Despite the proliferation of optical networks, copper lines remain the main type of cable at distances up to 100 meters. Easy to install and maintain, reliable and very economical. Yes, some manufacturers are trying to change the situation, but we can’t expect serious progress in this area in the next 15 years.
The most common copper cable today is twisted pair - four pairs of copper or copper-aluminum conductors with a diameter of 0.52 mm. There isn't a network engineer who hasn't encountered this cable. Let's look at the main types of twisted pair cables and how to handle them.
Twisted pair categories
Alexander Bell is considered the creator of the twisted pair cable, who proposed a twisted pair wire to protect a telephone line from interference caused by adjacent telegraph wires or power lines. This twisted pair of wires was used successfully for almost 100 years until it was replaced by modern types of copper cable.
Twisted pair. General form
Like any telecommunications equipment, international standards have been developed for copper cables. In this case, ISO/IEC 11801. In addition, there is the EIA/TIA 568 standard, which is valid in the United States and its satellites. These standards have been supplemented several times and today there are 8 categories of twisted pair cables:
- Category 1 (Cat1). The same twisted pair of Alexander Bell wires. Used only in analog telephony.
- Category 2 (Cat2). A two-pair cable designed for Arcnet and TokenRing networks and providing transfer speeds up to 4Mbps. Discontinued in the early 2000s.
- Category 3 (Cat3). The first cable is 4 pairs. Designed for 10Base-T Ethernet networks. Out of production in the 2000s.
- Category 4 (Cat4). 4-pair cable for Token Ring networks, 10/100Base-T. Out of production, but found on older networks.
- Category 5 (Cat5). The first cable capable of transmitting information at speeds up to 100 Mbps. Almost completely supplanted by its successor.
- Category 5e (Cat5e). Improved version of cat5. The most popular category today. The cable is capable of transmitting data at speeds up to 1 Gbit/s. It is found in two versions: two-pair and four-pair.
- Category 6 (Cat6). Introduced in 2002. The throughput of twisted pair is 10Gbps. The first cable capable of operating at 10Gbps, albeit over a short distance. Considered as a possible alternative to cat5e.
- Category 6A (Cat6a). Modification of the Cat6 standard, introduced in 2008. The throughput of twisted pair Cat6a - 10Gbps is maintained at distances of up to 100 meters. The actual analogue of Cat5e for 10GE networks.
- Category 7 (Cat7). Introduced in 2002 along with Cat6. The standard was initially positioned as a more powerful version of Cat6, capable of transmitting 10Gbps over a distance of over 50 m, but with the advent of Cat6A it lost its relevance.
- Category 7A (Cat7a). Deep modernization of Cat7, designed to work with 25GE. The bandwidth of this cable also allows you to transmit a 40GE signal, but only over a distance of 1-15 meters.
- Category 8 (Cat8). The newest standard, introduced in 2016. This four-pair cable is capable of transmitting a 40GE signal over a distance of up to 42 meters. Cat8 is divided into 2 categories: Cat8.1 - standardized to work with RJ-45 connectors and is backward compatible with Cat6A cables.
- Cat8.2 – designed for connectors such as TERA (developed by Siemens Company), GG45 (developed by Nexans), and ARJ-45 (developed by Bei Fuse Ltd). These connectors are proprietary and the prospects for their use are still vague.
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.
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
Cable termination tool
Before doing anything, you need to prepare, or rather prepare the tool. The minimum that is needed is a special crimping tool for terminating and cutting twisted pair cables. It is also called crimping, press tongs or crimper.
Note: I have shown an expensive professional tool as an example. It is heavy, massive and has already compressed about 1000 patch cords, but this is not the limit for it. There are cheaper, lighter and simpler pliers, but they all have the same meaning - to clamp the cable with knives in the RJ45 connector. It’s just that cheap ones are suitable only for one-time operations, but an installer or system administrator needs more reliable flares.
Any crimper has blades for cutting cables and blades for removing braiding from twisted pair cables, so for a person who already has a full hand, one will be enough. But for those who do this occasionally or for the first time in their life, another tool for removing insulation, a stripper, will be of great help.
