Network-based Localized Mobility Management (netlmm) ---------------------------------------------------- Charter Last Modified: 2007-01-11 Current Status: Active Working Group Chair(s): Phil Roberts Vidya Narayanan Internet Area Director(s): Jari Arkko Mark Townsley Internet Area Advisor: Jari Arkko 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 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 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 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. 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 Internet-Drafts: Posted Revised I-D Title ------ ------- -------------------------------------------- Feb 2006 Oct 2006 Goals for Network-based Localized Mobility Management (NETLMM) Feb 2006 Sep 2006 Problem Statement for Network-based Localized Mobility Management Apr 2006 Sep 2006 Security Threats to Network-Based Localized Mobility Management Request For Comments: None to date.