . . . . . . . . . . . . . . . . . . 18
7.2. Informative References . . . . . . . . . . . . . . . . . . 19
Appendix A. Change History . . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22
Intellectual Property and Copyright Statements . . . . . . . . . . 24
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1. Introduction
It is not an uncommon occurrence for a node to change its point-of
attachment to the network. This can happen due to mobile usage
(e.g., a mobile phone moving among base stations) or nomadic usage
(e.g., road-warrior case).
A node changing its point-of attachment to the network may end up
changing its IP subnet and therefore require re-configuration of IP-
layer parameters, such as IP address, default gateway information,
and DNS server address. Detecting the subnet change can usually use
network-layer indications such as a change in the advertised prefixes
(i.e., appearance and disappearance of prefixes). But generally
reliance on such indications does not yield rapid detection, since
these indications are not readily available upon node changing its
point of attachment.
The changes to the underlying link-layer status can be relayed to IP
in the form of link-layer event notifications. Establishment and
tear down of a link-layer connection are two basic events types.
Additional information can be conveyed in addition to the event type,
such as the identifier of the network attachment point (e.g., IEEE
802.11 BSSID and SSID), or network-layer configuration parameters
obtained via the link-layer attachment process if available. It is
envisaged that such event notifications can in certain circumstances
be used to expedite the inter-subnet movement detection and
reconfiguration process. For example, the notification indicating
that the node has established a new link-layer connection MAY be used
for immediately probing the network for a possible configuration
change. In the absence of such a notification from the link-layer,
IP has to wait for indications that are not immediately available,
such as receipt of next scheduled router advertisement,
unreachability of the default gateway, etc.
It should be noted that a link-layer event notification does not
always translate into a subnet change. Even if the node has torn
down a link-layer connection with one attachment point and
established a new connection with another, it may still be attached
to the same IP subnet. For example, several IEEE 802.11 access
points can be attached to the same IP subnet. Moving among these
access points does not warrant any IP-layer configuration change.
In order to enable an enhanced scheme for detecting change of subnet,
we need to define link-layer event notifications that can be
realistically expected from various access technologies. The
objective of this draft is to provide a catalogue of link-layer
events and notifications in various architectures. While this
document mentions the utility of this information for detecting
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change of subnet (or, detecting network attachment - DNA), the
detailed usage is left to other documents, namely DNA solution
specifications.
The document limits itself to the minimum set of information that is
necessary for solving the DNA problem [RFC4135]. A broader set of
information (e.g., signal strength, packet loss, etc.) and events
(e.g. link down) may be used for other problem spaces, such as
anticipation-based Mobile IP fast handovers [I-D.ietf-mobileip-
lowlatency-handoffs-v4]
[I-D.ietf-mipshop-fast-mipv6]. Separate documents that are backward-
compatible with this one can be generated to discuss further
enhancements.
These event notifications are considered with hosts in mind, although
they may also be available on the network side (e.g., on the access
points and routers). An API or protocol-based standard interface may
be defined between the link-layer and IP for conveying this
information. That activity is beyond the scope of this document.
1.1. Requirements notation
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 [RFC2119].
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2. Link-Layer Event Notifications
Link-layer event notifications are considered to be one of the inputs
to the DNA process. A DNA process is likely to take other inputs
(e.g., presence of advertised prefixes, reachability of default
gateways) before determining whether IP-layer configuration must be
updated. It is expected that the DNA process can take advantage of
link-layer notifications when they are made available to IP. While
by itself a link-layer notification may not constitute all the input
DNA needs, it can at least be useful for prompting the DNA process to
collect further information (i.e., other inputs to the process). For
example, the node may send a router solicitation as soon as it learns
that a new link-layer connection is established.
The link-layer event that is considered most useful to DNA process is
the link up event. The link up event is deterministic, and the link
up notification is provided to IP-layer after the event successfully
concludes. The link up events and notifications are associated with
a network interface on the node. The IP module may receive
simultaneous independent notifications from each one of the network
interfaces on the node.
"Link" is a communication facility or medium over which network nodes
can communicate. Each link is associated with a minimum of two
endpoints. An "attachment point" is the link endpoint on the link to
which the node is currently connected, such as an access point, a
base station, or a wired switch.
