A Load Distribution Scheme Over Multiple Controllers For Scalable Sdn

In this paper, we propose a load distribution scheme on a per-flow basis over multiple controllers in SDN (Software-Defined Networking). Specifically, when the capacity of a controller reaches a threshold, the controller makes incoming messages be migrated to other controllers to prevent them from being blocked. Analytical results show that our scheme has lower blocking probability and higher controller capacity utilization ratio than the conventional scheme.