draft-ietf-mip6-dsmip-problem-02.txt   draft-ietf-mip6-dsmip-problem-03.txt 
INTERNET Draft George Tsirtsis Network Working Group G. Tsirtsis
Internet-Draft Qualcomm
Expires: Jan 2007 Hesham Soliman Intended status: Standards Track H. Soliman
Expires: July 23, 2007 Elevate Technologies
January 19, 2007
Qualcomm Problem Statement: Dual Stack Mobility
Mobility management for Dual stack mobile nodes draft-ietf-mip6-dsmip-problem-03.txt
A Problem Statement
<draft-ietf-mip6-dsmip-problem-02.txt>
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This document is a submission of the IETF MIP6 WG. Comments should be This Internet-Draft will expire on July 23, 2007.
directed to the IPv6 WG mailing list, mip6@ietf.org. Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract Abstract
This draft discusses the issues associated with mobility management This draft discusses the issues associated with mobility management
for dual stack mobile nodes. Currently, two mobility management for dual stack mobile nodes. Currently, two mobility management
protocols are defined for IPv4 and IPv6. Deploying both in a dual protocols are defined for IPv4 and IPv6. Deploying both in a dual
stack mobile node introduces a number of inefficiencies. Deployment stack mobile node introduces a number of problems. Deployment and
and operational issues motivate the use of a single mobility operational issues motivate the use of a single mobility management
management protocol. This draft discusses such motivations. The draft protocol. This draft discusses such motivations. The draft also
discusses requirements for the Mobile IPv4 and Mobile IPv6 protocol
so that they can support mobility management for a dual stack node.
also hints on how the current [MIPv4] and [MIPv6] protocols could be Table of Contents
extended so that they can support mobility management for a dual
stack node.
1. Terminology 1. Requirements Notation . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Introduction and Motivation . . . . . . . . . . . . . . . . . 5
4. Problem Description . . . . . . . . . . . . . . . . . . . . . 6
4.1. The impossibility of Maintaining IP Connectivity . . . . . 6
4.2. Implementation Burdens . . . . . . . . . . . . . . . . . . 6
4.3. Operational Burdens . . . . . . . . . . . . . . . . . . . 7
4.4. Mobility Management Inefficiencies . . . . . . . . . . . . 7
4.5. IPv4 to IPv6 Transition Mechanisms . . . . . . . . . . . . 7
5. Conclusions and Recommendations . . . . . . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
8. Changes from version .02 . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
9.1. Normative References . . . . . . . . . . . . . . . . . . . 13
9.2. Informative References . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14
Intellectual Property and Copyright Statements . . . . . . . . . . 15
In addition to [KEYWORDS], this draft uses the following terms as 1. Requirements Notation
defined in [SIIT]: IPv4-capable node, IPv4-enabled node, IPv6-capable
node, IPv6-enabled node. 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].
2. Terminology
In addition to [RFC2119], this draft uses the following terms as
defined in SIIT [RFC2765]: IPv4-capable node, IPv4-enabled node,
IPv6-capable node, IPv6-enabled node.
The following terms are introduced in this document: The following terms are introduced in this document:
- MIPv4-capable node: A node that supports [MIPv4] in its - MIPv4-capable node:
implementation. This allows the mobile node to
configure a home address (statically or
dynamically) and use such address in its Mobile
IPv4 signaling. A MIPv4-capable node may also A node that supports MIPv4 [RFC3344] in its implementation. This
be IPv6-capable or IPv6-enabled and must be allows the mobile node to configure a home address (statically or
IPv4-capable. dynamically) and use such address in its Mobile IPv4 signaling. A
MIPv4-capable node may also be IPv6-capable or IPv6-enabled and
must be IPv4-capable.
- MIPv6-capable node: A node that supports [MIPv6] by configuring a - MIPv6-capable node:
home address and using such address in its
Mobile IPv6 signaling. A MIPv6-enabled node may
also be IPv4-capable or IPv4-enabled and must A node that supports MIPv6 [RFC3775] by configuring a home address
be IPv6-capable. and using such address in its Mobile IPv6 signaling. A MIPv6-
enabled node may also be IPv4-capable or IPv4-enabled and must be
IPv6-capable.
