When my internet connection slows down, I just run Speedtest once or twice. My providers detect that and restore the bandwidth they’d been stealing.
I will fire up the laptop, be getting 3.2-12 mbps, all of a sudden a fast.com speed test starts of sluggish and ramps up to 120-200 mbps.
Go figure. It happens every time, on multiple occasions, devices, browsers, all using the same internet connection and frequency.
Video bufferring frequently? Start a speedtest, problem (temporarily) solved!
To figure that out, you'd need to do a speed test to the target host, then do another one while simultaneously running Speedtest.
Your Internet speed is also affected by the peering agreements your ISP has, i.e. how "well connected" it is to the ISP of your target host. Speedtest targets (and Fast.com) are pretty well-connected; i.e. they have a lot of peers, so you can get to them in relatively few hops. Many times, they're even run by your ISP, so the number of hops is minimal.
I've noticed there's a big difference in both bandwidth and latency based on the network my requests actually go out on (from my university Internet connection). For some reason, the Univ. of Cal. Network > Commercial ISP > Internet2. (Not sure why Internet2 sucks so much, but it seems really slow for some reason.)
> A Comcast customer who is dissatisfied with Internet speeds set up a Raspberry Pi to automatically tweet at Comcast each time speeds are much lower than advertised.
> "I pay for 150Mbps down and 10Mbps up," Reddit user AlekseyP wrote over the weekend. "The Raspberry Pi runs a series of speed tests every hour and stores the data. Whenever the down[load] speed is below 50Mbps the Pi uses a Twitter API to send an automatic tweet to Comcast listing the speeds. I know some people might say I should not be complaining about 50Mbps down, but when they advertise 150 and I get 10-30 I am unsatisfied."