Twisted pair crimping: the correct cable crimping scheme for the Internet

What does twisted pair and Wi-Fi have to do with it?

Dear reader, I have a free blog here - so if everything is not interesting, immediately scroll through the Contents to the sections of the article that interest you. I'll start from afar. In a galaxy far, far away...

The fact is that the central element of a home Wi-Fi network is now a router. A modern router usually has wired connections:

From the router to the provider's network - the same cable from the entrance. There is regular Ethernet and telephone under ADSL - all these wires are called “twisted pair”. The first occurs more often, the second less and less often.
From a router to a computer or laptop - sometimes the connection is made not via Wi-Fi, but via wire. Likewise, computers without an adapter can be connected to the Internet, and seasoned players say the ping will be better.

So in a home network there is nowhere without a twisted pair cable.

BNC connectors

BNC connectors are a type of connector used in video surveillance systems to connect a coaxial cable (an electrical cable that includes a coaxially located central conductor and screen). It is considered the most reliable, even though it was created more than sixty years ago.

Special crimping of the BNC connector requires certain costs, but such costs are recouped due to the high reliability and durability of this type of jack. Most of the failures during the operation of a video surveillance camera are caused by poor-quality cable connections. BNC connectors ensure proper connection of coaxial cable, which prevents losses that may occur during signal transmission.

There are a huge number of BNC connectors available today. Plugs, or as they are also called “male connections,” are especially popular. Female connectors (female connections) are no less popular. The wide range of these products includes corner adapters and BNC terminations. Connectors trimmed with precious metals (silver or gold) are also in demand, because this design significantly reduces resistance and prevents oxidation.

If you have a choice of where to buy twisted pair connectors, choose a reliable one that has taken a leading position in the Russian market since 2007. Reasonable price and European quality are what distinguishes the company’s products from other organizations.

Problem

One of the most common reasons for the loss of Internet at home is a cable problem. There are many options:

A wire has frayed somewhere in the corner connections - it happens that someone shuffled it or kicked it.
The connection in the connector is broken - the wire there is open, so it may break. Sometimes the connection just drops. And over time, the crimp “dries out,” so you still have to improve the connection.

The bottom line is that when replacing a wire or repairing a connector, you still have to somehow reattach those same connectors. But this procedure is called crimping. And you can do this completely at home yourself (I’m telling you as a seasoned admin, and it wasn’t in times like these that you were cutting the cable). But you need a little theory - this is not electrical wiring. So first, a little theory, and then let's move on to practice.

A little about connecting cables

It wouldn’t hurt to talk a little about the cables themselves. This will make it easier for the user to understand what he is dealing with.

And if he has some non-standard cable at his disposal, he will know everything about it.

Cable categories by protection class

Protection of the data cable is needed in cases where you need to connect a device to a computer that is located at a considerable distance from it.

If you use a protected cable, you can minimize speed losses. According to the protection class, the following types are distinguished.

Fig.8. Classic twisted pair (UTP) with stripped insulation

UTP. The most common type of cable that is used when connecting a router to a PC or two computers on a network. Also called "twisted pair". Does not have any protection (except for the insulating material).
FTP. A network cable that is equipped with a protective layer of foil. This layer is located immediately after the insulating material. Such a cable is more protected from any magnetic radiation than the notorious “twisted pair”.
SSTP. A cable that is protected not only by a general foil shield. Each wire is also shielded. It is used in cases where it is necessary to extend the network over considerable distances with minimal speed losses.
SFTP. The most secure of all cables. There is a foil shield for each pair of cores, copper woven mesh, and an overall foil shield. Used in the most difficult situations. Provides complete speed preservation. But it's also worth a lot.

twisted pair

In the last section, we found out that twisted pair is a wire used for network connections in computer technology. Especially used at home to connect to the Internet.

It got its name from the building. Inside there are copper wires in a sheath, twisted in pairs. Twisting is done with a certain step depending on the number of such pairs. The whole point of such twisting is mutual cancellation of interference to improve the quality of the signal in the working network (after all, this wire also carries electricity, although not 220V, and reliability here is needed at a high level, but this is a topic for standards).

There are several types of twisted pair... Even many. The main classification is by device, not the main one - by protection. When installing at home, you will usually be dealing with a category 5 cable (if you want, look for it yourself, that’s not what the article is about).

