This should be added/registered to CUCM as 3rd Party SIP Phone.
follow the below guide for configuration assistance/example.
seems like the MTP is not getting allocated here:
we would see something as "countChange=1"next to the MTP if its allocated successfully and we don't see it here,
you can collect the below information from gwy to isolate further or try restarting ...
Check if the call even reaches the gateway/Trunk to send the call out.start with checking the Route_pattern/partion-css and route_group to send the call out(run DNA to verify all this)if it reaches till gateway then would have to verify CCM traces fo...