On Modeling Controller-switch Interaction in Openflow Based Sdns

With an increase in number of software defined network (SDN) deployments, and OpenFlow consolidating as the protocol of choice for controller-switch interactions, a need to analytically model the system for performance analysis is increasing. An attempt has previously been made in [1] to model the system considering both a controller and a switch as an M/M/1 queue. The method, although useful, lacks accuracy for higher probabilities of new flows entering the network. The approach is also deficient of details on how it can be extended to more than one node in the data plane . These two short-comings are addressed in this paper where the controller and switch are modeled collectively as Jackson’s network, with essential tuning to suit OpenFlow-based SDN. The consequent analysis shows the resilience of the model even for higher number of new flow entries. An example is also used to illustrate the case of multiple nodes in the data plane.