DSFSM: Delay-Sensitive Fractional Switch Migration For Multi-Controller Software-Defined Networks
Upendra Prajapati, Bijoy Chand Chatterjee, Amit Banerjee · 2025
Multi-controller software-defined networks (SDNs) are an emerging technology that transforms the networking industries by enhancing the system performance of applications with massive traffic. Delays due to frequent fractional switch migrations among controllers are a significant obstacle in the multi-controller SDN, degrading overall performance. To resolve the above issue, this paper proposes DSFSM, a delay-sensitive fractional switch migration approach in multi-controller SDN. DSFSM aims to minimize delay while performing fractional switch migrations among controllers. This delay is considered three-fold: first, the total time taken for a flow request travel from switches to the controller; second, the time taken by the controller to the request (i.e., nearest switch selection and fraction ratio calculation); and third, the time required to respond from the controller to the switch. We formulate DSFSM as an optimization problem using a mixed-integer linear program (MILP). When the network becomes large, or MILP is not tractable, we present a heuristic approach based on MILP. Numerical results demonstrate that the performance of the MILP and the heuristic approach outperforms the conventional scheme that follows the fractional switch migration approach in terms of delay and synchronization costs.