A Taxonomy and Analysis of Enhancements to Mobile IPv6 Route Optimization
RFC 4651

Network Working Group                                            C. Vogt
Request for Comments: 4651                   Universitaet Karlsruhe (TH)
Category: Informational                                         J. Arkko
                                            Ericsson Research NomadicLab
                                                           February 2007

               A Taxonomy and Analysis of Enhancements to
                     Mobile IPv6 Route Optimization

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.

Copyright Notice

   Copyright (C) The IETF Trust (2007).

IESG Note:

   This RFC is a product of the Internet Research Task Force and is not
   a candidate for any level of Internet Standard.  The IRTF publishes
   the results of Internet-related research and development activities.
   These results might not be suitable for deployment.

Abstract

   This document describes and evaluates strategies to enhance Mobile
   IPv6 Route Optimization, on the basis of existing proposals, in order
   to motivate and guide further research in this context.  This
   document is a product of the IP Mobility Optimizations (MobOpts)
   Research Group.

Vogt & Arkko                 Informational                      [Page 1]
RFC 4651          MIP6 Route Optimization Enhancements     February 2007

Table of Contents

   1. Introduction ....................................................3
      1.1. A Note on Public-Key Infrastructures .......................4
      1.2. A Note on Source Address Filtering .........................5
   2. Objectives for Route Optimization Enhancement ...................7
      2.1. Latency Optimizations ......................................8
      2.2. Security Enhancements ......................................8
      2.3. Signaling Optimizations ....................................9
      2.4. Robustness Enhancements ....................................9
   3. Enhancements Toolbox ............................................9
      3.1. IP Address Tests ..........................................10
      3.2. Protected Tunnels .........................................10
      3.3. Optimistic Behavior .......................................11
      3.4. Proactive IP Address Tests ................................11
      3.5. Concurrent Care-of Address Tests ..........................12
      3.6. Diverted Routing ..........................................13
      3.7. Credit-Based Authorization ................................14
      3.8. Heuristic Monitoring ......................................17
      3.9. Crypto-Based Identifiers ..................................18
      3.10. Pre-Configuration ........................................19
      3.11. Semi-Permanent Security Associations .....................20
      3.12. Delegation ...............................................21
      3.13. Mobile Networks ..........................................21
      3.14. Location Privacy .........................................22
   4. Discussion .....................................................22
      4.1. Cross-Layer Interactions ..................................23
      4.2. Experimentation and Measurements ..........................23
      4.3. Future Research ...........................................24
   5. Security Considerations ........................................24
   6. Conclusions ....................................................25
   7. Acknowledgments ................................................25
   8. References .....................................................26
      8.1. Normative References ......................................26
      8.2. Informative References ....................................26

Vogt & Arkko                 Informational                      [Page 2]
RFC 4651          MIP6 Route Optimization Enhancements     February 2007

1.  Introduction

   Mobility support for IPv6, or Mobile IPv6, enables mobile nodes to
   migrate active transport connections and application sessions from
   one IPv6 address to another.  The Mobile IPv6 specification, RFC 3775
   [1], introduces a "home agent", which proxies a mobile node at a
   permanent "home address".  A roaming mobile node connects to the home
   agent through a bidirectional tunnel and can so communicate, from its
   local "care-of address", as if it was present at the home address.
   The mobile node keeps the home agent updated on its current care-of
   address via IPsec-protected signaling messages [40].

   In case the correspondent node lacks appropriate mobility support, it