I had one time when I don't even have ADSL signal so can't connect to internet.

When I called up tmnut customer rep. and told her that my ADSL line is down, she ask me to go to speedtest.net and do a test for her with those usual steps like check modem, connect modem directly etc.
Told her again that I can't even online how to go website check then she only give me a report number...