Locality Awareness and ISP-Friendlinessfor P2P Live Streaming Applications

Abstract: The popularity of P2P live streaming applications has been growing rapidly the last years causing a remarkable increase in consumption of critical network resources. The peers that participate in the P2P overlays inherently establish random connections with each other without considering the locality of the generated traffic. As a result, higher costs and risks are shifted to the ISP side and cross-ISP links are used to connect remote peers. The network infrastructure will face problems in satisfying the aforementioned need and eventually both ISPs and P2P systems might suffer from this situation. In order to enhance the P2P overlays with locality-awareness and reduce this unnecessary cost for the ISPs, several schemes have been proposed. However, in the case of P2P live streaming applications, the randomness in overlay links seems more significant for the expected QoE than it is for the performance in other P2P systems. In this thesis, we describe an ISPF patch based on a decentralized, latency-biased, neighbor referral selection technique that is targeted for use in large commercial P2P live streaming systems. More specifically, we create an extra component that can work on the background of any existing P2P live streaming application. The component is able to promote a list of local peers as partner-candidate peers according to their latencies -measured by the peers themselves or referred to them by their known neighbors. The implementation of the ISPF component is coded and applied on an existing implementation of a Coolstreaming+ system and simulations of the two systems are executed on an eventbased simulator. The evaluation focuses on the comparison of performance and locality metrics between ISPFCoolstreaming and the native Coolstreaming+ simulation results. The comparison shows that the expected performance degradation is small and varies according to the churn levels and overlay sizes. More importantly, it is made clear that the achievements in locality-awareness are significant in all scenarios. We conclude that the ISPF component could be efficiently used in an optional mode by a P2P live streaming algorithm. It could be enabled during big size overlays where the impact in performance is absorbed better and the savings in resources are bigger.