Research On Storage Optimization For OpenFlow Flow Table Of Data Plane In Software Defined Networking

The traditional tight coupling networks have brought many convenience to people's life,at the same time,its shortcomings were criticized by many people.Therefore,many scholar have begun to study and explore the new network architecture in recent years,Software Defined Networking(SDN)came into being,SDN is a kind of innovative network architecture that separates the control plane from the data plane.SDN has network programmable features and control network traffic flexibly,which provides a good platform for network and application innovation.As OpenFlow software switches have the advantages of low-cost,flexible configuration and easy to deploy scheduling,so it is the first choice for building a network test platform and building a small and medium-sized SDN network.However,the number of flow entries in the switch will grow rapidly with the extensive deployment of the OpenFlow network and the width of the flow table will also increase as the version of the OpenFlow protocol continues to upgrade,which makes the flow table storage becoming a networking bottleneck.The studies of this paper are as follows:(1)Aiming at the problem of limited storage resource of TCAM in OpenFlow switches,this paper presents an efficient OpenFlow flow table splitting and compressing algorithm by exploiting the relationships among matching fields.Firstly,the paper analyzes coexistence and conflict relationships among matching fields,and divides a given flow table into multiple sub-flow tables.Then,we compress sub-flow tables by building a condition for each field.Finally,we evaluate the flow table compression performance of our proposed algorithm in virtue of real network traffic traces by experiments.The experimental results indicate that our proposed algorithm performs better than existing compression algorithms in terms of flow table storage compression rate,and effectively saves TCAM storage resources.(2)In order to improve the OpenFlow switches in the data forwarding and storage capacity,OpenFlow flow table storage optimization design,aiming at the congestion between the flow table entries stored in the switch leakage problems,an optimization scheme of flow table to store the genetic evolution cache strategy is proposed based on OpenFlow,first recorded in the OpenFlow cache temporal flow the center of the switch,build the OpenFlow flow table in the feature of temporal set,the cache area adaptive control algorithm of aggregation relationship OpenFlow flow,then the genetic evolutionary method of flow table design dynamic cache,cache OpenFlow flow table storage optimization strategy to replace,finally storage performance test results show that for OpenFlow flow table is stored using this solution can improve the flow information throughput,reduce the flow table resource adaptation Delay,improve the OpenFlow flow table storage performance.