Aastra Dialog 4420 IP Basic User Manual page 24

Outgoing Calls
d
u
#6* z #
#6#
24
Press.
Replace the handset to finish the procedure.
When an external line becomes free, you will be called back (recall
ring signal). You have to answer within eight seconds, otherwise
the Callback service is cancelled. While waiting for the Callback,
you can make and receive calls as usual.
Lift the handset when you are called back.
The system calls the external number.
Note: Only one Callback can be activated on a busy
external line.
Cancel any single Callback
Dial, enter the extension number and press.
Note: To cancel a single Callback on a specific external
line, dial the digit or digits to get a line instead of the
extension number.
Press.
Cancel all Callbacks
Dial.
Press.
Dialog 4420 IP Basic