Yalemzewd Negash (PhD)Sefinew Getnet2023-12-052023-12-052023-02http://etd.aau.edu.et/handle/123456789/245One of the main causes of the demise of deep-rooted networks has been the explosive expansion of internet service providers and current data traffic. Nowadays, the most recent advancements in networking is the introduction of software-defined networking (SDN), which emerged for rebuilding and modifiable features. The core idea of SDN is the separation of the control and data planes. When controlled by an SDN controller, SDN offers advantages in terms of flexibility, manageability, and efficiency in contrast to traditional networks. This thesis work offered the Performance analysis of POCO Framework under Failure Scenario to address the challenges like rigidity, uncontrollability, and inadequately used network resources for the adoption of SDN networks. Furthermore, the network dataset of AAU was encoded, examined and the selected platform for determining the optimal number of controllers and their ideal location in the Metropolitan Area Network (MAN) were applied with the goal of minimizing latency and cost of controllers. The optimization is done in two scenarios, (I) controller placement using failure free and (II) when either nodes or controllers fail, using the Pareto Optimal Controller Optimization Placement (POCO) framework. First, the controller’s placement in the aforementioned scenarios for different numbers of K controllers was found and investigated. Following this, results of altered metrics like latencies of controller-to-controller(C2C) and nodeto- controller(N2C). fault tolerance (for either node or controller failures), and controller imbalance for both the aforesaid scenarios were conducted accordingly. From the results, it is recommended that the minimum number of controllers required to adopt SDN in AAU-MAN be two controllers, considering the resiliency of controllers placed at Sidist kilo and Arat kilo. Also, we conclude that the POCO performance analysis under the failure-free scenario-based experiment showed minimum N2C latency compared to the worst-case scenario (node failure and up to K-1 controller failure). But showed minimum node failure C2C latency compared to failure free scenario.en-USThesis