Have you tried ping?
Do you mean pinngtest.net?
Just did it now. It was unable to check for packet loss because I don't have Java installed. Ping results were 20 ms, Jitter results were 11 ms, and connection was given a grade B.
I am not familiar with this site or what exactly their metrics mean.
However, I don't think this addresses my problem. My problem is not the speed or quality when it's working; it's that it intermittently just stops working.
try to uninstall the device and then re-scan. (device manager)
There's no extensive installation involved. It attaches to USB. They recommend downloading a specific driver, although it worked with out it. That said, I removed their driver and reinstalled, to no avail.