2. Introduction and motivation 3. Introduction and Motivation
A MIPv4-capable node can use Mobile IPv4 [MIPv4] to maintain A MIPv4-capable node can use Mobile IPv4 [RFC3344] to maintain
connectivity while moving between IPv4 subnets. Similarly, a MIPv6- connectivity while moving between IPv4 subnets. Similarly, a MIPv6-
capable node can use Mobile IPv6 [MIPv6] to maintain connectivity capable node can use Mobile IPv6 [RFC3775] to maintain connectivity
while moving between IPv6 subnets. while moving between IPv6 subnets.
One of the ways of migrating to IPv6 is to deploy nodes that are both One of the ways of migrating to IPv6 is to deploy nodes that are both
IPv4 and IPv6 capable. Such nodes will be able to get both IPv4 and IPv4 and IPv6 capable. Such nodes will be able to get both IPv4 and
IPv6 addresses and thus can communicate with the current IPv4 IPv6 addresses and thus can communicate with the current IPv4
Internet as well as any IPv6 nodes and networks as they become Internet as well as any IPv6 nodes and networks as they become
available. available.
A node that is both IPv4 and IPv6 capable can use Mobile IPv4 for its A node that is both IPv4 and IPv6 capable can use Mobile IPv4 for its
IPv4 stack and Mobile IPv6 for its IPv6 stack so that it can move IPv4 stack and Mobile IPv6 for its IPv6 stack so that it can move
between IPv4 and IPv6 subnets. While this is possible, it is also between IPv4 and IPv6 subnets. While this is possible, it does not
clearly inefficient since it requires: ensure connectivity since that also depends on the IP version support
of the network accessed. Supporting Mobile IPv4 and Mobile IPv6 is
also more inefficient since it requires:
- Mobile nodes to be both MIPv4 and MIPv6 capable. - Mobile nodes to be both MIPv4 and MIPv6 capable.
- Mobile nodes to send two sets of signaling messages on every - Mobile nodes to send two sets of signaling messages on every
handoff. handoff.
- Network Administrators to run and maintain two sets of mobility - Network Administrators to run and maintain two sets of mobility
management systems on the same network. Each of these systems management systems on the same network. Each of these systems
requiring their own sets of optimizations that may include requiring their own set of optimizations.
hierarchical Mobile IPv4, hierarchical Mobile IPv6 and Fast
Handoffs for Mobile IPv4, mechanisms that are currently in
development in the IETF.
This draft discusses the potential inefficiencies, IP connectivity This draft discusses the potential inefficiencies, IP connectivity
problems, and operational issues that are evident when running both problems, and operational issues that are evident when running both
mobility management protocols simultaneously. It also proposes a work mobility management protocols simultaneously. It also proposes a
work area to be taken up by the IETF on the subject and discusses
area to be taken up by the IETF on the subject and hints on a requirements for appropriate solutions.
possible direction for appropriate solutions.
3.0 Problem description 4. Problem Description
Mobile IP (v4 and v6) uses a signaling protocol (Registration Mobile IP (v4 and v6) uses a signaling protocol (Registration
requests in [MIPv4] and Binding updates in [MIPv6]) to set up tunnels requests in MIPv4 [RFC3344] and Binding updates in MIPv6 [RFC3775])
to set up tunnels between two end points. At the moment, Mobile IP
between two end points. At the moment Mobile IP signaling is tightly signaling is tightly coupled to the address family (i.e., IPv4 or
coupled with the "address family (i.e., IPv4 or IPv6)" used in the IPv6) used, in the connections it attempts to manipulate. There are
connections it attempts to manipulate. There are no fundamental no fundamental technical reasons for such coupling. If Mobile IP
technical reasons for such coupling. If Mobile IP were viewed as a were viewed as a tunnel setup protocol, it should be able to setup IP
tunnel setup protocol, it should be able to setup IP in IP tunnels, in IP tunnels, independently of the IP version used in the outer and
independently of the IP version used in the outer and inner headers. inner headers. Other protocols, for example SIP [RFC3261], are able
Other protocols, for example SIP, are able to use either IPv4 or IPv6 to use either IPv4 or IPv6 based signaling plane to manipulate IPv4
and IPv6 connections.
based signaling plane to manipulate IPv4 and IPv6 connections.
A node that is both MIPv4 and MIPv6 capable, will require the A node that is both MIPv4 and MIPv6 capable, will require the
following to roam within the Internet: following to roam within the Internet:
- The network operator needs to ensure that the home agent supports - The network operator needs to ensure that the home agent
both protocols or that it has two separate Home Agents supporting supports both protocols or that it has two separate Home Agents
the two protocols, each requiring its own management. supporting the two protocols, each requiring its own management.
