Random Network Coding in Peer-to-Peer Networks: From Theory to Practice

With random network coding, network nodes between the source and receivers are able to not only relay and replicate data packets, but also code them using randomly generated coding coefficients. From a theoretical perspective, it has been recognized that network coding maximizes the network flow rates in multicast sessions in directed acyclic network graphs. To date, random network coding has seen practical and real-world applications in peer-to-peer (P2P) networks, in which overlay network topologies are formed among participating end hosts, called “peers.” Due to uncertainties and dynamics involved with peer arrivals and departures, these network topologies are usually randomly generated in practice, and are referred to as “random mesh” topologies. Unlike structured topologies such as trees, random mesh topologies are practical to be implemented, and are resilient to the level of volatility typically experienced in peer-to-peer networks. It has been shown, from both theoretical and practical perspectives, that random network coding leads to performance benefits in these peer-to-peer networks with random mesh topologies. This paper presents a survey of existing results with respect to practical applications of random network coding in peer-to-peer networks. We focus on bulk content distribution and media streaming systems, as well as the computational overhead introduced by random network coding in modern off-the-shelf servers and mobile devices. Throughout the paper, we also show theoretical insights on why random network coding may become beneficial in practice.