A new optimization technique to solve the latency aware controller placement problem in software defined networks

Software defined networking (SDN) is a modern and upcoming standard in today's network as it centralizes the network intelligence by separating the control plane from the forwarding plane. Placing a controller in an appropriate location and minimizing the switch to controller (SC) latency are important factors in SDN. In this article, we proposed a mathematical algorithm to form the clusters and placed one controller in each cluster to shorten the worst-case SC latency. We have proposed a technique called the $-method by using the distance matrix of the network nodes and placed a $ whenever we have found the matrix element is greater than a given maximum distance. Initially, the maximum distance is calculated using the center of mass method that we have developed for minimizing the average SC latency. Our method guarantees that it will generate the minimum worst-case SC latency efficiently that one could ever achieve for a different number of controller placement. Simulation has been done under some real-world network topologies from the dataset of Internet Topology Zoo. Our result shows that the $-method performs better compared with other existing algorithms in terms of worst-case SC latency minimization with less number of controllers. Further, we have analyzed our method for the failure mode of a controller by assigning the switches of that failed controller to its nearest controllers which shows that our method also performs better in terms of network fault tolerance and improves network resilience.

Automated summary

Software Defined Networking (SDN) is a modern standard that centralizes network intelligence by separating the control plane from the forwarding plane. The study proposes a mathematical algorithm for minimizing worst-case SC latency and introduces the $-method to achieve this goal. Simulation results show that the $-method outperforms other existing algorithms in terms of worst-case SC latency minimization under real-world network topologies.