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 j umper with connectors is req uired for this proced ure. If the
link uses metallic cable, the metallic connector must be removed from the bac k
of the carrier, and a lightwav e transceiver connected in its place.
1. Note the condition of the yellow LED on the ci rcuit pack.
2. Busyout the circuit pac k.
3. Disconnect the transmit and receive fiber pair from the lig htwave
transceiver on the back of the c ircuit pack. Note whi ch is the transmit fiber
and which is the receive fib er for proper re-connec tion at the end of this
procedure.
4. Connect the transmit and receive j acks of the lightwave transc eiver with
the jumper cable.
NOTE:
Make sure that the total length of the fiber jump er cable does not
exceed the maximum length recommended for the fib er link
connections between c abinets. Otherwise, test results may b e
influenced by violation of connectivity guid elines.
5. At the front of the cabinet, observ e the yellow LED on the looped bac k
circuit pack.
■If the yellow LED flashes once per second , the circuit pac k or
transceiver should be rep laced.
■If the yellow LED flashes five times per second, the c ircuit pack or
its lightwave transceiver may need replacement. This cond ition
may also be due to a faulty system c lock on the port networ k (for an
EI) or the switch node carrier (for an SNI).
■If the yellow LED was flashing before starting this proc edure, and it
is now either solid on or solid off, this c ircuit pack and its lightwave
transceiver are functioning p roperly.
6. Replace the faulty compone nt(s) and reconnect the orig inal cables in their
correct positions. Be sure to use a lig htwave transceiver that match es the
one at the opposite end.
7. Release the circuit pack.
Loopback Tests for fiber fault isolation
Figure 5-5 shows the loopbac ks performed on the SNI circ uit pack for test 756
and test 757. Test 756 reports the result of the off-board loop back; test 757
reports the result of the on-board loop back. 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 p ack. Besides testing on-board compon ents, this test
is helpful for isolating p roblems between a circ uit pack and the lig htwave