A Framework for Supporting Structured Peer-to-Peer (P2P) Overlays over Large Scale Mobile Ad-Hoc Networks (MANETs)

Peer-to-Peer (P2P) and Mobile Ad-hoc Networks (MANETs) share similar characteristics in terms of their design goals and the principles of their routing and applications. They also fundamentally address the same problem: How to provide seamless connectivity and services in a dynamic and decentralised environment. Given their parallel objectives, these technologies, if unified, will realise MANETs as a commercial technology and enable the development of widespread distributed applications for MANETs. Unfortunately the existing body of P2P research is not directly transferable to the MANET domain as current P2P overlay networks, originally designed for the Internet, do not adequately cope with highly dynamic and unstable wireless environments. Before structured P2P overlay networks can be successfully deployed in a resilient and efficient manner over MANETs, solutions for a number of issues must be proposed. Starting with a motivation, this paper outlines the outstanding issues and unsolved challenges in this research space, presents framework that aims to minimise the impact of node mobility and provide scalable reliable services and finally describes current approaches for adapting P2P overlays to ubiquitous environments. Index Terms — P2P, MANET, Overlay networks, DHT. Overview 2P computing is a distributed computing paradigm that allows the sharing of computing resources and services by direct interaction between devices. Distributed file sharing systems first emerged as the most popular and widely used application of the P2P paradigm, with some of the most popular networks such as Napster, consisting of millions of nodes, generating more than 20% of IP network traffic in the USA within it’s first few months [1]. Despite drawbacks such as copyright infringements and persisting problems of illegal content distribution, P2P traffic, has continually been a dominant source of Internet traffic, contributing 60-80% of the traffic volume on ISP platforms in Europe and North America [ 2 ]. The popularity of P2P also extends beyond file sharing large VoIP networks such as Skype also use P2P technology, with Skype, currently the dominant communications provider for Internet telephony, having amassed approximately 80 million registered users. In parallel, MANETs have also received much attention from the research community in recent years due to their resiliency, ease of deployment, cost effectiveness and scalability. However, the relevance and the commercial potential of ad-hoc networks can only be justified by the availability of applications. The unpredictability of MANET wireless links combined with high node mobility and node churn make a client-server architecture extremely difficult to maintain and manage. As MANETs are typically deployed in situations where low overhead and quick setup times are required, it is preferable to localise communications as A Framework for Supporting Structured Peer-to-Peer (P2P) Overlays over Large Scale Mobile Ad-Hoc Networks (MANETs) Aisling O’ Driscoll, Susan Rea and Dirk Pesch, CAWS, Cork Institute of Technology, Ireland