DNA WG JH. Choi
Internet-Draft Samsung AIT
Expires: April 16, 2006 DongYun. Shin
Samsung Electronics
W. Haddad
Ericsson Research
October 13, 2005
Fast Router Discovery with L2 support
draft-ietf-dna-frd-00.txt
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 16, 2006.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
For efficient DNA, a host should quickly receive an RA (Router
Advertisement) upon a new link-layer connection. This draft presents
a quick RA acquisition scheme with the support of a link-layer
entity, PoA (Point of Attachment). Upon a new network attachment,
the PoA may either trigger an AR (Access Router) to immediately send
Choi, et al. Expires April 16, 2006 [Page 1]
Internet-Draft FRD October 2005
an unicast RA, "RA Triggering" or send such an RA for itself, "RA
Proxying". We may put "RA Triggering" or "RA Proxying" functionality
on a PoA to get the optimized result without IPv6 standard change.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Proposal Overview . . . . . . . . . . . . . . . . . . . . . . 6
3.1 RA Triggering . . . . . . . . . . . . . . . . . . . . . . 6
3.2 RA Proxying . . . . . . . . . . . . . . . . . . . . . . . 6
4. RA Triggering . . . . . . . . . . . . . . . . . . . . . . . . 8
5. RA Proxying . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 RA Caching . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1.1 Manual Configuration . . . . . . . . . . . . . . . . . 9
5.1.2 Scanning . . . . . . . . . . . . . . . . . . . . . . . 9
5.1.3 MICS (Media Independent Comment Service) . . . . . . . 9
5.2 RA Delivery . . . . . . . . . . . . . . . . . . . . . . . 10
5.2.1 802.11 . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2.2 802.16 . . . . . . . . . . . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
7. Security Considerations . . . . . . . . . . . . . . . . . . . 13
8. Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . . 15
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
9.1 Normative References . . . . . . . . . . . . . . . . . . . 16
9.2 Informative References . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 17
Intellectual Property and Copyright Statements . . . . . . . . 19
Choi, et al. Expires April 16, 2006 [Page 2]
Internet-Draft FRD October 2005
1. Introduction
Upon establishing a new link-layer connection, a host should detect
the identity of the currently attached link to ascertain the validity
of the existing IP configuration. If the host is attached to a
different link, it also needs to acquire the IP configuration for the
new link [4].
An RA (Router Advertisement) message is necessary when the host has
moved to a different link, so the number of messages needed for DNA
can be minimized if the RA also can properly represent the link
identity. Moreover to quickly check for link change, the host has to
receive the RA without delay.
DNA solution should be able to 1) check for link change with a single
RA message and 2) get the RA with minimum latency [5]. This draft
presents only the second component, quick RA acquisition. But the
proposed method can work with any link identify detection scheme
based on unsolicited RA, such as linkid prefix in [13] or CompleteRA
in [12].
There are several hindrances for sufficiently quick RA acquisition.
First, Neighbor Discovery protocol [1] limits routers to a minimum
interval of 3 seconds between sending multicast RA messages. Second,
it SHOULD delay the transmission for a random amount of time before a
host sends an initial RS (Router Solicitation) message. Third, a
router MUST delay a response to a Router Solicitation by a random
time too.
In cellular environments, it may not be cost-effective to broadcast
the RA over wireless link. For DNA purpose, it's generally
preferable to deliver the RA to the destination in unicast.
PoA (Point of Attachment) is the link endpoint of the link, such as
802.11 AP (Access Point) or 802.16 BS (Base Station). We propose a
scheme which uses the link-layer entity, PoA, in such a way that an
RA is delivered to the host in unicast just after L2 connection is
made without any random delay.
When a host makes a new link-layer connection with a PoA, the PoA
detects the new attachment. So at this moment, the PoA may either
trigger an AR (Access Router) to immediately send a suitable RA or
send such an RA for itself. For the latter case, the PoA needs to
cache a suitable RA, such as 'RA optimized for DNA' defined in [5]
For example, if AR and PoA are in the same box, whenever a new host
is attached, PoA module can deliver Link Up event to AR module so
that AR module can immediately fire an RA. Or, if AR and PoA are
Choi, et al. Expires April 16, 2006 [Page 3]
Internet-Draft FRD October 2005
separated, PoA can cache a suitable RA and deliver it to a new host
upon network attachment.
