im setting up a MGCP with FXS and FXO , im confused about the attendant DN , with FXO when i set the attendant DN number , it means this is the extension on cucm any incoming calls on that FXO will ring , but with FXS what does attendant DN do? what happens when u put a certain number there?
Attendant DN is not applicable to FXS ports. Not sure what version of CUCM you are running. There was a bug for attendant DN showing up for MGCP GS/LS config. If you add as POTS port instead of GroundStart/LoopStart the problem is not present. See the bug below.