1. Multicast at Interconnects
John Meylor
NANOG
November 8-10, 1998

2. 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

3. 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)

4. 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

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