2.3.18 Network-based Localized Mobility Management (netlmm)

NOTE: This charter is a snapshot of the 66th IETF Meeting in Montreal, Quebec Canada. It may now be out-of-date.
In addition to this official charter maintained by the IETF Secretariat, there is additional information about this working group on the Web at:

       Additional NETLMM Page

Last Modified: 2006-10-18


Phil Roberts <phil.roberts@motorola.com>
James Kempf <kempf@docomolabs-usa.com>

Internet Area Director(s):

Jari Arkko <jari.arkko@piuha.net>
Mark Townsley <townsley@cisco.com>

Internet Area Advisor:

Jari Arkko <jari.arkko@piuha.net>

Mailing Lists:

General Discussion: netlmm@ietf.org
To Subscribe: http://www1.ietf.org/mailman/listinfo/netlmm
In Body: to subscribe
Archive: http://www1.ietf.org/mail-archive/web/netlmm/current/index.html

Description of Working Group:

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

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 interface document will describe threats to the protocol when
the default, IP-level mobile node to router protocol is used, and will
prescribe how existing security protocols are used to counter the

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.

Goals and Milestones:

Done  Charter Working Group
Done  Working Group Last Call on Problem Statement and Requirements documents
Done  Discuss Last Call comments on Problem Statement and Requirements documents
Done  Submit Problem Statement and Requirements documents to IESG for publication as Informational RFCs
Done  Working Group Last Call on Threat Model documents. Submit Threat Model document to SAAG for review
Done  Working Group Last Call on Threat Model document
Done  IETF 66, Discuss Last Call comments on Threat Model document
Done  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 toAccess Router document
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


  • draft-ietf-netlmm-nohost-req-05.txt
  • draft-ietf-netlmm-nohost-ps-05.txt
  • draft-ietf-netlmm-mn-ar-if-01.txt
  • draft-ietf-netlmm-threats-04.txt

    No Request For Comments

    Meeting Minutes


    Security Threats to NETLMM
    NetLMM MN AR Interface
    NetLMM Protocol Overview