- Double the amount of configuration in the mobile node and the home
agent (e.g., security associations). - Double the amount of configuration in the mobile node and the
- Local network optimizations for handovers will also need to be home agent (e.g., security associations).
duplicated.
We argue that all of the above will hinder the deployment of Mobile - IP layer local network optimizations for handovers will also
IPv6 as well as any dual stack solution in a mobile environment. We need to be duplicated.
will discuss some of the issues with the current approach separately
in the following sections.
3.1. Implementation burdens We argue that all of the above will make the deployment of Mobile
IPv6 as well as any dual stack solution in a mobile environment
harder. We will discuss some of the issues with the current approach
separately in the following sections.
As mentioned above, a node that is IPv4 and IPv6 capable must also be 4.1. The impossibility of Maintaining IP Connectivity
Even if a mobile node is both MIPv4 and MIPv6 capable, connectivity
across different networks would not in fact be guaranteed since that
also depends on the IPv4/IPv6 capabilities of the networks the mobile
is visiting; i.e., a node attempting to connect via a IPv4 only
network would not be able to maintain connectivity of its IPv6
applications and vice versa. This is potentially the most serious
problem discussed in this document.
4.2. Implementation Burdens
As mentioned above, a node that is IPv4 and IPv6 capable must also be
MIPv4 and MIPv6 capable to roam within the Internet. Clearly this MIPv4 and MIPv6 capable to roam within the Internet. Clearly this
will add implementation efforts, which, we argue, are not necessary. increases the complexity of implementations for vendors that decide
to support both protocols.
In addition to the implementation efforts, some vendors may not Some vendors, however, may not support both protocols in either
support both protocols in either mobile nodes or home agents. mobile nodes or home agents. Although this is more of a commercial
Although this is more of a commercial issue, it does affect the issue, it does affect the large-scale deployment of mobile devices on
large-scale deployment of mobile devices on the Internet. the Internet.
3.2. Operational burdens 4.3. Operational Burdens
As mentioned earlier, deploying both protocols will require managing As mentioned earlier, deploying both protocols will require managing
both protocols in the mobile node and the home agent. This adds both protocols in the mobile node and the home agent. This adds
significant operational issues for the network operator. It would significant operational issues for the network operator. It would
certainly require the network operator to have deep knowledge in both certainly require the network operator to have deep knowledge in both
protocols which is something an operator may not be able to justify protocols which is something an operator may not be able to justify
due to the lack of substantial gains. due to the lack of substantial gains.
In addition, deploying both protocols will require duplication of In addition, deploying both protocols will require duplication of
security credentials on mobile nodes and home agents. This includes, security credentials on mobile nodes and home agents. This includes,
IPsec security associations, keying material, and new authentication IPsec security associations, keying material, and new authentication
protocols for Mobile IPv6, in addition to the security credentials protocols for Mobile IPv6, in addition to the security credentials
and associations required by Mobile IPv4. Such duplication is again and associations required by Mobile IPv4. Depending on the security
significant with no gain to the operator or the mobile node. mechanisms used and with some further work it might be possible to
optimize some of these processes. Assuming nothing else changes,
however, such duplication is again significant with no gain to the
operator or the mobile node.
3.3. Mobility management inefficiencies 4.4. Mobility Management Inefficiencies
Suppose that a mobile node is moving within a dual stack access Suppose that a mobile node is moving within a dual stack access
network. Every time the mobile node moves it needs to send two mobile network. Every time the mobile node moves it needs to send two
mobile IP messages to its home agent to allow its IPv4 and IPv6
IP messages to its home agent to allow its IPv4 and IPv6 connections connections to survive. There is no reason for such duplication. If
to survive. There is no reason for such duplication. If local local mobility optimizations were deployed (e.g., Hierarchical Mobile
mobility optimizations were deployed (e.g., hierarchical Mobile IP, IPv6 [RFC4140], Fast handovers for Mobile IPv4 [RFC4068]) the mobile
Fast handovers or local MIPv4 HA), the mobile node will need to node will need to update the local agents running each protocol.
update the local agents running each protocol. Ironically, one local Ironically, one local agent might be running both HMIPv6 and local
agent might be running both HMIPv6 and local MIPv4 home agent. MIPv4 home agent. Clearly, it is not desirable to have to send two
Clearly, it is not desirable to have to send two messages and messages and complete two sets of transactions for the same
complete two sets of transactions for the same fundamental fundamental optimization.
optimization.
