中文摘要：

研究了不同网络拓扑结构对IP组播效率的影响,给出了一种度量组播效率的方法,并进行了分析与仿真.结果表明：在随机选择组播树根节点的情况下,平均节点度越大的网络,组播效率越低;限制组播路由的通过性和适当选择组播根节点的位置能够有效提高组播效率;有源最短路径树在不同网络拓扑下的性能差异较大,并且不是一种能够适合于各种网络结构的高效组播树构建算法.

英文摘要：

This paper studied the influence of different network topologies on IP muhicast efficiency, and proposed a method to measure the effleieney of IP multieast. The analysis and simulation results show that under the condition that the root node of multicast tree is selected randomly, the higher the average degree of nodes the network has, the lower the multicast efficiency is. The analysis implies that the efficiency of multicast can be improved effectively by restricting multicast route and selecting the root node of multicast properly. Furthermore, the results indicate that the source-based shortest path tree arithmetic has very different performance on varied network topologies and is not an efficient arithmetic being fit for various structures of networks.