Efficient push-pull based P2P multi-streaming using application level multicast

P2P (peer-to-peer) streaming systems are getting more and more popular in recent years. P2P streaming architectures can be classified into tree-based and mesh-based. The tree-based architecture has low start-up delay, but is less resilient to node failures compared to the mesh-based architecture, and it would result in a low delivery ratio and unstable quality of received multimedia. In this paper, we propose an efficient P2P multi-streaming scheme called HyStream based on application level multicast to resolve these problems. First, we split video streaming data and build multiple trees to transfer streaming data. Second, we incorporate a forward error correction (FEC) algorithm to recover lost data. Finally, we integrate a pull-based method with the tree-based architecture, which is a push-based method. When encountering data loss, we use a pull-based data retransmission method to retrieve lost data. Simulation results show that the proposed HyStream has 11.7% improvement in delivery ratio against SplitStream under various node failure rates. The delivery ratio of HyStream is 2.2% higher than that of CoolStreaming in a peer churn environment. The start-up delay of 90^th percentile nodes of HyStream is 35 seconds shorter than that of CoolStreaming. Note that our approach has small overhead of 6% redundant packets due to FEC, compared to SplitStream and CoolStreaming. In addition, HyStream has no more than 0.5% extra control overhead compared to SplitStream and CoolStreaming, even in a high peer churn environment.