Multicast at Interconnects John Meylor <jmeylor@cisco.com> NANOG November 8-10, 1998

Objectives: support for native multicast routing use of scalable, policy-based routing in inter-domain space allow for variety of protocols and topologies in intra-domain space

Design elements: tree building/multicast forwarding protocol route exchange BGP or BGP4+ to provide scalable, policy based EGP tree building/multicast forwarding protocol PIM to allow for (M)BGP interdomain and IGP intradomain PIM DM initially (to flood s,g state to collocated RPs) PIM SM eventually (to reduce flood-prune, requires MSDP)

Design elements: method for identifying active sources media dense mode flooding of data to establish s,g state MSDP to flood only SA packets to MSDP peers media native broadcast, single packet per source fddi concentrator commonly used simple, reasonably common denominator eliminates variable of switching mechinisms initially

Topology example: Ames MIX AS10888---R----"MBone" | | multicast_interexchange (MIX) ---------------- / \ / \ mbgp_peer---R R---mbgp_peer \ / \ / --------------- FIX unicast_exchanges