According to the research and analysis of typical models for P2P (Peer to Peer) live streaming system, we overview
and summarize the strengths and weaknesses of existing technologies. This paper proposes a new model for P2P live
streaming system, which used a scheme combining unicast and multicast trees, and analysis the strategy of node
management. The model combines advantages of easy maintenance of unicast tree and load balancing of multicast tree,
and enhances the availability, stability and quality of service for live streaming system.