WDM网中基于服务等级约定限制的动态共享通路保护算法

Dynamic Shared Path Protection Algorithm in WDM Networks Under Service Level Agreement Constraints

服务等级约定(SLA)是用户与服务提供者之间达成的有关服务内容、服务质量等方面的合约,它规定了服务提供者必须为用户提供的具体服务参数.连接可靠性和恢复时间是涉及生存性问题的两个重要SLA参数,如何保证用户请求的连接可靠性和恢复时间要求以避免违约而受到惩罚,同时又最大限度地降低成本是服务提供者最关心的问题之一.针对上述问题,本文提出一种动态约束共享通路保护算法(DCSP)加以解决.DCSP同时考虑用户提出的上述两个SLA参数要求,利用K路由和部分链路分离保护思想为它们动态提供区分服务.DCSP既能保证用户的服务要求,同时又有利于全网负载均衡和提高资源利用率.最后对所提算法进行了仿真研究,给出了仿真结果.

The notion of service level agreement (SLA) has been proposed to capture Qualitatively and quantitatively defined performance contract between the service provider and the customers. Connection reliability and restoration time are two important SLA-parameters of the customers main concerns and should be carefully considered in survivable WDM networks. A sound scheme should carefully guarantee the two SLA-requirements simultaneously and benefit a network operator in resource efficiency and service scalability. Under the two SLA-parameter constraints, a novel dynamic constraint shared path-protection algorithm (DCSP) in WDM mesh networks is proposed. Based on the basic ideas of the K-shortest path and partial link-disjoint protection, DCSP can provide differentiated services for customers according to their SLA-parameters. Simulation results show that DCSP not only can efficiently guarantee the specific SLA requirements of customers, but also can achieve significant performance gain and lead to remarkable reduction in blocking probability.