A protocol to improve the state scalability of source specific multicast

Source specific multicast (SSM) is a viable solution for current multicast applications, since the driving applications to date are one to many, including Internet TV, distance learning, file distribution, streaming media, etc. It brings many benefits in billing, address allocation, and security. However, SSM still confronts the serious state scalability problem when there are a large number of simultaneous on-going multicast groups in the network. We propose a protocol to improve the state scalability of source specific multicast, which is called aggregated source specific multicast (ASSM). We design the detailed ASSM protocol and show that our solution can obtain significant multicast state and tree management overhead reduction while achieving transparency to end-users, compatibility with existing multicast technologies and low overhead.