ISP Throttling: How to Detect and Prove It with a VPN, a Dif

[Elliottvef]

How can I verify if my ISP is deliberately reducing my bandwidth to certain websites, except for speed test websites? I have observed that my internet speed varies widely, from 200KB/s to 1MB/s, but it averages around 400-500KB/s. However, whenever I visit a speed test website, my speed is consistently 10mbps, which is what I pay for. Moreover, I have noticed that my download speed increases dramatically, up to 18mbps, when I run a speed test while on the phone with tech support. This has been happening for over a year, and it does not change even when I upgrade my plan to get higher speed. My ISP denies any wrongdoing and blames it on external factors, such as interference or server issues, but I am not convinced. What methods or tools can I use to gather evidence of ISP throttling?

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