Providing VoD Services Based on Unstructured Overlay

It is still a challenging task to provide large scale video-on-demand (VoD) streaming services based on overlay network due to its inherent dynamicity and heterogeneity. Most of previous work has focused on how to construct a structured overlay to tackle this issue, i.e., tree-based overlay and DHT. However, they always suffer from inefficient resource utilization and poor reliability. In this paper, we propose a new solution based on unstructured overlay, called GridCast, in which a directional gossip protocol and a score-based partner selection algorithm are designed to explore multiple data suppliers for each joined peer. In this way, GridCast can make efficient use of the available upload bandwidth of peers to achieve better scalability and reliability. The experimental results from our early deployment show that it is feasible to provide scalable VoD services based on unstructured overlay.