移动IP路由优化实现及性能分析

为解决在标准移动IP中存在“三角路由”和切换期间通信时延两个问题,在网路仿真器中实现了移动IP的路由优化(ROMIP)扩展以及平滑切换机制,并在网络仿真器原有标准移动IP框架的基础之上,引入了绑定警告、绑定更新、绑定请求和绑定确认等绑定缓存管理消息.同时,使用后向型平滑切换机制来降低切换时延.仿真结果表明,较于标准的移动IP协议,ROMIP明显地提高了数据带宽,降低了通信对端节点与移动节点之间分组发送的端到端时延.由于平滑切换机制的实现,通信切换时延降低了50%以上.此外,该方法具有对硬件的透明性和在软件实现上的简易性,因而为移动IP网络的实时通信提供了一种有参考价值的实现方法.

Implementation and Performance of Route Optimization in Mobile IP

Mobile IP(MIP) based on IP layer offers a global mobility solution to support wireless Internet traffic.In this paper,to eliminate the triangle routing problem and minimize handoff latency,the route optimization extensions for Mobile IP(ROMIP) is complemented and the backward smooth handoff mechanism is utilized in Network Simulator(NS-2,Version: 2).Binding cache management messages(Binding Warning,BW;Binding Update,BU;Binding Request,BR;Binding Acknowledgement,BA,etc.) are introduced into the original NS-2 framework.Moreover,backward smooth handoff mechanism is used to minimize the handoff latency.The simulation results show that,compared with the standard Mobile IP protocol in ROMIP,the achieved bandwidth increases evidently while the end-to-end packet delay remains low.Owing to the implementation of smooth handoff,handoff latency is cut down more than 50%.Moreover,this method keeps transparent for hardware and convenient for software.The research provides a valuable and practical implementation method for real-time communication in Mobile IP network.