RFC 2103 (rfc2103) - Page 2 of 17

Mobility Support for Nimrod : Challenges and Solution Approaches

RFC 2103                Nimrod Mobility Support            February 1997


   this.  First, mobility is a non-trivial problem whose implications
   and requirements are still not well understood and will perhaps be
   understood only when a mobile internetwork is deployed on a large
   scale.  Second, a number of groups (for instance the Mobile-IP
   working group of the IETF) are studying the problem by itself and it
   is not our intention to duplicate those efforts.

   This attitude towards mobility is consistent with Nimrod's general
   philosophy of flexibility, adaptability and incremental change.

   While a mobility solution is not part of the "core" Nimrod
   architecture, Nimrod does require that the solution have certain
   characteristics.  It is the purpose of this document to discuss some
   of these requirements and evaluate approaches towards meeting them.

   We begin by identifying the precise nature of the functionality
   needed to accommodate mobile entities (section 2).  Following that,
   we discuss the effects of mobility on Nimrod (section 3).  Next, we
   classify current and possible approaches to a solution for mobility
   (section 4) and finally (in section 5) we describe how mobility can
   be implemented using the IETF's Mobile-IP protocol.

   This document uses many terms and concepts from the Nimrod
   Architecture document [CCS96] and some terms and concepts (in section
   5) from the Nimrod Functionality document [RS96].  Much of the
   discussion assumes that you have read at least the Nimrod
   Architecture document [CCS96].

2  Mobility :  A Modular Perspective

   Nimrod has a basic feature that helps accommodate mobility in a
   graceful and natural manner, namely, the separation of the endpoint
   naming space from the locator space.  The Nimrod architecture [CCS96]
   associates an endpoint with a globally unique endpoint identifier
   (EID) and an endpoint label (EL). The location of the endpoint within
   the Internetwork topology is given by its locator.  When an endpoint
   moves, its EID and EL remain the same, but its locator might change.
   Nimrod can route a packet to the endpoint after the move, provided it
   is able to obtain its new locator.












Ramanathan                   Informational