Network Working Group S. Jeong (Ed.)
Internet-Draft ETRI
Intended status: Informational C. Vogt (Ed.)
Expires: May 22, 2008 Ericsson
R. Wakikawa
Keio University
M. Liebsch
NEC Network Laboratories
S. Sugimoto
Ericsson
B. Sarikaya
Huawei Technologies USA
November 19, 2007
Problem Statement and Requirements for Route Optimization in PMIPv6
draft-jeong-netlmm-pmipv6-roreq-01.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 May 22, 2008.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Jeong (Ed.), et al. Expires May 22, 2008 [Page 1]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
Abstract
This document provides the problem statement for route optimization
in Proxy Mobile IPv6 (PMIPv6). It also investigates design goals and
requirements for route optimization considering the characteristics
of Proxy Mobile IPv6.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3
4. Application Scenarios for Route Optimization in Proxy
Mobile IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Route Optimization in Proxy Mobile IPv6 Design Goals . . . . . 5
5.1. Low Protocol Complexity . . . . . . . . . . . . . . . . . 6
5.2. Trust Relationship . . . . . . . . . . . . . . . . . . . . 6
5.3. Security Aspect . . . . . . . . . . . . . . . . . . . . . 6
5.4. Common Solution for IPv4 and IPv6 . . . . . . . . . . . . 7
5.5. Policy Control and Charging . . . . . . . . . . . . . . . 7
6. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
8. Security Considerations . . . . . . . . . . . . . . . . . . . 8
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 8
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9
Intellectual Property and Copyright Statements . . . . . . . . . . 12
Jeong (Ed.), et al. Expires May 22, 2008 [Page 2]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
1. Introduction
The Proxy Mobile IPv6 (PMIPv6) base protocol document specifies a
network-based local mobility management protocol [1]. The Proxy
Mobile IPv6 base protocol describes a mobility management solution
without a mobile node's participation in mobility management related
signaling process. The Proxy Mobile IPv6 base document considers
IPv6 home address mobility over IPv6 transport network. The IPv4
support document [2] extends the Proxy Mobile IPv6 base protocol in
order to support IPv4 home address mobility and IPv4 transport
network.
The Mobile IPv6 [3] and Enhanced Route Optimization [5] specify route
optimization procedures that allow a mobile node (MN) to register its
binding information to a corresponding node (CN). After the route
optimization procedures, the correspondent node can directly send and
receive packets from the mobile node's care-of address.
In Proxy Mobile IPv6, packets originated from or sent to a mobile
node are routed through bidirectional tunneling between Mobile Access
Gateway (MAG) and Local Mobility Anchor (LMA) by default, so packets
from/to the mobile can be delivered through longer path than the
optimized route, especially when the mobile node and a correspondent
node are in topologically close location and local mobility anchor is
away from the mobile node. Hence, route optimization is useful, when
Proxy Mobile IPv6 domain spans large area.
2. Terminology
Terminology used in this document is taken directly from [1].
3. Problem Statement
Conventional route optimization mechanisms in Mobile IPv6 [3][5]
assume no prior configuration and no trust relationship between route
optimization process participants, i.e., mobile node and correspond
node [4]. However, Mobile IPv6 route optimization mechanisms may not
be directly applicable to Proxy Mobile IPv6 because of the following
Proxy Mobile IPv6 characteristics.
o Since a mobile node is kept completely agnostic on its topological
location (i.e., care-of address), basically it is not possible for
the mobile node to perform correspondent binding update.
Jeong (Ed.), et al. Expires May 22, 2008 [Page 3]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
o Unlike Mobile IPv6, a mobile node does not participate in binding
management procedures and signaling is contained within the
network entities in Proxy Mobile IPv6. Hence, the mobile node
cannot perform binding registration to a correspondent node and
intermediate nodes in the network should do route optimization
procedures on behalf of the mobile node. However, since network
entity, such as mobile access gateway, is intermediate entity of
MN-CN communication, it does not seem to be easy to trigger Mobile
IPv6 route optimization.
o In Mobile IPv6, a correspondent node validates whether a mobile
node is reachable through the mobile node's home address and
care-of address and sets up trust relationship between the two
nodes. However, the correspondent node cannot establish trust
relationship with a mobile node in Proxy Mobile IPv6 domain,
because the reachability test is not applicable.
4. Application Scenarios for Route Optimization in Proxy Mobile IPv6
Since route optimization requires support on the side of a
correspondent node, application scenarios for route optimization can
be separated into the following three:
(1) The correspondent node supports (host-based) Mobile IPv6 [3] and
handles route optimization itself.
(2) Route optimization support on the correspondent node side is
handled by Proxy Mobile IPv6 in the correspondent host's network.
(3) Route optimization in Proxy Mobile IPv6 domain supporting IPv4
and IPv6.
