Working with ethernet

Pre-fabricated Cables and Testing

Start off by grabbing one of the blue cables (mostly CAT6) that you have laying around. They are usually provided when you purchase a router or switch. You’ll use this cable to see the output of the tester when it is hooked up to a good cable. The lights on both parts proceed in linear sequence 1 through 8. Feel free to use these cables to connect between a local switch and devices. Don’t run these cables through the house.
Figure 1. Ethernet continuity tester.  Image source:

Wire on the spool

When purchasing the gray/beige CAT 5 or 6 cable at the store, make sure that it is PLENUM rated for running through homes. With these cables, you can read the print on the side of the cable and see a UL


Look at the pre-made cables and Figure 2. Notice that the ordering
of the inner striped Green and striped Blue wires is different than the outer Orange and Brown wires. When inserting the wires into the connector make sure that they are going all the way to the end of the connector. When you crimp, you are pushing little metal teeth into the wire at the very end.

Don’t over trim the cable jacket. It is compressed by a plastic piece during the crimping to help hold everything in place.

The crimper is designed so that when you start crimping it doesn’t release until you’ve compressed everything all the way.

Test that the connector was successfully installed with the continuity tester.

Figure 2.  RJ45 Connector
Image source: 

Modular plug crimper