0.0000008 Mbps with an A+ rating: how a silent 403 from Cloudflare broke half of a bufferbloat test

The author analyzes a technical issue encountered during a bufferbloat test, where improper handling of HTTP errors led to skewed results. The test, which utilized speed.cloudflare.com, failed to detect a 403 Forbidden error during the download phase, resulting in misleading performance metrics. Consequently, the system assigned an 'A+' rating despite an actual data transfer speed of only 0.0000008 Mbps. The article details how this error affected testing verdicts and explains why it is critical for load generators to independently verify the actual volume of traffic being transmitted. The author emphasizes the need for stricter server response validation in network testing tools to prevent such anomalies, where the absence of actual load is incorrectly interpreted as an ideal connection state.