nt such as router and switches used in current network are closed system. The Vendor specific implementation of the control logic is implemented in the routers which are provided with a limited user interface. The SDN architecture distributes the tightly coupled control and forwarding logic into different layers. Open Network Foundation has given three layered reference architecture for the SDN networks. The Reference SDN architecture shown is Figure 3: Data Layer: The Data/Forwarding layer comprises the network elements, which are merely forwarding devices. They are exposed to the control layer through the South-bound communication interface. Control Layer: The Control Layer lies in the middle of the architecture and is responsible for translating the applications' requirements thus putting a more granular control over the network elements, while providing relevant information up to the SDN applications. This layer is logically centralized to manage all the connected OpenFlow elements in executing out the policies defined on them. Application Layer: The Application Layer has all the SDN applications residing over it. This layer communicates the SDN applications through the North-bound communication interface. Figure 3. SDN Reference Model APPLICATION LAYER SDN Applications Northbound Communication CONTROL LAYER Network Services Southbound Communication DATA LAYER Forwarding Devices Downloaded: 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Introduction to SDN and NFV Components of SDN The main components of SDN are Controllers, SDN switches and the infrastructural backbone networks. SDN Application: SDN provides a programmable network by an API called Northbound API on which applications can be developed using different high level language such as java, php or python. REST API's are used to fetch the data from the controller to develop web based application. The Types of Application that can be developed are: Network Engineering Applications: These set of applications include applicat