"Link up" is an event provided by the link-layer that signifies a
state change associated with the interface becoming capable of
communicating data packets. This event is associated with a link-
layer connection between the node and an attachment point.
The actual event is managed by the link-layer of the node through
execution of link-layer protocols and mechanisms. Once the event
successfully completes within the link-layer, its notification MUST
be delivered to the IP-layer. By the time the notification is
delivered, the link-layer of the node MUST be ready to accept IP
packets from the IP and the physical-layers. Each time an interface
changes its point of attachment, a link up event SHOULD be generated.
There is a non-deterministic usage of link up notification to
accomodate implementations that desire to indicate the link is up but
the data transmission may be blocked in the network (see IEEE 802.3
discussion). A link up notification MAY be generated with an
appropriate attribute (e.g., "risk" indicated by R-flag) to convey
the event. Alternatively, the link-layer implementation MAY choose
to delay the link up notification until the risk conditions cease to
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exist.
If a link up with the R-flag set was generated, another link up MUST
follow up as soon as the link-layer is capable of generating a
deterministic notification. The event attributes MUST indicate
whether the packets transmitted since the previous notification were
presumed to be blocked (B-flag) or allowed (A-flag) by the network if
the link-layer could determine the exact conditions. If the link-
layer cannot make a determination about the faith of these packets,
it MUST generate a link up without any additional indications (no
flags set).
A node may have to change its IP-layer configuration even when the
link-layer connection stays the same. An example scenario is the
IPv6 subnet renumbering [RFC2461]. Therefore, there exist cases
where IP-layer configuration may have to change even without the IP-
layer receiving a link up notification. Therefore, a link-layer
notification is not a mandatory indication of a subnet change.
A link up notification may optionally deliver information relating to
the attachment point. Such auxiliary information may include
identity of the attachment point (e.g., base station identifier), or
the IP-layer configuration parameters associated with the attached
subnet (e.g., subnet prefix, default gateway address, etc.). While
merely knowing that a new link-layer connection is established may
prompt DNA process to immediately seek other clues for detecting
network configuration change, auxiliary information may constitute
further clues (and even the final answers sometimes). In cases where
there is a one-to-one mapping between the attachment point
identifiers and the IP-layer configurations, learning the former can
reveal the latter. Furthermore, IP-layer configuration parameters
obtained during link-layer connection may be exactly what the DNA
process is trying to discover (e.g., IP address configured during PPP
link establishment).
The link-layer process leading to a link up event depends on the link
technology. While a link-layer notification MUST always indicate
that the link up event occurred, the availability and types of
auxiliary information on the attachment point depends on the link-
layer technology as well. The following subsections examine four
link-layer technologies and describe when a link-layer notification
must be generated and what information must be included in it.
2.1. GPRS/3GPP
GPRS is an enhancement to the GSM data transmission architecture and
capabilities, designed to allow for packet switching in user data
transmission within the GPRS network as well as for higher quality of
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service for the IP traffic of Mobile Terminals with external Packets
Data Networks such as the Internet or corporate LANs [GPRS][GPRS-
LINK].
The GPRS architecture consists of a Radio Access Network and a packet
domain Core Network.
- The GPRS Radio Access Network is composed of Mobile Terminals (MT),
a Base Station Subsystem and Serving GPRS Support Nodes (SGSN).
- An IP Core Network that acts as the transport backbone of user
datagrams between SGSNs and Gateway GPRS Support Nodes (GGSN). The
GGSN ensures the GPRS IP core network connectivity with external
networks, such as Internet or Local Area Networks. GGSN acts as the
default IP gateway for the MT.
A GPRS MT that wants to establish IP-level connections MUST first
perform a GPRS attach to the SGSN. This MUST be followed by a
request to the GPRS network to settle the necessary soft state
mechanism (GPRS tunneling protocol) between its serving SGSN and the
GGSN. The soft state maintained between the MT, the SGSN and the
GGSN is called a PDP Context. It is used for guaranteeing a
negotiated quality of service for the IP flows exchanged between the
GPRS MT and an external Packet Data Network such as Internet. It is
only after the PDP Context has been established, address
autoconfiguration and tunneling mechanism have taken place that the
MT's IP packets can be forwarded to and from its remote IP peers.
