Network Working Group W. Haddad
Internet-Draft S. Krishnan
Expires: December 3, 2006 Ericsson Research
F. Dupont
CELAR
June 2006
Mobility Signaling Delegation in OptiSEND
draft-haddad-mipshop-mobisig-del-01
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 December 3, 2006.
Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This memo describes a mechanism, which delegates the exchange of
mobility signaling messages between the mobile node and the
correspondent node(s) to the network infrastructure. Goals outlining
the proposed delegation are to further reduce the IP handoff latency
and to relieve the mobile node from exchanging a considerable amount
of signaling messages with the CN(s) while retaining full control on
Haddad, et al. Expires December 3, 2006 [Page 1]
Internet-Draft Mobility Signaling Delegation June 2006
the critical ones.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions used in this document . . . . . . . . . . . . . . 4
3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Suggested Solution . . . . . . . . . . . . . . . . . . . . . . 7
5. New Options and Messages . . . . . . . . . . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.1. Normative References . . . . . . . . . . . . . . . . . . . 11
7.2. Informative References . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12
Intellectual Property and Copyright Statements . . . . . . . . . . 13
Haddad, et al. Expires December 3, 2006 [Page 2]
Internet-Draft Mobility Signaling Delegation June 2006
1. Introduction
Optimized Mobile IPv6 (OMIPv6) protocol (described in [OMIPv6])
provides a mechanism, which allows significant reduction in the
amount of signaling messages generated by the Mobile IPv6 (MIPv6)
protocol ([MIPv6]), a shorter handoff latency and a better overall
security. However, a care-of address (CoA) test exchange between the
mobile node (MN) and each correspondent node (CN) remains a
compulsory step prior to exchanging critical mobility signaling
messages, namely binding update(s) and acknowledgment(s) messages
between them. The CoA reachability test involves two mobility
signaling messages (CoTI/CoT) and is unaffected by the optimization
introduced by OMIPv6 protocol.
This memo describes a mechanism, which delegates the exchange of
mobility signaling messages between the MN and the CN(s) to the
network infrastructure, as part of the ongoing work to design an
optimization to the IPv6 secure neighbor discovery (described in
[SEND]) protocol. Goals outlining the proposed delegation are to
further reduce the IP handoff latency and to relieve the MN from
exchanging a considerable amount of signaling messages with each CN
while retaining full control on the BU/BA messages.
Haddad, et al. Expires December 3, 2006 [Page 3]
Internet-Draft Mobility Signaling Delegation June 2006
2. Conventions used in this document
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 [TERM].
Haddad, et al. Expires December 3, 2006 [Page 4]
Internet-Draft Mobility Signaling Delegation June 2006
3. Motivation
OMIPv6 protocol achieves three different goals: it alleviates the
load of mobility signaling messages, improves the overall security
and reduces the IP handoff latency.
The latency reduction caused by OMIPv6 protocol is mainly due to
eliminating the MN's home IPv6 address reachability test, which
requires signaling messages exchange through the MN's Home Agent.
Another set of factors (excluding the link layer), e.g., network
detection, network prefix discovery and address configuration are
still among main contributors to the handoff latency. These factors
remain totally unaffected by using OMIPv6.
In addition, OMIPv6 still require a CoA reachability test with each
CN prior to updating them with its new CoA (nCoA), i.e., exchanging
BU/BA messages. Consequently, such exchange guarantees a residual
latency and additional mobility signaling messages.
Furthermore, it is important to mention that a fast growing class of
mobile devices tend to have very limited battery power. Thus the
available energy must be meticulously controlled and consumed, i.e.,
not to be wasted on exchanging non-critical signaling messages. Such
statement becomes more challenging when the MN is talking to
different CNs at the same time (which may probably be a very common
case) while moving fast.
In fact, it has been shown that the wireless transmission of one bit
can require over 1000 times more energy than a single 32-bit
computation [EALDC]. Consequently, a fast moving MN communicating
with multiple CNs will have to dedicate a significant amount of its
available energy to exchange only mobility signaling messages with
the CNs.
OMIPv6 provides a credit-based mechanism (described in [CBA]), which
aims to reduce further the latency caused by the care-of address test
exchange. However, such mechanism has two drawbacks: the CN may not
have this feature, in which case the latency problem remains unsolved
and it consumes battery power in both scenarios due to exchanging
signaling messages.
