Simulation of P2P overlays over MANETs: Impediments and proposed solution

Peer-to-Peer (P2P) overlays and Mobile Ad hoc Networks (MANETs) exhibit some common characteristics, such as dynamism, self-organization and decentralized control. The synergy between the two has been utilized by researchers to design distributed applications over MANETs. However, the available simulation platforms are far from perfect to evaluate the proposed designs. In most of the simulation platforms, good support is available for wired networks, wireless ad hoc networks and P2P overlays. However, P2P overlays in these platforms are programmed on top of wired networks, and there is no ready-to-use implementation of P2P over MANETs. In this paper, we present our experience and lessons learnt while simulating P2P over MANETs. We have tried different available platforms and concluded that OverSim over OMNeT++ is the best candidate for P2P simulation over MANET underlay. However, we need to incorporate a lot of changes and configurations to solve the purpose. We have designed a new underlay configurator by modifying an existing underlay model of OverSim to add wireless and mobility support in overlay nodes. The modified simulation setup is used for performance evaluation of P2P overlay over MANET at different mobility speeds and node densities. The results obtained are consistent with mobility and churn dynamics, thereby suggesting the utility of our simulation setup.