An Effective SDN Controller Scheduling Method to Defence DDoS Attacks

Distributed Denial of Service (DDoS) attack is a difficult issue which needs to be addressed in Software defined networking (SDN). In order to help the controller to weather out the DDoS attack, an efficient controller scheduling method is proposed. The proposed controller scheduling method uses the normalized waiting time, length and extent of the switch being attacked to choose the request that needs to be processed by the controller. The evaluation results validate that compared with the polling based controller scheduling method, the proposed one can significantly reduce the connection failure ratio and delay.