Improving the Fault Resilience of Overlay Multicast for Media Streaming

This paper addresses the problem of fault resilience of overlay-based live media streaming from two aspects: (1) how to construct a stable multicast tree that minimizes the negative impact of frequent member departures on existing overlay, and (2) how to efficiently recover from packet errors caused by end-system or network failures. In particular, this paper makes two contributions: (1) a distributed reliability-oriented switching tree (ROST) algorithm that minimizes the failure correlation among tree nodes. By exploiting both bandwidth and time properties, the algorithm constructs a more reliable multicast tree than existing algorithms that solely minimize tree depth, while not compromising the quality of the tree in terms of service delay and incurring only a small protocol overhead; (2) a simple cooperative error recovery (CER) protocol that helps recover from packet errors efficiently. Recognizing that a single recovery source is usually incapable of providing timely delivery of the lost data, the protocol recovers from data outages using the residual bandwidths from multiple sources, which are identified using a minimum-loss-correlation algorithm. Extensive simulations are conducted to demonstrate the effectiveness of the proposed schemes