How to Wire an Ethernet Connector Plug

Wiring your own ethernet cables can save money over purchasing custom-length wires.

Wiring your own ethernet cables can provide a way to save money on your computer network. Ethernet Cables use RJ-45 wire. RJ-45 wire consists of four pairs of color-coded wires that must be crimped into the ethernet plug (or RJ-45 plug) in a specific sequence depending on the usage for the cable. There are two types of RJ-45 cables; straight-through for cables that connect a computer to a router, or crossover cables that connect two computers to a hub or two hubs without an uplink port, (a port dedicated to connecting two hubs). The order of the colored wires is governed by a standard called T-568B, ensuring all properly wired cables are similar.

Things You'll Need

• CAT-5 ethernet cable
• RJ-45 plugs
• RJ-45 crimping tool
• Knife or wire stripper

Instructions

1. Cut the cable to the desired length and strip about one inch of the jacket off of the ends of the ethernet cable. Be careful not to nick the wires or you will need to start over. Leave extra length when stripping, just in case. Spread and untwist the wire pairs and set your ethernet plug so that the clip is facing the bottom and the closed end is facing away from you.

2. Insert the wires for a straight through connection as follows, from left to right:

   Orange-White

   Orange

   Green-White

   Blue

   Blue-White

   Green

   Brown-White

   Brown

   Do this for both ends of the cable. This is the T-568B standard, and should be followed so any technicians working on your lines can easily know and repair/replace them. Press the wires firmly into the guides on the plug, being careful not to cross them over until they are flush.

3. Insert wires for a crossover connection as for a straight through connection on one end of the wire, but for the other end, insert the wires in the following left to right order:

   Green-White

   Green

   Orange-White

   Blue

   Blue-White

   Orange

   Brown-White

   Brown

   This creates the crossover that an uplink port would normally take care of. Without this, an external crossover adapter would be needed to ensure proper linking of devices in crossover mode.

4. Use the RJ-45 crimper to crimp each plug firmly on the end. The crimper will automatically notch the inner wires at the connector, so it is not needed to strip them. Plug in your wire and test it by connecting it to your computer's ethernet port to see if the network is detected.

Tips & Warnings

• Check your current wires for wire color order if you are unsure if you need a straight-through or crossover cable.

• A wire stripper makes stripping the wires much easier than using a knife.

• The string inside of an ethernet cable jacket alongside the wires can also be used to help strip the wire by pulling it down firmly and gently through the jacket coating.

• Stick to the standard order of colors or future repairs may be complicated.

• Do not strip the wires inside the ethernet cable; this will make them non-functional.

• Do not over-strip the wires; you want the wire jacket to meet the end of the plug.

• Double-check your wire order before crimping, since there's no way to undo the crimping.

References

• The Internet Centre: Ethernet Cable - Color Coding Guide