Avaya S8700 Maintenance Manual page 178

Alarms, Errors, and Troubleshooting
If test results or the results of the status port-network command indicate that
there are 24 faults on the packet bus, the problem is probably caused by faulty
cables between carriers, or by defective or missing bus terminators. However,
before proceeding, make sure that the Maintenance/Test packet-bus port is not
generating a false report by looking for an M/T-PKT error in the error log. Then
test the Maintenance/Test packet-bus port with test port UUCSSpp. If any
problems are suspected, see
page 4-98.
NOTE:
If the carrier where a TN771D Maintenance/Test circuit pack is inserted
does not have a -5V power supply, the Maintenance/Test packet-bus port
reports 24 open leads in response to status port-network, or Test #572 of
the PKT-BUS test sequence. See
page 8-393
Considerations for Duplicated Systems
Some packet bus-related components are duplicated in systems with one of the
duplication options:
In a duplex- or high-reliability system (duplicated server, unduplicated
PNC):
— TN2312 IPSI circuit packs are unduplicated in a duplex
— A TN771D Maintenance/Test circuit pack is optional in an EPN.
— Maintenance/Test packet-bus reconfiguration is not enabled.
Whereas, in a critical-reliability system (duplicated server and PNC):
— TN2312 IPSI circuit packs are duplicated.
— TN771D Maintenance/Test circuit packs are required in every EPN.
— Maintenance/Test packet-bus reconfiguration is enabled.
If a packet-bus problem is caused by a duplicated component, switching to the
standby component may alleviate the problem and isolate the faulty circuit pack.
Start by executing the commands in the following list when they apply.
reset system interchange: If this command resolves the packet-bus
problem, the problem is with the IPSI's Packet Interface circuit that was just
switched to standby. Refer to
8-1238.
reset pnc interchange: If this command resolves the packet-bus problem,
the problem is with the EIs or the link on the PNC (a or b) that just became
the standby. Refer to
page
set tone-clock: If this command resolves the packet-bus problem, the
problem is with the Tone-Clock that just became the standby. Refer to
''TDM-CLK (TDM Bus Clock)'' on page
4-104 Issue 1 May 2002
''Special Precaution Concerning the TN771D'' on
to ensure that a -5 Volt power supply is available.
configuration and duplicated in a high-reliability configuration.
''EXP-INTF (Expansion Interface Circuit Pack)'' on
8-762.
''CARR-POW (Carrier Power Supply)'' on
''PKT-INT (Packet Interface)'' on page
8-1604.
555-233-143