Digital Trunks - Mitel MiVoice Business Troubleshooting Manual

Troubleshooting Guide

DIGITAL TRUNKS

SYMPTOM
General
Excessive Bit Error
Rate.
Excessive Slips.
System is not
Receiving Calls.
Outgoing calls are
dropping after a couple
of minutes into the
conversation.
Calls are connecting,
and the far end can
hear us but we cannot
hear them.
Trunks are
programmed but are
appearing as
Unassigned with the
STAT location ID
command.
T1 Trunk unstable or
3300 ICP resets or
both.
116
Table 33: Digital Trunk Troubleshooting
PROBABLE CAUSE
Faulty programming.
Faulty programming.
The DID trunk digit modification
number on the Trunk Attributes
form does not have anything
programmed in the absorb field. It
MUST have a minimum of 0, or no
calls will be accepted.
Faulty ANI/DNIS programming.
System is not receiving answer
supervision from the central office
and is timing out.
System is not receiving answer
supervision immediately from the
Central Office.
Card has not had the information
downloaded to update the status of
the trunks.
Improper cable. Cat 5 Ethernet
Cable for PC is not approved to use
as a standard RJ45/T1 cable.
CORRECTIVE ACTION
Make sure the system is programmed the same
as the CO, for B8Zs or AMI
Ensure the Network Synchronization form is
programmed and the system is clocking
appropriately. Use the Netsync Summary
maintenance commands to determine if
synchronization is taking place, If not, use Net Set
1 to set off the first clock source or NET SET
AUTO to select the best available clock source.
After you choose a synchronization clock source
always use the NET SET AUTO command to
confirm.
Ensure that there is an entry in the absorb field. It
cannot be left Blank.
Check ANI/DNIS programming to ensure there
has not been confusion with a DID trunk. For
ANI/DNIS to work the digit must be received from
the Central Office as *ANI*DNIS*. If the digits are
not being received in this format, turn off the
ANI/DNIS in the Class of service Options.
If the Central office cannot provide answer
supervision on answered calls go to the CO Trunk
Circuit Descriptor Assignment and change the
value in the field "fake answer supervision after
outpulsing" to Yes.
In the CO Trunk Circuit Descriptors form, change
the Supervision parameters in the value field
"audio inhibit until answer supervision after
outpulsing" to No.
Download the information to the NSU at an
appropriate time.
Use shielded R45-R45 T1 cable for T1, ISDN line
and/or DSU/DSU connections. Without proper
shielded pairs, the signal integrity on a T1 trunk is
not guaranteed. Refer to Mitel Knowledge Base
article 08-5191-00123 for additional details.
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