Optimization Model Research Of The Green And Efficient OpenFlow Packet Forwarding Performance

As an open network architecture separating data forwarding and control logic,softwaredefined networking(SDN)enhances the flexibility and manageability of networks,and reduces the construction,operation and maintenance cost of networks.Currently,SDN has been widely used in data centers,cloud computing and other network scenarios.However,the rapid development of software-defined networking is accompanied by key performance bottlenecks such as lookup energy consumption of flow tables in the data plane and load balancing of controllers in the control plane.In order to solve the above problems,this paper establishes OpenFlow packet forwarding performance optimization models and proposes the corresponding optimization methods,which provide theoretical references for achieving the green and efficient SDN.The main research works of this paper is as follows.(1)In the data plane of SDN,OpenFlow switches typically utilize ternary content addressable memory(TCAM)to store flow tables for fast wildcarding lookups.However,TCAM performs lookups in parallel,bringing about high energy consumption.Therefore,it is necessary to choose appropriate TCAM capacity to balance the delay and energy consumption of packet forwarding.For the typical scenario of Software-Defined Data Center Networks(SDDCN),this paper establishes a packet forwarding delay model based on the OpenFlow packet forwarding process and queuing characteristics.Meanwhile,we establish a hit rate model of TCAM flow tables based on flow distribution characteristics,to solve the relational expression between packet forwarding delay and TCAM capacity.Considering the energy consumption of TCAM lookups,we establish a joint optimization model of energy consumption and efficiency regarding packet forwarding,and design an optimization algorithm to solve the optimal TCAM capacity.The experimental results indicate that our proposed delay model can more accurately characterize OpenFlow-based packet forwarding delay than existing models.Meanwhile,we leverage the optimization algorithm to solve the optimal TCAM capacity with different parameter configurations,which provides a theoretical guidance for achieving the green and efficient SDN data plane.(2)In the control plane of SDN,the network is usually divided into multiple control domains,each of which deploys an SDN controller to manage the forwarding behavior of the switches.However,due to the dynamic variation of network traffic in time and space,the static mapping of switches and controllers will cause load imbalance among controllers.To this end,this paper establishes a switch migration decision model based on migration efficiency to achieve efficient and accurate selection of migration targets by considering switch migration costs and benefits.On this basis,we propose an SDN resiliency control algorithm based on switch migration,which enables load balancing among controllers by adjusting the dynamic mapping relationship between controllers and switches through switch migration,and make some controllers dormant when the control plane is under low load to reduce control plane energy consumption and improve control resource utilization.The experimental results show that our proposed SDN resiliency control algorithm based on switch migration can effectively improve the load balancing and resource utilization of the control plane,which provide a reference guideline for achieving the green and efficient SDN control plane.