Research and implementation of ALM tree maintenance policy

Application Level Multicast becomes an effective solution for live media streaming nowadays.Tree based ALM solution suitable for large-scale streaming is simple to construct and easy to maintain but weak in reliability.In this paper,with the study on peers stability and distance evaluation,a new tree -topology maintain policy is proposed based on peercast,a peer -peer streaming system is designed and implemented with this policy.Application shows that this algorithm works fine and can greatly deduce the influence on QoS when peers joining/leaving.