Network Layer Performance in Peer-to-Peer File Sharing Systems

Nowadays P2P applications dominate many networks. However, despite of their diffusion, the analysis of tele- traffic generated by these applications in real-time environment remains an open issue. In this paper we look at analytical and simulation models, which can be used for quantifying volumes of P2P teletraffic at the network layer, to ease still existing difficulties associated with monitoring such teletraffic. We present an event-driven simulator, able to simulate P2P teletraffic both at the application and network layers in large overlay networks (we have successfully tested it in networks used by up to 500,000 peers). The simulation model was developed for studying the impact that P2P systems have on the network layer performance. We studied also the application layer dynamics by looking at time evolution of file-downloading processes and at the offered load generated in such networks. We report the results of several simulation scenarios, in which we focused on the consequences such teletraffic has on the Internet access link of an enterprise network.