Centrality-Based Network Coder Placement for Peer-To-Peer Content Distribution

Abstract

Network coding has been shown to achieve optimal multicast throughput, yet at an expensive computation cost: every node in the network has to code.Interested in minimizing resource consumption of network coding while maintaining its performance, in this paper, we propose a practical network coder placement algorithm which achieves comparable content distribution time as network coding, and at the same time, substantially reduces the number of network coders compared to a full network coding solution in which all peers have to encode, i.e. become encoders.Our algorithm is derived from two key elements.First, it is based on the insight that coding at upstream peers eliminates information duplication to downstream peers, which results in efficient content distribution.Second, our placement strategy exploits centrality characteristics of the network topology to quickly determine key positions to place encoders.Performance evaluation using various topology and algorithm parameters confirms the effectiveness of our proposed method.