A greedy approach for minimizing SDN control overhead

In the SDN approach, the control and data planes are separated to enable programmability and interoperability, the control plane being logically centralized. Scalability and reliability are key properties for the SDN control plane. In WAN deployments, it is already envisioned as physically distributed to span across the networks and avoid single point of failure. In this paper, we tackle the problem of minimizing the overhead generated by distributed SDN controllers. We first model this problem as a Mixed Integer Program (MIP) and then propose a greedy algorithm. The results on the GEANT topology and on random graphs with up to 100 nodes show that our heuristic approaches to less than 3% the optimal in a manageable time.