Proactive Mitigation to Table-Overflow in Software-Defined Networking

Abstract

Table-overflow occurs frequently in switches due to the limited flow table storage space, which has seriously hampered thelarge-scale deployment of SDN. To mitigate this threat, we introduce a new, proactive switch space intelligent management framework that can react actively before table- overflow occurs. Our solution, referred to as CPD, contains three modules: flow table status collection, flow prediction and proactive flow entry deletion. To preserve the function of switch, flow prediction predicts the number of new flows entering the network based on historical information, and proactive flow entry deletion evaluates the likelihood of table-overflow according to the predicted value and the state of current flow table gathered by status collection and proactively deletes the flow entries through a flow-based eviction algorithm. Further, we determine the best sampling period by solving a multi-objective optimization problem. Finally, the simulation results show that CPD can prevent about 90% of table-overflow and significantly reduce over 20% occurrences of table-miss compared with existing mechanisms.