In this draft, we design a scheme for a PoA to trigger an RA, "RA
Triggering" and another one for a PoA to proxy an RA, "RA Proxying".
In RA Proxying, we present a way to cache a necessary RA and send the
RA in unicast without any delay.
IEEE 802.21 (Media Independent Handover) standard develops a
specification [21] that provides link layer intelligence and other
related network information to upper layers to optimize handovers
between heterogeneous media.
Utilizing the services defined in 802.21 MIH (Media Independent
Handover) standard, we can put 'RA Triggering' or 'RA Proxying'
functionality on a PoA to get the optimized result for quick RA
acquisition without IPv6 standard change.
Choi, et al. Expires April 16, 2006 [Page 4]
Internet-Draft FRD October 2005
2. Terminology
Access Router (AR)
- An Access Network Router residing on the edge of an Access
Network and offers IP connectivity to hosts.
Point of Attachment (PoA)
- The link endpoint on the link, such as 802.11 Access Point (AP)
or 802.16 Base Station (BS), where a host may be connected.
Link Up
- An event provided by the link layer that signifies a state
change associated with the interface becoming capable of
communicating data frames.
Media Independent Handover Fuction (MIHF)
- The MIH Function provides asynchronous and synchronous services
through well defined SAPs for lower layers and upper layers.
The services provided include the Media Independent Event
Service (MIES), the Media Independent Command Service (MICS),
and the Media Independent Information Service (MIIS).
Media Independent Handover (MIH) Protocol
- The Media Independent Handover protocol defines frame formats
for exchanging messages between peer MIH Function entities.
These messages are based on the primitives which are part of
MIES, MICS and MIIS. The MIHF Protocol allows peer MIH
Function entities to interact with each other.
Choi, et al. Expires April 16, 2006 [Page 5]
Internet-Draft FRD October 2005
3. Proposal Overview
When a host establishes a link-layer connection, in the process, a
link-layer entity, PoA (Point of Attachment), can detect the new
attachment and get the necessary information to deliver an unicast L2
frame to the host, such as 802.11 MAC address or 802.16 CID
(Connection Identifier) [19].
The PoA may forward the information to an AR (Access Router) and
trigger the AR to immediately send in unicast a suitable RA, such as
'RA optimized for DNA' defined in [5].
Or the PoA itself may cache such an RA beforehand and deliver the
cached RA to the host in unicast as soon as the link-layer connection
is established.
In this draft, we refer the first scheme "RA Triggering" and the
second "RA Proxying".
3.1 RA Triggering
In case PoA and AR are in the same box, when a new host is attached,
link-layer (PoA module) can deliver Link UP event notification [7] to
IP layer (AR module) to generate a suitable RA and immediately send
the RA (in an unicast L2 frame with the host's MAC address).
In case PoA and AR are separated, upon a new network attachment, the
PoA may deliver the AR the Link Up event notification with the
information necessary to deliver an unicast RA. Upon receiving this
notification, the AR can send a suitable RA in unicast without delay.
There are two ways for such a remote Link Up event notification. We
may use the MIES (Media Independent Event Service) defined in IEEE
802.21 [21] or RS with TSLLAO (Tentative Source Link-Layer Address
Option) [14].
3.2 RA Proxying
RA Proxying consists of "RA Caching" and "RA Delivery". RA Caching
is to get a suitable RA and store it. RA Delivery is to immediately
send the cached RA to a new host in unicast
There are several ways to cache the RA in a PoA. We may manually
cache the RA in the PoA or use the scanning scheme. AR (Access
Router)s periodically multicast a suitable RA, which goes through the
PoA. So the PoA may scan incoming L2 frames and cache a necessary
RA. The PoA can scan L2 frames either continuously or periodically
to update the cached RA. Or PoA and AR may use a special information
Choi, et al. Expires April 16, 2006 [Page 6]
Internet-Draft FRD October 2005
service, such as the MICS (Media Independent Command Service) defined
in IEEE 802.21 [21] in such a way that the AR can forward the PoA the
information necessary to generate a suitable RA and permit it to
porxy the RA.
