A Batch Join Scheme for Flash Crowd Reduction in IPTV Systems

Peer-to-peer (P2P) streaming is an effective and popular approach for large scale television multicasting over Internet. However, it is always a major challenge when thousands of peers join a popular P2P IPTV channel in a short time, so called the problem of flash crowd. When the problem occurs, a large number of users suffer from large latency in joining a channel and even get blocked. In the past, rare studies are focused on the flash crowd issue. In this paper, we identify several key factors that may cause the flash crowd problem: request congestion, stream congestion, control message, and maintenance overhead. Based on our analysis, we present a batch join scheme instead of processing new users one by one. Our batch join process also solves the problem of current join processes that only use existing active peers to serve new users. We generate a virtual sub tee based purely on a batch of new peers which is then connected to an active peer server. Simulation results demonstrate that our batch join scheme significantly mitigate the flash crowd situation. Moreover, both of the peer blocking rate and re-join times are significant reduced.