Design and implementation of a simulator for peer-to-peer networks: optimal-sim

Peer-to-peer (P2P) systems are the most popular research topic in recent years. Due to the large scale and the complexity of P2P networks, it is difficult to analyze their properties. And the mismatch between topologies of a P2P overlay network and the router-level physical network can also influence the performance of a P2P network. Therefore simulation is an effective way to evaluate the performance of a P2P network. In this paper, we review some existing P2P simulators and propose a simulator - Optimal-sim that can simulate the behavior of a P2P network on top of general Internet topology. Using Optimal-sim, we can evaluate the influence caused by the mismatch between the overlay topology and the underlying router-level topology. Such evaluation methods have not been introduced into existing P2P network simulators.