Path-aware multicast for efficient file distribution in peer-to-peer overlay networks

This paper discusses how to transmit the same file or the same part of a large file from a source peer to a group of destination peers efficiently. Considering the quality of overlay links and the restriction of Internet firewalls, we propose a hybrid approach of amplification and multicast, called amplicast, to improve the efficiency of file distribution. By intelligent peer selection and the support of replicate peers, the proposed amplicast approach constructs a series of multicast sub-trees to alleviate the load of the source peer and allow a requesting peer to decide when and where to join a tree, based on its own benefits. With link status cache and top-set sampling heuristic, the proposed PeerTop can significantly reduce the cost of exhausted network probing. Experiments with real-world Internet traffic data demonstrate that our approach can distribute contents very efficiently.