Sometimes, it may come complete with crimping. If you don’t have one at hand, then a regular stationery or slotted construction knife will do. Just use it very carefully - it cuts your fingers instantly, deeply and very painfully out of habit.
Also, personally, when I terminate a cable, I prefer to cut it with normal wire cutters, rather than with a blade on a crimper. Somehow I immediately got used to it and it’s more convenient for me.
Twisted pair crimping circuits
There are two main crimping schemes:
- Straight. Both ends of the cable are crimped equally. It is used when connecting computers to modems, switches or routers, as well as when connecting switches to routers.
- Cross (crimping twisted pair computer to computer). The first and second pairs of wires are swapped. Used for computer-to-computer connection, as well as for connecting router to router. Today it is practically not used, because devices have already learned to “rearrange” the contacts in the connector programmatically.
Twisted pair pinout for direct crimping and cross crimping
When terminating the cable, it is necessary to use a special tool - crimpers, which are also often called pliers. But if you urgently need to mount one or two connectors, but there is no crimper, you can use a flat-head screwdriver. But be careful. It is very easy to damage the connector or injure your hands.
Checking crimp quality
There are several ways to ensure cables are crimped correctly:
- Connecting devices for which twisted pair cables have been crimped. If the computers start interacting, then you haven't made any mistakes.
- Attach a multimeter to each wire on the connector, setting the level or minimum resistance. If there is no characteristic cracking sound when touched, then it needs to be replaced.
Set the switch to beep - Insert one end into the ethernet connector, and at the other, measure the resistance on each wire. If it is too large, then an error was made during crimping. Also, the resistance of both pairs should be approximately equal.
- When visiting a home, technicians use special LAN testers to assess the condition of communication lines. You can buy the same one and help your friends check it.
The design of LAN testers consists of 2 blocks, to which different connectors are attached. After connection, connect the device to the network and look at the indicator lights. If some of them do not light up, then these wires are not working.
Crimping twisted pair 8 cores (4 pairs): color scheme
Crimping a twisted pair cable into 8 cores occurs as follows:
Remove the sheath, outer shields and armor from the cable. The best thing is to have a tool at hand for cutting the cable sheath - a stripper. But if you don’t have one, a utility knife will do.
Unwind the pairs, straighten the cable cores and place them in the order of the color scheme in the photo
Trim all conductors to a length equal to approximately the width of your thumb from the edge of the cable sheath
Install the twisted pair connector. Make sure that all wires are fully seated and that the cable jacket fits into the connector.
Insert the connector into the socket of the crimping pliers and smoothly squeeze their handles until they stop.
The result of crimping a twisted pair into 4 pairs (8 cores)
Tools
To crimp an Internet cable at home, you need not only wire and connectors, but also a specific tool.
Cable
The stability of signal transmission depends on the correct choice of cable. You need to select a twisted pair cable of category CAT 5E and higher, preferably with four pairs. A wire with a fireproof braid will be more durable and reliable. Flat or round, it doesn't matter.
You need to consider where the wire will be located. If it is not put away in cable channels and is simply stretched around the room, the UTP type is suitable, otherwise you need to consider more expensive types of wire with a common shield or pair protection.
If you need to connect two PCs or a router and a PC with a cable, then a stranded wire is selected, but for ease of crimping it is better to use a single-core wire. For sockets - with one core.
Connector
In addition to the wire, you need to prepare a switching element, also known as a connector or Ethernet plug. Often referred to as RJ-45.
Many connectors have a similar design. Their body is made of transparent plastic for visual control of the crimping process. There is a latch on top that allows you to secure the plug after installation in the port. At the back there is a connector for cable entry, a little higher, on the case there is a fixing bar that ensures a reliable connection.
Inside, the connector consists of eight channels, the diameter of the cores. They go to the end wall of the plug, where there are 8 separate contacts. Initially, they are raised up and do not prevent the cable from entering through the channels until it comes into contact with the end wall. Each has pointed protrusions on the bottom.
