If you can't loop the T-1 jack

You are facing an interesting situation; you can loop the NIU but you can't loop the T-1 jack. There are only two variables between these two pieces of hardware:

• The first variable is the cabling that connects them.
• The second variable is the T-1 jack on your NIU into which that cabling is connected.

Follow these steps:

• Find your NIU (remember, it might be in a locked phone room somewhere else in your building).
• Place your male loopback plug in the jack where the cabling for your circuit begins.
  Depending on the results of the test, you have two scenarios:
  If your carrier can see the loopback plug and the NIU is good, the cabling is defective between it and your T-1 jack. In this case, you need to have the person who pulled that cabling dispatched to repair it.
  If your carrier can't see that loopback plug, the jack you are plugged into is defective and the local carrier needs to replace the NIU.