DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Alarms, Errors, and Troubleshooting
5-95Packet Bus Fault Isolation and Repair
5
Special Precaution Concerning the TN771D
A TN771D Maintenance/Test circuit pack must be taken to the customer site if:
■ The Maintenance/Test packet bus port indicates that a Packet Bus fault is
present by logging a Major or Minor alarm against PKT-BUS. A Major
alarm is indicated in the error log by Error Type 513; a Minor alarm is
indicated by Error Type 2049.
■ Test #572 of the PKT-BUS test sequence is the only test that fails.
This precaution is taken because certain failures of the Maintenance/Test circuit
pack can appear as packet bus failures. To ensure that the problem is indeed
with the packet bus, proceed through the following steps:
1. If the TN771D Maintenance/Test circuit pack is replaced during this
process, enter the
test pkt P long
command to determine if the packet
bus faults have been resolved. If there are still packet bus problems,
correct them by using the procedures in the sections that follow.
2. If the Maintenance/Test circuit pack was
not
replaced, enter
test pkt P
.
Record the results (PASS/FAIL/ABORT) and error codes for Test #572.
3. Enter
status port-network P
. Record the information listed for PKT-BUS.
4. Busyout the Maintenance/Test circuit pack with
busyout board UUCSS
.
5. Replace the Maintenance/Test circuit pack with the new circuit pack.
6. Release the Maintenance/Test circuit pack with
release board UUCSS
.
7. Enter the
test pkt P
and
status port-network P
commands as described
in Steps 2 and 3.
8. If the data matches the previously recorded data, a packet bus problem
exists, and the original TN771D Maintenance/Test circuit pack is not
defective. Reinsert the original TN771D, and correct the packet bus
problem by using the procedures in the sections that follow.
9. If the data does
not
match the previously recorded data, the original
TN771D circuit pack is defective. If there are still indications of packet bus
problems, correct them by using the procedures in the following sections.
Packet Bus Fault Isolation Flowchart
The flowchart below shows the steps to be taken for isolating and resolving
packet bus problems. The order in which the maintenance objects should be
examined can be determined by assessing how wide-spread the failure is. For
example, since all ISDN-BRI devices communicate with the TN1655 Packet
Interface circuit pack, this MO should be examined early in the sequence. On the
other hand, a failure of a TN570 circuit pack in an EPN may cause ISDN-BRI
failure in the EPN, but not in the PPN.
Whenever the flowchart refers to MO documentation, keep in mind that the repair
procedure for that MO may in turn refer to another MO’s repair procedure. The
flowchart tries to coordinate these procedures so that a logical flow is maintained
