A:Answer Okraku, if you have COMCAST's phone service you must use a modem that can filter voice calls; this DOCIS Modem does not perform that function. There are modems that you can purchase that can do this for you; just go google COMCAST approved modems and try to find your selection on Amazon, Wayfair, E-bay, etc.... Or if you really do not need the phone/voice service of a land line; stop paying for it and just get the COMCAST DOUBLEPLAY and rely on your cell phone only....or get installed a less expensive line by a local company ugh like ATT, VERIZON, etc..
