This modem cmx110 is an attbi "approved" modem. That means it'll work (unless defective) with AT&T broadband cable service...Everything worked fine except I noticed I couldn't have the modem too close to my PC or the LED by PC went out (Maybe RF interference). I checked its data rate and it was just behind a T1 (at the time I did it) so it transfers data quite successfully....Free shipping applies...