DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Alarms, Errors, and Troubleshooting
5-26Fiber Fault Isolation Procedure
5
transceiver. The loopback shown in this diagram shows only part what test 242
does. If no lightwave transceiver is connected to the Expansion Interface circuit
pack, an on-board loopback is performed on the Expansion Interface circuit
pack. For more information about test 242, see
‘‘EXP-INTF (Expansion Interface
Circuit Pack)’’.
Figure 5-4. Fiber fault isolation tests
If DS1Cs exist on the fiber link (check with
list fiber-link
), then additional
DS1CONV loopback tests can be run to further isolate the problem. The
loopback tests are shown in
Figure 5-5
. For more information about loopback
tests 788 and 789, see the
‘‘DS1 CONV-BD’’
section in. For more information
about DS1 facility loopback tests 797 and 799, see the
‘‘DS1-FAC (DS1 Facility)’’
section.
Figure 5-5. DS1 CONV Loopbacks
Tone
Clock
Tone
Detector
Test
#242
fiber-optic
cable
TDM BUS back skin
of cabinet
lightwave
transceivers
TN753
Switch
Node
Interface
Test
#757
Test
#756
TN570
Expansion
Interface
back skin
of cabinet
Test #989 (framing)Test #238 (framing)
Tests 788, 780, 797,
and 799 start here:
. . . . .
.
.
.
.
.
.
.
.
.
. . . . .
Test 797 loops at internal
interface for the DS1 facility
Test 789
loops here
Test 788
loops here
lightwave
transceiver
DS1 Facility
CSU 2
DS1C
2
CSU 1
DS1C
1
Test 799
LB 1
Test 799
LB 2
