Game Theoretic Peer Selection for Resilient Peer-to-Peer Media Streaming Systems

摘要

Peer-to-peer (P2P) media streaming quickly emerges as an important application over the Internet. A plethora of approaches have been suggested and implemented to support P2P media streaming. In our study, we first classified existing approaches and studied their characteristics by looking at three important quantities: number of upstream peers (parents), number of downstream peers (children) and average number of links per peer. We find that in existing approaches, peers are assigned with a fixed number of parents without regard to their contributions, measured, by the amount of outgoing bandwidths. Obviously, this is an undesirable arrangement as it leads to highly inefficient use of the P2P links. This observation motivates us to model the peer selection process as a cooperative game among peers. This results in a novel peer selection protocol such that the number of upstream peers of a peer is related to its outgoing bandwidth. Specifically, peers with larger outgoing bandwidth are given more parents, which makes them less vulnerable to peer dynamics. Simulation results show that the proposed protocol improves delivery ratio with similar number of links per peer, comparing with existing approaches in a wide range of settings.