Making your own ethernet cables

Making your own ethernet cables is simpler than you would think. It’s also pretty much a requirement if you plan on any serious home networking or automation. When the cost of a technician is factored in to wire a house (either old or new), knowing how to terminate ethernet cables yourself more than pays for itself.

The basic supply list is pretty short, and the cost is reasonable. Most of the equipment needed can be purchased at any home center or Amazon. I’ll include my equipment and links to purchase.

Ethernet cable

Why make your own ethernet cables

Making your own ethernet cables has several advantages. Perhaps the most obvious is that you will won’t have to buy cables from the store any more, but more than that you will be able to fix or upgrade your existing cables. Likewise, being able to create your own cables is essential for making patch cables in a medium or large home network. There are also advantages to wired networking over wifi that result in a more stable home network.

Equipment list

Cable

While this may seem obvious, choosing the right cable for the application is important. Several different types of ethernet (or LAN) cable exist, including CAT5, CAT5e, CAT6, and even CAT7. Fiber optic is also an option and can be considered (if you have the budget) for high-volume environments. For most home networks CAT5e or CAT6 is sufficient. As a rule of thumb, data capacity increases from CAT5 to CAT7. Likewise, you’ll notice that CAT5 cable is significantlly less substantial than CAT6 cable.

Ethernet cable types

If you are planning for whole-home networking plan for the future. While wifi standards tend to change fairly frequently, hardwired home networks tend to be a little more future-proof. That being said, some things do change, namely the cabling. CAT7 is the newest cable standard, and also the most expensive. When planning the backbone of a home network make sure your cabling is able to handle the data volume; CAT6 is the best option for this. CAT6 gets data transfer rates of up to 1000 Gb/s (or Gigabit speeds); CAT5e can also get up to 1000 Gb/s. CAT6 typically has better shielding and thus less interference, especially over longer distances.

Cable can be sourced from your local home supply store or various online retailers for anywhere from $70-$120 per 1000 feet. A few things to watch for:

  • Research the cable you buy; you want to steer clear of copper-clad aluminum. While cheaper, it isn’t the best for reliable data transfer.
  • While uncommon, you can still find braided wire; stick with solid copper.

Basic Tools

You need some basic tools to create good terminations. Like the cable, these can be found at any home store or online retailer.

  • Wire cutters (I’ve got Romex cutters pictured, simply because someone has made off with my good pair of cutters)
  • Cable strippers (Amazon). Usually found for $5-$10; the key feature is that the aperture for the cable needs to be adjustable.
  • A termination crimper for either pass-through or regular RJ-45 jacks (depending on the type). Pass-through crimper, standard crimper. Usually found for $15-$30.

Notably, you can buy most of these in a kit (See this one at Amazon). Most kits will include a standard crimping tool versus a pass-through terminator. One advantage of a kit is that it will often include a punch-down tool, crimper, stripper, network tester, and various bits and pieces. One disadvantage is that the contents are usually not as durable as those you buy separately.

Termination bits and pieces

RJ-45 terminations come in two flavors: standard and pass-through. While either will do the job, I find that the pass-through connectors are easier to work with. Pass-through connectors have a gap at the end of the plug that allows the wires to “pass-through” as the cable is pushed into the connector. This eliminates the need to even up the ends of the individual strands prior to termination. An optional item is the boot that goes on the end of the cable; while not required, this plastic boot can be used to color code your patch cables during your network planning.

Optional Equipment

An optional, but highly useful tool is a termination tester. While is it not necessary to check every cable if you are careful with your terminations, it is a good practice. Cables can have defects, or terminations can be mixed up. Its better to figure this out while you go rather than to find out you’ve got a bad cable once everything is wired up. Check at your local hardware store for one. This kit at Amazon is a pretty good option for beginners. The tester I have pictured will test correct pairing for CAT5/6 cable, telephone line pairing, and identify terminations for RJ6 coaxial.

Klein cable tester

The process

Remove the outer jacket

Regardless of the size cabling being used, the first step is to remove the sheath. Using the cable stripper, rotate it around the outer jacket once or twice to score the plastic about 3/4″ from the end of the cable. Gently bend at the score and snap the jacket off.

Gather the strand of fibers and cut using a pair of wire cutters or scissors. If a central rib is present to separate the twisted pairs, gently cut it as close to the sheathing as possible. Be careful not to nick the sheathing on the individual wires!

Stripped ethernet cable

Importantly, carefully inspect the individual pairs of wires to ensure that the cable stripper did not damage the wire coating. Any defect will result in data loss and potentially slower network speeds. If you see damage, adjust the spread of the stripper (maybe that should be phrased differently…), trim the damaged end off, and start again.

Organize the wires

RJ45 pinout

Before making any cables or doing any home wiring, decide on the pinout you will use. There are two standards: T-568A and T-568B. T-568B is standard in the US, but as long as you are consistent in your wiring and stick with the same standard throughout your network you can use either. The only difference between the two is the the orange and green paired wires are swapped.

Prior to starting, if you want to add cable boots add them. If not, start by untwisting each pair of wires down to the sheathing. Once untwisted, move each wire and flatten them out so they are ordered in the required pinout arrangement.

Add the termination connector

Add the connector. In the picture, note that the pass through connector has an opening for the wires to extend through past the end of the connector. A standard connector has no opening. If using standard connectors, using wire cutters, trim the wires to make the ends even. Additionally, you should trim the wire short enough so that the sheath extends partway in the plug, When crimped, a small clip will compress the sheath to both provide stress relief and hold the cable in place. If using pass-through connectors, simply insert the cable, ensuring that the individual strands do not get crossed and in the wrong place.

When inserting the cable, if the clip is down, the green/white (T-568A) or orange/white (T-568B) wire should be the first (or top) wire in the connector. Once inserted, carefully inspect the pairing order to ensure it matches the pinout. If you mess up here and crimp the end on, it’s worthless. Pass-through connectors are great here, since you can easily see the pairing order as the wires extend from the end of the connector. If using standard connectors, carefully look at the wires through the plastic to ensure correct placement. For either type connector, make sure all wires extend at least to the end of the connector. If any wires come up short, pull the cable out, reorganize, and try again.

Crimp and complete the connection

Using the appropriate crimping tool fix the connector to the cable. Note that a pass-through crimper will fix the connector to the cable while cutting the individual wires flush at the same time. Once attached, move the boot up to the connector to complete the end. If you’ve done everything correctly you should be able to see all 8 wire ends when viewing the connection end-on. Likewise, from the side you should be able to see the gold blades have pierced all wires and the connector has compressed the cable sheath. If individual wires extend from the back of the connector, or not all wires are visible at the end of the connector, clip it off and start over.

Optional (but highly recommended): Test the connection

The last step, while optional, is highly recommended. Once both cable ends have been created use a network tester to make sure the cable doesn’t have any defects and no pairs are crossed. Follow the instructions of your specific tester to interpret the results.

In the example for this cable, the Klein tester shows each pair has correctly terminated on both ends. If any pairs were in the wrong spot it would fail the data test and this tester would also show which end and which wires were in the wrong place. This is particularly useful for long cable runs.

Passed cable test

Wrapping up

Being able to create good RJ45 terminations is one step to creating a wired home network. In other posts I’ll go into how I planned and created my own home network, including the server rack, pulling wire, and creating end connections in the rack.

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