Security is one more concern with the SDN network. If the control channels Downloaded: 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Introduction to SDN and NFV have been compromised whole network can be hijacked. Control is also the most vulnerable point of attack for Dos and DDos attack. The protocols, API and Programming languages need to be standardized to provide a matured solution that will be universally accepted. RESEARCH CHALLENGES AND FUTURE DIRECTIONS Considering these challenges towards the growth of SDN networks the future works that needs to be done in the SDN can be categorize in 3 types. Protocols Standardization: The SDN protocols, API's i.e. South-bound and North bound API need to standardize SO that it will have wide-spread use. The device manufacture will use these standard protocols to build devices that support this protocol. Since SDN is working on Open Standard parallel development may lead to different version of the protocols that may create compatibility issues. Open Flow is one of standard protocol that is being used to develop open flow switches. There is also a need of development or selection of programming language that will used to develop 3rd party apps running over the controller. Replacement of Traditional Networks: Traditional network has been used for long time since its evolution and lot of work has already been done. There is a huge installation of switches as enterprise and backbone networks. It's neither feasible nor practical approach to attempt a replacement of traditional network in one go. SDN needs to start as running parallel to the traditional network. As an approach we have to develop devices that support both protocols from the traditional network as well as Open flow protocols. Second the protocols needs to be developed in such a way that it fully supports the interoperability of both types of network. Controller: The issues existed related to placement of controller, number of controller, hierarchical VS distributed controller, secu