Sony IT-A2500 Operating Instructions Manual page 19

Making calis
1
Pick up the handset.
The line indicator lights and you hear a dial tone.
LN)
Dial a phone number.
The phone number appears and scrolls off the display if it has
more than 5 digits. After a while the talk time appears.
Go
When you finish talking, replace the handset in the
cradie.
The call is disconnected and the talk time disappears.