Abstract：Based on SDN / OpenFlow network architecture,a new OpenFlow network congestion control mechanism is proposed so as to solve the congestion problem. The mechanism is based on OpenFlow controller that can globally manage network resources. When the network has nodes in a congestion control state,the controller can choose one or more suitable flow for rerouting in congestion node hop node. The experimental results show that this mechanism can effectively ease network congestion,ensure service quality,and also can enhance the utilization of network resources.

Keyword：SDN;OpenFlow;congestion control;flow table;