Bandwidth Allocation in Peer-to-Peer File Sharing Networks

We present a model of bandwidth allocation in a stylized peer-to-peer file sharing network. Given an arbitrary population of peers composed of sharers and freeriders, where all peers interconnect to maximize their allocated bandwidth, we derive the expected bandwidth obtained by sharers and freeriders. We show that sharers are always better off than freeriders and that the di®erence decreases as the size of the network grows. This paper constitutes a first step towards providing a general analytical foundation for resource allocation in peer-to-peer networks.