In terms of protection, there is also nothing difficult - there is with protection, there is without protection. Protection does not mean from falling stools, but from the same interference that creates interference. This is usually not required at home, but you never know what you can get your hands on. The section is larger for the fact that you will have to open the cable during crimping, and you need to be prepared for anything) So a little anatomy for the system administrator and the home enthusiast to surf VKontakte.

So, there are pairs of wires inside - usually 2 or 4. The wire can be protected - we are talking about foil or braid. In this case, protection can be either for the whole wire or separately for each pair. There are a lot of subtleties, it’s better to open it right away and look locally. In home cable there is usually nothing like this - one braid, and there are pairs in it at once.

Twisted pair markings:

UTP – regular, without protection, for home. If you need to restore a piece of your house and go to the store, just look for something like UTP5 - it will do just fine.
FTP - with foil, also sometimes used indoors.
SFTP – metal braid, used outdoors.
STP – protection on each pair. When the wire is on the street near power lines (I hope you didn’t get caught there).

In total, the different options are arranged in the following figure:

An additional bonus is that there are multi-core and single-core cables. Stranded ones are used at home - the wire comes out flexible, just for active movements. It is better to use a single-core wire for industrial installation - up to the socket, the wire does not bend, but the signal transmission is much better.

I don’t even want to mention flammable and non-flammable, round and flat here - after all, this is not a system administrator’s textbook, but simply helping those in need at home. So if you have questions, run to the comments.

Attention! Leave your comments. We will help everyone!

Types of twisted pair

In addition to categories, copper cables are distinguished by design. The following types of cable are distinguished:

UTP is a cable with a simple sheath, without armor or protective shield (unshielded twisted pair). Usually installed indoors.
FTP – shielded twisted pair (foil shield).
STP - Here each pair of wires is placed in a protective shield and a wire mesh armor is laid between the two shells.
S/FTP, also known as SSTP, is a double shielded cable. The first one braids each pair separately, the second one covers the entire bunch.
U/STP – similar to STP, but without external armor.
SFTP - This shielded twisted pair cable has the thickest cable of all. It has three screens: an internal one covering paired wires and two external ones. One is made of foil, the other is made of wire mesh.

The differences in performance are by no means limited to cable design. The materials from which it is made also play a role. Thus, conductors made of pure copper have better conductivity characteristics compared to their counterparts made of copper-plated aluminum. Another thing is that copper conductor is much more expensive than aluminum.

Shell materials should also be differentiated. The most popular shell today is polyvinyl chloride (PVC). A cable with such a sheath is marked with the letters PVC and is most often painted gray. It is intended for installation indoors. This casing is very cheap, but burns well and has limited resistance to heat and cold.

Another popular cable sheath material is polyethylene (designated PE). It is used in cables for outdoor installation. Outdoor twisted pair cables withstand temperature changes well and are not afraid of dampness. In a number of options it is equipped with a support cable. This allows you to stretch the cable between the supports without the risk of damaging the conductors.

Street twisted pair cable with cable

In recent years, twisted pair cables with a sheath made of a low-smoke, halogen-free compound (LSZH marking) for indoor installation have been gaining popularity. It burns poorly and does not emit harmful substances. Therefore, if strict fire safety requirements are imposed on lines or premises, this should be chosen. Yes, it is more expensive than PVC, but it is more durable and safer.

There are also rarer cable sheaths. For example, the FRNC marking means that the cable sheath is fireproof and corrosion resistant. The polyurethane (PUR) shell offers excellent resistance to oil and repeated bending. Such cables are used in robotics and other areas with special requirements for conductors.

Wire selection and standards

In the last section I mentioned the categories of twisted pair, here we will consider this point in a little more detail. After all, the anatomy and transmission speed on the cord also depend on the category.

I recommended that you take category 5, but category 6 (CAT5, CAT6) is also suitable. All options are shown in the following table:

It will be important to choose a cable for the required speed. And this also depends on the number of wires inside. It usually happens like this:

2 pairs (4 wires) – up to 100 Mbps
4 pairs (8 wires) – from 100 Mbit/s

Typically, ISP technology limits you to 100 Mbps internet speed. But soon this threshold will be passed. What do I mean - usually there will be exactly 2 pairs on the Internet cable, but on home cables (from the router to the computer) there are already 4 pairs.

