Design And Implemention Of Northbound Interface Of Transport-SDN

At present,under the wave of global informationization and ICT(information and communication technology)industry development and transformation,the traditional transmission network is difficult to meet the needs of business complexity and traffic bursting growth,and the development of transmission network is facing increasing challenges.The emergence of SDN(Software Defined Network)technology provides a solution to the dilemma faced by the transport network.SDN is an emerging architecture for designing,building,and managing networks.The basic idea of it is to abstract the underlying complexity and separate the control management plane from the data plane.The International Organization ONF(Open Network Foundation)proposed the SDN Transport Network Architecture(T-SDN),which introduced SDN into the transport network and was widely referred to as SDTN(Software Defined Transport Network).In SDTN,the transport network architecture is divided from top to bottom into application layer,control layer and data forwarding layer.The SDTN architecture has three characteristics:control and forwarding separation,logical centralized control and open programmable control interface.It is open,scalable and heterogeneous.In the SDTN architecture,there are many southbound interface protocols,and interoperability between devices from different vendo-rs using different southbound interface protocols has become a pri-mary issue that restricts the development of SDTN.The unification of the northbound interface can normalize different southbound tec h-nologies and protocols to uniformly extract the southbound view f or the upper layer application.The standardized and open interface tr-ansmission of the northbound interface can overcome the interope rability of the transmission network equipment and promote the inn o-vation,automation and intelligent management of the SDTN netw or-k.The northbound interface is expected to be implemented in an o-pen,device vendor neutral and interoperable manner.The development and evaluation of northbound interface solutio-ns and protocols has become a hot topic in the field of SDTN res-earch.The author of this paper participates in the Transport-SDN n-orthbound interface project of the ONF affiliated open source SDN project team and the China Information and Communication Researc h Institute.It assists ONF in proposing the SDTN Northbound Inte-rface T-API(Transport Application Programming Interface,TAPI)a-nd evaluating it.The SDTN northbound interface is the focus of t-his paper and one of the main directions for continuous exploration and research in the industry.Based on the above background,the main research content of t-his paper includes the following three aspects:1.In-depth study of the status quo of the transport network,the advantages of the transport network to introduce SDN technology,and the current status of SDTN northbound interface research.Participate in the design of the northbound interface TAPI by analyzing the requirements of the northbound interface.2.Develop and implement the SDTN northbound interface TAPI.TAPI uses the REST-style interface to invoke the network resources described by the information model.The information model is constructed in a visual UML class diagram and generates an interface code format suitable for REST interface data transmission.3.Study the test method of SDTN northbound interface,perfor-m protocol conformance test and interoperability test on the northb-ound interface TAPI implemented in this paper,and evaluate the te-st results.