An efficient RP(Rendezvous Point) replacement mechanism for rendezvous-based multicast routing

There are basically three types of multicast routing protocols: broadcast and prune, membership advertisement and rendezvous-based whose examples can be DVMRP MOSPF and PIM-SM respectively. In rendezvous-based protocol, each multicast group address is mapped to a address called ´core´ or ´rendezvous-point´ (RP). Members willing to receive data sent to the group first join the RP When a RP fails, a new RP should be selected and the multicast group should be mapped to it. In this paper, unlike bootstrap mechanism which redistributes RP-set should a RP fails, we propose a mechanism to construct a RP table at each PIM-SM router and to distribute a pair of (RP_primary, RP_secondary) which is a column of the RP table. In this mechanism initially a multicast group addresses are mapped to RP_primaries. When a RP_primary fails corresponding RP_secondary takes over the function of the failed RP_primary (i.e. becomes RP_primary), selects a new RP_secondary from the table, updates the table with the new (RP_primary, RP_secondary) and distributes the new (RP_primay, RP_secondary) to all routers in the domain. When the RP_secondary fails the RP_primary selects a new RP_secondary from the table, updates the table and distributes the new (RP_primary, RP_secondary) pair to all routers. Each router in the domain after receiving the (RP_primary, RP_secondary), updates its table accordingly RP_primary, RP_secondary exchange live message periodically to check each others liveliness.