How to Wire a RJ45 Ethernet Plug

Cabling Ethernet using standard T568A Wiring Color Code

Oct 10, 2008

Wired Ethernet gives the best network security and reliability, even in the home. Making up the ends means cables can be run through small 1/4 inch holes.

Media servers and similar demanding network applications mean that wired Ethernet still has a place in the home despite the problems of running cables through the voids.

Most domestic installations are eased using RJ45 plugs directly on the cables wired to the equipment, rather than using patch panels. Home equipment like media servers and the network switches are usually static so using solid-core cable taken directly from switch to equipment is not a problem. If a piece of equipment needs to be plugged and unplugged frequently, then take the network cable to a wall-mounted socket of a type that aesthetically matches the mains sockets in the building. A premade patch cable can then complete the circuit.

Rather than buying various lengths of patch cables, it is cheaper to fit the plugs after the cables have been run through the house. This way the size of the holes are minimised since each hole only has to be large enough to let the wire through rather than passing the RJ45 ethernet plugs.

However, it is essential to wire the right colors of the cable cores to the right pins of the plug. If this is not done properly then the cable will suffer excessive crosstalk, increasing packet loss and reducing throughput.

Making up Ethernet Cables – What is Needed

RJ45 Ethernet Cable Color Code (T568A)

Looking at a plug with the hook underneath and the cable running toward the viewer’s body, pin 1 is on the left (see picture)

There is another variant of this color code called T568B which the color green is switched with orange (both solid and striped) which will also work, but it is important to pick one and stick with it in any one cable. Color code charts and more information about the color codes is available in RJ45 Ethernet Computer Network Color Code

Wiring the RJ 45 Ethernet Plug

If a shroud (a.k.a. boot) will be used (see images) slide this over the cable first. The crimp tool will have a depth gauge to cut back the outer sheath of the cable, this needs to be done carefully to avoid nicking the inner insulation. There is no need to strip the inner insulation. Tease the cable out so that the wires are in a line following the RJ45 color code above, and feed this into the plug carefully, keeping the colors aligned.

Push the cable fully home into the plug, and double check the color code. Crimp the plug, and observe that the outer sheath goes into the plug. Repeat on the other end of the cable and it is ready for use.

Wired Ethernet versus WiFi

Wired Ethernet gives improved speed, reliability and security in a home network compared to wireless LANs. For applications like web browsing Wifi is adequate, but wired Ethernet comes into its own for media servers, where interruptions in the data stream cause unpleasant hiccups in the replayed audio or video.

Even if a Wifi connected media server works flawlessly on installation, it can suffer problems later on if neighbours install WiFi products that contend for channel space.

The copyright of the article How to Wire a RJ45 Ethernet Plug in Computer Networking is owned by Richard Mudhar. Permission to republish How to Wire a RJ45 Ethernet Plug in print or online must be granted by the author in writing.