Software Defined Networking: Research Issues, Challenges and Opportunities

Objectives: This paper focuses on challenges, opportunities and research issues of software defined networking (SDN), as well as how to select the best possible SDN controller, which in result will help to reduce the complexity of a network, price of implementation and maintenance of the network in any big organization. Methods/Statistical Analysis: In order to meet the objective, the review of literature has been carried out in the following contexts; Software defined networking, SDN protocol (Open Flow) and SDN research challenges. Software defined networking is one of the most discussed topic these days. This technology is being considered one of the favorable technologies for isolation of control plane and data plane and logical placement of centralized control from SDN controller. This research focuses on major issues, challenges and current requirements of network implemented in any big organization where traditional network is being implemented. Findings: To solve the issues of multiple located branch networks, cost, technical resources at each location, expertise, separate control plane for configurations, decentralized visibility of network devices, separate VLANs for each branch, complex traffic engineering, limited physical access of branches w.r.t working hours, bandwidth bottleneck at each branch, we surveyed literatures and web resources for the existing SDN controllers like NOX, POX, Ryu, Floodlight, and Open Daylight etc. All these controllers are based on Open Flow protocol. The primary concern is that a conventional system develops gradually, it has a generally abnormal state of operational expenditure and moderately static in nature. SDN holds the guarantee of overcoming those confinements. Major issues which are being faced are increasing requirements from user side, bandwidth availability, hardware (switches requirement at every place), technical resources are required at remote site for configurations, scalability issues, cost, high level processing power at each device, traffic engineering, resiliency against failures, decentralized visibility of hardware devices etc. SDN will helps to improve centralized visibility as all the underlying open flow switches are connected to controller, all switches can be configured from SDN controller without accessing individual switches. Research papers referred in this paper provide a bird eye view of what may cause hurdles further in development and technology integration of technology. Application/Improvements: This research will help how to select the best possible SDN controller which in result will help scalability, less hardware and software requirements, less technical resources requirements, centralized visibility, hassle free traffic engineering and high availability of network.