Not true. I have installed 20 of them in an doctors office exam room envirnment. Believe it or not, you can guide your self through the menu of the phone if you follow a phone with a display. You can actaully blindly program the settings of the phone if you can figure out which screen is displaying. This is done by watching the blinking lights on the phone after startup to figure out what screen is displaying or lack of. The AVAYA manual will indicate what the varying blinking lights means. Catalyst and AVAYA told me this was not possible until I proved them it could be done. They were rather shocked. They also said if you send a address via dhcp, the phone could never be used again because there was no way to change the address or default the phone. I laughed at that an said "so the phones are a one time use and throw away" Thats rediculous. They are basically a worthless phone, hard to use and not pratical for use. They are a pain to trouble shoot and is not worth the hassel. I would follow the suggestion of the other posters. Get rid of them and use the 5602's if you can...