Consistent update scheme based on shortest average delay in software defined network

In response to the problem of inconsistent control caused by the inevitable delays between the controller and switches in the software defined networking (SDN), the average delay between controller and switches in SDN are obtained through controller-to-switch message through Openflow protocol, and a consistent update scheme based on shortest average delay (namely CUSBSAD) for control logic in SDN is designed. In addition, an objective optimization model based on the shortest average delay of nodes is constructed. This model is then used to find the minimum-delay route while retaining the logical consistency in the SDN network. The simulation results demonstrate that the proposed scheme is feasible and effective.