AT&T MERLIN LEGEND System Reference Manual page 335

Features
QCC Features
2-286 Queued Call Console
Both inside and outside calls ring on Call buttons on the QCC. Unlike the
direct-line console (DLC) on which many incoming calls can ring simultaneously.
the QCC receives one call at a time, regardless of the number of incoming calls
to the system. When a call rings on a Call button, call origin information is shown
on the display.
To direct calls to other users, the system operator presses the Start button or a
DSS button. The call automatically goes on hold at the Source button (the green
LED next to the Source Button flashes). An outside caller hears Music-on-Hold, if
it is programmed, or silence if Music-on-Hold is not programmed. An inside
caller hears silence, and the system operator hears a dial tone on the same Call
button. The display shows that the call is split. If the Start button was pressed
first, the system operator can use the dialpad, a Directory feature, or a DSS
button to dial the number.
If the Extended Call Completion option is set for manual completion, and the
system operator uses a DSS button to dial, the system operator can speak to the
person at the extension. while the call is in the split condition, the system
operator can speak with the caller by pressing the Source button. The green
LED next to the Destination button flashes to indicate the destination is on hold
and the system operator is connected to the original caller. If the system
operator needs to converse with both people (source and destination), pressing
the Join button connects all three people together. To complete the call
extending process, the system operator either presses the Release button to
connect the call (the call is released from the console) or presses the Cancel
button to cancel the extend process, drop the destination, and return the system
operator to the original caller.
If the Extended Call Completion option is set to automatic completion, the
extension is automatically dialed and the call is released as soon as the system
operator presses the DSS button. In systems with Extended Call Completion set
to automatic completion, if the system operator wants to consult with the person
at the extension before connecting the call, the system operator can press the
Start button then manually dial the extension by using the dialpad or a Dlrectory
feature.
The MLX-20L telephone is the only telephone that can be assigned as a QCC
through system programming. A QCC system operator cannot use feature
codes to activate features. The QCC system operator can only use the features
that can be selected from the display or that are assigned as fixed features to
buttons on the console. To simplify call handling, the Home screen includes
features used often by a system operator: Camp-On, Pickup, Group Pickup,
Loudspeaker Page, and Directory.
The 7-line, 24-character display also provides the system operator with
descriptive information about incoming and outgoing calls. This information
includes extension numbers and any programmed labels (such as names),
trunk identifiers, reasons for call return and redirection, and the number of
unanswered calls waiting in the queue. See "Display" in this chapter for details
on call information displays.