Streaming Live Media over Peers
Hrishikesh Deshpande, Mayank Bawa, Héctor García-Molina · 2002
The high bandwidth required by live streaming video greatly limits the number of clients that can be served by a source using unicast. An efficient solution is IP-multicast, but it suffers from poor deployment. Application-level multicast is being increasingly recognized as a viable alternative. In this work, we discuss and evaluate a tree-based overlay network called {\em PeerCast} that uses clients to forward the stream to their peers. PeerCast is designed as a live-media streaming solution for peer-to-peer systems that are populated by hundreds of autonomous, short-lived nodes. Further, we argue for the need to take end-host behavior into account while evaluating an application-level multicast architecture. An end-host behavior model is proposed that allows us to capture a range of realistic peer behavior. Using this model, we develop robust, yet simple, tree-maintenance policies. Through empirical runs and extensive simulations, we show that PeerCast provides good QoS, which gracefully degrades with the number of clients. We have implemented a PeerCast prototype, which is available for download.