The aim of PDP Context establishment is also to provide IP-level
configuration on top of the GPRS link-layer attachment.
Successful establishment of a PDP Context on a GPRS link signifies
the availability of IP service to the MT. Therefore, this link-layer
event MUST generate a link up event notification sent to IP-layer.
An MT has the possibility to establish a secondary PDP Context while
re-using the IP configuration acquired from a previously established
and active PDP Context. Establishment of a secondary PDP Context
does not provide additional information to IP-layer. Such a second
PDP Context would basically have a different QoS profile so that a
different type of application can be served. In that case,
activation of the secondary PDP Context MUST NOT generate another
link up event notification. However, a secondary PDP Context
establishment that triggers a new IP configuration is to be treated
from the IP layer as indicated above.
With IPv4, the auxiliary information carried along with this
notification MUST be the IPv4 address of the MT which is obtained as
part of the PDP Context. With IPv6, the PDP Context activation
response does not come along with a usable IPv6 address.
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Effectively, the IPv6 address received from the GGSN in the PDP
address field of the message does not contain a valid prefix. The MN
actually only uses the interface-identifier extracted from that field
to form a link-local address, that it uses afterwards to obtain a
valid prefix (e.g., by stateless [RFC2462][GPRS-CN] or stateful
[RFC3315] [GPRS-GSSA] address configuration). Therefore no IPv6-
related auxiliary information is provided to IP-layer.
2.2. cdma2000/3GPP2
cdma2000-based 3GPP2 packet data services provide mobile users wide
area high-speed access to packet switched networks [CDMA2K]. Some of
the major components of the 3GPP2 packet network architecture consist
of:
- Mobile Station (MS), which allows mobile access to packet-switched
networks over a wireless connection.
- Radio Access Network, which consists of the Base Station
Transceivers, Base Station Controllers, and the Packet Control
Function.
- Network Access Server known as the Packet Data Switching Node
(PDSN). The PDSN also serves as default IP gateway for the IP MS.
3GPP2 networks use the Point-to-Point Protocol (PPP [RFC1661]) as the
link-layer protocol between the MS and the PDSN. Before any IP
packets may be sent or received, PPP MUST reach the Network-Layer
Protocol phase, and the IP Control Protocol (IPCP [RFC1332], IPV6CP
[RFC2472]) reach the Opened state. When these states are reached in
PPP, a link up event notification MUST be delivered to the IP-layer.
When the PPP is used for 3GPP2 Simple (i.e., non-Mobile) IPv4
Service, IPCP enables configuration of IPv4 address on the MS. This
IPv4 address MUST be provided as the auxiliary information along with
the link up notification. IPV6CP used for Simple IPv6 service does
not provide an IPv6 address, but the interface-identifiers for local
and remote end-points of the PPP link. Since there is no standards-
mandated correlation between the interface-identifier and other IP-
layer configuration parameters, this information is deemed not useful
for DNA (nevertheless it MAY be provided as auxiliary information for
other uses).
2.3. IEEE 802.11/WiFi
IEEE 802.11-based WiFi networks are the wireless extension of the
Local Area Networks. Currently available standards are IEEE 802.11b
[IEEE-802.11b], IEEE 802.11g [IEEE-802.11g], and IEEE 802.11a [IEEE-
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802.11a]. The specifications define both the MAC-layer and the
physical-layer. The MAC layer is the same for all these
technologies.
Two operating modes are available in the IEEE 802.11 series, either
infrastructure mode or ad-hoc mode. In infrastructure mode, all
link-layer frames are transmitted to an access point (AP) which then
forwards them to the final receiver. A station (STA) MUST establish
a IEEE 802.11 link with an AP in order to send and receive IP
packets. In a WiFi network that supports Robust Secure Network (RSN
[IEEE-802.11i]), successful completion of 4-way handshake between the
STA and AP commences the availability of IP service. The link up
event notification MUST be generated upon this event. In non-RSN-
based networks, successful association or re-association events on
the link-layer MUST cause a link up notification sent to the IP-
layer.
