ADTRAN ISU 2x64, User Manual

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Chapter 10. Troubleshooting
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ISU 2x64 Dual Port ISDN Service Unit User Manual 61200051L1-1D
To isolate the problem, use the following procedure:
A. Ensure the ISU 2x64 is set up for the correct switch type.
B. Ensure the quality of the line is satisfactory by checking
for near- and far-end block errors (NEBEs and FEBEs).
If the counts are non-zero, there may be a physical link
problem as described under
Link Down (Step 3).
C. Try another piece of functioning ISDN equipment on
the ISDN line.
D. With the ISU 2x64 connected to the ISDN line and pow-
ered up, talk to the service provider’s repair group and
tell them you have an ISDN basic rate line that appears
physically okay but has no terminal endpoint identifier
(TEI). Ask them to check the line translation and ensure
that the line supports dynamic TEI allocation. If using
the ISU 2x64 part number 1200051L1 or 1200051L3 with
the U-interface, tell them that you have an NT1 and ter-
minal adapter device connected to the line.
5. If the ISU 2x64 continuously reads Register SPID #1, the ISU
2x64 is physically connected to the local telephone service
provider and has established logical layer 2. The ISU 2x64 is
unable to establish layer 3. The problem is in one or both of
the following places:
• The ISU 2x64 software setup
• The telephone service provider’s software setup
To isolate the problem, perform the following procedure:
A. Ensure the ISU 2x64 is set up for the correct switch type.
B. Ensure the ISDN line is multipoint.
C. Ensure that the ISU 2x64 is set up with the correct
SPIDs and LDNs.
D. Try another piece of functioning ISDN equipment on
the ISDN line.