Troubleshooting guide

Trunking
115
T1 Trunk unstable or
3300 ICP resets or
both.
Improper cable. Cat 5 Ethernet
Cable for PC is not approved to use
as a standard RJ45/T1 cable.
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.
T1 E&M trunk call
cannot be transferred
or put on hold.
Release Link Trunk (RLT) setting
in the Trunk Attributes form is set to
YES. This setting is only intended
for T1 integration to centralized
attendant. If the RLT field is set to
YES for normal operation, it will
cause these symptoms.
For normal T1 E&M trunks, set the RLT field in the
Trunk Attributes form to NO.
NSU does not come
into service after you
change links from T1
to E1 or vice versa.
The NSU failed to download the
new virtual Digital Service Unit
(VDSU) files from the controller.
Enter the “force dl” command from the NSU
maintenance port. This command causes the
NSU to reboot and get the proper VDSU files.
The NSU maintenance port is set for 38400 baud
rate, 8N1 parity
External forwarding of
an incoming PRI call is
not successful.
The COS of the incoming PRI does
not allow Public-to-Public trunk
connection.
In the COS of the incoming PRI trunk, enable
“Public Network to Public Network connection
allowed”.
There is a COR restriction against
the incoming PRI trunk in the ARS
route.
For COR restriction, ensure the COR number of
the PRI trunk is not included in the COR group
defined for the specified route in the ARS Routes
form. See the document “Using CDE to Prevent
Toll Fraud on the 3300 ICP” for more information.
This document is available in the 3300 ICP
System Administration Tool online help.
Q.Sig Private network access is
enabled in PRI link descriptor.
For the link descriptor assignment used by the
PRI link, set “Q.Sig Private network access” to
NO. (This option should not be enabled for normal
PRI. It should only be set if the link is intended for
Q.Sig.)
After you install or
initially program an
embedded E1 module,
the DASS II link does
not work.
In the Link Descriptor Assignment
for the DASS II link, the CRC-4 is
set to “Yes”.
In the Link Descriptor Assignment for the DASS
link, set the CRC-4 setting to “No” and then reset
the controller. If you alter the CRC-4 setting, you
MUST reset the controller to enable the new, or
changed, setting.
DASS II circuit fails to
return to service after
programmed reboot.
The MN 3300 NSU. takes
approximately seven minutes to
come back after a programmed
reboot. The service provider has a
threshold of only five minutes, after
which they will take the link out of
service.
Refer to Mitel Knowledge Base article
04-3849-00502.
Table 34: Digital Trunk Troubleshooting
Symptom Probable Cause Corrective Action
Page 2 of 6