DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Alarms, Errors, and Troubleshooting
5-25Fiber Fault Isolation Procedure
5
A short optical fiber jumper with connectors is required for this procedure. If the
link uses metallic cable, the metallic connector must be removed from the back
of the carrier, and a lightwave transceiver connected in its place.
1. Note the condition of the yellow LED on the circuit pack.
2. Busyout the circuit pack.
3. Disconnect the transmit and receive fiber pair from the lightwave
transceiver on the back of the circuit pack. Note which is the transmit fiber
and which is the receive fiber for proper re-connection at the end of this
procedure.
4. Connect the transmit and receive jacks of the lightwave transceiver with
the jumper cable.
NOTE:
Make sure that the total length of the fiber jumper cable does not
exceed the maximum length recommended for the fiber link
connections between cabinets. Otherwise, test results may be
influenced by violation of connectivity guidelines.
5. At the front of the cabinet, observe the yellow LED on the looped back
circuit pack.
■ If the yellow LED flashes once per second, the circuit pack or
transceiver should be replaced.
■ If the yellow LED flashes five times per second, the circuit pack or
its lightwave transceiver may need replacement. This condition
may also be due to a faulty system clock on the port network (for an
EI) or the switch node carrier (for an SNI).
■ If the yellow LED was flashing before starting this procedure, and it
is now either solid on or solid off, this circuit pack and its lightwave
transceiver are functioning properly.
6. Replace the faulty component(s) and reconnect the original cables in their
correct positions. Be sure to use a lightwave transceiver that matches the
one at the opposite end.
7. Release the circuit pack.
Loopback Tests for fiber fault isolation
Figure 5-5 shows the loopbacks performed on the SNI circuit pack for test 756
and test 757. Test 756 reports the result of the off-board loopback; test 757
reports the result of the on-board loopback. Test 756 and test 757 can run
individually or as part of the test board UUCSS long command for an SNI circuit
pack.
Test 242 can be run as part of the test board UUCSS long command for an
Expansion Interface circuit pack. Besides testing on-board components, this test
is helpful for isolating problems between a circuit pack and the lightwave