Application scenario (2) can furthermore be subdivided to reflect the
relative topological location of mobile and correspondent hosts:
(2a) On the same mobile access gateway
(2b) On different mobile access gateways, but the same local
mobility anchor
(2c) On different mobile access gateways and different local
mobility anchors from the same Proxy Mobile IPv6 domain
Jeong (Ed.), et al. Expires May 22, 2008 [Page 4]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
(2d) On different mobile access gateways and different local
mobility anchors from different Proxy Mobile IPv6 domains
Application scenario (3) can furthermore be subdivided based on IPv4
support cases:
(3a) The mobile node and the correspondent node support IPv4 home
address mobility
(3b) The mobile node and the correspondent node belong to different
mobile access gateways and both mobile access gateways support
IPv4 transport to the same local mobility anchor
(3c) The mobile node and the correspondent node belong to different
mobile access gateways and the mobile access gateways support
different IP version transport to the same local mobility
anchor
(3d) Two local mobility anchors have either IPv4 or IPv6 when the
mobile node and the correspondent node anchored to different
local mobility anchor
5. Route Optimization in Proxy Mobile IPv6 Design Goals
This section investigates the fundamental design goals which serve to
identify requirements for route optimization solutions in Proxy
Mobile IPv6.
The function of route optimization is to enable the mobile node and
the correspondent node to communicate through a path that is shorter
(in terms of hop count) than the path chosen by base Proxy Mobile
IPv6. The benefit of this is a reduction in packet propagation
delays, in bandwidth consumption and in congestion at local mobility
anchor.
The general design goals for route optimization solutions are to
reduce handover latency, to provide security, and to require low
signaling overhead [5]. Based on these fundamental route
optimization design goals, this section describes special features
and goals concerning route optimization design. Route optimization
in Proxy Mobile IPv6 have following unique properties to consider.
Route optimization solutions should be designed so that the following
design goals can be satisfied.
Jeong (Ed.), et al. Expires May 22, 2008 [Page 5]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
5.1. Low Protocol Complexity
In the case of Mobile IPv6 route optimization, if route optimization
is used, the mobile node and the correspondent node maintain the
binding cache about the mobile node's home address and care-of
address. However, since mobility related signaling is exchanged
between network entities in Proxy Mobile IPv6, it is expected that
route optimization is also performed by the network entities. Thus,
route optimization will create state on the network. Therefore,
route optimization solutions should be secure, lightweight, and
scalable. Also, since route optimization participants are network
entities, a mobile node and a correspondent node should not be aware
of route optimization procedures.
5.2. Trust Relationship
In Mobile IPv6 route optimization, it is assumed that the mobile node
and the correspondent node do not have any trust relationship [4],
whereas in Proxy Mobile IPv6, network entities that perform route
optimization are managed objects by the network and owned by the same
administrative domain. Thus, different approaches are possible to
establish trust relationship.
When route optimization support on the correspondent node side is
handled by Proxy Mobile IPv6, route optimization solutions need to
benefit from a trust relationship between network entities in Proxy
Mobile IPv6. However, we may not assume trust relationship between
network entities located in Proxy Mobile IPv6 domain.
When the correspondent node supports Mobile IPv6 and handles route
optimization itself, route optimization solutions cannot assume trust
relationship between network entities and the correspondent node.
5.3. Security Aspect
Security threats and limitations to route optimization in Mobile IPv6
are investigated in [4]. Return routability procedures [3] and
enhanced route optimization [5] address the threats without public-
key infrastructure or a preexisting relationship between the mobile
node and the correspondent node. Thus, route optimization solutions
in Proxy Mobile IPv6 also need to mitigate or to provide sufficient
defense against those security threats. When Proxy Mobile IPv6 route
optimization participants are administered within the same domain,
infrastructure-based authorization mechanisms, such as IPsec, also
may be usable.
Jeong (Ed.), et al. Expires May 22, 2008 [Page 6]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
5.4. Common Solution for IPv4 and IPv6
Proxy Mobile IPv6 base protocol specification and extension document
enable a Proxy Mobile IPv6 domain to support both IPv6 and IPv4. As
defined in the IPv4 extension document in Proxy Mobile IPv6 [2], the
mobile node and the correspondent node can be provided IPv4 home
address mobility in the Proxy Mobile IPv6 domain. Furthermore, the
transport network between mobile access gateway and local mobility
anchor can provide IPv4 transport and NAT may reside inside the
network. Thus, route optimization solutions should provide home
address mobility and transport support for both IPv6 and IPv4. Also,
in the case of IPv4 transport support, NAT traversal mechanism may
need to be in place.
5.5. Policy Control and Charging
In general, network operators that provide IP mobility service to the
mobile nodes want to monitor the user traffic for the purposes of
policy control and charging. Therefore, it is desirable to ensure
that route optimization solutions are designed so that network
operators can figure out where to place enforcement point of policy
control and charging.
