A comparison of streaming extensions to BitTorrent

Peer-to-peer (P2P) protocols have been widely accepted by users and operators alike as efficient mechanisms for non real-time content distribution. It is therefore reasonable to extend these protocols to also handle more demanding applications, such as multimedia streaming. Many researchers have proposed modifications to the well known BitTorrent protocol in order to adapt it to the needs of such applications. In this paper we present findings from our experiments with three proposals for the integration of multimedia streaming into BitTorrent: the fixed-size window approach, the high-priority set approach and the stretching window approach. We evaluate these proposals under identical circumstances using our detailed packet-level BitTorrent simulator, showing that while all approaches are reasonably capable of supporting multimedia streaming, their different design choices have a pronounced effect on their streaming performance.