P2P视频会议系统中的媒体流组播树的生成与维护

P2P的技术把视频会议服务器的功能分散到客户端,从而解决视频会议系统中存在的网络和系统资源瓶颈问题.本文综合利用P2P技术和传统视频会议的优点,提出一种有中心管理服务器的P2P视频会议系统结构,并对节点间的数据交互和控制机制进行了研究.根据当前的Internet跨网段间不支持IP层组播的实际情况,提出在局域网内采用IP组播、在子网间采用单播的应用层组播方式进行媒体流传输.考虑P2P网络中每个节点都有自治的、动态的、自利的等特性,本文提出一种基于投标-招标机制的媒体流组播树的生成与维护算法.

Construction and Maintenance of the Multicast Tree for a P2P Video-conferencing System

As video severs' tasks are distributed to its clients in P2P systems,a P2P based video conferencing system is able to solve the bottleneck problem of network and system resources.Taking advantage of P2P technology and traditional video conferencing systems,a P2P based video conferencing architecture is proposed and a new scheme of peer management and communication is put forward in this paper.Considering the fact that Internet can't support IP-layer multicasting between LANs,media-stream transmission adopts IP layer multicasting only within a LAN,and application-layer multicasting between LANs.According to autonomation,dynamic,selfishness of peers in P2P systems,a new algorithm for constructing and maintaining muticasting tree is designed with the principle of invitation and bidding.