Avaya S8700 Maintenance Manual page 508

Maintenance Object Repair Procedure
When a user goes off-hook to place a call, dial tone is returned to the user,
indicating that a tone detector is connected and ready to receive and interpret
tones. The tone detector is in use until the total number of digits needed is
collected or until a time-out occurs. If every tone detector in the system is being
used simultaneously, the next user to go off-hook will not receive dial tone until a
tone detector becomes available. It is therefore necessary to have a sufficient
number of tone detectors in the system to prevent delays in receiving dial tone.
The list measurements tone-receiver command shows the level of tone
detector usage.
In order to prevent dial-tone delays and other shortcomings in system
performance, threshold levels for the 3 types of tone receivers are administered
on the change system-parameters maintenance form. Whenever the number
of tone receivers in service falls below the administered threshold for that type of
tone receiver, an alarm is logged against the TTR Level MO. At this point, the
system is operating properly, but call processing capacity is reduced. Another
alarm is logged if the number falls to zero. At this point, system operation is
severely compromised.
Typical causes of these events are:
1. The threshold for GPTD-PTs or DTMR-PTs is administered incorrectly on
the maintenance-related system parameters form.
2. Too many GPTD-PTs, DTMR-PTs, or CLSFY-PTs have been taken out of
service, possibly by maintenance software or a demand busyout.
3. A tone detector circuit pack has been removed or suffered a fatal failure,
resulting in the loss of all its ports.
4. The system has an insufficient number of TN748/TN744/TN420 circuit
packs.
8-1204 Issue 1 May 2002 555-233-142