Note that the suggested protocol does not prevent both endpoints from
using the CBA mechanism on top of the suggested protocol.
On the other side, the Optimized Secure Neighbor Discovery (OptiSEND)
protocol (described in [OptiSEND]) is an ongoing work, which aims to
better adapt the requirements for securing the IPv6 neighbor
discovery to low computation and battery power devices (e.g., mobile
devices and sensors). OptiSEND enables fixed/mobile nodes to avoid
using expensive RSA signatures to secure neighbor discovery messages
Haddad, et al. Expires December 3, 2006 [Page 5]
Internet-Draft Mobility Signaling Delegation June 2006
exchange, by providing a mechanism to quickly share a long lifetime
symmetric key with the AR(s). On the infrastructure side, OptiSEND
enables ARs to use one-way hash chains to authenticate the Router
Advertisement (RtAdv) messages sent to the fixed/mobile node(s)
attached to the same link.
Haddad, et al. Expires December 3, 2006 [Page 6]
Internet-Draft Mobility Signaling Delegation June 2006
4. Suggested Solution
Our proposal delegates the task of performing CoA reachability
test(s) to the network infrastructure, which in turn enables
eliminating the residual latency due to the CoA rechability test,
ensures that the messages exchanged are authenticated and optimize
the battery power consumption by relieving the MN from performing CoA
reachability tests. In fact, our protocol adopts another approach to
perform reachability tests, which consists on testing the
reachability of the new MN's 64-bit subnet prefix only instead of
testing the reachability of the whole nCoA, and thus relies on two
new messages to perform such test.
For these purposes, the MN must securely send to the access network
infrastructure necessary information (called mobility package) to
enable performing the CoA reachability test(s) on its behalf and also
to forward the mobility package to potential new ARs. To achieve
this goal, a new message called "Router Mobility Solicitation"
(RtMoSol) is used by the MN to send its mobility package to its
current AR(s). The RtMoSol message MUST carry all CNs'IPv6 addresses
and the MN's IPv6 home address(es) (HoAs) and MUST be authenticated
with the shared key obtained from OptiSEND.
Upon receiving a valid RtMoSol message, the selected AR SHOULD reply
with a unicast and authenticated "Router Mobility Acknowledgment"
(RtMAck) message. The content of the RtMoSol message SHOULD be
forwarded to neighboring ARs and should be stored together with data
obtained from running OptiSEND protocol.
The RtMoSol message is also used by the MN to add or delete entries
from a mobility package stored in the AR cache memory. For example,
when the MN establishes a session with a new CN, it SHOULD send a
RtMoSol message to its current AR and SHOULD set a new bit (called
Add "A" bit) to request the AR to forward the new CN's IPv6 address
to potential new AR(s). Similarily, the MN MAY also set another bit
(called Suppress "S" bit) to request the AR(s) to remove an existing
CN's IPv6 address from its list.
In order to eliminate the residual latency due to performing the CoA
reachability test, the nAR SHOULD perform the test immediately after
receiving a first hint (e.g., on layer 2) indicating an attachment of
the MN (e.g., when using [FRD]) and SHOULD forward the message(s)
sent by the CN(s) to the MN after it attaches to the nAR. For this
purpose, the nAR SHOULD use its source address, which includes the
prefix advertised on the link and MUST authenticate the message with
a mobility signaling key (Kms). We call such message "Prefix Test
Init" (PreTI). In addition, the PreTI message MUST carry the MN's
HoA to allow the CN to fetch/generate the Kms associated with the
corresponding BCE in order to validate the message authenticity.
Upon receiving a valid PreTI message, the CN computes a prefix keygen
Haddad, et al. Expires December 3, 2006 [Page 7]
Internet-Draft Mobility Signaling Delegation June 2006
(prekey) token from the prefix used in the IPv6 source address and
the long lifetime shared secret (i.e., kbmperm) generated from using
OMIPv6 protocol. After computing the token, the CN SHOULD send back
an acknowledgment message called "Prefix Test" (PreT), which will
carry the prekey token to the same IPv6 source address carried in the
PreTI message. The PreT message MUST also carry the MN's HoA and
MUST be authenticated with Kms.
