构建和维持一个高带宽路由结构是P2P流媒体中的一个重要问题。针对节点频繁地加入和退出覆盖会话的现状，本文设计了基于链路可用带宽的负载均衡路由算法LBR，利用已知的物理拓扑知识，在多条路由路径中选择一条对网络可用带宽影响最小的路由路径，得到轻负载的覆盖边。该算法能够动态维护高带宽的多播树，平衡覆盖会话中节点间的负载和链路间的流量。仿真实验表明，在动态环境下算法能够缓解路由上的拥塞问题，达到负载均衡的效果。

An important problem in P2P streaming is building and maintaining a highbandwidth routing structure. To accommodate the current situation that nodes can frequently join and leave the overlay session, this paper presenta a load balancing algorithm based on the link available bandwidth. This algorithm utilizes the known knowledge of the physical topological structure, chooses the routing path that has the least effect on the available bandwidth among multiple routing paths, so as to obtain a lightlyloaded overlay edge. The algorithm can dynamically maintain highbandwidth multicast trees, balance the load of nodes and traffic on the links in the overlay session. The results of the simulation demonstrate that the algorithm can mitigate routing congestion, and achieve a load balancing effect in the dynamic environment.