AT&T System 25 - Manual (Page 12)

Callback
❑
2 After confirmation tone and dial tone, press # 6 0 .
If a System 25 extension or outside line is busy when you place a
call, you can request a callback. Your call will wait in a line (a
“queue” ) for the extension or line to become available. The
system will then ring you back and complete the call.
For inside calls, use Callback when you hear a busy or special
ringback tone. For outside calls, use Callback only when you
hear a fast busy tone. (You may hear the callback request
queueing tone automatically when you place certain calls.)
Requesting Callback
1 Press the switchhook.
❑ ❑ ❑
3 Listen for queueing tone, then hang up.
NOTE: If you do not hear queueing tone, your request has
not been accepted for this call.
Completing Callback
1 When you hear priority ring, lift the handset.
NOTE: If you remained off-hook after requesting Callback,
you will not receive priority ring.
2 Listen for dequeueing tone.
Your call will be completed as dialed.
Canceling Callback
1 Lift the handset (or press the switchhook) and listen for dial
tone.
❑ ❑ ❑
2 Press # 6 1 and hang up
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