When crimping, the contacts move down, pierce the insulation and establish a connection with the conductors. They are recessed flush with the surface of the connector and form contact pads for connecting to the port of a router, PC or other device.
Some connectors have auxiliary inserts that make it easier to correctly insert the cores into their positions under the contacts.
When purchasing connectors, you should also buy a protective cap. It is cheap, but it will protect the LAN cable from being bent, the latch from breaking, and the port and plug from dust.
Crimping tool
The following tool is used to crimp twisted pair cables:
- Crimper. These are crimping pliers. To crimp a connector, place the edge of the wires into them, then install the connector into the socket on the tool and squeeze the handles until they click. You need large pliers (light pliers break quickly), but comfortable and light so that your hand does not get tired. The crimper halves must be even in relation to each other, otherwise the plug will break during the crimping process of the wire.
- Stripper. A tool for cutting cables, stripping insulation, or otherwise working with it. Much more convenient than a simple stationery knife.
- Tester or multimeter for crimp diagnostics.
It is not necessary to use a professional tool for crimping, especially if laying the wire will be done once. But with it it will be easier to complete the task, and the result will be higher.
Crimping twisted pair 4 cores diagram
The arrangement of conductors in the connector for a cable with 4 cores (2 pairs) stands out. In this case, the first 3 cores are placed similarly to the 4-pair circuit, and the last one takes place in the sixth pin (position) of the connector.
Crimping diagram for twisted pair 4 cores
The main problem here is not to make a mistake with the placement of the last wire. One way to avoid this is to insert it after the previous three.
Connecting a twisted pair cable to an outlet
Wiring a cable to a power outlet is a little easier due to the fact that the wiring diagram is printed directly on the contact panel of the outlet. The main thing is not to confuse anything. When installing sockets, it is recommended to use a tool for sealing twisted pair cables, for example, a jointing knife-eskractor. Some modern sockets allow you to do without it - after distributing the conductors, simply close the socket cover and it will fix the connections.
Connecting a twisted pair cable to an outlet using a connector
A special case of connecting to a socket is connecting twisted pair cables through a coupling. Here everything is similar to a socket, only the operation is repeated twice: first for the first cable, and then for the second. Perhaps the easiest way to connect two patch cords is with a special RJ-45 twisted-pair connector made from two sockets placed in one box.
Spacers for installing RJ-45 sockets:
Palladin Tools PT-1913 - UTP/STP stripper with 110 spacing
- Stripping UTP/STP cable categories CAT-5, 5e, 6
- Connecting twisted pair cables to cross-connect 110
- High quality performance
- Easy to use
- Self-regulation of cable stripping depth
Jonard Tools ENI-110 - cable terminations for cross-connect 110
- Purpose: connecting wires to 110 cross
- Two blades: with wire cutter and without cutter
- Handle color: light blue
- Weight: 64 g
Jonard EPD-9Krone - impact tool for cutting cables KRONE
- Includes blade for cross-country knife type KRONE
- Durable impact mechanism
- Two driving force modes Hi and Low: 18.14 kg and 13.6 kg
- Hook for removing the conductor from the cross
- Two-color handle for mode identification
- Blade storage compartment with locking mechanism
- Tool life: 100,000 operations in Hi driving mode (18.14 kg / 178 N)
- Weight without blade: 127 g
Procedure for crimping with pliers
Crimping tool (crimper)
To crimp twisted pairs you will need the following tool:
- crimper (pliers for crimping wire lugs rj 45);
- stripper (cutter for removing insulation);
- stationery knife.
If you do not have such a tool at home, it is better to seek help from specialists.
Cable preparation
First you need to select a cable according to the required number of cores and cut a piece of the required length from it. For a home network, you need to take a four-core wire with copper conductors. Unused conductors are simply not used. For high-speed data transmission, an eight-core cable must be connected.
