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 probab ly caused by fa ulty
cables between c arriers, or by defective or missing bus terminators. However,
before proceeding , make sure that the Maintenance/Test packet bus p ort is not
generating a false report b y looking for an M/T-PKT error in the error log. Then
test the Maintenance/Test packet bus por t with test port UUCSSpp. See
‘‘Special Precaution Concerning the TN771D’’ above if an y problems are
suspected.
NOTE:
If the carrier into which a TN771D Maintenance/Test circuit pac k is inserted
does not have a -5V power supp ly, 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 supp ly is available.
Considerations for Duplicated Systems
Some packet bus-related c omponents are duplic ated in systems with one of the
duplication op tions:
■In Hig h Reli abil ity s ystem s (du plic ate d SPE, si mple x PNC), Pack et
Interface circuit p acks are duplic ated 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 (dup licated SPE and PNC), the Packet
Interface circuit p acks are duplic ated, Maintenance/Test circuit packs are
required in all port networks, a nd packet b us reconfiguration by the
Maintenance/Test circuit packs is enab led.
If a packet bus p roblem is caused b y a duplicated component, switchi ng to the
standby comp onent may alleviate the problem and isolate the faulty circuit p ack.
Start by executing the co mmands in the following list when they ap ply.
■reset system interchange: If this command resolves the p acket bus
problem, the problem i s with the Packet Interface in the SPE which was
just switched to standb y. Refer to ‘‘PKT-INT (Packet Interface Circuit
Pack)’’ in Chapter 9, ‘‘Maintenance Object Repair Procedures ’’.
■reset pnc interchange: If this command resolves the pa cket bus
problem, the problem is with the EIs or the link on the PNC (a or b) that just
became the standb y. Refer to ‘‘EXP-INTF (Expansion Interface Circuit
Pack)’’ in Chapter 9, ‘‘Maintenance Object Repair Procedures ’’.
■set tone-clock: If this command resolves the p acket bus prob lem, the
problem is with the Tone/Clock that just became the stand by. Refer to
‘‘TDM-CLK (TDM Bus Clock)’’ in Chapter 9, ‘‘Maintenance Object Repair
Procedures’’ of this document.
Continue with the procedures in the ne xt section.