6. Requirements
This section lists the requirements on route optimization for Proxy
Mobile IPv6.
R1: The route optimization solutions MUST NOT conflict with design
goals and requirements for network-based localized mobility
management as they are described in [6].
R2: The route optimization solutions SHOULD have no negative impact
on the scalability of a network-based localized mobility
management domain.
R3: Route optimization solutions SHOULD be scalable in Proxy Mobile
IPv6 domains.
R4: Route optimization solutions MAY use preconfigured or pre-
established information for authenticating/authorizing route
optimization participants and any signaling message for route
optimization.
Jeong (Ed.), et al. Expires May 22, 2008 [Page 7]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
R5: Any signaling message for route optimization SHOULD be
exchanged securely during route optimization procedures.
R6: Route optimization solutions SHOULD mitigate or provide
sufficient defense against possible security threats
investigated in [4].
R7: Route optimization solutions SHOULD maintain route optimization
states efficiently when mobile nodes handover in Proxy Mobile
IPv6 domain(s).
R8: Route optimization solutions SHOULD operate over IPv6 and IPv4
transport networks.
R9: Route optimization solutions MAY consider support both IPv6,
IPv4 and dual stack mobile nodes.
R10: Route optimization solutions MAY provide NAT traversal
mechanism for IPv4 private transport network.
R11: Route optimization solutions MUST NOT conflict with an
operator's policy to protect its network.
7. IANA Considerations
No action is required by IANA for this document.
8. Security Considerations
Security issues are handled in Section 5.3.
9. Contributors
This contribution is a joint effort of several people. The
contributors can be reached at (in alphabetical order):
Sangjin Jeong
sjjeong@etri.re.kr
Long Le
Long.Le@nw.neclab.eu
Jaehwoon Lee
Jeong (Ed.), et al. Expires May 22, 2008 [Page 8]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
jaehwoon@dongguk.edu
Marco Liebsch
liebsch@netlab.nec.de
Alice Qinxia
alice.Q@huawei.com
Behcet Sarikaya
bsarikaya@huawei.com
Shinta Sugimoto
shinta@sfc.wide.ad.jp
Christian Vogt
christian.vogt@ericsson.com
Ryuji Wakikawa
ryuji@sfc.wide.ad.jp
10. References
[1] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and
B. Patil, "Proxy Mobile IPv6, draft-ietf-netlmm-proxymip6-06
(work in progress)", September 2007.
[2] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy Mobile
IPv6, draft-ietf-netlmm-pmip6-ipv4-support-01 (work in
progress)", July 2007.
[3] Johnson, D., Perkins, C., and A. Arkko, "Mobility Support in
IPv6", RFC 3775, June 2004.
[4] Nikander, P., Aura, J., Montenegro, G., and E. Nordmark, "Mobile
IP Version 6 Route Optimization Security Design Background",
RFC 4225, December 2005.
[5] Arkko, J., Vogt, C., and W. Haddad, "Enhanced Route Optimization
for Mobile IPv6", RFC 4866, May 2007.
[6] Kempf, Ed., J., "Goals for Network-Based Localized Mobility
Management (NETLMM)", RFC 4831, April 2007.
Jeong (Ed.), et al. Expires May 22, 2008 [Page 9]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
Authors' Addresses
Sangjin Jeong
Electronics and Telecommunications Research Institute
138 Gajeongno, Yuseong
Daejeon, 305-700
Korea
Email: sjjeong@etri.re.kr
Christian Vogt
Ericsson Research, NomadicLab
Hirsalantie 11
02420 Jorvas,
Finland
Email: christian.vogt@ericsson.com
Ryuji Wakikawa
Keio University
5322 Endo
Fujisawa, Kanagawa 252-8520
Japan
Email: ryuji@sfc.wide.ad.jp
Marco Liebsch
NEC Network Laboratories
Kurfuersten-Anlage 36
69115 Heidelberg,
Germany
Email: liebsch@netlab.nec.de
Shinta Sugimoto
Nippon Ericsson K.K.
Koraku Mori Building
1-4-14, Koraku, Bunkyo-ku
Tokyo, 112-0004
Japan
Email: shinta.sugimoto@ericsson.com
Jeong (Ed.), et al. Expires May 22, 2008 [Page 10]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
Behcet Sarikaya
Huawei Technologies USA
1700 Alma Dr. Suite 500
Plano, TX 75075
USA
Email: sarikaya@ieee.org
Jeong (Ed.), et al. Expires May 22, 2008 [Page 11]
Internet-Draft Proxy Mobile IPv6 RO Problem Statement November 2007
Full Copyright Statement
Copyright (C) The IETF Trust (2007).
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.
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, THE IETF TRUST 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.
Intellectual Property
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.
Acknowledgment
Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA).
Jeong (Ed.), et al. Expires May 22, 2008 [Page 12]