Thanks for the help in advance. I run a call center and have a dialer. I also have an asterisk box with a 4port digium FXO and (2) 1 port FXO all made by digium. I have 4 phone lines plugged into the 4 port and a Viking SO-24 service observing unit plugged into one of the one port cards. On our old PBX this worked fine. The service observing unit is used to listen the calls on the dialer station by station (changing stations by dialing “#”). This unit can be plugged into a analog phone or into a PBX trunk. How do I set this up to work, it doesn’t supply dial tone. I have it setup as a trunk on the FXO, but when you dial it the system reports that the circuit is busy. Is there some special setup I must use for this?