I have a Norstar phone at a location where the users cannot hear the phone ring. I need to increase the ringing volume louder than the max on the phone. I could only find one external ringer that is compatible with Norstar phones but it's a little expensive. I was thinking instead of getting an ATA-2 and then connecting a cheap external ringer that works of analog. My problem is this : An ATA-2 uses a station port, can I change the DN that is given with the port to the same DN that is on the phone I need to ring louder? As I need the external ringer to trigger when the phone rings. Also, the Norstar phone has Answer DN's, will they also alert the external ringer? Any tips on how to program the ATA to meet my needs would be helpful. And if anybody also knows of any other external ringers that are compatible with Norstar. Thank you.