A Peer-to-Peer Scheme to Discover and Select QoS Enhanced Alternate Paths

Increasing number of communication softwares are built on distributed architectures based on the Peer-to-Peer (P2P) model, such as Skype [1], and PeerCast [2]. This model provides several significant benefits, such as deployment scalability, resilience to single points of failure, communication cost sharing, and anonymity. In a former contribution, we proposed an unstructured Super-Peer architecture (SPAD) that further uses the P2P paradigm to provide enhanced Quality of Service (QoS) between two users of these communication softwares. SPAD allows the discovery and use of composite alternate end-to-end paths that experience better delay than the path given by the default IP routing mechanisms. This paper extends SPAD's capabilities to multi-QoS constrained alternate-paths. It presents two extensions: i) the capability to discover alternate paths with better packet-loss and/or delay, ii) multiple schemes to select among the discovered paths the ones that best meets the requirements of the users.