Research On Scalability Of Software-defined Networks Based On Early Flow Table Deletion Strategy For Connection-oriented Protocols

In view of the current situation that users have more stringent requirements for network flexibility and robustness,the defects of traditional network architecture are increasingly exposed,so it is urgent to design a new network architecture.The SDN network is well adapted to the current needs,and its rise can be said to provide a directional study for future network development.SDN is different from the traditional design concept of network system.It improves the flexibility and controllability of network by separating control plane from data plane and developing network programmability.However,due to the limited storage capacity of Ternary Content Addressable Memory(TCAM),which is widely used in SDN switches,its switches are unable to face the expanding network scale and network traffic explosion,resulting in the scalability of SDN.This is undoubtedly a restraint for the application of SDN networks,so this paper aims to solve and improve the scalability of SDN by proposing an early eviction strategy.This paper proposes an early eviction strategy,which combines Connection-oriented Protocol with SDN network architecture,by detecting the disconnection signaling of Connection-oriented Protocol in SDN network architecture to evict invalid flow entries in advance to solve this problem.The detection behavior is implemented by adding a specific SDN rule set between the controller and the switch.This article first combines the Transmission Control Protocol(TCP)in the Connection-oriented Protocol with the SDN network,and then combines the Stream Control Transmission Protocol(SCTP)in the Connection-oriented Protocol with the SDN network.The simulation results of both methods show that compared with the original mechanism of the SDN network,the solution proposed in this paper can greatly reduce the occupation of invalid flow entries,improve the available space of the switch,and improve the scalability of the SDN network.The simulation also shows the significant advantages of this method in the aspect of flow table miss rate,and no significant increase in signaling overhead.Aiming at the current situation of SDN network scalability restriction,this paper proposes a feasible way to improve its scalability,in the hope that SDN network scalability research can obtain greater results,so that SDN networks can be better applied in practice.