Challenges in Net Neutrality Violation Detection: A Case Study of Wehe Tool

The debate on "Net-neutrality" and events pointing towards its possible violations have led to the development of tools to detect deliberate traffic discrimination on the Internet. Given the complex nature of the Internet, neutrality violations are not easy to detect, and tools developed so far suffer from various limitations. In this paper, we study many challenges in detecting the violations and discuss possible approaches to mitigate them. As a case study, we focus on the tool Wehe \cite{wehe} and discuss its limitations and propose the aspects that need to be strengthened. Wehe is the most recent tool to detect neutrality violations. Despite Wehe's vast utility and possible influences over policy decisions, its mechanisms are not yet fully validated by researchers other than original tool developers. We seek to fill this gap by conducting a thorough and in-depth validation of Wehe. Our validation uses the Wehe App, a client-server setup mimicking Wehe's behavior and its theoretical arguments. We validated the Wehe app for its methodology, traffic discrimination detection, and operational environments. We found that the critical weaknesses of the Wehe App are due to its design choices of using port number 80, overlooking the effect of background traffic, and the direct performance comparison.