PeerGraph: A Distributed Data Structure for Peer-to-peer Streaming

Video streaming over peer-to-peer networks has received significant attention recently. Accordingly, much work is done on video streaming under the assumption that all the peers have the whole movie. However, it is likely that many peers may only store a fraction of the movie due to their resource constraints. Therefore, there is a need to develop appropriate mechanisms to facilitate efficient streaming when each user stores a fraction of the movie. With this in mind, we propose a distributed data structure called PeerGraph in which each peer determines other peers having the previous or subsequent fractions of the movie and maintains pointers to these peers. In our model, a peer has full control on how many segments it wants to store. However, we require it to store consecutive segments. In order to stream, a client first finds a peer that contains the first segment and then uses the proposed PeerGraph to locate subsequent segments. We use extensive simulations to investigate the effect of various parameters. Simulation results support feasibility of the proposed scheme.