Hence, such parallel operation of Mobile IPv4 and Mobile IPv6 will Hence, such parallel operation of Mobile IPv4 and Mobile IPv6 will
complicate mobility management within the Internet and increase the complicate mobility management within the Internet and increase the
amount of bandwidth needed at the critical handover time for no amount of bandwidth needed at the critical handover time for no
apparent gain. apparent gain.
3.4. The impossibility of maintaining IP connectivity 4.5. IPv4 to IPv6 Transition Mechanisms
A final point to consider is that even if a mobile node is both MIPv4
and MIPv6 capable, connectivity across different networks would not The IETF has standardized a number of transition mechanisms to allow
in fact be guaranteed since that also depends on the IPv4/IPv6 networks and end nodes to gain IPv6 connectivity while the Internet
capabilities of the networks the mobile is visiting; i.e., a node is migrating from IPv4 to IPv6. A cursory examination of such
attempting to connect via a IPv4 only network would not be able to transition mechanisms indicates that none of them is designed to deal
maintain connectivity of its IPv6 applications and vice versa. This with mobile nodes. While some transition mechanisms can be combined
is potentially the most serious problem discussed in this document. with Mobile IPv4 or Mobile IPv6, non of the known mechanisms have
been shown to assist with the issues described in this document.
4. Conclusion and recommendations 5. Conclusions and Recommendations
The points above highlight the tight coupling in both Mobile IPv4 and The points above highlight the tight coupling in both Mobile IPv4 and
Mobile IPv6 between signaling and the IP addresses used by upper Mobile IPv6 between signaling and the IP addresses used by upper
layers. Given that Mobile IPv4 is currently deployed and Mobile IPv6 layers. Given that Mobile IPv4 is currently deployed and Mobile IPv6
is expected to be deployed, there is a need for gradual transition is expected to be deployed, there is a need for gradual transition
from IPv4 mobility management to IPv6. Running both protocols from IPv4 mobility management to IPv6. Running both protocols
simultaneously is inefficient and has the problems described above. simultaneously is inefficient and has the problems described above.
The gradual transition can be done when needed or deemed appropriate The gradual transition can be done when needed or deemed appropriate
by operators or implementers. In the mean time, it is important to by operators or implementers. In the mean time, it is important to
ensure that the problems listed above can be avoided. Hence, this ensure that the problems listed above can be avoided. Hence, this
section lists some actions that should be taken by the IETF to section lists some actions that should be taken by the IETF to
address the problems listed above, without mandating the use of two address the problems listed above, without mandating the use of two
skipping to change at page 5, line 9 skipping to change at page 9, line 21
from IPv4 mobility management to IPv6. Running both protocols from IPv4 mobility management to IPv6. Running both protocols
simultaneously is inefficient and has the problems described above. simultaneously is inefficient and has the problems described above.
The gradual transition can be done when needed or deemed appropriate The gradual transition can be done when needed or deemed appropriate
by operators or implementers. In the mean time, it is important to by operators or implementers. In the mean time, it is important to
ensure that the problems listed above can be avoided. Hence, this ensure that the problems listed above can be avoided. Hence, this
section lists some actions that should be taken by the IETF to section lists some actions that should be taken by the IETF to
address the problems listed above, without mandating the use of two address the problems listed above, without mandating the use of two
mobility management protocols simultaneously. mobility management protocols simultaneously.
In order to allow for a gradual transition based on current standards In order to allow for a gradual transition based on current standards
and deployment, the following work areas seem to be reasonable: and deployment, the following work areas seem to be reasonable:
- It should be possible to run one mobility management protocol that - It should be possible to run one mobility management protocol
can manage mobility for both IPv4 and IPv6 addresses used by upper that can manage mobility for both IPv4 and IPv6 addresses used by
layers. Both Mobile IPv4 and Mobile IPv6 should be able of performing upper layers. Both Mobile IPv4 and Mobile IPv6 should be able of
performing such task. It may not be possible to support route
optimization for Mobile IPv6 in all cases; however, mobility
management and session continuity can be supported.
such task. It may not be possible to support route optimization for - It should be possible to create IPv4 extensions to Mobile IPv6
Mobile IPv6 in all cases; however, mobility management and session so that an IPv4 and IPv6 capable mobile node can register its IPv4
continuity can be supported. and IPv6 home addresses to an IPv4 and IPv6 enabled Home Agent
using MIPv6 signaling only.
