Avaya MCC1 Maintenance Procedures page 170

Troubleshooting
Fiber link fault isolation
NOTE:
If a fiber out-of-frame condition exists and lightwave transceivers are used, verify that
both lightwave transceivers are the same type, (9823a or 9823b). If not, replace one of the
transceivers so that they match. [A 9823A supports distances up to 4900 feet (1493 m),
and a 9823B supports distances up to 25,000 feet (7620 m).]
• If No, is a DS1 CONV administered on the fiber link? If no, follow normal escalation
procedures.
• If Yes, is there an SNI-BD 513 alarmed error (display errors, category = pnc)? If yes,
replace cabling between the SNI circuit pack and the DS1C circuit pack.
• If the alarm persists, replace the DS1C and the SNI circuit packs, and return to Step 4.
• If No, if the connected circuit pack is an EXP-INTF, did Test #238 fail?
If Yes, replace cabling between the EXP-INTF circuit pack and the DS1C circuit pack. If Test
#238 continues to fail, replace the DS1C and the EXP-INTF circuit packs, and return to
If No, busyout and test board UUCSS long for both DS1C circuit packs, and note every test
failure or abort.
In a standard-, duplex-, or high-reliability system (nonduplicated PNC), did the test return
"Board not inserted" for either the near-end circuit pack (nearest the server) or far-end
circuit pack? If so, replace the cabling between the DS1C circuit pack and the SNI or EXP-INTF
circuit pack.
Wait 1 minute and retest.
If the board is still not inserted, replace the DS1C circuit pack and the EXP-INTF or SNI
connected to it, and return to
If No, check to see if any of the CSU devices are looped back. Busyout and test ds1-facility
UUCSS external-loop for each DS1 facility. The tests should fail.
If any test passes, the facility is looped back, and the loopback should be removed. If the DS1C
complex has only one DS1 facility, this test cannot be executed at the far-end circuit pack (farthest
from the server).
Did Test #788 pass and Test #789 fail? If yes, at the other end of the DS1C complex, replace the
DS1C and its lightwave transceiver (if present). See
page 172 and
If No, did Test #788 fail or abort and Test #789 fail or abort? If yes, execute test ds1-facility
UUCSS long command for each administered and equipped DS1 facility.
If No, did Test #797 fail?
If Yes, run the test ds1-facility UUCSS external-loopback command for each administered and
equipped DS1 facility.
This test requires manually altering the external connections of the DS1 facility. Place the
loopbacks at as many points as your CSU capabilities will allow (see
Loopbacks,
• If Test #799 fails at LB1, the problem is with DS1C #1, CSU #1, or the connections in
between.
• If Test #799 passes at LB1 but fails at LB2, the problem is with CSU #1.
• If Test #799 passes at both LB1 and LB2, the problem is with the DS1 facility, CSU #2,
connections to CSU #2, or DS1C #2.
170
Step 4.
Figure 25, DS1 CONV Loopbacks,
on page 172).
Figure 24, Tests for isolating fiber faults,
on page 172. Return to Step
Figure 25, DS1 CONV
Maintenance Procedures
Step 4.
on
4.
December 2003