We have recently installed a UC540 system with two BRI connections to the ISDN.
Incoming and outgoing calls are fine however when a call is received the phone displays 'Unknown number' and 'From: <blank>' regardless of the caller. Even numbers within the local directory show up like this. Any assistance with this would be appreciated!
As mentioned in so many other posts on the very same subject.
Take "debug isdn q931" with "term mon"
If no calling number is present, complain to telco.
Hello every one!
I got the same problem; but I can't execute the debug what Paolo says. My router are running Version 15.0(1)M1 of IOS, and there's imposible introduce it. I tried with many options and searched with "?":
Rotuer#debug isdn q931
% Invalid input detected at '^' marker.
Paolo, can you post here the links about your other posts. Please :) .