Mobile IPv6 Fast Handovers
RFC 5268

Network Working Group                                     R. Koodli, Ed.
Request for Comments: 5268                              Starent Networks
Obsoletes: 4068                                                June 2008
Category: Standards Track

                       Mobile IPv6 Fast Handovers

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Abstract

   Mobile IPv6 enables a Mobile Node (MN) to maintain its connectivity
   to the Internet when moving from one Access Router to another, a
   process referred to as handover.  During handover, there is a period
   during which the Mobile Node is unable to send or receive packets
   because of link switching delay and IP protocol operations.  This
   "handover latency" resulting from standard Mobile IPv6 procedures,
   namely movement detection, new Care-of Address configuration, and
   Binding Update, is often unacceptable to real-time traffic such as
   Voice over IP (VoIP).  Reducing the handover latency could be
   beneficial to non-real-time, throughput-sensitive applications as
   well.  This document specifies a protocol to improve handover latency
   due to Mobile IPv6 procedures.  This document does not address
   improving the link switching latency.

Koodli, Ed.                 Standards Track                     [Page 1]
RFC 5268                  MIP6 Fast Handovers                  June 2008

Table of Contents

   1. Introduction ....................................................3
   2. Terminology .....................................................3
   3. Protocol Overview ...............................................6
      3.1. Addressing the Handover Latency ............................6
      3.2. Protocol Operation .........................................8
      3.3. Protocol Operation during Network-Initiated Handover ......11
   4. Protocol Details ...............................................11
   5. Other Considerations ...........................................15
      5.1. Handover Capability Exchange ..............................15
      5.2. Determining New Care-of Address ...........................16
      5.3. Prefix Management .........................................16
      5.4. Packet Loss ...............................................17
      5.5. DAD Handling ..............................................18
      5.6. Fast or Erroneous Movement ................................19
   6. Message Formats ................................................20
      6.1. New Neighborhood Discovery Messages .......................20
           6.1.1. Router Solicitation for Proxy Advertisement
                  (RtSolPr) ..........................................20
           6.1.2. Proxy Router Advertisement (PrRtAdv) ...............22
      6.2. Inter - Access Router Messages ............................25
           6.2.1. Handover Initiate (HI) .............................25
           6.2.2. Handover Acknowledge (HAck) ........................27
      6.3. New Mobility Header Messages ..............................28
           6.3.1. Fast Binding Update (FBU) ..........................28
           6.3.2. Fast Binding Acknowledgment (FBack) ................30
      6.4. Unsolicited Neighbor Advertisement (UNA) ..................31
      6.5. New Options ...............................................32
           6.5.1. IP Address/Prefix Option ...........................33
           6.5.2. Link-Layer Address (LLA) Option ....................34
           6.5.3. Mobility Header Link-Layer Address (MH-LLA)
                  Option .............................................35
           6.5.4. Binding Authorization Data for FMIPv6 (BADF) .......35
           6.5.5. Neighbor Advertisement Acknowledgment (NAACK) ......36
   7. Related Protocol and Device Considerations .....................37
   8. Evolution from and Compatibility with RFC 4068 .................38
   9. Configurable Parameters ........................................39
   10. Security Considerations .......................................39
      10.1. Peer Authorization Database Entries when Using IKEv2 .....41
      10.2. Security Policy Database Entries .........................42
   11. IANA Considerations ...........................................42
   12. Acknowledgments ...............................................43
   13. References ....................................................44
      13.1. Normative References .....................................44
      13.2. Informative References ...................................45