Panasonic KX-TVS50 Installation Manual page 63

b)
Assignment of IRNA (Intercept Routing No Answer) destination:
1)
Go to the "3-1 Trunk Group" screen.
2)
Assign "Intercept Destination Day/Night" for the trunk (CO line) group.
3)
Click "Apply" to save the changed data.
Note:
Specify the FDN for the extension group to which VM or AA has been assigned.
Screen output:
Installation Manual
INTEGRATING THE VPS WITH PANASONIC KX-T PHONE SYSTEMS
63