# Performance and Scalability Analysis of SDN-Based Large-Scale Wi-Fi Networks
###### Abstract
Currently, wireless technology is taking over the whole world. Currently implemented scenarios predict an increase in demand for SDN-based Wi-Fi. SDN has less support than wireless technologies like Wi-Fi, Wi-MAX 802.16, WLAN 802.11, and Bluetooth 802.15 [5]. We searched through the research literature but were unable to find any significant implementation of these technologies in SDN [6; 7; 8; 9]. This research project has produced methods that will deploy Wi-Fi on SDN. Limitations on current applications include the following: On the SDN architecture, there are not many Wi-Fi features accessible. The installation of SDN for end users is not supported by current Wi-Fi networks [7]. Users may construct, configure, alter, and troubleshoot using SDN, which effectively enables programmatic network administration. Thus, it is a significant idea that will shape networks in the future [10]. The static network designs, or classical architectures, are more difficult than the new ones that are developed programmatically, are overcome by the notion of SDN, making them more flexible and simple to alter and debug [11]. The work already done on traditional networks cannot adequately address a number of new challenges that the SDN paradigm introduces. Scalability: In SDN, the issue of complexity and scalability has been brought up. In large data centers, the demand for bandwidth reaches its peak during peak hours. Networks are unable to handle heavy data loads in high-speed traffic flows. Vendors have created their own architectures and specifications for networking devices [6]. Scalability issues can be resolved by laboriously standardizing SDN networking hardware. Placement of the controller: This is also known as the network operating system, and it is an important aspect for research and discussion in SDN. Whether the position is fixed or dynamic, it needs to be adjusted to the network environment. In controller layout [12], a number of layout indicators are discussed along with their significance in relation to the surrounding network layout [13; 14]. Resilience: The centralized controller architecture comes with a number of built-in restrictions. The main problem with a centralized controller is the single point of failure. Data throughput across the entire network is more efficient thanks to the centralized design [15]. People might be more open to giving up greater flexibility for greater efficiency. Research on the SDN distributed controller architecture demonstrates that it can offer more flexibility. The abovementioned challenges are addressed through this research work by providing the performance and scalability analysis of SDN-based large-scale Wi-Fi networks. In our proposed work, the Wi-Fi-based scenarios are generated and tested using the network protocols (TCP and UDP) for their stability in various dynamic environments. The main contributions of this work are listed below:  
* We analyzed the performance of the SDN Wi-Fi network using simple, linear, and tree topologies. * For the purpose of performance analysis, we made use of a large-scale SDN-based Wi-Fi network. * We were able to observe the scalability of the SDN Wi-Fi network in addition to its resilience by taking into consideration a variety of dynamic situations of the network. * We explored the performance metrics of the SDN Wi-Fi controller via TCP and UDP protocols, such as bandwidth, flow setup delay, jitter, and round-trip time. The remaining part of this paper is organized as follows: Section 2 delivers the related work. Section 3 highlights the background knowledge. Section 4 gives the details of the proposed SDN-based architecture. Section 5 provides experiments, results, and discussion. Finally, Section 6 concludes the work.