Problem Statement: Dual Stack Mobility
RFC 4977
Network Working Group G. Tsirtsis
Request for Comments: 4977 Qualcomm
Category: Informational H. Soliman
Elevate Technologies
August 2007
Problem Statement: Dual Stack Mobility
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Abstract
This document discusses the issues associated with mobility
management for dual stack mobile nodes. Currently, two mobility
management protocols are defined for IPv4 and IPv6. Deploying both
in a dual stack mobile node introduces a number of problems.
Deployment and operational issues motivate the use of a single
mobility management protocol. This document discusses such
motivations. The document also discusses requirements for the Mobile
IPv4 (MIPv4) and Mobile IPv6 (MIPv6) protocol so that they can
support mobility management for a dual stack node.
Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Introduction and Motivation . . . . . . . . . . . . . . . . . . 2
3. Problem Description . . . . . . . . . . . . . . . . . . . . . . 3
3.1. The Impossibility of Maintaining IP Connectivity . . . . . 4
3.2. Implementation Burdens . . . . . . . . . . . . . . . . . . 4
3.3. Operational Burdens . . . . . . . . . . . . . . . . . . . . 4
3.4. Mobility Management Inefficiencies . . . . . . . . . . . . 4
3.5. IPv4 to IPv6 Transition Mechanisms . . . . . . . . . . . . 5
4. Conclusions and Recommendations . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . . 6
Tsirtsis & Soliman Informational [Page 1]
RFC 4977 Problem Statement: Dual Stack Mobility August 2007
1. Terminology
This document uses the following terms as defined in Stateless IP/
ICMP Translation (SIIT) [RFC2765]: IPv4-capable node, IPv4-enabled
node, IPv6-capable node, IPv6-enabled node.
The following terms are introduced in this document:
- MIPv4-capable node:
A node that supports MIPv4 [RFC3344] in its 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 be IPv6-capable or IPv6-enabled and
must be IPv4-capable.
- MIPv6-capable node:
A node that supports MIPv6 [RFC3775] by configuring a 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 be
IPv6-capable.
2. Introduction and Motivation
A MIPv4-capable node can use Mobile IPv4 [RFC3344] to maintain
connectivity while moving between IPv4 subnets. Similarly, a MIPv6-
capable node can use Mobile IPv6 [RFC3775] to maintain connectivity
while moving between IPv6 subnets.
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
IPv6 addresses and thus can communicate with the current IPv4
Internet as well as any IPv6 nodes and networks as they become
available.
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
between IPv4 and IPv6 subnets. While this is possible, it does not
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:
Tsirtsis & Soliman Informational [Page 2]
RFC 4977 Problem Statement: Dual Stack Mobility August 2007
- Mobile nodes to be both MIPv4 and MIPv6 capable.
- Mobile nodes to send two sets of signaling messages on every
handoff.
- Network Administrators to run and maintain two sets of mobility
management systems on the same network, with each of these systems
requiring its own set of optimizations.
This document discusses the potential inefficiencies, IP connectivity
problems, and operational issues that are evident when running both
mobility management protocols simultaneously. It also proposes a
work area to be taken up by the IETF on the subject and discusses
requirements for appropriate solutions.
3. Problem Description
Show full document text