The Reaserch On Mulitiple Controller System Based On WmSDN Environment

Wireless mesh network(WMN)is a new network technology,which has many outstanding advantages,including high capacity,good stability,flexible structure and easy deployment,etc.So it is one of the hottest topics in the field of wireless communication technology.Software defined network(SDN)is a new kind of network structure,which departs the control plane from the traditional switch,and concentrates the control ability of all the switchs to the controller.Because of the programmable ability which SDN introduce to the network,it makes the network easier to take full advantage of the whole network's resource.This paper builds an wireless mesh software defined network(wmSDN)system through introducing the SDN structure to WMN,which use the OLSR protocol to route the control message between switch and controller,and use the controller to decide the flow table of data message,so that it combines the advantage of SDN and WMN to the wmSDN.Nowadays,openflow protocol is most widely useed in the communication between controller and switch.According to the openflow protocol,the whole network is controlled by just one controller,which introduces some disadvantage to the network,including the lack of stability or expandability.To avoid the disadvantage introduced by the single controller system,this paper builds a multiple controller system in wmSDN.Firstly,this paper introduces the southern and northern interface technology of SDN structure,including the knowledge of openflow protocol,POX controller and openvswtich.Secondly,we make a deep investment and survey on the topic of how to build a multiple controller system in wmSDN network,and then build such a system.Thirdly,this paper also introduces the detail technology of the realization process,and use the experiment to test the function and the show the performance of the system.The results show our system has better performance in the delay and cost of the processing of flow table requesting compare to the single controller system or other multiple controller system.