Performance Study of Unstructured P2P Overlay Streaming Systems

One of the major differences among current P2P solutions for multimedia streaming is the way they organize the exchange of multimedia data among their peers. We compare the performance of two of these organizations, namely, an unrestricted mesh using a tit-for-tat incentive policy and a directed mesh that allows peers to dynamically replace poorly performing parents. We first observe that both organizations performed fairly well under ideal circumstances where all peers were cooperating and connections never failed. We then considered how the same two organizations would perform in the presence of connection failures and observe that the sole organization capable of providing a high quality of service was an unrestricted mesh organization that allowed at least eight concurrent downloads per peer. The same was not true for the directed mesh whose performance actually decreased when we allowed more than four concurrent downloads.