ADTRAN user manual The Express L128/L128T software setup

Chapter 4: Troubleshooting

H.With the Express L128/L128T 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.

4.If the Loop Status in the Express L128/L128T Status menu continuously reads Getting TEI #1, then the Express L128/L128T is physically connect- ed to your local telephone service provider but is unable to establish logi- cal layer 2. The problem is in one or more of the places listed below:

•The Express L128/L128T software setup

•The telephone service provider’s software setup

•Hardware configuration, if the line is extended from the switch

To isolate the problem, perform the following procedure:

A.Ensure the Express L128/L128T is setup for the correct switch type.

B.Ensure the quality of your 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 in step 3.

C.If possible, try another piece of functioning ISDN equip- ment with a U-interface on the line.

D.With the Express L128/L128T 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 ap- pears physically okay but has no terminal endpoint iden- tifier (TEI). Ask them to check the line translation and ensure that the line supports dynamic TEI allocation. Tell them that you have an NT1 and terminal adapter device connected to the line.

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