etely replacing all forwarding decisions in their conventional network with those made by the centralized controller (Wackerly, 2014). Lastly, it scales much more gracefully in terms of the number of OpenFlow rules it pushes to switches (Wackerly, 2014). CONCLUSION OpenFlow along with ONF is mainly responsible for the concept of SDN in the today's world of computer networking, by providing the first legacy of SDN control: Methods in determining path of the packets Centralized control point Provides Northbound API which reveals the topology Presents Standardized Southbound API for instantiating the forwarding state on multivendor infrastructure Allocating services to the application of the controller OpenFlow has been around from several years results in adopted and deployed by many different vendors, but it needs lot more modifications regarding Hardware Implementation, Interoperability and Conformance. Regrettably, there is no concept of standardized Northbound API along with any standardized east-west state protocol for application portability and controller vendor interoperability. OpenFlow still faces challenges in the interoperability between switches of different vendor's which implements different features. Additionally, OpenFlow specification changes swiftly and some of the feature are not well-defined, which results in different behaviour of switches and controllers. OpenFlow provides advance protocols for flow/traffic control, only for those network elements which are fully configured with the OpenFlow. There is need to work on the hybrid model which allows configuration of OpenFlow on switches from different vendors and interoperability between them to achieve high performance, scalability and reducing risk. Downloaded 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Introduction to OpenFlow REFERENCES Cisco. (2005). DiffServ -- -The Scalable End-to-End QoS Model. Retrieved March 30, 2017, from https://www.cisco.com/en/US/technologies/tk543/tk766/technologies white_paper09186a