Quantitative evaluation of unstructured peer-to-peer architectures

This paper provides an extensive performance evaluation of the main features of current unstructured super-peer P2P architectures. It quantifies the performance benefits of each feature over the previously proposed community-based message flooding protocol. Our main results show that the hierarchical super-peer architecture itself and a content-aware query routing mechanism are each responsible for significant reductions on system load, compared with the community-based protocol, with no impact on the number of successfully responded queries. Furthermore, user-controlled query retransmission gives users the flexibility to trade higher query success rates and shorter download times for longer latency and higher load. Finally, our results also show that, unlike one might expect, swarm download may degrade download time if the peers from which the download is performed are not carefully selected.