Design And Implementation Of Multi-Controller System Based On SDN In Mobile Communication Scene

In mobile communication networks,increasingly diverse mobile communication tasks place higher demands on network configuration and interoperability.Applying software-defined networks to mobile communication networks can simplify network configuration and improve network flexibility.However,due to the high dynamics of the mobile communication network,synchronization of data by multiple controllers will cause problems of slowly network update and highly controller overhead.At the same time,the link between the switch and the controller in the mobile communication network is disconnected during the movement process,resulting in the switch being unable to process the new data stream.This thesis designs and implements the SDN multi-controller system.The main work contents are as follows:(1)Aiming at the problem that the synchronization of data by multiple controllers leads to slowly network update and highly controller overhead,this thesis designs a controller topology synchronization scheme..Firstly,the network awareness module is designed to collect network status information,including link delay and link remaining bandwidth.Then,the inter-domain link maintenance module is designed to discover inter-domain links and maintain inter-domain link information,and establish virtual links between the inter-domain switches of the same network according to the intra-domain information collected by the network awareness module.Finally,an abstract version of the global network information is generated by inter-domain links and virtual links.(2)The switch connection management scheme is designed for the problem that the link between the switch and the controller is disconnected by mobility.First,the controller creates a configuration object for the connected switch,enabling the controller to remotely configure the switch through the OVSDB management protocol.Then,the controller periodically collects the delay between the controller and the switch,controller determines the link status of the switch and the controller through the delay information,?Controller performs switch migration when detecting that the switch has a more suitable controller.This thesis designs and implements the SDN multi-controller system in the mobile communication scenario,and tests the function and performance of the network abstraction scheme and switch connection management scheme in the system.The experimental results of system function and performance test show that the SDN multi-controller system designed in this thesis can avoid the excessive synchronization cost of the controller in the mobile communication network scenario,and can effectively reduce the situation that the switch cannot process the new data stream.The scene has certain research significance.