面向SDN的流规则拆分分配算法

Flow Rule Splitting and Allocation Algorithm in SDN

软件定义网络(Software Defined Networking,SDN)是一种新兴的网络技术,OpenFlow作为SDN中的通信协议,通过在三态内容寻址寄存器(Ternary Content Addressable Memory,TCAM)中安装流规则来进行网络通信.由于TCAM的容量有限,因此在TCAM中合理放置流规则至关重要.为高效利用TCAM空间,本文提出了基于拆分分配的流规则放置算法,在满足网络需求的前提下,使得拆分后流规则总数更少.首先,本文设计了两种拆分分配算法,一种是基于矩形拆分分配算法,另一种是基于平均拆分分配算法.最后将本文设计的算法与基准机制相对比,实验结果表明:基于矩形拆分分配算法的流规则平均增加率为34.1%,相较于基准机制降低了76.46%;基于平均拆分分配算法的流规则平均增加率为55.5%,相较于基准机制降低了70.31%.

Software Defined Networking(SDN)is a novel network technology.As a communication protocol in SDN,OpenFlowimplements network communication by installing flow rules in the Ternary Content Addressable Memory(TCAM).Due to the limited capacity of the TCAM,it is important to place the flow rules reasonably in the TCAM.In order to utilize TCAMspace efficiently,this paper proposes a flow rule placement algorithm based on splitting and allocation,which reduces the total number of flow rules by splitting under the premise of satisfying the network requirements.Firstly,this paper designs two splitting and allocation algorithms.One is the rectangular-based splitting and allocation algorithm and the other is the average-based splitting and allocation algorithm.Finally,this paper compares the proposed algorithm with the benchmark mechanism.The experimental results show that the flow rules of the rectangular-based splitting and allocation algorithm averagely increases by 34.1%,which is 76.46%lower than the benchmark mechanism.The flow rules of the average-based splitting and allocation algorithm averagely increases by 55.5%,which is 70.31%lower than the benchmark mechanism.