As part of the link establishment, Basic Service Set Identification
(BSSID) and Service Set Identifier (SSID) associated with the AP is
learned by the STA. BSSID is a unique identifier of the AP, usually
set to the MAC address of the wireless interface of the AP. SSID
carries the identifier of the Extended Service Set (ESS) - the set
composed of APs and associated STAs that share a common distribution
system. BSSID and SSID MUST be provided as auxiliary information
along with the link up notification. Unfortunately this information
does not provide a deterministic indication of whether the IP-layer
configuration MUST be changed upon movement. There is no standards-
mandated one-to-one relation between the BSSID/SSID pairs and IP
subnets. An AP with a given BSSID can connect a STA to any one of
multiple IP subnets. Similarly, an ESS with the given SSID may span
multiple IP subnets. And finally, the SSIDs are not globally unique.
The same SSID may be used by multiple independent ESSs. See Appendix
A of [DNA4] for a detailed discussion. Nevertheless, BSSID/SSID
information may be used in a probabilistic way by the DNA process,
hence it is provided with the link up event notification.
In ad-hoc mode, mobile stations (STA) in range may directly
communicate with each other, i.e., without any infrastructure or
intermediate hop. The set of communicating STAs is called IBSS for
Independent Basic Service Set. In an IBSS, only STA services are
available, i.e. authentication, deauthentication, privacy and MSDU
delivery. STAs do not associate with each other, and therefore may
exchange data frames in state 2 (authenticated and not associated) or
even in state 1 (unauthenticated and unassociated) if the
Distribution System is not used (i.e., "To DS" and "From DS" bits are
clear). If authentication is performed, a link up indication can be
generated upon authentication. Concerning the link layer
identification, both the BSSID (which is a random MAC address chosen
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by a STA of the IBSS) and SSID may be used to identify a link, but
not to make any assumptions on the IP network configuration.
2.4. IEEE 802.3 CSMA/CD
IEEE 802.3 CSMA/CD (commonly referred to as Ethernet) is the most
commonly deployed Local Area Network technology in use today. As
deployed today, it is specified by a physical layer/medium access
control (MAC) layer specification [IEEE-802.3]. In order to provide
connection of different LANs together into a larger network, 802.3
LANs are often bridged together [IEEE-802.1D].
In this section, the terms 802.3 and Ethernet are used
interchangeably. This section describes some issues in providing
link-layer indications on Ethernet networks, and shows how bridging
affects these indications.
In Ethernet networks, hosts are connected by wires or by optic fibre
to a switch (bridge), a bus (e.g., co-axial cable), a repeater (hub),
or directly to another Ethernet device. Interfaces are symmetric, in
that while many different physical layers may be present, medium
access control is uniform for all devices.
In order to determine whether the physical medium is ready for frame
transfer, IEEE 802.3 Ethernet specifies its own link monitoring
mechanism, which is defined for some, but not all classes of media.
Where available, this Link Integrity Test operation is used to
identify when packets are able to be received on an Ethernet segment.
It is applicable to both wired and optical physical layers, although
details vary between technologies (link pulses in twisted pair
copper, light levels in fibre).
2.4.1. Link Integrity Tests in 802.3 Networks
Link Integrity Tests in 802.3 networks typically occur at initial
physical connection time (for example, at the auto-negotiation
stage), and periodically afterwards. It makes use of physical-layer
specific operations to determine if a medium is able to support link-
layer frames [IEEE-802.3].
The status of the link as determined by the Link Integrity Test is
stored in the variable 'link_status'. Changes to the value of
link_status (for example due to Link Integrity Test failure) will
generate link indications if the technology dependent interface is
implemented on an Ethernet device [IEEE-802.3].
The link_status has possible values of FAIL, READY and OK. When an
interface is in FAIL state, Link Integrity Tests have failed. Where
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status is READY, the link segment has passed integrity tests, but
autonegotiation has not completed. OK state indicates that the
medium is able to send and receive packets.
Upon transition to a particular state the Physical Medium Attachment
subsystems generates a PMA_LINK.indicate(link_status). Indications
of OK state MAY be used to generate a link up event notification.
