How to Make a T1 Crossover Cable

By Richard Asmus

T1 lines carry 1.544 Mbps signals for computer network connections in the immediate area, across town or across the country. T1 cables use four wires: two for the transmit signal and two for the receive. In some network applications, the equipment is so close together that a "crossover cable" just a few feet long makes the connection. The T1 signal transmitted from each of the two units "crosses over" to the receive signal of the other. Use crossover cables to connect T1 servers, private telephone switches (PBXs) or other T1 network devices together.

Step 1

Cut the cable to the desired length. Strip the outer covering off to expose the eight pairs of wires at each end.

Step 2

Place the wires into a RJ-45 connector at one end or the cable. Put the white with blue marks into pin 1 and the blue with white marks into pin 2. Place the white wire with orange marks into pin 4 and the orange with white into pin 5. Cut the other wires off at the end of the outer insulation. Some connectors require you to strip the insulation off the wires, but the most convenient make the connection when you make the crimp.

Step 3

Place the connector in the crimping tool and squeeze the handles until they stop. Remove the connector from the tool.

Step 4

Place wires into the connector at the other end of the cable. Place the white wire with orange marks into pin 1 and the orange with white marks into pin 2. Place the white wire with blue marks into pin 4 and the blue with white into pin 5. Cut the other wires off at the end of the outer insulation.

Place the connector in the crimping tool and squeeze the handles until they stop. Remove the connector from the tool. Your crossover cable is finished.

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