Under CUCM Serviceability you can select "Configuration" from the "Trace" drop down menu and then go through the motions of setting trace filters, output settings, etc.
One thing that puzzles me is the checkmark box called "Trace On" because having this box checkmarked does NOT actually enable the trace.
I know that you have to actually turn traces on and off under the badly misnamed "Troubleshooting Trace Settings" menu option.
So question is what is the "Trace On" checkbox really for? The documentation I've read just says to check it and it seems to be checked by default for every service.