چکيده
Software Defined Networking (SDN) has emerged as a transformative networking paradigm, offering centralized control and programmability to overcome the limitations of traditional network architectures. However, as networks grow in scale and complexity, the scalability of a single controller architecture becomes a critical challenge. Deploying multiple controllers in SDN offers enhanced scalability, reliability, and fault tolerance, but it introduces the Controller Placement Problem (CPP) and the need for effective load balancing mechanisms. This report investigates load balancing strategies for SDN enabled networks with multiple controllers, drawing insights from a comprehensive review of recent research literature. We present a detailed taxonomy of load balancing techniques based on their operation level (data plane, control plane, and other dynamic mechanisms), analyzing their strengths and weaknesses, and highlighting the trade offs involved in choosing different approaches. We also examine emerging trends in SDN load balancing research, such as the use of Artificial Intelligence (AI), the shift towards distributed control, and the focus on application specific solutions. Our findings provide valuable insights for network operators and researchers, guiding the design and deployment of efficient and scalable multi controller SDN networks.
