面向卫星网络的流量工程路由算法

摘要

针对卫星网络链路长时延、拓扑时变等特征,将链路传输时延引入并基于MPLS网络中源一目的节点对已知这一先验知识,提出了一种面向卫星网络的MPLS流量工程路由算法.该算法基于卫星网络时变拓扑模型的卫星拓扑快照,定义链路初始权重为链路剩余带宽、传输时延的综合函数,在为当前节点对建路时考虑其余节点对将来建路的可能需求计算链路的关键度,在此基础上通过链路权重的动态调整及延期选用实现流量工程,从而优化卫星网络的链路利用.实验表明,此算法在请求拒绝数、吞吐量、平均跳数及平均时延等方面性能都有较理想的提升.%With regard to long transmission delay and dynamic topology characters in satellite network, a novel routing algorithm was proposed in multi-protocol label switching satellite network. The algorithm uses the prior knowledge of source-destination pairs, and link propagation delay is also considered. Based on time-varying topology snapshot of satellite network, initial link weight is defined as function of transmission delay and residual bandwidth. Both current request and future requests are in account when calculate critical degree. Thus traffic engineering is realized by link weight dynamic adjustment and critical links extension loaded, which guarantee resource utilized better. Simulation results demonstrate the algorithm performs better in terms of request reject ratio, total available flow, average hop and transmission delay of least interference paths.