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Chapter 11. Troubleshooting
61202.029L2-1 ISU 128 User Manual 79
G. With the ISU 128 connected to the ISDN line and powered up, talk to
your service provider's repair group and inform them that your ISDN
basic rate line has a physical layer 1 problem. Ask them to check the
ISDN line. Tell them that you have an NT1-like device at the end of the
ISDN line.
4. If the ISU 128 continues to read Getting TEI #1, the ISU 128 is physically
connected to your local telephone service provider but is unable to estab-
lish logical layer 2. The problem may be one or more of the following:
• The ISU 128 software setup
• The telephone service provider's software setup
• Hardware configuration if the ISDN line is extended from the switch
To isolate the problem, use the following procedure:
A. Ensure the ISU 128 is set up for the correct switch protocol by selecting
CONFIG, Netw. options, Dial Line, Switch protocl.
B. Ensure the line quality is satisfactory by checking for near- and far-end
block errors (NEBEs and FEBEs). To do this, select Test, NEBE/FEBE. If
the counts are non-zero and incrementing, there may be a physical link
problem as described under Link Down (Step 3).
C. Try another piece of functioning ISDN equipment with a U-interface
on the line.
D. With the ISU 128 connected to the line and powered up, talk to your
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 ISDN line translation and ensure
that the ISDN line supports dynamic TEI allocation. Tell them that you
have an NT1 and terminal adapter device connected to the line.