An Improved Switch Migration Approach to Controller Load Balancing in SDN

The distributed SDN network has improved the scalability and reliability of controller. However, such deployment architecture introduces a new challenge to the load balancing of controllers when uneven loads distribution among controllers because of the static configuration between switch and controller. To address this problem, we improve the existing switch migration approach and propose a Staged Switch Migration Strategy (SSMS) to balance controller loads in multi-domain network. SSMS includes two stages. In stage 1, integrated several controller overheads, we select the migration objects included switch immigration domain and switch emigration domain based on genetic algorithm. In stage 2, the sequential migrating of switches are implemented through setting subdomain migration degree and switch validity. Simulation shows that SSMS can achieve the effective controller load balancing with better performance in distributed SDN network.