Research On The Vnf State Synchronization And Distributed Firewall Policy In Software Defined-Networks

Defining a firewall policy as an access control type rule in software-defined network and deploying it distributedly in the network can improve the quality of service of the session.In addition,compared with the Software Defined network architecture,with the rapid development of the new Network Functiong Virtualization architecture,the combination with the software-defined network structure is one of the development directions of the future network architecture.The development of a joint architecture simplifies network management and provides a more reasonable scheduling and distribution method for network resources.Therefore,in this context the thesis studies the OpenFlow rule placement problem and the joint of the VNF state synchronization and routing scheduling problem as follows:In order to reduce the number of rules placed in the network,a heuristic algorithm of Rules Allocation(HARA)is proposed.The algorithm considers the traffic load of the TCAM storage space of the commodity switch and the link of the end switch,and solves the rule placement problem of the multi-route unicast session with different throughput by establishing a mixed integer linear programming model aiming at minimizing the number of rule placements.In order to solve the problem of VNF state synchronization and routing scheduling for different VNF instances of the same type,this thesis proposes a two-step fast heuristic algorithm TPFA.The algorithm is divided into the following two stages.In the first stage,the TPFA algorithm selects the optimal number and placement of VNF instances under the condition of NFV resource constraints,and determines the routing of clint flow.In the second stage,by forwarding the rules update method,aiming at maximizing the economic utility,the optimal transmission path is selected for the control flow of different VNF instances,and the goal of consistency of different VNF instances is achieved.