ADTRAN 1200070L1, 1200070L2 user manual Troubleshooting

Chapter 4: Troubleshooting

2.Disconnect the Express XL/XLT. From a functioning voice phone, call the local directory number(s) provided with your line. Calling a good ISDN line with nothing connected usually results in a ring or fast busy tone. If someone answers, or you get a not-in-service intercept, there is probably something wrong with the translation of the line. The phone service pro- vider should be able to help.

3.If the Loop LED still remains off, then there is a physical problem with the phone line (more than likely, a problem with the Layer 1 setup). The prob- lem is in one or more of the places listed below:

•The Express XL/XLT software setup

•The Express XL/XLT 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 XL/XLT con- nector marked ISDN BRI U on the back of the Express XL/XLT.

B.Make sure the Express XL/XLT is configured for Dial line service.

C.If possible, try another piece of functioning ISDN equip- ment 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 cod- ing).

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 equipment such as an NT1 in a wiring closet.

F.Make sure nothing else is bridged across the line pair.

108 Express XL/XLT User Manual 61200.070L1-1