For Time Warner and all of thr other "Digital" phone companys, they are using the internet to be the interface into their cable line, for your phone service. Your Broadband converter is how they hook up your phone. ADT could tap into the phone at the broadband unit. But I think that why they want an analog phone line is, regular phone service rarely goes down, and how often now a days, do you lose your cable signal. ADT wants a "sure" connection, so that they can monitor your house, should the alarm trips. At least that is what I an thinking.