Removing insulation
The insulating layer must be removed from the ends of the cable section. It is enough to step back 3-3.5 cm from the edge and, using a stripper, make a cut on the insulation with a light circular motion. The cut must be done carefully, without pressing hard, otherwise the shell of the cores will be damaged. This will entail a decrease in data transfer speed. The braid is cut not to its full depth, but to half. Then it is bent and it bursts along the cut line.
If you do not have a stripper at hand, the insulation can be removed using a regular or stationery knife.
Preparing cores for loading into connections
Preparing the cable for loading into the connector
The exposed conductors twisted into pairs after stripping the insulation must be unbraided and straightened. Copper conductors are quite soft, so this operation must be performed carefully so as not to tear their sheath.
Next, all conductors are aligned relative to each other, after which they are cut perpendicularly evenly, 3-4 mm away from the edge. This procedure is best performed with scissors. The result should be a straight end row of 4/8 braided cores.
Next, a plastic connector of 8P format (8 contacts) will be used, with the help of which crimping will be carried out - contact fastening of copper cores.
There are no 4-pin connectors; only 8-pin connectors are used for computer networks.
Pad crimping
Installation and fixation of the connector
The rear part of the 8P connector is an input gateway for introducing copper conductors. This gateway has 8 rectangular cells into which cores of the appropriate color are loaded.
The copper conductors of the network cable are loaded into the connector gateway without removing the insulating layer. The conductors just need to be inserted into the channels until they stop.
Next, you need to crimp the conductors using a crimper for type 8P8C connectors. The pliers block must be placed on the plastic connector, then squeeze the tool handles until a characteristic click is heard.
How to make twisted pair installation easier: secrets from practice
It is worth noting some other subtleties of twisted pair installation:
- To measure 1 meter of cable it is not necessary to look for marks on it. A length of 1 meter is the distance from the fingertips to the opposite shoulder along the chest line of a person of average height.
- The cable sheath must fit into the connector and be crimped. This helps prevent accidental disconnection of the connector. If you remove too much casing, try stretching the rest. Please note that this does not always work in cables with a thick sheath.
- After installing the twisted pair connector, make sure that all wires are inserted into the connector until they stop. Gaps lead to poor contact.
- Use twisted pair testers to monitor the quality of connector installation. Often the simplest models are sufficient. More advanced devices allow you to collect the maximum available information and even draw up a small report.
LAN tester for twisted pair: advanced model from Softing
- If the situation requires connecting cable cores using twisted pair tapes, it is advisable to stock up on a special tool - crimpers for push-button connectors. Unlike pliers, they do not harm the connectors and significantly speed up the installation of adhesive tapes.
- If you are crimping an FTP/STP cable with shielded twisted pair connectors, it is recommended that you first prepare the wires for installation as for a UTP cable, and then cut off more of the sheath and crimp the intact shield.
- Remember that although the cross-section of the twisted pair core is about 0.5 mm, its use as a conductor is allowed only in low-current systems. It is strictly prohibited to use twisted pair cables to power active equipment.
A set of tools for working with twisted pair cables
And one last thing. If you often have to work with twisted copper cable, collect your own set of tools or take a ready-made set of tools for the system administrator. You can take a ready-made one or assemble the components of the kit at your discretion.
Selecting a cable for a local network
The main task when planning structured cabling networks (SCN) is to create an infrastructure that will be used for many years. Therefore, the first thing you need to decide is the purpose of the local network. What devices will connect to it? Where will the cable be laid?
For example, twisted pair cable with 4 cores of category 5e remains an excellent choice for the “last meter” in FTTx networks, where 100 Mbps of throughput is quite enough, and a smaller number of pairs significantly saves the budget. In addition, the average lifespan of such a cable is about 3 years, and putting an ultra-reliable cable there is unprofitable.
Cat5e is still in demand in the world
On the other hand, the local network of a modern business center will be in operation for a long time. Here it is much more promising to use twisted pair cable of category 6.
In general, the main criteria for choosing a twisted pair are as follows:
- Twisted pair category 5e for 2 pairs (4 cores) - low-current systems (alarm, access control), cable networks with a throughput of no more than 100Mbps.
