基于策略和流分类的MPLS显式路由算法

Policy and traffic classification based MPLS explicit routing algorithm

提出一种基于策略和流分类的多协议标记交换(MPLS,Multi-Protocol Label Switch)流量工程显式路由算法,算法分离线计算和在线计算2个步骤实施.离线计算基于多商品流问题,计算使网络总体资源耗费最低,并且能够满足流的带宽需求的每链路每流带宽分配值.在线计算根据这种带宽分配结果,实时计算最短路径作为单个流的显式路由.离线计算和在线计算相结合可使网络流按照其固有的流量分布特征合理地映射到网络物理拓扑中,在一定程度上避免了因路由计算不合理而导致的网络性能退化和资源使用不均衡等问题.算法综合考虑网络流量、资源、管理策略等要素,能够较好地平衡网络资源的使用,提高网络资源利用率,有效实施MPLS流量工程.

An explicit routing algorithm based on policy and traffic classification was proposed. The algorithm was implemented in two steps： offline and online computation. The process of offline computation outputted the bandwidth for each type of traffic flow and the algorithm was based on multi-commodity problem, which got the minimum network resource consumption while meeting the bandwidth demands for all kinds of traffic flows in the network. The process of online route computation outputted the shortest path for each flow according to the pre-allocated bandwidth values of the offline process. The combination of offline and online computation mapped the traffic flows to the network topology according to the traffic distribution property, and thus could alleviate the performance degeneration problem existing in the traditional routing algorithms. The network traffic distribution state, resource situation and network management policy were taken into consideration in the process of explicit route computation, which could improve the utilization of network resource and provide the explicit route for facilitating MPLS traffic engineering and traffic control effectively.