动态路由模拟策略研究

Research on dynamic routing mechanism in network simulation

网络模拟路由策略的基本目标是真实地反映模拟数据包的转发过程。拓扑变化会影响路由选择结果。现有模拟器在处理动态路由时会让所有节点同时感知到拓扑变化信息,这与实际网络中的情况并不相符。给出并分析动态路由模拟抽象模型,进而提出计算不同节点对拓扑变化感知时间的策略;提出动态MTree_Nix路由策略,以静态路由表和拓扑变化消息序列作为动态路由表,通过比较节点的感知时间查找路由。实验结果表明,此算法能够更真实地模拟网络中的动态路由,并且具有较高的模拟效率。

A fundamental requirement for any network simulation environment is the realistic forwarding of packets from a source to a destination in the simulated topology. The routing decisions will be affected by topology changes. In almost all current simulators, all the nodes know the topology changes instantaneously, which is obviously unrealistic. The model of dynamic routing was presented and analyzed. Further an approach was proposed to compute the time needed for each node to know the topology changes, and dynamic MTree Nix routing mechanism was presented, which maintains static routing table and a message queue of topology changes, and looks up routing states according to the known time of different changes. Experimental results show that our approach can improve the realism of dynamic routing in network simulation, with high simulation efficiency.