OverSim:可扩展的应用层组播网络仿真框架

摘要

应用层组播作为IP组播的一个可行替代方案日益成为Internet应用研究的一个热点.如何仿真大规模、动态的应用层组播覆盖网络已经成为应用层组播方案研究人员面临的一个共同问题.本文在分析当前几款主流的覆盖网络仿真软件的基础上,提出了采用基于OMNet++网络仿真环境的OverSim覆盖网络仿真框架来模拟大规模、动态的应用层组播覆盖网络,并在此基础上研究分析可扩展的应用层组播方案.最后我们采用OverSim实现了对应用层组播协议Scribe的仿真并对结果进行了分析.仿真结果表明,OverSim可以在有限的硬件环境下,稳定地仿真高达上万个节点的大规模动态覆盖网络,仿真过程中内存消耗较低,且与覆盖网络规模呈线性关系.%As a viable alternative of IP multicast, application-layer multicast is increasingly becoming a hot research topic of Internet applications. How to simulate large-scale, dynamic application-layer multicast overlay network has become a common problem faced by the application layer multicast scheme researchers. Based on the analysis of several mainstream network simulators, this paper proposes the OMNet++ based overlay network simulation framework OverSim in order to simulate the large-scale and dynamic application layer multicast overlay network, and further analyzes the solution of scalable application layer multicast. At last, we simulate the application-layer multicast protocol Scribe on the OverSim and analyze the simulation results. The simulation results show that the OverSim can steadily simulate overlay network with thousands of nodes under the limited hardware environment. Besides, the simulation consumes low system memory that is linearly related with the overlay network scale.