1.2.4 When the Dialled Line is Busy or There is No Answer– Reserving a Busy Line (Automatic Callback Busy)– Setting Callback on an ISDN Line (Completion of Calls to Busy Subscriber [CCBS])– Sending a Call Waiting Notification (Call Waiting)– Leaving a Message Waiting Indication/Calling Back the Caller Who Left an Indication (MessageWaiting)– Joining an Existing Call (Executive Busy Override)– Monitoring Another Extension (Call Monitor)– To an Extension Refusing the Call (DND Override)Reserving a Busy Line (Automatic Callback Busy)You can set the telephone to receive callback ringing:• when a dialled extension becomes idle.• when your desired outside line that is in use by another extension becomes idle.You cannot set Automatic Callback Busy for a busy party outside of the PBX.When you answer the callback ringing:• For an outside call: The line is seized.• For an intercom call: The called extension starts ringing automatically.To set (for both extension and outside line)PT/SLT/PSWhile hearing a busy toneEnter 6.6On-hook.C.ToneTo answer the callback ringing from an idle extensionOff-hook.PT/SLT/PSTalk.While hearing a callback ringingR.B.ToneUser Manual 411.2.4 When the Dialled Line is Busy or There is No Answer