This indication do not definitively ensure that packets will be able
to be received through the bridge domain, though [see the next
section]. Such operations are governed by bridging.
2.4.2. IEEE 802.1D Bridging and Its Effects on Link-layer Event
Notifications
Ethernet networks commonly consist of LANs joined together by
transparent bridges (usually implemented as switches). Transparent
bridges require the active topology to be loop free. The Spanning
Tree Protocol (STP) achieves this by the exchange of Bridge Protocol
Data Unit (BPDU), as defined in [IEEE-802.1D], which leads to, where
required, the blocking of ports (i.e., not forwarding).
By default, the spanning tree protocol does not know whether a
particular newly connected piece of Ethernet will cause a loop.
Therefore it will block all traffic from and to newly connected ports
with the exception of some unbridged management frames. The STP will
determine if the port can be connected to the network in a loop-free
manner.
For these technologies, even though the link-layer appears available,
no data packet forwarding will occur until it is determined that the
port can be connected to the network in a loop-free environment.
For hosts which are providing indications to upper layer protocols,
even if the host itself does not implement bridging or STP, packet
delivery across the network can be affected by the presence of
bridges.
Where the host is not running STP itself, no explicit indication that
forwarding has begun is sent from a bridge. Therefore, a host may
not know when STP operations have completed, and when it is safe to
inform upper layers to transmit packets.
Where it is not known that forwarding operations are available, a
host needs to assume that STP is being performed, and may indicate
full connectivity only based on timeouts or reception of BPDUs.
Most hosts today do not listen to BPDU frames. For these hosts,
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connectivity to the a port which is potentially bridged (any Ethernet
port) carries the potential of frame loss if transmissions occur
before any bridges' ForwardDelay timers have expired twice. This
timeout defaults to 30 seconds (2 * 15 seconds), but may be as high
as 60s [IEEE-802.1D]. When sending indications to upper layers, the
period where frame forwarding is potentially unavailable should be
indicated to upper-layer protocols.
Alternatively, a host can listen for BPDUs and use them to determine
the length of port blockage which will occur in their particular
circumstances.
In either case, as soon as link_status becomes OK a link up
notification with the attribute (R-flag) that indicates the risk of
packet loss MAY be sent.
Upon learning that an adjacent port is running STP or RSTP, the host
MUST send a link up notification upon expiry of calculated delays to
indicate that general packet transfer is available across the LAN.
If no bridge configuration messages are received within the
Bridge_Max_Age interval (default 20s), then it is likely that there
is no visible bridge whose port is enabled for bridging (S8.4.5 of
[IEEE-802.1D]), since at least two BPDU hello messages would have
been lost. Upon this timeout, a link up notification MUST be
generated.
It is not easy for a non-STP host to distinguish between Disabled
bridge ports and non-bridge ports with no IP nodes on them, as
Disabled ports will have no traffic on them, and incur 100% sender
loss.
Upon this Bridge_Max_Age timeout, a link up notification must be
generated. If an earlier link up was generated with the R-flag set,
this new one MUST set the A-flag showing that packets sent within the
prior interval were likely to have traversed the forwarding path
(unless the port is disabled).
If a BPDU is received, and the adjacent bridge is running the
original Spanning Tree Protocol, then a host cannot successfully send
packets until at least twice the ForwardDelay value in the received
BPDU has elapsed. After this time, a link up notification MUST be
generated. If the previous link up notification had the R-flag set,
then the B-flag) MUST be set in this notification. The B-flag
signifies that the packets sent within the prior interval were lost.
If the bridge is identified as performing Rapid Spanning Tree
Protocol (RSTP), it instead waits Bridge_Max_Age after packet
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reception (advertised in the BPDU's Max Age field), before
forwarding. For ports which are known to be point-to-point through
autonegotiation, this delay is abbreviated to 3 seconds after
autonegotiation completes [IEEE-802.1D].
2.4.3. 802.1AB Link-Layer Discovery Protocol
The recently defined 802.1AB Link-Layer Discovery Protocol (LLDP)
provides information to devices which are directly adjacent to them
on the local LAN [IEEE-802.1ab].
