AASTRA 4420 IP Basic (SIP) for MX-ONE User Guide - Manual (Page 24)

Outgoing Calls
Dialog 4420 IP Basic 24
u z
Lift the handset and dial the common Speed Dialing number.
Dial by a function key
Both features and phone numbers can be programmed on a
function key. To program a key, see section “ Web Server ” on
page 56. u
Lift the handset.
Head office
Ô
Press the function key.
This function key is preprogrammed by you.