A hierarchical clustered BitTorrent(CBT)system is proposed to improve the file sharing perfor-mance of the BitTorrent system,in which peers are grouped into clusters in a large-scale BitTorrent-likeunderlying overlay network in such a way that clusters are evenly distributed and that the peers within thecluster are relatively close to each other.A fluid model is developed to compare the performance of theproposed CBT system with the BitTorrent system,and the result shows that the CBT system can effectivelyimprove the performance of the system.Simulation results also demonstrate that the CBT system improvesthe system scalability and efficiency while retaining the robustness and incentives of the original BitTorrentparadigm.