- Category 5e twisted pair for 4 pairs (8 cores) - local networks for home and small offices, video surveillance networks and access control systems. Using Cat 5e for GE networks is undesirable because... These speeds can only be achieved with high quality cables that are comparable in price to Cat6.
- Twisted pair category 6/6A - access level for local networks of an office or administrative building at speeds up to 3-5 Gbit/s.
- Twisted pair category 7/7A - internal networks of data centers and communication centers, aggregation level of corporate local networks with a bandwidth of up to 10GE inclusive. It should be borne in mind that the use of twisted pair cable of category 7 is justified only in small areas of up to 50 meters.
- Category 8 twisted pair cable—internal data center connections at distances from 5 to 15 meters. At shorter distances, it becomes more profitable to use direct-attach cables (SFP modules connected by cable).
Don't forget about the cable design. Unshielded twisted pair UTP is great for connecting workstations or telephone jacks. In a word, places where the presence of external interference is not critical.
In turn, shielded twisted pair FTP is more suitable for connecting office Wi-Fi access points, thin client workstations that require constant connection to the data center and other lines that are sensitive to interference.
Last, but not least, is the price of the issue. The difference between the nearest cable categories can reach 100%. But a lot of cable is required. In addition, modernizing the cable network in most cases means the need for cosmetic repairs to the premises. Yes, the problem is often solved by using cable boxes. But they do not always fit into the interior.
For office Wi-Fi it is better to use Cat6A
Today, the most promising access cable is Cat6. The throughput of twisted pair cables in this category fully covers the needs of an office data transmission network for the next 5-7 years.
If we are talking about access points, then it is better to use a shielded Cat6A/7 cable. Wi-Fi speeds are growing by leaps and bounds, and in recent years there has been a trend towards creating wireless office networks. And here the requirements for throughput become more stringent.
Wire selection
When choosing twisted pair cable for your home network or Internet connection, it is recommended to use CAT5E cable. CAT6 and CAT7 are suitable, but you don't need to pay for them unless you really need them.
When planning a local network, it is recommended to immediately lay a cable with four pairs of cores. Two pairs are enough for speeds up to 100 Mbit/s, but if the speed is increased in the future, you will need to re-stretch the wire.
A single-core cable is suitable for Internet outlets; a multi-core cable is suitable for connecting PCs, routers and PCs.
If the cable is located away from the electrical wire, then the UTP type is suitable. Otherwise, you need to look at types of twisted pair cables with a shield that protects against external interference.
What kind of twisted pair will there be tomorrow?
Despite serious competition from optical cable, twisted pair continues to firmly hold the “last meter” segment. An important role here is played by the price and dimensions of optical transceivers, which do not allow their use in personal computers and laptops.
Indeed, in many cases, optical cables turn out to be more promising than copper cables, due to greater reliability and a huge margin for modernization. The same pair of fibers can transmit both 1GE and 40GE. At the same time, the optical cable is absolutely not subject to electromagnetic interference and is more resistant to bad weather and humid environments. Yes, installing a fiber optic cable is much more complicated than copper lines, but if the distance between network nodes exceeds 70 meters, take optics - you won’t go wrong.
However, the twisted pair market will continue to grow in the coming years. As ResearchAndMarkets experts expect, [12] by 2023, more than 90% of the data cable market will be UTP copper twisted pair. Cat5e cable is already losing ground to more modern Cat6/6A cables, and Cat7 cable will expand its market presence, filling the niche currently occupied by Cat6A.
As for exotics like twisted pair with 6 pairs of conductors, it is rapidly becoming a thing of the past, not least thanks to the spread of IP telephony. IP devices have already caught up in price with their analog counterparts, so today it is easier and cheaper to transfer both data and telephony over a single UTP than to use combined solutions.
In fact, the main competitor of twisted pair in its “last meter” niche is not optical, but wireless lines. The introduction of the Wi-Fi 6 standard can seriously change the balance of power in this area, and how events will develop will become clear very soon, after 2022.
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.
