一种IP网络友好的Overlay路由机制

摘要

在现存的多层路由中,上层Overlay网络在路由决策时通常对底层的IP网络性能和状态缺乏有效的协调和感知,致使上层Overlay路由和底层IP路由常常处于非协同、非优化工作状态,产生大量路由抖动和次优路由.为解决这些问题,提出了一种底层IP网络友好的Overlay路由机制,其基本思路为:增加Overlay网络的层感知能力,减少路由抖动,增加Overlay路由的稳定性.Overlay网络根据底层IP网络的节点跳数、链路带宽、丢包率等反映底层IP网络性能的信息作出路由决策.实际网络中,通过调整Overlay网络的链路代价,有效控制Overlay网络的路由决策.仿真结果表明,与传统双重路由(dual routing)相比,此IP网络友好Overlay路由机制在减少Overlay网络路由抖动、降低Overlay网络路径代价膨胀、提高Overlay网络故障恢复成功率和满足Overlay业务需求等方面有优势.%Existent Overlay networks are not IP network-aware enough..The Overlay routing is usually lack of aware of the IP network' s performance and status.So the Overlay network appears sub-optimal routing and has route flaps that have seriously affected the Overlay network applications' performance.This paper proposed an IP network-friendly Overlay routing mechanism.The basic idea was: enhance the Overlay network' s ability of lay awareness and flexibility.Overlay network routes based on the IP.network' s information (e.g.: number of route hops, link bandwidth and packet loss rate).Changing the Overlay network' s linkcost was useful to control the Overlay routing.The simulation results show that: compared to the traditional dual routing, this IP network-friendly Overlay routing mechanism has advantages in reducing the path cost inflation and route flaps, increasing the success rate of recovery, meeting the need of Overlay applications.