Research And Design Of SDN Protocol Conformance Testing Based On OpenFlow

The emergence of software-defined networks brings disruptive change to the traditional network architecture. It decoupling the data plane and control plane, network administrator can use software to determine the processing of network flow. OpenFlow protocol is the interface between controller and switch in SDN architecture, Equipment produced by different manufacturers only need to comply with the relevant specifications and it would be able to successfully achieve interoperability, it Breaks the traditional network barriers. However,because of the two meanings of the protocol and the different understanding of different manufacturers, the realization of the OpenFlow protocol will inevitably appear deviation, in order to achieve better communication; the OpenFlow conformance test is imminent. At the same time, it is also a hot spot for the generation of effective test sequences.First of all, this thesis analyzes the characteristics of SDN network architecture and the characteristics of OpenFlow protocol. Based on the consistency test theory, the extended finite state machine and OpenFlow data stream processing, EFSM model was established for OpenFlow protocol. The model can clearly describe the process of OpenFlow protocol data stream processing.Next, focusing on the problem of test case generation for EFSM model, the feasible path of the EFSM model is studied under the condition of different coverage criterions, Firstly, the state diagram of the EFSM model and the state transition sequence is generated. Then the evaluation function, which combines the conditions in the EFSM model that the guard variable may lead to infeasible paths, is constructed according to the path to determine the feasibility of each path, finally, a feasible transition path is obtained from the generated migration sequence using genetic algorithm. In the model generated by the OpenFlow protocol, the decision algorithm is used to generate and determine the migration sequence.In this paper, we study the consistency test modeling and test sequence generation problem of OpenFlow protocol. It provides assistance for the further research of OpenFlow protocol testing.