Enforcing timely network policies installation in OpenFlow-based software defined networks

As an efficient network innovation enabler, software defined network is designed to address the networking needs that are poorly addressed by existing networks, and makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. The OpenFlow API enables secure communication between controllers and switches, and standardizes the communications. However, there exist critical issues during the procedure of distributing network policies among the switches (especially for in-band communication schemes), which impose various implicit negative impacts on network reliability and efficiency, such as additional computation overhead on both controllers and switches, communication overhead on secure channel, and waste of storage resources on switches. Based on these observations, this paper proposes four practical solutions to deal with these issues. The evaluation results reveal that the proposed solutions reduce the network latency by 50%, improve the goodput by 10-15%, and decrease the hardware cost by 25% at most, which convinces the effectiveness of proposed solutions.