Hybrid Protocol for Application Level Multicast for Live Video Streaming

A hybrid protocol for application level multicast (HPAM) for live video streaming without native IP multicast support is proposed. HPAM exploits the simplicity and optimality of a lightweight, centralized server with the robustness and scaleability of distributed clients. HPAM self-organizes clients on the fly to form efficient source-based overlay trees while the server facilitates peer discovery and also serves as a reliable backup should the distributed algorithms fails. Tree construction, refinement and recovery from partitions are carried out independently by the clients. Simulation results show that HPAM can build and maintain reasonably latency-efficient overlay trees with a lower overhead than a fully centralized system (host based multicast) and yet more responsive to group dynamics and network environment than a fully distributed system (host multicast).