"if you have a sustained transfer, you’ll see speeds rising and falling over time, from “not passing traffic” to 5, 10, 30, 50, 100, 150, 200, 250, 200, and back down to “not passing traffic” over the course of a few minutes. I’d assume it’s related to the distance to the satellite, somehow, but just because you get a 250Mbit speed test does not mean it’s actually going to sustain 250Mbit"