I have an emergency situation.
I plugged an pstn line to ucm 6510 witch have been configured as grandstream documents stated.
now the problem is I can make outbound calls but no incoming calls get to my IVR or destination extention.
the pcap file from ucm interface shows incomming invite from fxo gateway but nothing happens and outside caller just hear ringing tone and nothing else🤕
it solved by reducing the "number of rings before pickup " within gateway