Extensions to OSPF for tunnel multicasting

We extend an existing multicast routing protocol, multicast extension to OSPF (MOSPF), to achieve tunnel multicasting. The extension is as follows. Tunneling is introduced for supporting tunnel multicasting, which aims at reducing the protocol overhead associated with MOSPF. Simulation results show that the extension can reduce protocol overhead significantly without affecting the per-destination shortest path characteristics of a resulting tree or introducing any extra control overhead.