It seems that 5312 phones do not record call history for internal calls. When I make and internal outgoing call and look into OUTGOING CALLS the internal extension I called to is not there. Is there any way to enable it?
I found this note in the system help, probably recording internal calls cannot be enabled:
Note: Calls within a cluster are considered internal calls. These calls do not generate call history records. Calls to another cluster are considered external calls and do generate records.