Friendly P2P: Application-Level Congestion Control for Peer-to-Peer Applications

Peer-to-Peer (P2P) file sharing applications use multiple TCP connections between peers to transfer data. The aggressiveness and robustness of P2P technology remarkably improve transfer efficiency and network bandwidth utilization. However, while the network bottleneck link is congested, P2P applications tend to unfairly steal bandwidth from other traditional Internet applications (Client/Server mode), which deteriorates the performance of traditional Internet applications. The paper proposes a friendlyP2P system with new application-level approaches for congestion detection and avoidance to keep fairness between P2P traffic and traditional Internet traffic. friendlyP2P, which is friendly to ISPs, namely to Internet networks and traditional Internet traffic, detects network congestion via throughput measurements and alleviates network congestion by optimization of the number of P2P connections from the viewpoint of P2P users. friendlyP2P system requires neither network node support nor TCP modification, which makes it easy to deploy. Simulation experiments demonstrate that fairness and congestion avoidance can be achieved in presence of congestion, and network bandwidth can be effectively utilized in absence of congestion with friendlyP2P technology.