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Knowledge Base / Hardware / How do I make a T1/E1/J1 loopback connector?

How do I make a T1/E1/J1 loopback connector?
Views: 7823, Votes: 4

Posted:
26 Apr, 2006 - Support D.

Updated:
14 Mar, 2008 - Savage B.
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Building a T1/E1 Loopback Connector.

In order to perform a loopback test, a loopback plug is needed. A T1/E1/J1 loopback connector can easily be made using a single RJ45 connector and 2 four inch wires.

Materials Needed:
  • Unused RJ-45 plug
  • Two strands of cat-5 or similar wire
  • Crimpers
RJ45 Plug
Figure 1: RJ45 Plug

Procedure:
  1. Insert one end of wire 1 into pin 1 of the RJ45 connector. Make sure that the wires go all the way into the end of the plug or else there will not be a good connection. Refer to Figure 1 for an example of an RJ45 pin layout.
  2. Insert the other end of wire 1 into pin 4 of the RJ45 connector.
  3. Insert one end of wire 2 into pin 2 of the RJ45 connector.
  4. Insert the other end of wire 2 into pin 5 of the RJ45 connector.
  5. Now that both ends of the wires are inserted into the plug it can be crimped.
Now you have a single RJ45 connector with pins 1 to 4 and 2 to 5.



The zttool utility should report green on the specific span that you have the T1/E1/J1 loopback connector plugged into.  If the specific span which the T1/E1/J1 loopback connector is plugged into does not go green, then the T1/E1/J1 loopback connector was made incorrectly.
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