4 pairs, or 8 wires

Crimping theory

And now we are approaching the crimping procedure. But there is still something to clarify, the final frontier.

You have all seen the connector at the end of a twisted pair cable, which also goes into the network connector of a network card or router. This plug has a special marking. The one that is mainly used now in the home local network is RG-45. A little about the connector design and connection.

The twisted pair is installed in the connector socket.
The twisted pair wires are routed through special grooves in the connector.
The contact mechanism of the connector is knives. In store condition, they are separated, providing a path for the cable wires.
When crimping, apply pressure to the knives, and they cut through the sheath and ensure tight contact with the wire cores.
On the other hand, the contacts of the knives remain open - they provide a connection to the network adapter when connected.

Here is a picture of how the knives work:

And here is the connector in an enlarged view (the same wire tip or “jack”):

This connection is reliable and transmits the signal perfectly. But beginners may not be able to do enough at first - and either there will be no connection, or it will be established at a low speed (this is one of the reasons for the decrease in speed on the network). The best way to fix it is to squeeze it harder again, or re-press it again. In practice, at our university this procedure did not work out for everyone the first time - so everyone starts somewhere.

Crimping twisted pair

The main advantages of copper cable compared to optical cable are its low cost and ease of deployment. All that is required for termination is a twisted pair crimping tool (twisted pair crimping pliers) and an RJ45 connector. In this case, the installer does not require special equipment or training. Laying copper cable indoors does not require the use of protective covers or corrugated pipes, like optical patch cords. And if the connector gets dirty, you can easily clean it or install a new one.

For use, copper cables must be terminated with appropriate connectors. The most commonly used is 8P8C, better known as RJ-45. The latter, by the way, is a popular misconception. A real RJ-45 connector has a slightly different shape and is incompatible with the connectors of its namesake.

Crimpers for installing modular RJ-45 connectors:

Jonard Tools UC-864

Crimping RJ22, RJ11, RJ12 and RJ45 connectors
Cable type: Twisted pair STP/UTP 0.32 - 0.64 mm
Two-component rubberized handles
Knife for cutting cables or conductors
Stripper for stripping insulation from round cables
Flat cable stripper
Steel structure, oxide coating
High carbon steel dies
Finger safety clips

Jonard UC-4569 - crimper for through connectors

Crimping of Through and Standard RJ45 Connectors
Guillotine for removing protruding wire
Crimping RJ22, RJ11, RJ12 and RJ45 connectors
Cable type: Twisted pair STP/UTP 0.32 - 0.64 mm
Two-component rubberized handles
Knife for cutting cables or conductors
Stripper for stripping insulation from round cables
Flat cable stripper
Steel structure, oxide coating
High carbon steel dies
Finger safety clips

Greenlee PA1561

Crimping RJ22, RJ11, RJ12 and RJ45 connectors
Non-slip handles
Knife for cutting cables or conductors
Stripper for stripping insulation from round cables
Mechanism for releasing the crimp connector
Weight: 390 g

Greenlee 45553

Installing RJ-11 and RJ-45 connectors
Reliable ratchet mechanism
Strictly perpendicular course of the matrix
Guaranteed long tool life
High crimp quality
Knife for cutting cables or conductors
Stripper for stripping insulation from round cables

Hobbes Tooltest - crimper with LAN tester

Crimping RJ22, RJ11, RJ12 and RJ45 connectors
Knife for cutting cables or conductors
Stripper for stripping insulation from round cables
Built-in RJ-45 cable tester
Testing the cable for continuity, breakage, mixed-up conductors, short circuit.
Low battery indicator.
Crimping tool and cable tester in one

Tools

The main thing when crimping is to make a high-quality cut with knives on the shell. And for this you need to create the right strong pressure on the contacts. Well, we couldn’t do it without creating tools, although we can do without them.

Pros use a special tool - crimping pliers, or crimper. I’ve also seen names like “wire crimpers” or “connector crimpers.” Here, who already has what taste, you will probably hear some other versions.

