SDN-enabled Switch Placement in Multi-domain Hybrid SD-WAN

Software Defined Networking (SDN) helps in distributing network capacity more effectively by dynamically adjusting to changing demands, and managing failure more rapidly. However, considering the next-generation Wide Area Networks (WANs), which are required to be fast, scalable, reliable and cost effective, the transition to completely SDN infrastructure will be challenging. One of these challenges is that a full deployment of SDN, whereby all nodes on the network are SDN-enabled, cannot be straightforwardly accomplished in the diminutive period. Therefore a possible and efficient solution is to shift to the adoption of SDN hybrid networks while retaining legacy infrastructure. In hybrid SDN networks the placement of multiple SDN controllers and limitation of SDN-enabled switches on the hybrid network is still a challenge due to network operation stability and financial constraints. In this paper, we adopt the idea of network partition to solve the SDN-enabled switch placement in hybrid SD-WAN. In order to address this challenge we implement Agglomerative Hierarchical Clustering (AHC) algorithm to solve the SD-WAN partitioning and switch placement problem and use a cluster validity measure to determine the number of optimal clusters. A performance evaluation experiment was conducted for the proposed approach against the Optimized K-means.