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 indi cates that a Packet Bus fault is
present by loggi ng a Major or Minor alarm against PKT-BUS. A Major
alarm is indicated i n 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 tha t fails.
This precaution is taken because certain failures of the Maintenance/Test circuit
pack can ap pear as packet b us failures. To ensure that the problem is indeed
with the packet bus, p roceed through the followin g steps:
1. If the TN771D Maintenance/Test circuit pack is replac ed during thi s
process, enter the test pkt P long command to d etermine if the packe t
bus faults have been resolved. If th ere are still packet bus p roblems,
correct them by using the procedures in the sec tions 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 pac k with the new circuit pa ck.
6. Release the Maintenance/Test circuit pack with release board UUCSS .
7. Enter the test pkt P and status port-network P command s as described
in Steps 2 and 3.
8. If the data matches the previousl y recorded data, a p acket bus prob lem
exists, and the original TN771D Maintenanc e/Test circuit pack is not
defective. Reinsert the original TN771D, and correct the pac ket bus
problem by using the procedures in the sec tions that follow.
9. If the data does
not
match the previously record ed data, the orig inal
TN771D circuit pack is d efective. If there are still indicati ons of packet bus
problems, correct the m by using the proc edures in the following secti ons.
Packet Bus Fault Isolation Flowchart
The flowchart below shows the step s to be taken for isolating and resolving
packet bus p roblems. The order in which the maintenanc e objects should b e
examined can be d etermined by assessing how wide-spread the failure is. For
example, since all ISDN-BRI devices c ommunicate with the TN1655 Packet
Interface circuit p ack, this MO should be ex amined early in the sequence. O n the
other hand, a failure of a TN570 circuit p ack 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 proced ure. The
flowchart tries to coordinate these procedures so that a logical flow is maintained