For RA Delivery, PoA may put the cached RA into an unicast L2 frame
with the host's MAC address (or CID for 802.16) and deliver it to the
host in unicast immediately after link-layer connection is
established.
Choi, et al. Expires April 16, 2006 [Page 7]
Internet-Draft FRD October 2005
4. RA Triggering
In case PoA and AR are in the same box, when a new host is attached,
Link Up event notification with the information necessary to deliver
an unicast RA, such as the host's MAC address, can be propagated
upwards from the link-layer (PoA module) to the IP layer (AR module)
within a local stack. Then IP layer (AR module) can immediately send
a suitable RA in an unicast L2 frame with the new host's MAC address.
In case PoA and AR are separated, we may use 802.21 MIES (Media
Independent Event Service) [21] to enable a PoA to trigger a remote
AR to fire an immediate RA in unicast.
MIES (Media Independent Event Service) refers to the events sent from
the lower layers to the higher layers. Events can also be sent from
a local MIH entity to a peer MIH entity. Events may carry useful
information. For example, Link Up event can carry a new host's MAC
address.
When a new host is attached to a PoA, the PoA may use Link Up event
and MIH Protocol to notify a remote AR the new attachment with the
information necessary to deliver an unicast RA, such as the host's
MAC address. Then the AR can immediately send a suitable RA in an
unicast L2 frame with the new host's MAC address.
Choi, et al. Expires April 16, 2006 [Page 8]
Internet-Draft FRD October 2005
5. RA Proxying
RA Proxying is used only when AR and PoA are separated. If they are
in the same box, we recommend to use RA Triggering instead.
5.1 RA Caching
We present 3 different ways to store a suitable RA in PoA.
5.1.1 Manual Configuration
In the simplest way, we can manually configure in PoA a suitable RA,
such as RA with the linkid prefix in [13] or CompleteRA in [12]. In
many cases, AR and PoA are under same administration and usually RA
(Router Advertisement) message doesn't change so often.
5.1.2 Scanning
A PoA may scan incoming L2 frame for a suitable RA and store it.
First it scans L2 frame header to see whether it is a multicast
frame. If not, the PoA sends that frame down link and scans a next
L2 frame. If so, the PoA looks IP header to check whether it
contains a suitable RA. If incoming L2 frame doesn't contain a
suitable RA, the PoA sends that frame down link and scans a next L2
frame. When the PoA finds a suitable RA, it stores it and sends a
copy down link.
A PoA can scan continuously, updating an old RA with a new RA. Or if
it costs too much for the PoA to scan every incoming L2 frame, we can
control the scanning rate. For example, we can set timer and execute
scanning every T seconds. Or we can make the PoA to be able to send
RS (Router Solicitation) message. Periodically the PoA sends an RS
and an AR will reply a suitable RA and the PoA caches it. It is
noted that the PoA doesn't need to have IP address since it can use
unspecified address as its source address.
To help RA Caching, we may make it a rule that, whenever an AR
changes its RA information, the AR advertises the new information
several times, so that PoA can properly update its cached RA.
5.1.3 MICS (Media Independent Comment Service)
We may use 802.21 MICS (Media Independent Comment Service) and MIH
(Media Independent Handover) Protocol [21] to enable an AR to send a
suitable RA to a PoA and delegate the PoA to proxy the RA.
MICS (Media Independent Comment Service) refers to the commands sent
Choi, et al. Expires April 16, 2006 [Page 9]
Internet-Draft FRD October 2005
from the higher layers to the lower layers. Commands can also be
sent from a local MIH entity to a peer MIH entity. These commands
may carry the upper layer information to the lower layers on local
device entity or at remote entity, and thus control the behavior of
lower layers. For example, a new AR may send its IP address to old
PoA with a Remote MIH Command, "MIH Network Address Information".
