How to Make Your Own Gigabit Ethernet Cables Using Simple Tools

Dec 12, 2023

Wiring your own Ethernet cables is fairly easy to do with a few simple tools, and is a useful skill to learn.

Wired Ethernet connections have a higher bandwidth compared to wireless connections. They are also very reliable. There is no bandwidth reduction due to wireless interference. Wired connections always have less latency, which is essential when playing games online.

You may prefer to use wireless only for convenience. Even so, you should still connect the backbone network (between routers) using a cable. Wired network routers and switches have a significant long service life. Making your own LAN cables is easy, and only requires inexpensive tools. Once you get a hang of it, your wired network will not only be fast but also neat, because you can cut every cord to the exact length.

These are the necessary tools to make LAN cables:

Having evolved over a period of decades, Ethernet cables offer a faster network connection than Wi-Fi. Each cable has eight wires twisted into four pairs.

The wires carry the signals, and each cable supports a certain frequency. The maximum frequency is determined by the gauge of the wire and the shielding around the pairs. The higher the frequency, the greater the bandwidth. Choosing the right Ethernet cable is the first and most important step to attain the desired network speed.

The speed of various Cat (category) Ethernet cables over their maximum length is as follows:

Cat Model

Frequency

Network Speed

Cat5

100 MHz

100 Mbps

Cat5e

100 MHz

1 Gbps

Cat6

250 MHz

1 Gbps

Cat6A

500 MHz

10 Gbps

Cat7

600 MHz

10 Gbps

Cat8

2000 MHz

40 Gbps

The price difference between the cables is not much, and the reasons to choose gigabit Ethernet are clear. Cat6A hits the right spot for both performance and price. Consider how bandwidth intensive computing applications have become, and will be in the future. Hence, it is best to choose a cable that supports 10 Gbps at least.

You might not use the full bandwidth right away if your routers and switches are 1 Gbps. But when you do, you don't have to tear the walls apart to change the cabling. The good news is that all the cables are backward compatible.

The registered Jack 45, popularly known as an RJ45 jack, is a connector used for Ethernet cables. Each jack has eight pins. When crimped, the pins pierce the individual Ethernet wires and make an electrical contact. The jacks have a strain latch and a retaining latch to keep the wire connected to the Ethernet port.

Pass-through RJ45 connectors have holes at the end and allow the wires to come out of the connector. This is a very useful feature to get the color coding right, and to prevent shorts.

Crimping is process of fixing a RJ45 connector to a cable. For this, you need to use a specialized tool called an RJ45 crimping tool. When force is applied, its metal teeth push the pins of the RJ45 jack into the Ethernet wires. The tool also has a couple of cutters built-in which are useful to remove the shield and trim the wires.

To test the quality of crimping and the cable itself, an Ethernet cable tester will prove useful. It works using a 9V battery; the individual LEDs glow when the electrical path through the wire is intact.

There are two pin standards: 568A and 568B. The most common standard is 568B with the color-coded wires placed as shown in the picture below. You must hold the RJ45 connector with the pins pointed towards you, and the clip away from you.

A straight-through cable, as the name suggests, has the same pin configuration at both ends of the cable. Any wiring color will work perfectly as long as the pattern is the same at both ends, because all the wires are the same gauge. But make sure you stick to the same pattern across all your cables. In this example, both ends of your straight-through cable will have the T568B pin configuration.

A straight-through cable is useful when connecting the Ethernet port of a computer to a router. But what if you want to connect two computers without using any network equipment in between?

For this you need to use a special type of wiring, called a crossover cable. One end of the cable still follows the T568B standard. The other end's wiring is different: the Transmit (TX) pins terminate at the Receive (RX) pins on the other end. This removes the need for network equipment in between.

Many newer Ethernet cards are auto-sensing. Hence, they will detect the pinout automatically. This facilitates the use of straight-through cables for crossover use. However, if you have legacy equipment, you will need a true crossover cable.

Shown below is the pinout of a gigabit crossover cable. It is backward compatible with 100 Mbps Ethernet cards too. The jack on the left side is T568B; the one on the right is the differently wired jack.

The crimping process is the same. Once completed, use the cable tester to check the connections. As you can see, the LEDs glow according to the crossover pin arrangement.

Crossover cables are very fast, even faster than straight-through cables that carry data through a router or a switch. The reason is that switches have buffer memory which stores the data and forwards it. A crossover mechanism does not need to store the packets, thus it can operate at the theoretical maximum speed. Crossover cables are also used to connect a hub to another hub, or a switch to another switch—essentially similar equipment.

Issue: The Ethernet cable is not working.

Solution: Check the cable with a tester. For longer cables, the master unit and the remote unit of the tester can be split and used for testing.

Issue: Unlike factory made cables, my cable feels loose at the jack.

Solution: Check if the strain latch is holding the cable. If not, crimp a new RJ45 connector with the cable pushed in thoroughly.

Issue: The cable does not operate at the desired speed

Solution: Check the rating of the cable. If that is good, and the network equipment supports the speed, manually set the speed of the ports to the desired speed. (On Windows, open Device Manager, select your network adapter, select Properties, click the Advanced tab, select Speed, and set value to 1 Gbps.)

Making your own Ethernet cables is a useful skill to learn. The tools required are easy to get, and it is simple to do. Once you make your own cables, what you learn is not just the crimping process, but a whole lot about how networking works.

Vishnu is a technology enthusiast. He has expertise in Linux, single-board computers, and cloud computing. His tech journey started when he developed a dictionary website for a contest. Over time, he has worked with various server technologies and improved the speed of his websites.His DIY style of implementation got him acquainted with a wide variety of computer hardware and software applications. He uses numerous computers, on his desks and in the cloud, and a majority of them run Linux. He is a strong proponent of the cloud and believes that all computing will happen there in due time.He enjoys explaining tech and reviewing gadgets through his writing at MUO and videos on his YouTube channel.