SDN中基于链路特征的路由控制机制

Routing control mechanism based on link features in SDN

针对数据中心网络中存在的由于多对一通信模式造成的网络拥塞问题,提出了一种在软件定义网络(SDN)体系架构中基于链路特征的路由控制机制(RCMLF)。该机制采用带滤波的带宽估计算法,引入阻尼阈值参数,设计了一种自适应的拥塞避免算法,针对网络中不同的链路带宽占用情况,自适应地调整传输策略,解决了网络中由于“流量抖动”而造成的系统不稳定问题、由于路由算法自身性质造成的网络拥塞问题以及不能够合理利用带宽资源而造成的资源浪费问题。最后,通过软件模拟的方式搭建数据中心网络仿真平台进行性能测试,实验结果表明,所提出的算法相比最小跳数路由(MHR)、等价多路径路由(ECMP)、最宽最短路由(WSP)、Hedera四种传统算法,吞吐量平均提高了75.63%,丢包率平均降低了49.88%,平均时延平均降低了41.99%。该算法在数据中心的多对一通信模式下具有较好的性能,同时使链路资源得到更合理的利用。

Aiming at the network congestion caused by the many-to-one communication mode in data center networks, a Routing Control Mechanism based on Link Features (RCMLF) in the SDN (Software Defined Network) architecture was proposed. In this mechanism, with a bandwidth estimation algorithm with filtering adopted, damping threshold parameters indroduced, an adaptive congestion avoidance algorithm was designed. The transmission strategy was adaptively adjusted according to the occupancy of link bandwidth in the network, solving the problems including system instability due to “traffic jitter”, network congestion due to the nature of the routing algorithm itself and resource waste caused by the irrational utilization of bandwidth resources. Finally, a data center network simulation platform was built by software simulation to test the performance. The experimental results show that the proposed algorithm improves throughput by 75.63% averagely, decreases packet loss rate by 49.88% averagely and reduces average delay by 41.99% averagely compared with the traditional algorithms MHR (Minimum Hop Routing), ECMP (Equal-Cost Multipath Routing), WSP (Widest Shortest Path) and Hedera. This algorithm has better performance in multi-to-one communication mode in the data center, and makes more rational use of link resources.