customer has an ACS r3.0. They have an Avaya(believe manuf. by viking) and a viking controller connected to the Acs switch via line 4 port on the system. As far as I know it was working up to about 2 months ago and now when you push the button it makes a bdbdbdbd sound and the phones don't ring at all. They have a button on the phones that is labeled "door" and like I said up till about 2 months ago it worked fine. Any ideas?? Thanks Dave