We just switch from Comcast to Verizon Fios and then noticed that there was obviously no coax cable on the back of the modem and in place was a phone line outlet. We live in an old house we are renting and it only has one phone line outlet in the whole house, it also looks like a dog gnawed on it so we arnt sure if it would even send a signal. So im guessing it has to be functional for the modem to work at all, correct? We wouldnt have to get a land line just for the modem would we?