Multicast Mobility (multimob) Chairs: TBD Internet Area (int) Directors: Jari Arkko Mark Townsley Internet Area Advisor: Jari Arkko Security Area Advisor: Marshall Eubanks . Mailing Lists: General Discussion: multimob@ietf.org Subscribe online at: https://www1.ietf.org/mailman/listinfo/multimob Description of Working Group The Multicast mobility (multimob) will develop a set of protocol extensions and provide guidance appropriate for IPv4 and IPv6 multicast in a mobile environment. It will consider both source specific multicast (SSM) and any source multicast (ASM) multicast models. The scope of work will be limited to group management and mobile IP protocols - proxied or client-based. Work requiring modifications of multicast routing protocols (PIM-SM, PIM-DM, etc.) is out of scope. Specific goals are: - Specify IGMP/MLD extensions methods for reducing join/leave latency. - Specify a dormant mode operation for IGMPv3/MLDv2. - Update PMIPv6 to support remote subscription, fast handover and IPv4 multicast. - Provide guidance and specify methods for multi-homing support for multicast. Multimob will specify a set of extensions to IGMPv3/MLDv2 for mobile environments. IGMPv3/MLDv2 has been specified for wired networks with shared links. Mobile nodes also have other needs (e.g. entering a dormant mode to conserve battery power, minimising the latency for joining and leaving a group in support of movement). The working group will assess existing solutions for group management, and determine if these methods are sufficient. This will include defining best current practice for selection of timer values and protocol parameters. If these methods are not sufficient, the working group shall propose new solutions as updates to existing protocols (including possible introduction of additional message types). It is a goal for the working group to ensure backward compatibility with the current implementations of group management protocols. Message structures supported in current deployed networks will not be modified. Unicast mobility protocols (Mobile IPv6, Dual-Stack Mobile IPv6 and also Mobile IPv4) provide basic multicast support and enable mobile nodes to perform bi-directional tunneling and receive multicast traffic anchored at the home agent. However, such basic support suffers from the 'avalanche' problem as the home agents replicate the packets and unicast them to the mobile nodes as well as from non-optimal, triangular routing, 'remote subscription' suffers from possible loss of data during handovers. The WG will address these issues within the context of Proxy Mobile IPv6 (PMIPv6). Currently PMIPv6 (and mobility extension protocols like FMIPv6 and HMIPv6) does not support multicasting explicitly. Basic support for multicast with bi-directional tunneling will be documented for PMIPv6 (with no new message types or changes to the message parameters). PMIPv6 that handles IPv4 and IPv6 will be extended to also support multicasting with IPv4. Finally, PMIPv6 basic multicast support will be extended to support remote subscription and fast handover. A multi-homed mobile node may wish to join multicast groups and to direct different multicast flows to its interfaces. The working group will define multi-homing support for multicast, including an efficient per-interface subscription management in the case of multi-homed mobility and multicast flow binding. In performing this work, the Multimob working group will work closely with NETLMM working group and will coordinate work on IGMP/MLD extensions with the MBONED working group. GOALS and MILESTONES: six months: - Submit a document on multihoming support for multicast as a BCP RFC. - Submit a document on minimal deployment for PMIPv6 remote subscription for multicast as a BCP RFC One year: - Submit a document on IGMP/MLD extensions for multicast mobility as an EXP/PS RFC. - Submit a document on extensions for multicast mobility in PMIPv6 as an EXP/PS RFC. Recharter or close working group.