基于SDN的胖树数据中心网络的多路径路由算法

SDN-based Multipath Routing Algorithm for Fat-tree Data Center Networks

近年来,具有多路径能力的胖树拓扑结构已经被应用在很多数据中心网络(DCNs)中,以提高网络带宽和容错性。但其使用的传统路由协议对多路径路由的支持是非常有限的,并没有充分利用胖树数据中心网络的多余的可用带宽。因此研究了基于SDN的胖树网络的多路径路由。首先提出一个属于线性规划范畴的问题并证明它的NP完全性;然后提出了一个利用软件定义网络架构优点的实用算法,其依赖于一个中心控制器来收集网络状态信息,以作出最优的路由转发决策;最后把算法实现为OpenFlow控制器的一个模块并进行仿真验证。实验结果表明,所提算法无论在提高吞吐量还是减小端到端时延方面都优于传统的基于拓扑感知启发式的多路径算法。

To increase bandwidth and improve fault tolerance, the fat tree topology with multipath capability has been used in many data center networks （DCNs） in recent years. But traditional routing protocols have only limited support for multipath routing,and can not fully utilize the available bandwidth in such networks. This paper studied the SDN- based multipath routing for fat tree networks. Firstly, a linear programming problem was proposed and its NP-completeness was proved. Secondly, a practical solution which takes advantage of the emerging software defined networking paradigm was proposed. Our algorithm relies on a central controller to collect necessary network state information in order to make optimized routing decisions. Finally, the algorithm was implemented as an OpenFlow controller module and was validated by simulation. Experimental result shows that the algorithm outperforms the traditional multipath algorithm based on random assignments both in increasing throughput and reducing end-to-end delay.