LLDP sends information periodically, and at link status change time
to indicate the configuration parameters of the device. Devices may
either send or receive these messages, or both.
The LLDP message may contain a System Capabilities TLV, which
describes the MAC and IP layer functions which a device is currently
using. Where a host receives the Systems Capabilities TLV which
indicate that no Bridging or Repeating is occurring on the LLDP
transmitter, then no delays for STP calculation will be applied to
packets sent through this transmitter, if the host does not perform
STP itself. This would allow the generation of a link up
notification.
Additionally, if a host receives a Systems Capabilities TLV which
indicates that the LLDP transmitter is a bridge, the host's
advertisement that it is an (end-host) Station-Only, may tell the
bridge not to run STP, and immediately allow forwarding.
Proprietary extensions may also indicate that data forwarding is
already available on such a port. Discussion of such optimizations
is out-of-scope for this document.
Due to the protocol's newness and lack of deployment, it is unclear
how this protocol will eventually affect DNA in IPv4 or IPv6
networks.
2.4.4. Summary
Link-Layer indications in Ethernet-like networks are complicated by
additional unadvertised delays due to Spanning Tree calculations.
This may cause re-indication (link up with A-flag) or retraction
(link up with B-flag) of indications previously sent to upper layer
protocols.
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3. IANA Considerations
This document has no actions for IANA.
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4. Security Considerations
A faked link-layer event notification can be used to launch a
denial-of service attack on the node and the associated network.
Secure generation and delivery of these notifications MUST be
ensured. This is a subject for link-layer and network stack designs
and therefore it is outside the scope of this document.
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5. Contributors
In addition to the people listed in the author list, text for the
specific link-layer technologies covered by this document was
contributed by Thomas Noel (IEEE 802.11b), and Greg Daley (IEEE
802.3). The authors would like to thank them for their efforts in
bringing this document to fruition.
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6. Acknowledgements
The authors would like to acknowledge Bernard Aboba, Sanjeev Athalye,
JinHyeock Choi, John Loughney, Pekka Nikander, Brett Pentland, Tom
Petch, Dan Romascanu, Pekka Savola, and Muhammad Mukarram bin Tariq
for their useful comments and suggestions.
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7. References
7.1. Normative References
[CDMA2K] "IS-835 - cdma2000 Wireless IP Network Standard", .
[GPRS] "Digital cellular telecommunications system (Phase 2+);
General Packet Radio Service (GPRS) Service description;
Stage 2", 3GPP 3GPP TS 03.60 version 7.9.0 Release 98.
[GPRS-LINK]
"Digital cellular telecommunications system (Phase 2+);
Radio subsystem link control", 3GPP GSM 03.05 version
7.0.0 Release 98.
[IEEE-802.11a]
Institute of Electrical and Electronics Engineers, "IEEE
Std 802.11a-1999, supplement to IEEE Std 802.11-1999, Part
11: Wireless MAN Medium Access Control (MAC) and Physical
Layer (PHY) specifications: High-speed Physical Layer in
the 5 GHZ band", IEEE Standard 802.11a, September 1999.
[IEEE-802.11b]
Institute of Electrical and Electronics Engineers, "IEEE
Std 802 Part 11, Information technology -
Telecomunications 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",
IEEE Standard 802.11b, August 1999.
[IEEE-802.11g]
Institute of Electrical and Electronics Engineers, "IEEE
Std 802.11g-2003, Amendment to IEEE Std 802.11, 1999
edition, Part 11: Wireless MAN Medium Access Control (MAC)
and Physical Layer (PHY) specifications. Amendment 4:
Further Higher Data Rate Extension in the 2.4 GHz Band",
IEEE Standard 802.11g, June 2003.
[IEEE-802.11i]
Institute of Electrical and Electronics Engineers,
"Supplement to STANDARD FOR Telecommunications and
Information Exchange between Systems - LAN/MAN Specific
Requirements - Part 11: Wireless Medium Access Control
(MAC) and physical layer (PHY) specifications:
Specification for Enhanced Security", IEEE IEEE 802.11i,
December 2004.
