Software-defined networks offer flexible and intelligent network operations by splitting a traditional network into a centralized control plane and a programmable data plane. The controller in the control plane is the fundamental element used to manage all operations of the data plane. Hence, the performance and capabilities of the controller itself are essential in achieving optimal performance. Furthermore, the tools used to benchmark their performance must be accurate and useful in measuring different evaluation parameters. There are dozens of controller proposals for general and specialized networks in the literature. However, there is a very limited comprehensive quantitative analysis for them. In this article, we present a comprehensive qualitative comparison of different SDN controllers, along with a quantitative analysis of their performance in different network scenarios. We categorize and classify 34 controllers and present a qualitative comparison. We also present a comparative analysis of controllers for specialized networks such as the Internet of Things, blockchain networks, vehicular networks, and wireless sensor networks. We also discuss in-depth capabilities of benchmarking tools and provide a comparative analysis of their capabilities. This work uses three benchmarking tools to compare 9 controllers and presents a detailed analysis of their performance, along with discussion on performance of specialized network controllers.

中文翻译：

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SDN控制器

软件定义网络通过将传统网络拆分为集中控制平面和可编程数据平面，提供灵活和智能的网络操作。控制平面中的控制器是用于管理数据平面所有操作的基本元素。因此，控制器本身的性能和能力对于实现最佳性能至关重要。此外，用于对其性能进行基准测试的工具在测量不同的评估参数时必须准确且有用。文献中有许多针对通用网络和专用网络的控制器建议。然而，对它们的综合定量分析非常有限。在本文中，我们对不同的 SDN 控制器进行了全面的定性比较，以及对它们在不同网络场景中的性能的定量分析。我们对 34 个控制器进行了分类和分类，并进行了定性比较。我们还对物联网、区块链网络、车载网络和无线传感器网络等专用网络的控制器进行了比较分析。我们还深入讨论了基准测试工具的功能，并对其功能进行了比较分析。这项工作使用三个基准测试工具来比较 9 个控制器，并详细分析它们的性能，并讨论专用网络控制器的性能。我们还对物联网、区块链网络、车载网络和无线传感器网络等专用网络的控制器进行了比较分析。我们还深入讨论了基准测试工具的功能，并对其功能进行了比较分析。这项工作使用三个基准测试工具来比较 9 个控制器，并详细分析它们的性能，并讨论专用网络控制器的性能。我们还对物联网、区块链网络、车载网络和无线传感器网络等专用网络的控制器进行了比较分析。我们还深入讨论了基准测试工具的功能，并对其功能进行了比较分析。这项工作使用三个基准测试工具来比较 9 个控制器，并详细分析它们的性能，并讨论专用网络控制器的性能。