In a similar way, we may define a new Remote MIH Command, "MIH Router
Advertisement Information" in 802.21 in such a way that 1) a PoA can
use the command and MIP Protocol to request a suitable RA from an AR
and permission to proxy the RA and 2) the AR can use the command and
MIH Protocol to send a suitable RA to the PoA and delegate the PoA to
deliver the RA to a new host upon network attachment
5.2 RA Delivery
We present a way to immediately deliver an RA in unicast upon network
attachement for 802.11 and 802.16 respectively. The procedures
describes in here can be extended to apply to other wireless
technologies such as 3GPP and 3GPP.2.
5.2.1 802.11
In 802.11 Wireless LAN technology, when a new host arrives at an
AP(Access Point), it should associate with the AP. The host sends an
Association Request Message with its MAC address. Then the AP sends
an Association Response Message to grant association.
As soon as association is made, the AP sends a cached RA to the host
in an unicast 802.11 frame with the MAC address from the Association
Request message. The host receives the unicast RA just after
association is made, which is the earliest possible time in current
standard.
5.2.2 802.16
IEEE 802.16 spec [19] is rather different from Ethernet or 802.11 and
it's still unclear how to run IPv6 over 802.16. So we give a rough
sketch of RA delivery over 802.16 and mention that further
clarification is needed.
The 802.16 MAC is connection-oriented. All services, including
inherently connectionless services, are mapped to a connection.
Connections are referenced with 16-bit connection identifiers (CIDs).
Each 802.16 host has a standard 48-bit MAC address, but this serves
mainly as an equipment identifier, since the primary addresses used
during operation are the CIDs.
Choi, et al. Expires April 16, 2006 [Page 10]
Internet-Draft FRD October 2005
Upon entering the network, the host is assigned three management
connections, the basic connection and the primary management
connection and the secondary management connection.
The secondary management connection is used for the transfer of
standards-based management messages such as Dynamic Host
Configuration Protocol (DHCP). It is not decided yet but Neighbor
Discovery messages, such as RS, RA, NS (Neighbor Solicitation) and NA
(Neighbor Advertisement) may be delivered with this connection.
To establish a link layer connection, an 802.16 host performs Ranging
to acquire the correct timing offset and power adjustment. The host
sends the RNG-REQ message and the 802.16 BS (Base Station) replies
RNG-RSP message to provide Basic and Primary Management CIDs for the
host.
Afterwards the host performs Registration, which is the process by
which the host is allowed entry into the network and receives its
Secondary Management CID.
After Registration is completed, the 802.16 BS may send a cached RA
to the host with the Secondary CID. The RA will be delivered in
unicast 802.16 frame and the host will receive it with minimum
latency.
We point out that it's not decided yet that the Secondary CID is used
for RA message transfer. It's possible for RA to be delivered with a
different CID.
Choi, et al. Expires April 16, 2006 [Page 11]
Internet-Draft FRD October 2005
6. IANA Considerations
No new message formats or services are defined in this document.
Choi, et al. Expires April 16, 2006 [Page 12]
Internet-Draft FRD October 2005
7. Security Considerations
Because DNA is based on Neighbor Discovery, its trust models and
threats are similar to the ones presented in RFC 3756 [10]. Nodes
connected over wireless interfaces may be particularly susceptible to
jamming, monitoring and packet insertion attacks.
The threats specific to DNA are that an attacker might fool a node to
detect attachment to a different link when it is in fact still
attached to the same link, and conversely, the attacker might fool a
node to not detect attachment to a new link.
In case PoA and AR are in the same box, there is no FRD specific
security problem, because all procedures are executed within a local
stack. In case PoA and AR are separated, FRD can be performed in
secure manner, if there is a secure path between PoA and AR. For
example, MIH (Media Independent Handover) services can be made
available at L2 through secure port.
