ADTRAN Express 4100 Network Router User Manual


 
Chapter 4. Troubleshooting
4-2 Express 4100/4110 User Manual 61200176L2-1
fast busy tone. If someone answers, or you get a not-in-service inter-
cept, there is probably something wrong with the translation of the
line. The phone service provider should be able to help.
3. If the PWR LED still flashes, there is a physical problem with the
phone line (more than likely, a problem with the Layer 1 setup). The
problem is in one or more of the places listed below:
The Express 4100/4110 software setup
The Express 4100/4110 hardware
The wiring on your premises
The telephone service provider’s wiring
The telephone service provider’s hardware
The telephone service provider’s software setup
To isolate the problem, perform the following procedure:
A. Ensure the line is plugged into the Express 4100/4110 connector
marked ISDN on the back of the Express 4100/4110.
B. Make sure the Express 4100/4110 is configured for Dial line ser-
vice.
C. If possible, try another piece of functioning ISDN equipment with
a U-interface on the line.
D. Talk to your service provider and ensure you have an ISDN Basic
Rate U-Interface with 2B1Q line coding.
(Wrong options are an S or T interface or AMI line coding).
E. Ensure that your phone line is connected to the actual telephone
line (U-interface) provided by your telephone company. Make
sure your line is not connected through another piece of equip-
ment such as an NT1 in a wiring closet.
F. Make sure nothing else is bridged across the line pair.
G. With a minimum of extra wiring, try connecting to the line pair at
the point where the service provider’s wiring ends.
H. With the Express 4100/4110 connected to the 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 line. Tell them that you have an NT1-like device
at the end of the line.