Re: Internal WG Review: MIPv6 Signaling and Handoff Optimization (mipshop)

[gabriel montenegro <gab@sun.com>]

Harald Tveit Alvestrand wrote:
> as soon as we have an updated charter that documents this understanding 
> in a place where the community can see it, I'll be happy to pass on it.

Ok, attached, please find the revised charter.

Changes:

- clarified that item #4 is for informational status.
- added one paragraph after item #4 to capture our agreement to
  document the security issues as feedback to other efforts or
  groups.
- modified milestones slightly to take into account the new extra
  work.

tnx,

-gabriel



Mobile IPv6 specifies routing support to permit IP hosts using IPv6 to
move between IP subnetworks while maintaining session
continuity. Mobile IPv6 supports transparency above the IP layer,
including maintenance of active TCP connections and UDP port bindings.

To accomplish this, the mobile node notifies its home agent (and
potentially also its correspondent nodes) of the current binding between its
home address and its care of address. This binding allows a mobile node
to maintain connectivity with the Internet as it moves between
subnets.

Depending on what steps a mobile node must perform on a new subnet, the
lag between when the mobile node has layer 2 connectivity and when it
begins sending and receiving packets on the new link may be substantial. A
mobile node must first detect at layer 3 that its point of attachment has
changed, then it must perform configuration on the new link, including
router discovery and configuring a new care of address. After that,
the mobile node must perform binding updates with the home address and
any correspondent nodes.  Any packets between the correspondent node
and the mobile node sent or in-flight during this time arrive at the
old care of address, where they are dropped since the mobile node no
longer has link connectivity with the old subnet. Such packet loss may
have significant adverse effects.

The Mobile IP Working group had previously been developing two
technologies to address the issues of signaling overhead and handoff
latency/packet loss:

 - Hierarchical Mobile IPv6 mobility management (HMIPv6)

   HMIPv6 deals with reducing the amount and latency of signaling
   between a MN, its Home Agent and one or more correspondents by
   introducing the Mobility Anchor Point (MAP) (a special node located
   in the network visited by the mobile node).  The MAP acts somewhat
   like a local home agent for the visiting mobile node by limiting
   the amount of signaling required outside the MAP's domain.

 - Fast Handovers for Mobile IPv6 (FMIPv6)

   FMIPv6 reduces packet loss by providing fast IP connectivity as
   soon as a new link is established. It does so by fixing up the
   routing during link configuration and binding update, so that
   packets delivered to the old care of address are forwarded to the
   new. In addition, FMIPv6 provides support for preconfiguration of
   link information (such as the subnet prefix) in the new subnet
   while the mobile node is still attached to the old subnet. This
   reduces the amount of preconfiguration time in the new subnet.

These two technologies can be used separately or together to reduce or
eliminate signaling overhead and packet loss due to handoff delays in
Mobile IPv6.

Scope of MIPSHOP:

The MIPSHOP Working Group will complete the FMIPv6 and HMIPv6 work
begun in the Mobile IP Working Group. Specifically, the WG will:

1) Complete the specification of HMIPv6 protocol.

2) Complete the specification of FMIPv6 protocol.

   Because work (ongoing or originating) in other working groups may
   suggest changes or alternative designs for HMIPv6 and FMIPv6, these
   specifications will be advanced as Experimental RFCs until more
   experience is obtained with IP mobility in IPv6.

3) Complete work on a set of requirements for "Localized Mobility
   Management (LMM)", whereby a Mobile Node is able to continue
   receiving packets in a new subnet before the corresponding changes
   in either the Home Agent or Correspondent Node binding.  It is the
   intention that the requirements be consistent with the FMIPv6 and
   HMIPv6 protocols; in the event that there are inconsistencies, they
   will be documented.

4) Complete work on the applicability of FMIPv6 in the specific case
   of 802.11 networks for advancement as Informational RFC.

Additionally, there are new security issues that arise because of
the highly dynamic nature of the security relationships between, say,
a mobile node and its mobility anchor points, or--to an even greater
extreme--between a mobile node and its access routers in a fast handover
scenario. These new problems are not yet entirely understood and
may not be conclusively solved in the experimental and informational
protocol specifications produced by the working group. Nevertheless,
the working group will document the shortcomings in the corresponding
protocol specifications.  This will provide valuable feedback to other
groups or subsequent efforts.


Schedule
--------

OCT 03 - Working Group Last Call on draft-ietf-mipshop-lmm-requirements-XX.txt

NOV 03 - Working Group Last Call on draft-ietf-mipshop-hmip-xx.txt.

NOV 03 - Discuss Last Call comments and security analyses at IETF 58.

DEC 03 - Working Group Last Call on draft-ietf-mipshop-fmipv6-xx.txt.

DEC 03 - Submit draft draft-ietf-mipshop-lmm-requirements-XX.txt to IESG
	 for consideration of publication as Informational.

JAN 04 - Submit draft-ietf-mipshop-hmip-xx.txt to IESG for consideration 
	 of publication as Experimental.

FEB 04 - Submit draft-ietf-mipshop-fmipv6-xx.txt to IESG for consideration 
	 of publication as Experimental.

FEB 04 - Working Group Last Call on draft-ietf-mipshop-80211fh-xx.txt
         for Informational

APR 04 - Submit draft-ietf-mipshop-80211fh-xx.txt to IESG for 
	 consideration of publication as Informational.