Abstract: This paper presents a hierarchical DHT topology structure based on dynamic time coordinate for large-scale P2P VoD system.In this coordinate system，peer’s coordinate maintains constant unless the peer’s play occasion jumps to another point of the stream.Thus DHT based lookup protocols are adopted to track buffer information of peers with small overhead.Simulations show that the design achieves good performance.

摘要： 提出了一种基于动态时间坐标的分层DHT拓扑结构，解决了因大规模P2P点播系统要求细粒度追踪而难以应用DHT的问题。在动态时间坐标系中，节点的播放点坐标不再随着节点的播放而移动，从而使得DHT能够用于追踪点播系统节点缓存位置。仿真结果证明了方法的有效性。