Analysis of Block-Aware Peer Adaptations in Substream-Based P2P

Peer-to-Peer (P2P) video delivery using substreams supports uplink heterogeneities of the peers and hence could optimise sharing capabilities with minimum free-riding peers. Therefore, substream-based applications such as PPLive and CoolStreaming have been well accepted after successful deployments in the public Internet. In this approach, a child peer can find a parent peer for a substream independent of the other parent peers that it receives the remaining substreams. In general, there can be more than one substream between a parent and a child. The block-aware adaptation algorithm in CoolStreaming changes the parent peer for all such substreams when a child peer experiences poor performance even on one of its substreams from the parent. However, lagging of one substream in such a scenario is likely while others are not affected, when the parent receives its substreams through multiple paths. We propose a fine-grained approach (changing substream by substream) in peer adaptations to improve overlay network performance. This approach will in turn, is designed also to minimise the diversity of parents at a child peer by attempting to join with a well-performing another parent, which is expected to curtail complexities in a network-assisted P2P framework.