ADTRAN 1200051L5, 61200051L1, 1200051L6, 1200051L2 user manual Troubleshooting

Chapter 10. Troubleshooting

D.Talk to the 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) when using ISU 2x64 part number 1200051L1 or 1200051L3. If your ISDN line is extended from a PBX with an S/T line card, make sure you are using ISU 2x64 part number 1200051L2, 1200051L4, 1200051L5, or 1200051L6.

E.Ensure that the phone line is connected to the actual telephone line or PBX provided by your telephone com- pany. If using ISU 2x64 part number 1200051L1 or 1200051L3 with the U-interface, make sure your line is not connected through another piece of equipment such as an NT1 in a wiring closet somewhere.

F.Ensure nothing else is bridged across the ISDN line pair.

G.With a minimum of extra wiring, try connecting to the ISDN line pair at the point where service provider’s wiring ends.

H.With the ISU 2x64 connected to the ISDN line and pow- ered 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. If using the ISU 2x64 1200051L1 or 1200051L3 with the U- interface, tell them that you have an NT1-like device at the end of the ISDN line.

4.If the ISU 2x64 continuously reads Getting TEI #1, the ISU 2x64 is physically connected to the local telephone service provider but is unable to establish logical layer 2. The prob- lem is in one or more of the following places:

•The ISU 2x64 software setup

•The telephone service provider’s software setup

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

61200051L1-1D ISU 2x64 Dual Port ISDN Service Unit User Manual 79