DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Alarms, Errors, and Troubleshooting
5-101Packet Bus Fault Isolation and Repair
5
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
. See
‘‘Special Precaution Concerning the TN771D’’
above if any problems are
suspected.
NOTE:
If the carrier into which 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. Refer to CARR-POW maintenance in Chapter
9 to ensure that a -5 volt power supply is available.
Considerations for Duplicated Systems
Some packet bus-related components are duplicated in systems with one of the
duplication options:
■ In High Reliability systems (duplicated SPE, simplex PNC), Packet
Interface circuit packs are duplicated with the SPEs, a Maintenance/Test
circuit pack is required in the PPN, and Maintenance/Test packet bus
reconfiguration is not enabled.
■ In Critical Reliability Systems (duplicated SPE and PNC), the Packet
Interface circuit packs are duplicated, Maintenance/Test circuit packs are
required in all port networks, and packet bus reconfiguration by the
Maintenance/Test circuit packs 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 Packet Interface in the SPE which was
just switched to standby. Refer to
‘‘PKT-INT (Packet Interface Circuit
Pack)’’ in
Chapter 9, ‘‘Maintenance Object Repair Procedures’’
.
■ 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 ‘‘EXP-INTF (Expansion Interface Circuit
Pack)’’ in Chapter 9, ‘‘Maintenance Object Repair Procedures’’.
■ 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)’’
in Chapter 9, ‘‘Maintenance Object Repair
Procedures’’ of this document.
Continue with the procedures in the next section.
