Mario Gerla, Aiguo Fei, Jun-Hong Cui, Michalis Faloutsos

1. Current Multicast Limitation • Poor Scalability: • Router keeps forwarding entries for all groups • The number of entries grows with groups • Must reduce multicast forwarding state Decapsulate Bandwidth wastage DR DR Decapsulate Bandwidth wastage DR DR Encapsulate SR SR Decapsulate DR DR Traditional Multicast Aggregated Multicast Analysis and Simulation Reducible State Reduction: Rrs=1-(Sa-Si)/(S0-Si) Sa=states for aggregated multicast S0=states for traditional multicast Si=states corresponding to edge routers BW=Bandwidth Waste Implementation Considerations • Must distribute multicast traffic of different groups over a shared aggregated tree • Encapsulation/Decapsulation • Use MPLS • Must introduce a tree manager to handle • aggregated tree management • match between m-cast groups & aggregated trees • Must establish aggregated tree • Predefine tree based on traffic pattern from long–term measurements • Establish tree on demand and change or remove tree dynamically based on traffic measurements Aggregated Multicast Mario Gerla, Aiguo Fei, Jun-Hong Cui, Michalis Faloutsos {gerla, afei, jcui} @ cs.ucla.edu, michalis @ cs.ucr.edu Group Communications (1 to n / n to n): Audio/Video Conferencing, Internet TV, Tele-education, Shared Whiteboard, etc. How to make all these efficient??? ---Multicast New Idea: Aggregated Multicast • Multiple Groups Share Single Tree • This approach reduces multicast state and tree maintenance overhead • But it introduces possible bandwidth wastage UCLA CS NRL