Record calls that pass through a trunk

Hi all, im new on FreePBX (i use version 1.7.0), and I’d want to record
the inbound and outbound calls (routed to an outside number via ring group)
from an extension,
i’ve changed: General Settings ->Extension Recording Override Disabled
Extensions -> inbound recording / oubound recording Always

But i don’t see anything on my monitor directory (/var/spool/asterisk/monitor)

Thank you all
I wait your answers