Even when there is no secure path between PoA and AR, FRD doesn't
introduce a new security vulnerability. For the worst case, a host
may reject the proxyed RA from PoA but will not make a false
decision. Currently any node in a link can cache an RA and
retransmit it. Use of [9] to secure Neighbor Discovery are important
in achieving reliable detection of network attachment. DNA schemes
SHOULD incorporate the solutions developed in IETF SEND WG if
available, where assessment indicates such procedures are required.
In the presence of SEND, RA Caching may raise security concerns,
since the PoA can be considered a man in the middle. Especially it
may be difficult for RA Caching with Scanning (Sec 5.1.2) to work
with SEND. If a router sends an RA with a SEND Timestamp option, it
puts upper bound on how long the RA remains valid after the router
advertises it. So if a PoA caches the RA too long, it will become
invalid and a host will discard it.
We may resolve this issue by including a unique 64 bit number called
an Ownership Proof (OP) in an RA. The 64 bit number, OP, is the hash
of a nonce and proves to a host that the RA was indeed generated by
the router which is listed as the source of the RA. The router must
keep a table associating each OP to the nonce which was used to
generate it. When an RA carrying an OP option is received, a host
may ignore the SEND Timestamp option if it falls outside the
allowable window.
With OP, DNA procedure is as below. A PoA caches a suitable RA with
an OP. When a new host makes an attachment, the PoA immediately
sends it the cached RA with an OP. With this cached RA, the host may
Choi, et al. Expires April 16, 2006 [Page 13]
Internet-Draft FRD October 2005
perform DNA regardless of its SEND Timestamp and at the same time
send an RS with the OP option. Upon receiving the RS, the router may
send an RA immediately because it is solicited in unicast. When the
router responds with a solicited RA it includes the nonce used to
generate the OP. Upon receiving the RA, the host may check if the
hash of this nonce matches the OP received in the initial cached RA
to verify it. If not, the host stops the DNA procedure with the RA
and restarts it with a new RA.
DAN scheme should not result in excessive signaling. A PoA performs
FRD procedures to generate an RA message only when a new host is
attached to itself. Usually there is an upper bound for the number
of hosts (wireless stations) that a PoA can support at a moment. So
the number of RA messages from FRD procedure is also limited by this
upper bound.
Choi, et al. Expires April 16, 2006 [Page 14]
Internet-Draft FRD October 2005
8. Acknowledgment
We gratefully acknowledge the generous assistance we received from
Xiaoyu Liu, YounHee Han and James Kempf for notifying us the
usability of 802.21 standard and clarifying the MIH Spec to us. We
show our special gratitude to HeeJin Jang, Subba Reddy and Surekha
Biruduraju for implementing and testing FRD scheme to provide
enlightening insights. The authors wish to express our appreciation
to Syam Madanapalli and Wable Ranjitsingh for valuable feedback.
Thanks to Suresh Krishnan, Greg Daley, Brett Pentland, Nick Moore and
YongGeun Hong for their contributions to this draft.
Choi, et al. Expires April 16, 2006 [Page 15]
Internet-Draft FRD October 2005
9. References
9.1 Normative References
[1] Narten, T., Nordmark, E., and W. Simpson, "Neighbor Discovery
for IP Version 6 (IPv6)", RFC 2461, December 1998.
[2] Thomson, S. and T. Narten, "IPv6 Stateless Address
Autoconfiguration", RFC 2462, December 1998.
[3] Hinden, R. and S. Deering, "Internet Protocol Version 6 (IPv6)
Addressing Architecture", RFC 3513, April 2003.
[4] Choi, JH. and G. Daley, "Goals of Detecting Network Attachment
in IPv6", RFC 4135, August 2005.
9.2 Informative References
[5] Choi, J. and E. Nordmark, "DNA solution framework",
draft-ietf-dna-soln-frame-00 (work in progress), April 2005.
[6] Nordmark, E. and J. Choi, "DNA with unmodified routers: Prefix
list based approach", draft-ietf-dna-cpl-01 (work in progress),
July 2005.
