Imagine being unable to call your internet provider because your phone, which is derived through the computer, is out also. So, what if I go to someone's else's place, borrow the phone, call the cable people and they say, "Okay, let's try something. Is your computer on?"
Of course, I have not yet imagined what happens when I respond, "No, I'm calling from a house 3 miles from my home."
(Afterthought: Our first internet phone service was great. It was $199/yr. - TOTAL. The day I signed up they were offering an extra year free! That brought the total monthly cost down to $8.33 with unlimited long distance and features galore but, of course, at that price they went bankrupt after 7 months.
I then transferred us to Vonage and am upset that their $24.99/mo. advertised price has been billed at $31.71 the past two months. But this is America and we Americans accept an additional 27% in taxes and fees as nothing to get huffy about! )