Packet-in Messages Handling Scheme to Reduce Controller Bottlenecks in OpenFlow Networks

this paper proposes a mechanism that handles the packet-in messages to reduce the bottlenecks of controller in SDN/OpenFlow network. In SDN networks, the Openflow switches send many packet-in messages to forward every new flow of data. Then, the controller responds the flow rule for each packet-in message. Therefore, the bottlenecks can occur between controller and switches for sending three packets (one flooding and two packet-in messages) to add a new flow. The proposed system can reduce this bottleneck effect by adding a couple flow rules only with a single packet-in message. It is implemented using Mininet emulator to create a network topology and Ryu OpenFlow controller to manage the forwarding plane by the controller. The evaluation indicates that the proposed system is able to reduce one-third of packet overhead compared to original OpenFlow.