- It should be possible to create IPv4 extensions to Mobile IPv6 so - It should be possible to create IPv6 extensions to Mobile IPv4
that an IPv4 and IPv6 capable mobile node can register its IPv4 and so that an IPv4 and IPv6 capable mobile node can register its IPv4
IPv6 home addresses to an IPv4 and IPv6 enabled Home Agent using and IPv6 home addresses to an IPv4 and IPv6 enabled Home Agent
MIPv6 signaling only. using Mobile IPv4 signaling only.
- It should be possible to create IPv6 extensions to Mobile IPv4 so
that an IPv4 and IPv6 capable mobile node can register its IPv4 and - It should also be possible to extend MIPv4 [RFC3344] and MIPv6
IPv6 home addresses to an IPv4 and IPv6 enabled Home Agent using [RFC3775] so that a mobile node can register a single care-of
Mobile IPv4 signaling only. address (IPv4 or IPv6) to which IPv4 and/or IPv6 packets can be
- It should also be possible to extend [MIPv4] and [MIPv6] so that a tunneled.
mobile node can register a single care-of address (IPv4 or IPv6) to
which IPv4 and/or IPv6 packets can be tunneled.
Following the steps listed above, a vendor can choose to support one Following the steps listed above, a vendor can choose to support one
mobility management protocol while avoiding the incompatibility and mobility management protocol while avoiding the incompatibility and
inefficiency problems listed in this document. Similarly, operators inefficiency problems listed in this document. Similarly, operators
can decide to continue using one mobility management protocol while can decide to continue using one mobility management protocol while
addressing the transition scenarios that a mobile node is likely to addressing the transition scenarios that a mobile node is likely to
face when roaming within the Internet. face when roaming within the Internet.
Further work in this area, possibly independent of Mobile IP, may 6. Security Considerations
also be of interest to some parties in which case it should be dealt
with separately from the incremental Mobile IP based changes.
5. Authors Addresses This documents is a problem statement which does not by itself
introduce any security issues.
George Tsirtsis 7. IANA Considerations
Qualcomm Flarion Technologies
Phone: +1 908 947 7059
E-Mail: Tsirtsis@Qualcomm.com
E-Mail2: tsirtsisg@yahoo.com
Hesham Soliman This document does not introduce any IANA considerations.
Qualcomm Flarion Technologies
Phone: +1 908 997 9775
E-mail: HSoliman@Qualcomm.com
6. References 8. Changes from version .02
[KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate - Re-wrote draft using XML template
- Changed title to fit in under 47 characters
- Rearranged subsections under Section 4
- In Section 4.2, clarified that implementation complexity is
increased for vendors that decide to support both versions of the
protocol
- In Section 4.3, clarified that some optimizations might be
possible with respect to duplicated security mechanisms for MIPv4
and MIPv6
- Added a section on transition mechanisms (Section 4.5)
- Added "Security Considerations" Section 6
- General clean up and a number editorial corrections.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[MIPv4] Perkins, C., "IP Mobility Support for IPv4", RFC 3344, [RFC2765] Nordmark, E., "Stateless IP/ICMP Translation Algorithm
(SIIT)", RFC 2765, February 2000.
[RFC3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344,
August 2002. August 2002.
[MIPv6] Conta, A. and S. Deering, "Generic Packet Tunneling in [RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
IPv6 Specification", RFC 2473, December 1998. in IPv6", RFC 3775, June 2004.
[SIIT] Nordmark, E., "Stateless IP/ICMP Translator (SIIT)", RFC 9.2. Informative References
2765, February 2000. [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
June 2002.
Intellectual Property Statement [RFC4068] Koodli, R., "Fast Handovers for Mobile IPv6", RFC 4068,
July 2005.
[RFC4140] Soliman, H., Castelluccia, C., El Malki, K., and L.
Bellier, "Hierarchical Mobile IPv6 Mobility Management
(HMIPv6)", RFC 4140, August 2005.
Authors' Addresses
George Tsirtsis
Qualcomm
Phone: +908-443-8174
Email: tsirtsis@qualcomm.com
Hesham Soliman
Elevate Technologies
Phone: +614-111-410-445
Email: hesham@elevatemobile.com
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
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OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
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Full Copyright Statement
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except as set forth therein, the authors retain all their 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
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ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
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This Internet-Draft expires January, 2007. Funding for the RFC Editor function is provided by the IETF
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