This thing isn't that expensive. You can find a working copy for less than 1000 rubles. For a one-time repair at home, the thing is useless. But their main feature is their functionality tailored for twisted pair cables:

Cut the braid exactly to the level of the wires
Stripping wire insulation down to the core
Simultaneous crimping of all knives with the required force
Sometimes there is a socket for crimping and telephone cable (RG-11)

This is what they look like:

No tool

In my life I have seen many crimping methods. But the most interesting of them was teeth, because... a person’s mother-in-law was a dentist... So sometimes you don’t even need a tool at all.

Another handy tool that everyone has is a screwdriver. Moreover, this is perhaps the most popular tool at home. The main thing is not to break anything and push through the contacts efficiently. If the connection is not established during the test, you just need to try again. The working method is difficult, everything constantly slides off - but without fish there is fish.

Another home helper is pliers. But my advice is that it’s better to suffer with a screwdriver. The pliers do not provide strong indentation (especially in the middle), and with great Russian heroic prowess they easily break the connector into small pieces.

Crimping diagram - pinout

And now the science itself. It’s one thing to apply pressure, another thing is to correctly insert the wires into the cores (and this is the most important thing in order to correctly crimp a twisted pair), and into both connectors - a random set will not work here. The order is very important. In total, the connector has 8 grooves for 8 cores. If 4-core wires are crimped, some of the grooves are left empty, the main thing is to get it right.

First, let's look at the classic crimping of an 8-core wire. There are 2 ways:

Direct cable crimping (type B, 568B) is used in 99% of cases. Used to connect peripheral devices to a router/hub/switch.
Cross crimp (crossover, type A, 568A) - used for direct computer-to-computer connections.

For reference . Now modern adapters understand both of these methods, but the first option of direct crimping remains preferable.

The names of twisted pair crimping circuits are taken from the way the wires are arranged in relation to each other. Look at the images below and you will understand everything. The main thing here is a view of the connectors from below (where there is no leg).

Direct crimp

Use this pinout diagram!

If the pictures are suddenly unavailable for some reason, the arrangement by color is:

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

Cross circuit

Four wires

Another option for 4 cores is the case when there are only 2 pairs. This is how they usually do it:

The whole point of proper pinout is to match the wires on both sides of the cable, without even knowing how the connector on the other side was crimped. An unspoken standard where you don’t have to run to the provider’s shield. The numbers 1-8 in the pictures are sometimes squeezed out on the sockets, this is for those who do not want to confuse the order.

Required tools and crimping procedure

For crimping you need:

twisted pair;
2 RJ-45 connectors or jacks, also known as 8P8C;
crimper or crimping pliers.

Connectors can be monolithic or two-component. The insert, in theory, should make it easier to assemble the conductors into the jack.

call me back

Leave your contact details and our manager will contact you within one business day

A classic twisted pair cable consists of 8 wires twisted in pairs. The economical 4-core cable version is relevant for the installation of 100-megabit computer networks. It lacks blue and black pairs of conductors. The procedure is the same in both cases. Is it possible that with a cheaper cable there is less hassle with inserting the cores into the connector (they tend to fall out due to careless movements and inexperience).

Using the cable crimper's stripping area, remove the outer protective sheath, 25-30 mm long.
Unravel and line up all the wires in a row according to the crimping pattern.
Trim them to about 15mm using the wire trimming area on the crimping pliers.
Insert the conductors into the contact points of the connector in accordance with the selected crimping pattern until it stops.

Look at the connector from the contact side.

In this case, the outer shell must fit into the seat, where it will be fixed during the crimping process. If this is not done, during operation, especially if the cable is often disconnected or the laptop is moved around the apartment with it, the conductors can quickly become mechanically damaged.

The figure shows a correct installation (A) and an incorrect installation (B). In the second case, the wires should be pulled out of the connector and trimmed further.

Check the correct placement of the wires (colored so that they reach the stop) and place the connector in the appropriate socket of the tool.

Squeeze the crimper handles until you hear a characteristic click.

Crimp the other end of the wire in the same way.

During crimping, the crimper presses the contact legs of the connector deeper into the body. In the process, they strip the insulation of the conductors and make contact with each of them. The polymer cable retainer is also pressed in.

The network cable can be successfully crimped without a crimper, for example, with a straight screwdriver, knife or other thin metal object.

When using a connector with an insert, the cores are placed into it and then into the connector body. The solution should make it easier for inexperienced users to crimp a network cable.

