作　　者： ; ; ; ;

机构地区： 华南理工大学电子与信息学院

出　　处： 《华南理工大学学报（自然科学版）》 2008年第8期54-58,74,共6页

摘　　要： 目前多协议标签交换(MPLS)网络中大多采用启发式算法进行抢占,造成了带宽资源的浪费.文中通过分析MPLS网络中支持Diffserv流量工程的抢占策略,基于抢占策略包括标签交换路径(LSP)的数目、LSP的优先级和抢占带宽3个主要抢占准则的思想,提出了一种优化的启发式算法B-PREPT(Backtracking Preemption).该算法基于回溯法的原理求解NP(Nondeterministic Polynomial)完全问题.仿真结果表明,与算法V-PREPT(Versatile Preemption)相比,算法B-PREPT抢占代价更小,抢占结果更准确,计算效率相当,适用于实际网络.研究中还对抢占策略下的路由方法进行了探讨. There exists a waste of bandwidth resources due to the heuristic algorithms for the preemption in multiprotocol label-switching （MPLS） networks. In order to solve this problem, the preemption policy for the Diffserv- Aware Traffic Engineering in MPLS networks is analyzed and an optimized heuristic algorithm is proposed based on three main preemption optimization metrics, namely the number of label-switched paths （LSPs） to be preempted, the preemption priority of LSPs and the preemption bandwidth. The proposed algorithm, marked as B-PREPT （ Backtracking Preemption）, employs the backtracking method to solve the nondeterministic polynomial （NP） -complete problem. Simulated results indicate that, as compared with the well-known heuristic algorithm V-PREPT （Versatile Preemption）, the proposed algorithm is of lower cost, higher accuracy and almost equal efficiency. Thus, it is applicable in actual networks. A path selection scheme based on the preemption policy is also investigated .

关 键 词： 流量工程 多协议标签交换网络 抢占 启发式算法

领　　域： [电子电信] [电子电信]