In traditional networks, the static configuration of devices increases the complexity of network management and limits the development of network functions. Software-Defined Networking (SDN) employs controllers to manage switches, thereby simplifying network management. However, with the expansion of network scale, the early single controller architecture gradually became a performance bottleneck for the entire network. To solve this problem, SDN uses multiple controllers to manage the network, which improves the scalability of the network. However, due to the dynamic change in network traffic, multi-controller architectures face the challenge of load imbalance among controllers. In recent years, researchers have proposed various novel load optimization strategies to improve resource utilization and the performance of SDN networks. This paper reviews load optimization strategies in SDN, including the latest research results in switch migration and controller placement. Subsequently, we analyze the advantages and disadvantages of existing load optimization strategies. Finally, we discuss the future development direction of the load optimization strategy.

中文翻译：

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软件定义网络中的控制器负载优化策略：一项调查


在传统网络中，设备的静态配置增加了网络管理的复杂性，限制了网络功能的发展。软件定义网络 （SDN） 使用控制器来管理交换机，从而简化网络管理。然而，随着网络规模的扩大，早期的单控制器架构逐渐成为整个网络的性能瓶颈。为了解决这个问题，SDN 使用多个控制器来管理网络，从而提高了网络的可扩展性。然而，由于网络流量的动态变化，多控制器架构面临着控制器间负载不均衡的挑战。近年来，研究人员提出了各种新颖的负载优化策略，以提高 SDN 网络的资源利用率和性能。本文综述了 SDN 中的负载优化策略，包括交换机移植和控制器布局方面的最新研究成果。随后，我们分析了现有负载优化策略的优缺点。最后，我们讨论了负载优化策略的未来发展方向。