[7] Yegin, A., "Link-layer Event Notifications for Detecting
Network Attachments", draft-ietf-dna-link-information-02 (work
in progress), July 2005.
[8] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in
IPv6", RFC 3775, June 2004.
[9] Arkko, J., Kempf, J., Sommerfeld, B., Zill, B., and P.
Nikander, "SEcure Neighbor Discovery (SEND)",
draft-ietf-send-ndopt-06 (work in progress), July 2004.
[10] Nikander, P., Kempf, J., and E. Nordmark, "IPv6 Neighbor
Discovery (ND) Trust Models and Threats", RFC 3756, May 2004.
[11] Pentland, B., "An Overview of Approaches to Detecting Network
Attachment in IPv6", draft-dnadt-dna-discussion-00 (work in
progress), February 2005.
[12] Narayanan, S., "Detecting Network Attachment in IPv6 Networks
(DNAv6)", draft-pentland-dna-protocol-01 (work in progress),
July 2005.
[13] Madanapalli, S. and J. Choi, "DNA Solution: Link Identifier
Choi, et al. Expires April 16, 2006 [Page 16]
Internet-Draft FRD October 2005
based approach", draft-jinchoi-dna-protocol2-01 (work in
progress), July 2005.
[14] Daley, G., "Tentative Source Link-Layer Address Options for
IPv6 Neighbour Discovery", draft-daley-ipv6-tsllao-02 (work in
progress), July 2005.
[15] Aboba, B., "Detecting Network Attachment (DNA) in IPv4",
draft-ietf-dhc-dna-ipv4-16 (work in progress), September 2005.
[16] Nordmark, E., "MIPv6: from hindsight to foresight?",
draft-nordmark-mobileip-mipv6-hindsight-00 (work in progress),
November 2001.
[17] Kempf, J., Khalil, M., and B. Pentland, "IPv6 Fast Router
Advertisement", draft-mkhalil-ipv6-fastra-05 (work in
progress), July 2004.
[18] Daley, G. and J. Choi, "Movement Detection Optimization in
Mobile IPv6", draft-daley-mobileip-movedetect-01 (work in
progress), May 2003.
[19] IEEE 802.16-2001, "IEEE Standard for Local and Metropolitan
Area Networks - Part 16: Air Interface for Fixed Broadband
Wireless Access Systems," Apr. 8, 2002.
[20] IEEE 802.16 TGe Working Document (Draft Standard), "Amendment
for Physical and Medium Access Control Layers for Combined
Fixed and Mobile Operation in Licensed Bands",
IEEE 802.16e/D8, May 2005.
[21] IEEE 802.21 Working Document (Draft Standard),
"IEEE P802.21/D00.01: Draft IEEE Standard for Local and
Metropolitan Area Networks: Media Independent Handover
Services," July, 2005
Authors' Addresses
JinHyeock Choi
Samsung AIT
Communication Lab
P.O.Box 111 Suwon 440-600
KOREA
Phone: +82 31 280 9233
Email: jinchoe@samsung.com
Choi, et al. Expires April 16, 2006 [Page 17]
Internet-Draft FRD October 2005
DongYun Shin
Samsung Electronics
Device Solution Group
P.O.Box 111 Suwon 440-600
KOREA
Phone: +82 2 2191 4868
Email: yun7521@samsung.com
Wassim Haddad
Ericsson Research
8400 Decarie Blvd.
Town of Mount Royal, QC
Canada
Phone: +1 514 345 7900 #2334
Email: Wassim.Haddad@ericsson.com
Choi, et al. Expires April 16, 2006 [Page 18]
Internet-Draft FRD October 2005
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
The IETF has been notified of intellectual property rights claimed in
regard to some or all of the specification contained in this
document. For more information consult the online list of claimed
rights.
Disclaimer of Validity
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The Internet Society (2005). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
Choi, et al. Expires April 16, 2006 [Page 19]
Internet-Draft FRD October 2005
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
Choi, et al. Expires April 16, 2006 [Page 20]
