6 Steps to Build a Network Cable: DIY Guide

• Bulk cable: Cat6 is the sensible default today. For patch cords, use stranded cable, which flexes without cracking. Solid-conductor cable is meant for runs inside walls that terminate on jacks and patch panels.
• RJ45 connectors rated for your cable: Cat6 connectors for Cat6 cable, and matched to stranded or solid conductors. Pass-through connectors, where the wires poke out the front, make alignment much easier for beginners.
• Strain-relief boots: optional, but they keep the clip from snapping off.
• A crimp tool that fits your connectors. Pass-through plugs need a crimper with a built-in trimming blade.
• A cable jacket stripper or a careful hand with the crimper's stripping blade.
• A cable tester. Even an inexpensive continuity tester will catch miswires and opens.

One warning on buying cable: skip the bargain spools labeled "CCA" (copper-clad aluminum). They look like copper, cost less, and cause headaches with Power over Ethernet and longer runs. We explain why in pure copper vs. copper-clad aluminum cable.

Measure the route the cable will actually take, around the desk leg and under the cable tray, and add a little slack. Cut clean with the crimper's blade. Then slide both boots onto the cable before you do anything else, facing outward toward the ends. Forgetting the boot until after you've crimped is a rite of passage, and the only fix is cutting the connector off.

Remove about an inch of the outer jacket. Score it lightly and bend it until it breaks, rather than cutting straight through, so you don't nick the insulation on the pairs inside. Cat6 usually has a plastic spline separating the pairs. Trim it flush with the jacket. If there's a rip cord, cut that off too.

Untwist the four pairs and straighten them. Then line them up, left to right, with the connector's clip facing away from you, in the T568B order used by most US businesses:

1. White/orange
2. Orange
3. White/green
4. Blue
5. White/blue
6. Green
7. White/brown
8. Brown

The other standard, T568A, swaps the orange and green pairs. Either works as long as both ends of the cable use the same standard and the rest of your building matches. Pick one and stick with it. Mixing them across a building makes every future troubleshooting session harder.

Holding the wires flat and in order, trim them straight across so about half an inch sticks out past the jacket. Keeping the untwisted section short matters. The twists are what reject interference, so every extra bit of untwisted wire costs signal quality, and it shows up on longer or faster links. With pass-through connectors you can leave them a little longer, because the crimper trims the excess.

Slide the wires into the connector with the clip facing down, and push until every conductor reaches the very front of the plug. Look through the end: you should see eight copper tips all the way forward, still in order. The outer jacket should sit inside the back of the connector, where the strain-relief tab can grab it. If the jacket stops short, the crimp will hold loose wires, and the cable will fail the first time someone yanks it.

Put the plug in the crimper and squeeze firmly until the tool bottoms out. On pass-through plugs the blade trims the protruding ends in the same stroke. Slide the boot down over the connector, and repeat everything on the other end.

Connect both ends to the tester and watch the lights step through pins 1 to 8 in order on both sides. Anything out of sequence is a miswire. A missing light is an open conductor, usually a wire that didn't reach the front of the plug. Cut off the bad end and redo it. Don't skip this step. A cable that "mostly works" is the one that causes an intermittent problem three months from now.

• Different standards on each end. One end T568A and the other T568B gives you a crossover cable. Modern equipment with Auto-MDI-X usually copes, but it's not what you meant to build.
• Too much untwisted wire. It can pass a basic continuity test and still perform poorly at speed.
• Solid wire in a patch cord. It'll work until the conductors fatigue and crack from being flexed.
• Going past 100 meters. A standard Ethernet channel is limited to 100 meters in total, patch cords included.

Not sure which category to buy? Our guide to UTP cable categories breaks down Cat5e through Cat8.

Is T568A or T568B better?

Neither performs better. T568B is the more common choice in US commercial buildings. What matters is using the same standard on both ends of every cable and across the whole site.

Do I still need crossover cables?

Rarely. Most switches, routers, and computers made in the last decade support Auto-MDI-X and adjust automatically, so a standard straight-through cable works for nearly every connection.

Is it cheaper to make my own patch cables?

For a handful of odd lengths, making them is convenient. For dozens of cables, factory-made patch cords are usually more consistent and often cost about the same once you count connectors and your time.

Can I use this method for cable inside walls?

No. In-wall runs use solid-conductor cable terminated on keystone jacks and patch panels with a punch-down tool, and they should be certified with proper test equipment after installation.

A homemade patch cable is a fine fix for the desk. The permanent cabling in your walls and ceilings is a different job. It has to meet code, pass certification testing, and hold up for fifteen years or more. If you're opening a new office, adding drops, or untangling a closet nobody wants to touch, our structured cabling team designs, installs, and certifies it. Reach out and we'll walk the space with you.