A membership management protocol for mobile P2P networks

MANETs are self-organizing networks composed of mobile wireless nodes with often scarce resources. Distributed applications based on the P2P paradigm are the best candidates to run over such networks. To profit from the service provided by a P2P overlay (e.g. file sharing using BitTorrent), a node needs to be permanently informed about the other members of the overlay (e.g. other peers interested in the same file as currently provided by the BitTorrent central tracker). This P2P membership management is a costly and difficult task in such dynamic and resource limited environment. We focus on this problem and we propose a robust, network friendly and decentralized membership management protocol allowing peer discovery and update. Compared to flooding, client-server or multicast based approaches, our protocol achieves significantly lower network overhead and lower pollution of caches caused by peers who have left. Moreover, as network splits are very frequent in MANETs, our protocol is designed to be partition-aware. Namely, it allows separate overlays providing the same service to efficiently merge together when communication opportunities occur. The efficiency of our solution is validated through extensive NS-2 simulations

Reducing Routing Overhead in Random Walk Protocol under MP2P Network

Due to network dynamics in self-organizing networks the resource discovery effort increases. To discover objects in unstructured peer-to-peer network, peers rely on traditional methods like flooding, random walk and probabilistic forwarding methods. With inadequate knowledge of paths, the peers have to flood the query message which creates incredible network traffic and overhead. Many of the previous works based on random walk were done in wired network. In this context random walk was better than flooding. But under MANETs random walk approach behaved differently increasing the overhead, due to frequent link failures incurred by mobility. Decentralized applications based on peer-to-peer computing are best candidates to run over such dynamic network. Issues of P2P service discovery in wired networks have been well addressed in several earlier works. This article evaluates the performance of random walk based resource discovery protocol over P2P Mobile Adhoc Network (MP2P) and suggests an improved scheme to suit MANET. Our version reduces the network overhead, lowers the battery power consumption, minimizes the query delay while providing equally good success rate. The protocol is validated through extensive NS-2 simulations. It is clear from the results that our proposed scheme is an alternative to the existing ones for such highly dynamic mobile network scenario