The goal of this paper is to minimize service disruption, a unique phenomenon in peer-to-peer (P2P) streaming system and the major contributing factor to degrade user experience. In order to improve its streaming quality and stability, a P2P system should select peers with abundant bandwidth resource and prospect longevity as the parents of other peers. Towards this end, we propose PRW (peer resilient weight), a metric to evaluate a peer's healthiness regarding these two aspects. The theoretical background of PRW originates from the optimization framework based on the generalized flow theory. To show PRW's applicability to a wide variety of P2P streaming solutions, we propose several parent selection algorithms guided by PRW under the single-tree, multi-tree, and mesh structures. Using MSN and PPLive traces, we find our algorithms to be able to achieve lower service disruption and lower peer rejection, compared to several existing heuristics and algorithms.

Peer-to-peer (P2P) traffic is arguably the biggest contributor to today's Internet traffic. So far, very limited effort has been paid to theoretically analyze the effect of bringing locality-awareness into P2P applications. In this paper, we analyze three locality-awareness policies for BitTorrent-like system: tracker locality(neighbor selection), choker locality(choking and unchoking) and picker locality(piece picking). Based on an H-sphere model which captures the essential property of Internet topology, we analyze how much network load saving can be expected for these locality policies, as well as their impact to the downloading efficiency of the system. Through analytical study and simulation, we have the following findings. First, when the system enters the steady state, the locality policies proposed in this paper can achieve the same downloading efficiency as the standard BitTorrent system. Second, these locality policies can significantly alleviate the traffic load on the Internet. Finally, we find that there exists no all-around winner. Instead, each policy performs the best under different system configuration parameters, such as number of unchoked peers.

Recent advancement in multimedia and network has enabled the development of video accelerator for video sharing website where users can upload, view and share video clips (e.g. YouTube) to achieve better user experience. Several applications have already been developed. The paper examines these technical issues. The benefits of these techniques are discussed. Also the performances of these applications are evaluated by analyzing the network traffic.

This paper presents the measurement study of locality-aware P2P solutions over real-world Internet autonomous systems (AS) topology. By using the accesses of nodes of PlanetLab testbed, we create a detailed AS-level map including the end-to-end path of all nodes, as well as the relationship of all involved ASes. Based on this map, we evaluate the performance of a set of locality-aware P2P solutions, including an optimal solution guaranteeing the minimum AS hop count, as well as modified BitTorrent system with locality-awareness built into its neighbor selection, peer choking/unchoking, and piece selection processes. Our findings suggest that locality-awareness can help existing P2P solution to significantly decrease load on Internet, and achieve shorter downloading time. By comparing the performance of different kinds of locality-aware and traditional BitTorrent systems, we also point out the necessity to tradeoff between the goals of optimizing AS-related performance and achieving fairness among peers such as intra-AS traffic and peer burden fairness.

Recent theoretical and simulation-based studies have confirmed the tremendous benefit of peer-to-peer (P2P)communication at reducing the cost of running a VoD service.To date, very limited effort has been paid to validate the concept of peer-assisted VoD service, especially in terms of system implementation and service deployment. In this paper, we present the case study of a peer-assisted video-on-demand (VoD) system. We designed and developed Bit-Tube, a BitTorrent-compliant VoD system. By combining client/server and P2P downloading, it supports seamless transition across the spectrum from pure client-server mode to BitTorrent mode. Within this framework, we experiment with a series of piece picking policies to enhance BitTubepsilas support to video streaming and promote locality-aware P2P downloading. We evaluate our system over PlanetLab,which hosts the user-side component of the BitTube system and emulates the global-scale user requests to the VoD service.