RFC 3374 (rfc3374) - Page 3 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 exchanges. If the host is required to re-establish those services by the same process as it uses to initially establish them, delay- sensitive real time traffic may be seriously impacted. An alternative is to transfer enough information on the context transfer-candidate service state, or context, to the new subnet so that the services can be re-established quickly, rather than require the mobile host to establish them from scratch. The transfer of service context may be advantageous in minimizing the impact of host mobility on, for example, AAA, header compression, QoS, policy, and possibly sub-IP protocols and services such as PPP. Context transfer at a minimum can be used to replicate the configuration information needed to establish the respective protocols and services. In addition, it may also provide the capability to replicate state information, allowing stateful protocols and services at the new node to be activated along the new path with less delay and less signaling overhead. In this document, a case is made for why the Seamoby Working Group should investigate context transfer. 2.0 Reference Definitions Context The information on the current state of a service required to re- establish the service on a new subnet without having to perform the entire protocol exchange with the mobile host from scratch. Context Transfer The movement of context from one router or other network entity to another as a means of re-establishing specific services on a new subnet or collection of subnets. Context Transfer Candidate Service A service that is a candidate for context transfer. In this document, only services that are concerned with the forwarding treatment of packets, such as QoS and security, or involve granting or denying the mobile host access to the network, such as AAA, are considered to be context transfer-candidate services. 3.0 Scope of the Context Transfer Problem The context transfer problem examined in this document is restricted to re-establishing services for a mobile host that are, in some sense, related to the forwarding treatment of the mobile host's Kempf Informational
