A Review of Enhancing QoS in Software-Defined Networks through Optimized Controller Placement and Strengthened Security Mechanisms

Software Defined Networks (SDNs) is a programmable novel mechanism that managed networks centrally through separating the control logic plane and the data forwarding plane. However, the challenge to place the multiple controllers in the network and issue of security vulnerability affects the Quality of Service (QoS) in SDN environments. This manuscript focuses that a better controller placement and enhancing security measures could improve the Quality of Service (QoS) in SDN networks. This study survey the existing art of state on load balancing strategies, algorithms for controller placement, and security frameworks which considers intrusion detection systems, encryption, and secure communication protocols. A comparison of previous studies shows that current methods have some clear trends, some advances in performance, and some problems. This manuscript highlights that employing security measures and optimized controller placement mechanisms combined the significantly SDN fast, minimize the failure to reliable the system. Also, the security mechanism prevents from attacks and threats. The proposed mechanism is found appropriate for modern programable SDN environments and could be useful for cloud networks, latest 5G networks, data centers, and Internet of Things (IoT) network infrastructures.