AT&T MERLIN LEGEND System Reference Manual page 234

Features
Calls-in-Queue Alarm
Threshold
Overflow Coverage
The Calls-in-Queue Alarm Threshold is the number of calls (1-99) allowed in the
queue before calling group members are notified. When the number of waiting
calls is equal to or greater than the programmed Calls-in-Queue Alarm
Threshold, the calling group members can be notified in one of two ways:
Via an assigned external alert connected to an analog multiline telephone by
using a Supplemental Alert Adapter (SAA), or connected to an MLX
telephone by using an MFM. Since the tone sent to the alert is continuous, it
is recommended that only a device such as a strobe light be used, which
stays lit until the number of calls drops below the limit. Only one external alert
can be assigned to each calling group and each external alert can be
assigned to only one calling group.
Via the LED associated with a button programmed with the calling group's
extension or a DSS button that corresponds to the extension. The LED
associated with either type of button does not go out until the number of calls
drops below the limit. There is no limit to the number of buttons that can be
programmed to provide the Calls-In-Queue Alarm indication.
When the number of calls waiting in the calling group queue reaches a
programmed threshold of 1-99 (the factory setting is 1), calls can be sent to an
Overflow Coverage group, which can be another calling group or a queued call
console (QCC) queue. Only one calling group or QCC queue can be
programmed to provide Overflow Coverage for the same calling group, and
each calling group or QCC queue can provide Overflow Coverage for more than
one calling group.
Before calls are directed to an overflow calling group, the following conditions
must be met:
The number of calls in the queue is equal to or greater than the programmed
threshold.
The overflow calling group has an available calling group member.
There are no calls queued for the overflow calling group.
If any of the conditions are not met, the call continues to wait on the sending
calling group queue until a calling group member is available or until the
overflow renditions are met and the call can be directed to the overflow calling
group.
If all conditions are met, calls are directed to the overflow calling group on a
first-in/first-out basis until the number of queued calls in the covered calling
group is less than the programmed threshold. The system searches for an
available calling group member according to the hunt type assigned to the
overflow calling group. Since the calls wait in the original calling group queue,
they are not eligible for the overflow group's Overflow Coverage.
When the overflow calling group's group type is set to Auto Logout and an
overflow call is not answered within 30 seconds (5 rings), the overflow calling
group member is logged out. The call is returned to the original calling group's
queue and is placed at the front of the queue. The caller does not hear the delay
announcement even if the call was sent to the overflow calling group before the
caller heard the delay announcement.
Group Calling 2-185