The Prekey token MUST be computed by the CN in the following way:
Prekey Token = First [64, SHA1 (SA_Prefix | nonce | SHA1 (Kbmperm))]
Where SA_Prefix is the 64-bit prefix included in the IPv6 source
address sent in the PreTI message and Kbmperm is the long lifetime
shared secret generated by the CN when running OMIPv6 protocol.
As mentioned above, the prefix reachability test SHOULD be
authenticated with Kms. In order to do so, Kms SHOULD be computed
from using the symmetric key generated from running OptiSEND protocol
and the MN's HoA, and MUST be send encrypted to each CN. One way to
achieve a confidential transmission of Kms is to send it encrypted in
the first BU message sent by the MN. In such scenario, the MN will
use its Kbm (computed from running the return routability procedure)
to encrypt Kms. Finally, Kms will be carried in a new option called
signaling delegation (SID).
Upon receiving a BU message carrying a SID option, the CN SHOULD
decrypt the Kms and store it in the MN's corresponding BCE. All
subsequent reachability test messages SHOULD be sent by the MN's
current AR on behalf of the MN and SHOULD be authenticated with Kms.
Haddad, et al. Expires December 3, 2006 [Page 8]
Internet-Draft Mobility Signaling Delegation June 2006
5. New Options and Messages
TBD
Haddad, et al. Expires December 3, 2006 [Page 9]
Internet-Draft Mobility Signaling Delegation June 2006
6. Security Considerations
This draft proposes a scheme to delegate mobility signaling from the
mobile node to the network infrastructure. Since the network
infrastructure nodes are well known and trustworthy, it makes
firewalling easier at the administrative boundaries. Also since the
network infrastructure nodes are likely to be more powerful than
mobile nodes, this scheme will allow us to use higher strength crypto
to protect the signaling. This draft does not introduce any new
security holes into existing route optimization solutions.
Haddad, et al. Expires December 3, 2006 [Page 10]
Internet-Draft Mobility Signaling Delegation June 2006
7. References
7.1. Normative References
[MIPv6] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in
IPv6", RFC 3775, June 2004.
[SEND] Arkko, J., Kempf, J., Sommerfield, B., Zill, B., and P.
Nikander, "Secure Neighbor Discovery (SEND)", RFC 3971,
March 2005.
[TERM] Bradner, S., "Key Words for Use in RFCs to Indicate
Requirement Levels", RFC 2119, BCP , March 1997.
7.2. Informative References
[CBA] Vogt, C. and J. Arkko, "Credit-Based Authorization for
Concurrent Reachability Verification", Internet
Draft, draft-vogt-mobopts-simple-cba-00.txt,
February 2006.
[EALDC] Barr, K. and K. Asanovic, "Energy Aware Lossless Data
Compression", ACM Proceedings of MobiSys, May 2003.
[FRD] Choi, J., Shin, D., and W. Haddad, "Fast Router Discovery
with L2 Support", Internet
Draft, draft-ietf-dna-frd-01.txt, June 2006.
[OMIPv6] Vogt, C., Arkko, J., and W. Haddad, "Applying CGA and CBA
to Mobile IPv6", Internet
Draft, draft-arkko-mipshop-cga-cba-04.txt, June 2006.
[OptiSEND]
Haddad, W., Krishnan, S., and J. Choi, "Secure Neighbor
Discovery (SEND) Optimization and Adapation for Mobility:
The OptiSEND Protocol", Internet
Draft, draft-haddad-mipshop-optisend-01.txt, March 2006.
Haddad, et al. Expires December 3, 2006 [Page 11]
Internet-Draft Mobility Signaling Delegation June 2006
Authors' Addresses
Wassim Haddad
Ericsson Research
Torshamnsgatan 23
SE-164 80 Stockholm
Sweden
Phone: +46 8 4044079
Email: Wassim.Haddad@ericsson.com
Suresh Krishnan
Ericsson Research
8400 Decarie Blvd.
Town of Mount Royal, QC
Canada
Phone: +1 514 345 7900
Email: Suresk.Krishnan@ericsson.com
Francis Dupont
CELAR
Email: Francis.Dupont@point6.net
Haddad, et al. Expires December 3, 2006 [Page 12]
Internet-Draft Mobility Signaling Delegation June 2006
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.
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 (2006). 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.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
Haddad, et al. Expires December 3, 2006 [Page 13]