RFC 3374 (rfc3374) - Page 2 of 14
Problem Description: Reasons For Performing Context Transfers Between Nodes in an IP Access Network
Alternative Format: Original Text Document
RFC 3374 Context Transfer Problem Statement September 2002
Table of Contents
1.0 Introduction................................................2
2.0 Reference Definitions.......................................3
3.0 Scope of the Context Transfer Problem.......................3
4.0 The Need for Context Transfer...............................4
4.1 Fast Context Transfer-candidate Service Re-establishment....4
4.1.1 Authentication, Authorization, and Accounting (AAA).........4
4.1.2 Header Compression..........................................5
4.1.3 Quality of Service (QoS)....................................6
4.2 Interoperability............................................6
5.0 Limitations on Context Transfer.............................7
5.1 Router Compatibility........................................7
5.2 Requirement to Re-initialize Service from Scratch...........7
5.3 Suitability for the Particular Service......................7
5.4 Layer 2 Solutions Better....................................7
6.0 Performance Considerations..................................8
7.0 Security Considerations.....................................8
8.0 Recommendations.............................................9
9.0 Acknowledgements............................................9
10.0 References.................................................10
11.0 Complete List of Authors' Addresses........................12
12.0 Full Copyright Statement...................................14
1.0 Introduction
In networks where the hosts are mobile, the routing path through the
network must often be changed in order to deliver the host's IP
traffic to the new point of access. Changing the basic routing path
is the job of a IP mobility protocol, such as Mobile IPv4 [1] and
Mobile IPv6 [2]. But the success of real time services such as VoIP
telephony, video, etc., in a mobile environment depends heavily upon
the minimization of the impact of this traffic redirection. In the
process of establishing the new routing path, the nodes along the new
path must be prepared to provide similar routing treatment to the IP
packets as was provided along the old routing path.
In many cases, the routing treatment of IP packets within a network
may be regulated by a collection of context transfer-candidate
services that influence how packets for the host are treated. For
example, whether a particular host has the right to obtain any
routing at all out of the local subnet may depend on whether the host
negotiated a successful AAA exchange with a network access server at
some point in the past. Establishing these services initially
results in a certain amount of related state within the network and
requires a perhaps considerable amount of time for the protocol
Kempf Informational