How can I make an ethernet cable

Make your own network cable - that's how it works!

Marco Chiappetta

A network with prefabricated cables quickly leads to a cable clutter. It doesn't have to be! PC-Welt shows you step-by-step how to make your own network cable. A treat for hobbyists and IT fans.

You want to set up a home network and need appropriate cables. These are bought quickly. Often, however, they are not the ideal solution. Reason: The cables are usually only available in certain sizes. Cables that are too short must be extended. This can be done using cable clamps or other connection modules. So that cables that are too long do not cause too much cable clutter, they are bundled together. However, such solutions usually look ugly and are located near network switches, routers, restrictive hubs.

There is another way

It is often better if you use network cables of the correct length. In these step-by-step instructions, we will show you how to cut the cables with the necessary know-how and the appropriate tools and how to attach the respective plugs. The last operation is known as crimping.

The preparation: cables and tools

To make your own network cable, you need the appropriate cables (CAT 5, 5e, 6, 7). You will also need some RJ45 plugs and crimping pliers for RJ-11 and RJ45 plugs, cable cutters and wire strippers. Ideally, you have a cable tester. This provides information about the achievable data transmission rates and whether the cable is working properly. With a cable tester you save time, because you no longer have to laboriously search for a faulty connection or a defective cable.

At first glance, the purchase may sound expensive - but it isn't. There are inexpensive sets. Depending on the content, these include crimping pliers, stripping tools and cable tester or network patch cables with molded anti-kink sleeve and RJ45 plug. The prices start at around 15 euros for a network tool set with a bag (it-budget.de). Cable and connector sets are somewhat more expensive, but cables sold by the meter and RJ-45 connections are cheaper than pre-assembled cables in the long term. As a bonus, you also get a properly laid home network.

Standardized circuit diagrams and cable types

The "Telecommunications Industry Association’s T568A" and "T568B" define the standard for telecommunications technology. The standard circuit diagrams describe the sequence of the individual wires and the pin assignment for eight-pin modular plugs and sockets, such as those used for network cables. Depending on the wiring, there are “straight-through” (also known as patch cables) or “crossover” cables. In this section we explain the different cable types to you.

For most home networks, T568B and straight-through cables are sufficient. These types of cables connect broadband modems, routers, PCs and media players to your network switch. T568A cables, on the other hand, are used in some pre-installed networks in homes or other similar projects. In our experience, ready-made network cables for T568B networks are predominantly available in stores.

Crossover cables are special cables. These are only used to connect similar devices to one another without the aid of a network switch or hub. Two computers can be connected directly to one another via a crossover cable. Even if switches are to be wired to one another, a crossover cable is sometimes required. Modern switches, hubs, routers and similar devices now have an Auto-MDIX port. This automatically detects which device is connected to the other end of the cable and decides whether a crossover cable is required. Depending on the device type, the port is configured with MDI or MDIX.

The cables CAT 5, 5e and 6 have four twisted wires in different colors. These are orange with orange / white, green with green / white, blue with blue / white and brown with brown / white. There may be other fibers responsible for tensile strength that can simply be cut off after crimping as no current will flow on them.

For a straight-through cable, you must arrange the internal wires so that both ends are identical to the connectors for the T568B (or T568A). You create a crossover cable by sorting the wires according to T568A at one end and according to T568B at the other end. This does not apply to a 1-gigabit-compatible crossover cable. In this case you have to bridge all four pairs of wires.