I have noticed, over the last 10 years or so, that every now and then - maybe once per month, sometimes a few months - the internet will disconnect at exactly 1.30am. It then always stays off for approx 6-7 mins (I've kept records). It's happened wherever I have lived - I've moved around 3 - 4 times since I noticed this happening. Different plans, different routers, different ONT's, diff cables, etc. The one thign that is the same is that time - 1.30am. 6-7 minutes.
Do they do some sort of maintenance or something?