AT&T MERLIN LEGEND System Reference Manual page 353

Features
2-304 Queued Call Console
Assign QCC system operator to receive calls on individual trunks. The
factory setting assigns no system operator to receive calls on individual
trunks.
Lines Trunks -> More -> QCC Oper
Specify that calls to unassigned (invalid) extension numbers received on DID
trunks, dial-in tie trunks, or by Remote Access users receive a fast busy
signal or are directed to a backup position (the factory setting). Calls must
be directed to a backup position if QCC system operators who receive talk
are assigned for this call type.
LinesTrunks -> DID -> InvalDstn
Specify that calls to unassigned (invalid) extension numbers received on DID
trunks, dial-in tie trunks, or by Remote Access users are directed to the QCC
queue. The factory setting directs calls to the primary system operator. Calls
must be directed to the QCC queue if one or more system operators are
assigned for this call type.
Options -> More -> Unassigned
Assign the call types that ring into the QCC queue, the system operator who
receives the calls, and the priority level.
Operator -> Queued Call -> Call Types
Specify length of time (5-30 seconds, the factory setting is 0) before calls
waiting in the queue are automatically reprioritized to a higher level (Elevate
Priority).
Operator -> Queued Call -> ElvatePrior
Specify whether calls on hold return to the QCC queue after the Hold Timer
has expired twice. The factory setting is that calls remain on hold.
Operator -> Queued Call -> Hold Rtrn
Select the Automatic Hold or Automatic Release (the factory setting) feature
for all QCC positions.
Operator -> Queued Call -> HoldRelease