Efficient Data Dissemination in Bandwidth-Asymmetric P2P Networks

As broadband Internet becomes widely available, Peer-to-Peer (P2P) applications over the Internet become increasingly popular. One example of P2P applications, is video multicast in which, a source node streams its video to a large number of destination nodes through an overlay multicast tree consisting of peers. These overlay multicast-based applications, however, do not exploit the full bandwidth of every peer as the leaf nodes in the overlay multicast tree do not contribute their bandwidth to the system. On the other hand, all the peers in a properly constructed overlay mesh can contribute their bandwidth, resulting in high overall system throughput. In this talk, we define the notion of throughput efficiency to measure the performance of different data dissemination schemes from a single source node to multiple destination nodes. Using the proposed throughput efficiency, we propose a hybrid P2P system for optimal data dissemination in a bandwidth-asymmetric network such as Digital Subscriber Line (DSL) access network. Our hyprid P2P system consists of one or more Supernodes responsible for node management and a large number of streaming nodes, Peers which are responsible for the actual data delivery. Our system is designed to achieve (1) bandwidth fairness, i.e. a node receives the same amount of bandwidth that it contributes to the system, (2) small end-to-end delay, (3) small node management’s overhead, and (4) optimal bandwidth usages of all the nodes. Both simulations and experimental results of a prototype system consisting of PlanetLab nodes demonstrate the aforementioned qualities.