Design And Implementation Of P2P Video System

Along with the application of P2P technology becomes more and morepopular，P2P streaming system based on P2P technology has become one ofthe hotspot researches in distributed system.This subject attempts to make acombination of P2P Internet and streaming technology. On basis of presentmodel and technology researching, we established a video live system basedon P2P, and made an in-depth research on the relative issues, includingdesign of P2P overlay network, optimized arithmetic of balanced load basedon bottom network status, pretreatment of data resource, Buffer managementmechanism, error control and recovery.The contribution of this paper is as following:1. According to the specialty and requirement of streaming application,Single Source Application Layer Multicast protocol (SSAMP) is made indistributed environment, and discuss the SSAMP core arithmetic of nodeadding, node status maintenance, node leaving and invalidation, loopinspecting and canceling when supporting the streaming application.2. To reach the goal of load balance, corresponding optimized tragedy isimported. This tragedy balances the system load, effectively makes thediameter and the average delay of source to end on the multicast tree shorter.At the same time, after optimized several times, the better nodes are locatedat the site nearer to root node because of their greater contribution. On thecontrary, the worse nodes go down and are located as leaf nodes for theirlittle contribution, utilization rate of bandwidth is higher in this way.3. Pretreatment of live system video data. The process, mainly includingcoding and splitting, splits the media file into several segments with the same time-length for sending and saving temporarily on overlay topology.4. Effective buffer management mechanism. Because of node instabilityand dynamic specialty of network, network connection among peers is inunstable status, the transmission of video streaming data may be interruptedin a short time. Therefore, any node in the network must have some ability ofcaching to save video streaming data temporarily in a fixed time-length, andmanages the buffer according to the time interval so as to keep the continuityof video streaming playing in the process of multicast tree recovery.5. Error control and recovery. As for the video live system of, re-send allthe data which was error is unpractical, so we should make a limit to there-sending mechanism and adopt the re-send methods with criteria to fulfillthe requirement of real time application.