【摘要】 互联网上大规模Peer-to-Peer(P2P)点播服务存在高效资源调度和不可预知用户行为等挑战。借鉴BitTor-rent(BT)算法原理,提出基于异步传输的P2P点播系统。该系统采用集中式节点定位以及非结构化拓扑,通过异步传输机制提升文件资源共享度和利用率,并引入视频数据块的优先级和稀有程度改进系统播放连续度。数据包及仿真实验表明本系统在播放连续度、启动时延以及服务器压力等性能指标上的良好性能,充分验证了点播系统中异步传输机制的可行性。更多还原

【Abstract】 Provding video-on-demand(VoD)service over the internet remains some challenges in terms of efficient resource utilization and unpredictable user action.Inspired by the success of BitTorrent(BT)in the field of file sharing,we presented a Peer-to-Peer(P2P)VoD system based on asynchronous data transfer.This system is specified with centralized directory and unstructured overlay.By using asynchronous data transfer mode,it could improve sharing and utilization on resources.We also considered the priority and rareness of video data blocks to smooth video playback.Packet-level simulations show the benefits of system performance metrics on playback continuity,launch delay and server stress,and demonstrate the feasibility of the asynchronous transfer.更多还原