关于覆盖组播中拓扑发现的研究  

Research on Topology Discovery in the Overlay Multicast

作　　者：曹佳[1,2] 鲁士文[1] 

机构地区：[1]中国科学院计算技术研究所 [2]中国科学院研究生院北京100080

出　　处：《计算机研究与发展》2006年第5期784-790,共7页Journal of Computer Research and Development

基　　金：国家"八六三"高技术研究发展计划基金项目(2002AA742052);国家高技术产业发展基金项目(20032040)~~

摘　　要：覆盖组播的主机自己完成拓扑发现和构建转发树的工作.其中一个重要问题就是上层传输路径在底层可能是迂回的.如果拓扑发现可以揭示足够的底层拓扑信息,那么就可以尽力减小迂回程度.主要探讨在随机拓扑发现策略中上述迂回程度和k值的关系.发现每个主机至少随机选择Θ(logn)个不同的其他主机进行测试,就能保证在测试拓扑中从源到任意主机是可达的;至少随机选择2.997×n0.5312个不同的其他主机就能保证从发送源到任意主机的路径长度最多是直接采用单播传输的2倍.最后通过模拟实验验证了当满足上述条件时,再增大k值已不会使覆盖组播传输路径的迂回程度有十分明显的改善.In the overlay muhicast, hosts perform the topology discovery and build multicast tree by themselves. This may ruthlessly wastes network resources if the overlay paths mismatch the underlay paths. Otherwise, it will be improved. In this paper, an active topology discovery method based on the random directed graph is analyzed. It is shown that if each node chooses Θ（log n ） nodes randomly to test, the topology will be non-strong connective, and if test, the length from the source host to any hosts path. The simulations show that the path will not the /e reaches a certain value. each node chooses [2.997×n^0.5312] nodes randomly to will be at most two times the length of directed unicast be improved obviously with the increase of k value, after

关 键 词：随机有向图 覆盖组播 拓扑发现 连通 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]