Subject: WG Review: Network-based Localized Mobility Management (netlmm)

From: The IESG <[email-masked]>
Date: Wed, 21 Dec 2005 09:40:15 -0500

A new IETF working group has been proposed in the Internet Area. The IESG has
not made any determination as yet. The following draft charter was submitted,
and is provided for informational purposes only.  Please send your comments to
the IESG mailing list ([email-masked]) by December 28th.

+++

Network-based Localized Mobility Management (netlmm)
====================================================

Current Status: Proposed Working Group

Chairs
------
TBD

Internet Area Director(s):
Mark Townsley <[email-masked]>
Margaret Wasserman <[email-masked]>

Internet Area Advisor:
Margaret Wasserman <[email-masked]>

Mailing List
------------
[email-masked]
https://vesuvio.ipv6.cselt.it/mailman/listinfo/netlmm to subscribe

Charter
-------

There is considerable evidence that mobility for IP nodes can be more
efficiently handled if mobility management is broken down into localized
mobility management and global mobility management. Local mobility involves
movements across some administratively and geographically contiguous set of
subnets, while global mobility involves movements across broader administrative,
geographical, and topological domains. Previous work in the IETF has focused on
supporting localized mobility management for a Mobile IPv6 node, and the
protocols developed have required mobile node-side support at the IP layer.
Recently in the IETF, new work on global mobility management approaches other
than Mobile IPv6 suggests that a localized mobility management approach
decoupled from the global mobility management protocol might result in a more
modular mobility management system design and therefore more longevity and an
easier evolution path. In the WLAN infrastructure market, WLAN switches, which
perform localized mobility management without any mobile node involvement , have
seen widespread deployment, indicating the technical feasibility and positive
user acceptance of this approach. This suggests a design paradigm that could be
used to accommodate global mobility management protocols of different types
while not increasing software complexity: a network-based, localized mobility
protocol with no mobile node software to specifically implement localized
mobility management and no requirement for a network interface to change IP
address when the mobile node changes to a new router. The task of the NETLMM
Working Group is to design a protocol solution for network-based localized
mobility management. 
The network-based localized mobility management protocol will conform to the
following framework. Mobility anchor points within the backbone network maintain
a collection of routes for individual mobile nodes.
The routes point to the access routers on which mobile nodes currently are
located. Packets for the mobile node are routed to and from the mobile node
through the mobility anchor point. When a mobile node moves from one access
router to another, the access routers send a route update to the mobility anchor
point.  While some mobile node involvement is necessary and expected for generic
mobility functions such as movement detection and to inform the access router
about mobile node movement, no specific mobile node to network protocol will be
required for localized mobility management itself. The working group will
develop a protocol between the access routers and mobility anchor points that
minimally has the following functions:

- Handles a new mobile node that powers on or moves from another localized
mobility management domain, or an existing mobile node that shuts down without
any notice (i.e. crashes), - Handles routing update when a mobile node moves
from one access router to another within the localized mobility management
domain,The necessity for additional protocol functions may arise during Working
Group discussions, so this list should not be taken as final.

The protocol will be independent of any particular global mobility management
protocol, and it will be link-layer agnostic by running on top of IP.
The protocol itself will be agnostic with respect to the last hop link layer
protocol between the mobile node and the access router.  Adaptation of the
protocol to different kinds of last hop link layers is accomplished through an
interface on the access router common to all link layers under which specific
link layer mechanisms (possibly together with authentication mechanisms) can
provide a reliable handover indication and unique identity for the mobile node.
This will enable the access router to do a route update using NETLMM on behalf
of the mobile node. In addition to the NETLMM protocol document, the Working
Group will produce an informational document that describes how existing and
developing IETF standards for node to access router communication on the local
link can be used to accomplish secure triggering of route update. This document
will be informational only, because some link protocols are expected to provide
their own mechanisms.  The scope of the work is initially limited to IPv6 both
in the backbone and on the edges, and is primarily for networks covering larger
geographical regions such as multiple corporate campuses and metropolitian
areas. The protocol will not attempt to hide handover between two separate
interfaces on the mobile node.
The protocol will not define a new tunneling protocol but will reuse existing IP
tunneling mechanisms if necessary. The NETLMM protocol will maintain
compatibility with other IETF standards, both existing and developing, such as
DNS, DNA, and global mobility protocols such as Mobile IPv6 and NEMO Basic
Support.

Security between access routers and the mobility anchor will be defined for the
protocol based on an IETF-approved threat model giving preference to existing
security solutions where applicable. The threat model will be described in a
document delivered sufficiently in advance of completion of the protocol design
that the protocol design can accommodate mitigation measures. In addition, the
mobile node to router interfacea document will describe threats to the protocol
when the default, IP-level mobile nodea to router protocol is used, and will
prescribe how existing security protocols are useda  to counter the threats. 
The Working Group has the following deliverables:

- A problem statement document that clearly and succinctly describes the
problem posed by localized mobility management and why a network-based approach
is desirable,
- A requirements and gap analysis that examines a selection of existing IETF
protocols, particularly within the mobility space, for applicability as a
solution. If a proposed protocol is insufficient as a solution, the reasons why
will be clearly stated.
- A threat model draft that describes the threats to a netlmm protocol, based on
the framework described in this charter, and how the threats can be mitigated
giving preference to existing security solutions where applicable.
- A protocol design for an interoperable, scalable network-based localized
mobility management protocol between the access routers and the mobility anchor
point including security for the access router to mobility anchor interface,
- A document describing how existing or developing IETF protocol standards can
be used between the access router and the mobile node to inform the access
router about the arrival of a mobile node, for use when the wireless link
protocol does not provide support for this function. This document will also
discuss threats and security countermeasures for mobile node identification.

Out of scope for the first design are: route optimization, inter-access router
tunneling to optimize handover, mechanisms for handover between localized
mobility management domains (other than standard global mobility management
protocols), IPv4 support, and multiple mobility anchor points. During the design
process, these enhancements will be kept in mind, but actual work to incorporate
them or other enhancements will be deferred until after the initial design is
complete and the working group recharters.

Schedule
--------

Jan. 2006 - Charter Working Group.

March. 2006 - Working Group Last Call on Problem Statement and Requirements
documents.

First draft of NETLMM threat model document.

March 2006 - IETF 65, Discuss Last Call comments on Problem Statement and
Requirements documents.

Discuss NETLMM Threat Model document.

April 2006 - Submit Problem Statement and Requirements documents to IESG for
publication as Informational RFCs.

June 2006 - Working Group Last Call on Threat Model documents. Submit Threat
Model document to SAAG for review.

July 2006 - Working Group Last Call on Threat Model document

Aug. 2006 - IETF 66, Discuss Last Call comments on Threat Model document.

Sept. 2006 - Submit Threat Model document to IESG for publication as an
Informational RFC.

Oct. 2006 - Working Group Last Call on Protocol draft. Working Group Last Call
on Mobile Node to Access Router document.

Nov. 2006 - IETF 67, Discuss last call comments on Protocol document and Mobile
Node to Access Router document.

Discuss rechartering.

Dec. 2006 - Submit Protocol draft to IESG for publication as Proposed Standard
and Mobile Node to Access Router document for publication as Informational.

Jan. 2007 - Recharter to address enhancements.

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