Efficient information sharing among distributed controllers of OpenFlow network with bi-connectivity

The OpenFlow has been widely used as a standard protocol to actualize Software Defined Networking. With the object of reliability and scalability in a control plane of a more realistic network, management methods utilizing multi-controllers has been getting more developed these days. However, implementing the management methods on multi-controllers might cause inter-controller communication delays between controllers and boost necessary state information shared by them when a network becomes larger. Then, this paper proposes a method to keep the delay shorter and reduce the shared information by layering and clustering a control plane.