TorrentLab: investigating BitTorrent through simulation and live experiments

BitTorrent is probably the most popular file sharing protocol nowadays. Since it is a complex protocol which was created mostly as an engineering effort, there have been attempts to evaluate and understand the behavior of BitTorrent, exposing drawbacks and identifying opportunities for improvement. Simulation(al) and experimental evaluation are two important methodologies for the investigation of BitTorrent implementations and protocol variations, but using them with BitTorrent and P2P in general represents a challenge. In this paper, we introduce TorrentLab, a testbed in which BitTorrent simulations as well as live experiments can be performed under both controlled and uncontrolled settings. For a given swarm, we compare results obtained by means of simulation and live experiments, and show that both are in line with the expected behavior.