We have a CIX 670 with a ISDN T1. I have a DID set to Dialing Digits to extention 230 for a Analog Fax machine. Everything works fine except, when the extention is in use and another call comes in on that DID it just rings until either the incoming line drops the call or the Extention is free and picks up.

How to i set this to give me a busy signal when the extention is in use.

Thank for the help.