Home Agent-Assisted Route Optimization between Mobile IPv4 Networks
RFC 6521

Internet Engineering Task Force (IETF)                         A. Makela
Request for Comments: 6521                       Aalto University/Comnet
Category: Experimental                                       J. Korhonen
ISSN: 2070-1721                                   Nokia Siemens Networks
                                                           February 2012

  Home Agent-Assisted Route Optimization between Mobile IPv4 Networks

Abstract

   This document describes a home agent-assisted route optimization
   functionality for the IPv4 Network Mobility Protocol.  The function
   is designed to facilitate optimal routing in cases where all nodes
   are connected to a single home agent; thus, the use case is route
   optimization within a single organization or similar entity.  The
   functionality enables the discovery of eligible peer nodes (based on
   information received from the home agent) and their network prefixes,
   and the establishment of a direct tunnel between such nodes.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for examination, experimental implementation, and
   evaluation.

   This document defines an Experimental Protocol for the Internet
   community.  This document is a product of the Internet Engineering
   Task Force (IETF).  It represents the consensus of the IETF
   community.  It has received public review and has been approved for
   publication by the Internet Engineering Steering Group (IESG).  Not
   all documents approved by the IESG are a candidate for any level of
   Internet Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6521.

Makela & Korhonen             Experimental                      [Page 1]
RFC 6521                          HAaRO                    February 2012

Copyright Notice

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   document authors.  All rights reserved.

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Table of Contents

   1. Introduction and Motivations ....................................3
   2. Terms and Definitions ...........................................6
   3. Mobile IPv4 Route Optimization between Mobile Networks ..........8
      3.1. Maintaining Route Optimization Information .................9
           3.1.1. Advertising Route-Optimizable Prefixes ..............9
           3.1.2. Route Optimization Cache ...........................11
      3.2. Return Routability Procedure ..............................13
           3.2.1. Router Keys ........................................15
           3.2.2. Nonces .............................................15
           3.2.3. Updating Router Keys and Nonces ....................16
      3.3. Mobile-Correspondent Router Operations ....................16
           3.3.1. Triggering Route Optimization ......................17
           3.3.2. Mobile Router Routing Tables .......................17
           3.3.3. Inter-Mobile Router Registration ...................18
           3.3.4. Inter-Mobile Router Tunnels ........................20
           3.3.5. Constructing Route-Optimized Packets ...............21
           3.3.6. Handovers and Mobile Routers Leaving Network .......21
      3.4. Convergence and Synchronization Issues ....................22
   4. Data Compression Schemes .......................................23
      4.1. Prefix Compression ........................................23
      4.2. Realm Compression .........................................25
           4.2.1. Encoding of Compressed Realms ......................25
           4.2.2. Searching Algorithm ................................27
           4.2.3. Encoding Example ...................................27

Makela & Korhonen             Experimental                      [Page 2]
RFC 6521                          HAaRO                    February 2012

   5. New Mobile IPv4 Messages and Extensions ........................30
      5.1. Mobile Router Route Optimization Capability Extension .....30
      5.2. Route Optimization Reply ..................................31