Abstract—Software Defined Networking (SDN) is an inventive network architecture and theoretical framework. SDN separates the control plane (control logic: how to forward data in the network) and Data plane (the actual physical network of forwarding device) to implement adjustable network management. The core essence of the SDN is a centralize management plane. For a large SDN, multiple controllers require to control the network and hence, it is necessary to synchronizing the control plane in order to achieve centralize management. Controller Placement Problem (CPP) is one of the major challenges in SDN, which impacts the network’s latency, reliability, and performance. Most of the work done to solve CPP in SDN considers only controller to switch latency while neglecting the latency among controllers. In this study we updated and modify “Capacitated Controller Arrangement (CCA)”, formulated in our previous study using meta-heuristic optimization algorithm Particle Swarm Algorithm (PSO). Further, a cumulative latency has been proposed considering the dual, switch-controller and controller-controller latency. Mixed Integer Linear Programming (MILP) has been used to formulate the problem for optimally balancing the cumulative average latency. The main objective of this work is to minimize the cumulative latency by optimizing controller placement, simultaneously minimizing the number of controllers while maintaining optimal balance between the average controller-controller & switch-controller latency. The result demonstrates the effectiveness of the suggested approach in solving the CPP for the optimal controller placement while taking cumulative latency into account as a constraint. A discussion of the persuasiveness of the proposed approach is presented after the results are evaluated and verified.

 

Cite: Gagan Deep Singh, Vikas Tripathi, Ankur Dumka, Tiansheng Yang, and Rajkumar Singh Rathore*, “Optimizing Controller Placement in Software Defined Networking: A Capacitated and Latency- Aware Approach," Journal of Communications, vol. 20, no. 3, pp. 272-281, 2025.

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