Crimping procedure

Now let's move on to the correct way to crimp the cable. Be careful when working - the main thing is not to damage yourself, and the connectors are cheap)

Step 1. Remove the insulation

First, remove the insulation from the wire - you can carefully pry it off with scissors or use a stripper on a crimper - insert it, turn it, and the wrapper comes off. It is fragile and can be removed quite easily. You don't need to remove much insulation - a couple of centimeters from the end is enough. If anything happens, you can trim everything later. The pliers have special marks indicating at what level the coating should be cut.

Step 2. Straighten the wires

Now we take our wires, straighten them and arrange them according to the pinout diagram. From the recommendations - try straightening them with a pencil or hand - they become smooth and closely spaced to each other - which is what we need.

Step 3. Trim

Now is the time to cut and straighten our wires. We cut it either with wire cutters, or with the same pliers, or even with a knife. Leave about a centimeter of clean wire. With practice, you will learn to accurately check the distance.

Step 4. Getting into the connector

The hardest part. Now we need to insert our design into the connector. When inserted, the connector is positioned with the leg down. Why is it difficult - the wires try not to fall into their grooves, they crawl into neighbors, bend, and get tangled. Here the recommendation - patience and once again paying attention to the pencil treatment - helps.

Step 5. Insert all the way

After the hit, we press on the cable so that the wires go all the way. In this case, the wrapper will be hidden in the connector itself. If the wrapper does not fit into the connector, fractures are possible in the future. If the opposite turns out to be short, the wires will not reach the knives. So everything is done with experience and by eye.

Step 6. Crimping

Now is the time to tighten our knives - the methods were discussed above, but it is better to use pliers. Take it and live it.

Step 7. Check and refinement

Be sure to check the connection on your computer or router before putting away your tools. Sometimes it may not work out the first time. The easiest way to correct the situation before getting upset is to squeeze the knives again, but harder. It helps a lot.

If there is no connection, pay attention to this:

Are the wires routed exactly according to the diagram? Didn't they fly out? Look through the connector.
Have the wires reached the stop of the connector? Were the knives able to reach them?

The rest can only be attributed to cable failure.

Initially, before crimping the network cable, you can install these casings. They perfectly protect against bending near the connector, but in practice everything works without them. There are a lot of species, that’s not what the article is about. For reference.

How to crimp an internet cable with your own hands

Pinouting the communication wire with your own hands is quite simple. To do this, you will only need a few items; you can find and purchase them at your nearest computer store. You also need to know the parameters of your network equipment that needs to be connected. Because the crimp type (straight or cross) is selected depending on whether Auto-MDIX is supported.

Tools and accessories

To manually crimp a twisted pair of eight cores, you must have the following tools:

stationery or mounting knife.

Also, in addition to the tool itself, it is advisable to stock up on several connectors, in case the first attempt is unsuccessful.

Work order

The process itself is not complicated, it is only important to follow the procedure:

The top layer of insulation is cut lengthwise to a length of approximately 3 cm - using a stationery or mounting knife. It is important not to damage individual wiring - this may lead to communication problems;

after this, each of the 8 wires must be carefully moved to the side;

all cores are disassembled in order as they should be crimped in the connector;

The connector has special grooves, and each core should be inserted into them in order.

When all of the above operations are completed, it is necessary to perform crimping. This can be done either using special pliers or using a regular slotted screwdriver.

Cable check

Checking a crimped twisted pair is quite simple using a multimeter set to continuity mode. It is necessary to connect the wires by color using contact probes - they should all ring well. If the sound signal is not heard, you should press the connector contacts - they are not tightly pressed to the copper conductors.

You can also check the connection using a special device. It checks the strength of the transmitted signal - accordingly, this device will make it easy to detect poor-quality pinouts.

Examination

There are also options to check the cable connection. The key is to get both ends. In practice, this does not always work out at home - after all, the provider will not give you his end of the line. Therefore, it’s easier to check on the device - if everything works, then it’s great. No - we are looking for a different reason.

LAN testers are used professionally. This device shows for sure which vein has a signal and which does not:

Additionally, you can use a multimeter, but here you will have to ring each wire separately. But what can you do, because Russian people can do everything)

Thank you all for your attention! If you still have questions, write in the comments. We press, we press and we will press)