LiveSwarms: Adapting BitTorrent for end host multicast
Michael Piatek, Colin Dixon, Arvind Krishnamurthy · 2005
The lack of universal multicast support in core internet routers has motivated the development of so-called end host multicast systems. These rely on participating hosts to forward data to other users via a carefully designed overlay mesh. While such strategies have the potential to improve scalability and lower bandwidth costs, the unreliability and heterogeneity of end hosts in practice have proven to be substantial obstacles to deployment. To overcome these difficulties, we design, implement and evaluate a live swarm—an unstructured overlay to disseminate live multicast data. While swarms have proven highly effective for very large file transfers, ours is the first comprehensive evaluation of a practical swarming design for real-time multicast delivery. Our system is based on a small number of enhancements to the popular file transfer system BitTorrent; we show that the result is highly robust to nodes with asymmetric bandwidth, high rates of churn, flash crowds, resource constraints, and selfish users.