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[IEEE-802.1D]
Institute of Electrical and Electronics Engineers, "IEEE
standard for local and metropolitan area networks - common
specific ations - Media access control (MAC) Bridges",
ISO/IEC IEEE Std 802.1D, 2004.
[IEEE-802.1ab]
Institute of Electrical and Electronics Engineers, "Draft
Standard for Local and Metropolitan Networks: Station and
Media Access Control Connectivity Discovery (Draft 13)",
IEEE draft Std 802.1AB, 2004.
[IEEE-802.3]
Institute of Electrical and Electronics Engineers, "IEEE
standard for local and metropolitan area networks -
Specific Require ments, Part 3: Carrier Sense Multiple
Access with Collision Detection (CSMA/CD) Access Method
and Physical Layer Specifications", ISO/IEC IEEE
Std 802.3, 2002.
[RFC1332] McGregor, G., "The PPP Internet Protocol Control Protocol
(IPCP)", RFC 1332, May 1992.
[RFC1661] Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51,
RFC 1661, July 1994.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2462] Thomson, S. and T. Narten, "IPv6 Stateless Address
Autoconfiguration", RFC 2462, December 1998.
[RFC2472] Haskin, D. and E. Allen, "IP Version 6 over PPP",
RFC 2472, December 1998.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC4135] Choi, JH. and G. Daley, "Goals of Detecting Network
Attachment in IPv6", RFC 4135, August 2005.
7.2. Informative References
[GPRS-CN] "Technical Specification Group Core Network;
Internetworking between the Public Land Mobile Network
(PLMN) supporting packet based services and Packet Data
Networks (PDN) (Release 6)", 3GPP 3GPP TS 29.061 version
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6.1.0 2004-06.
[GPRS-GSSA]
"Technical Specification Group Services and System Aspect;
General Packet Radio Service (GPRS) Service description;
Stage 2 (Release 6)", 3GPP 3GPP TS 23.060 version 6.5.0
2004-06.
[I-D.ietf-mipshop-fast-mipv6]
Koodli, R., "Fast Handovers for Mobile IPv6",
draft-ietf-mipshop-fast-mipv6-03 (work in progress),
October 2004.
[I-D.ietf-mobileip-lowlatency-handoffs-v4]
Malki, K., "Low Latency Handoffs in Mobile IPv4",
draft-ietf-mobileip-lowlatency-handoffs-v4-11 (work in
progress), October 2005.
[RFC2461] Narten, T., Nordmark, E., and W. Simpson, "Neighbor
Discovery for IP Version 6 (IPv6)", RFC 2461,
December 1998.
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Appendix A. Change History
The following changes were made on draft version 00:
- IEEE 802.11 ad-hoc mode discussion added.
- IPv6 address configuration over 3GPP networks clarified.
The following changes were made on draft version 01:
- Text for IEEE 802.3 added.
- Multiple 3GPP PDP Contexts scenario clarified.
The following change was made on draft version 02:
- Editorial fixes as suggested by WG last call feedback.
The following change was made on draft version 03:
Link down events were removed since they are not relevant to DNA
References updated
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Authors' Addresses
Suresh Krishnan (editor)
Ericsson Research
8400 Decarie Blvd.
Town of Mount Royal, QC
Canada
Email: suresh.krishnan@ericsson.com
Nicolas Montavont
LSIIT - University Louis Pasteur
Pole API, bureau C428
Boulevard Sebastien Brant
Illkirch 67400
France
Phone: +33 390 244 587
Email: montavont@dpt-info.u-strasbg.fr
Eric Njedjou
France Telecom
4, Rue du Clos Courtel BP 91226
Cesson Sevigne 35512
France
Phone: +33 299124202
Email: eric.njedjou@france-telecom.com
Siva Veerepalli
Qualcomm
5775 Morehouse Drive
San Diego, CA 92131
USA
Phone: +1 858 658 4628
Email: sivav@qualcomm.com
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Alper E. Yegin (editor)
Samsung Advanced Institute of Technology
75 West Plumeria Drive
San Jose, CA 95134
USA
Phone: +1 408 544 5656
Email: alper01.yegin@partner.samsung.com
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Krishnan, et al. Expires April 9, 2007 [Page 24]
