【作者】 潘耘； 王励成； 余镇危； 梁辉；

【Author】 PAN Yun~1,WANG Li-cheng~2,YU Zhen-wei~3,LIANG Hui~4 (1.Computer School,Communication University of China,Beijing 100024,China; 2.Department of Information Security,Beijing University of Posts and Telecommunications,Beijing 100876,China; 3.Department of Computer,China University of Mining and Technology-Beijing,Beijing 100083,China; 4.Information Engineering School,Communication University of China,Beijing 100024,China)

【机构】 中国传媒大学计算机学院； 北京邮电大学信息安全中心； 中国矿业大学(北京)计算机系； 中国传媒大学信息工程学院；

【摘要】 论述了对Overlay网络中组播的服务质量进行量化评价的必要性,引入了组播树二度同胚约简的概念,推广了Bowman评价单播数据流服务质量的随机进程代数方法,提出用随机进程代数对Overlay网络中组播的服务质量进行评价的建模方案,并用PEPA workbench模拟工具针对具体的组播实例的服务质量进行了定量分析.模拟结果表明,传统网络中的IP组播抖动小于Overlay网络中的组播抖动;而后者又进一步小于在传统网络中用单播技术来实现组播时的抖动,与实际情况吻合.更多还原

【Abstract】 The arguments on the necessary for quantized evaluation toward quality of services (QoS) of multicast in Overlay networks are given.The concept of two-degree homeomorphism reduction multicast tree is introduced,extend Bowman’s method for evaluating QoS of unicast dataflow by using stochastic process algebra(SPA) is promoted,a modeling scheme is proposed for quantized evaluating QoS of concrete multicast instances in Overlay networks with simulation tool PEPA workbench.Simulation suggests that the jitter of IP multicast is lighter than the jitter of Overlay multicast,and the latter is further lighter than the jitter of multicast by using unicast technique.更多还原