Controller placement optimization for Software Defined Wide Area Networks (SDWAN)

Abstract

Software Defined Networking (SDN) has emerged as a promising solution to revolutionize network deployment, operations and economic growth. This paradigm aims to address management and configuration complexities in legacy networks so as to reduce the total cost associated with deploying and running telecommunication infrastructures. At the heart of SDN is a controller which oversees orchestration of resources. An important problem that must be addressed during the initial design of an SDN-based network deployment is to find the optimal number of controllers and their locations, to achieve desired operational efficiency. This problem constitutes competing objectives such as latency, load balancing, and reliability. We apply Silhouette Analysis, Gap Statistics and the Partition Around Medoids (PAM) algorithms and, unlike previous work, we add a new method for solving the controller placement problem using an emulation orchestration platform. Our approach aims to optimize controller-to-node latency, alleviate control-plane signalling overhead and ensure control-plane resiliency. Our results for South African national research network (SANReN) reveal that deploying two controllers yields the lowest latency, reduces control-plane signalling overhead and guarantees control-plane resiliency. Our approach can be used by network operators as a guideline to start integrating SDN or plan a new SDN deployment, by helping them make quick automatic decisions regarding optimal controller placement.

An Efficient Controller Placement Algorithm using Clustering in Software Defined Networks

“…We employ a method called the ideal meeting point algorithm to identify the most advantageous coordinate for the controllers. We test this against the algorithm used in [9]. Any of the points whose distance is lower than the distance at the centroid will be the point with the shortest distance travelled.…”

“…Finally, four strategies are demonstrated for weighting and rating individual solutions. Article [9] discusses the method used to solve the issue of placing SDN controllers by figuring out how many SDN controllers should be placed, and when, in a wide area network, along with describing any performance and financial consequences. The authors apply the PAM algorithm to cluster the network and utilize the Johnson algorithm to identify the most optimal positions for the placement of controllers.…”

Controller placement problem during SDN deployment in the ISP/Telco networks: A survey

“…The clustering approach separates the network into domains, which makes figuring out how many controllers are needed easier. 66 A CPP Solutions' Strategy: the network-partitioned-based CPP and clustering approach have potential benefits in the context of large WAN ISP/teleco networks. Recent findings state that the controller's response time is influenced by both the load on the controller and the S2C latency influence the controller's response time.…”

“…Although adaptive CPP splits the entire network at regular intervals, clustering methods may be useful for deciding where to deploy the initial controllers. The clustering approach separates the network into domains, which makes figuring out how many controllers are needed easier 66 …”

“…Mamushiane et al 66 extended and used a facility location approach known as Partition Around Medoids (PAM) with propagation latency to determine the optimum places to put SDN controllers. This study suggested using the Silhouette and Gap Statistics algorithms to decide how many controllers to deploy in a wide‐area network.…”