'''Originally Posted By: akurek'''

Ania Kurek, Shabana Kazi<br><br>What are the roles of the following in PIM-SM? <br><br>(a) Rendezvous Point - special router; listens for JOIN messages; performs multicast<br><br>(b) Bootstrap Router - keeps track of RP; locates local RP for Designated Routers<br><br>(c) Designated Router - responds to the host multicast message -> asks Bootstrap Router for local RP -> opens a tunnel to RP using PIM Register message.

'''Originally Posted By: eturkov'''

PIM-SM = Protocol Independent Multicast - Sparse Mode<br><br>(a) Rendezvous Point - Each group will have one of these, usually designated automatically or statically. Receives periodic join/prune messages from the designated router. All routers must explicitly join through the rendezvous point.<br><br>(b) Bootstrap Router - The BSR mechanism provides a way in which viable group-to-RP mappings can be created and rapidly distributed to all the PIM routers in a domain. It is adaptive, in that if an RP becomes unreachable, this will be detected and the RP-Sets will be modified so that the unreachable RP is no longer used.<br><br>(c) Designated Router - responds to the host multicast message -> asks Bootstrap Router for local RP -> opens a tunnel to RP using PIM Register message. The RP opens the Register message and knows what to do with it.