twisted pair is a type of copper cable that is used in telephone communication and on most Ethernet networks. A pair of wires forms a circuit through which data can be transferred. The wires of a pair are intertwined to protect against crosstalk, which is noise generated by adjacent pairs of cable wires. Pairs of copper wires are encased in colored plastic insulation and woven together. Bundles of twisted pairs are protected by an outer braid.

When electricity flows through a copper wire, a magnetic field is created around the wire. The circuit consists of two wires, each of which has a magnetic field of opposite charge. If two circuit wires are close to each other, magnetic fields suppress each other. This is called the mutual compensation effect. Without it, network communications would be slow due to interference caused by magnetic fields.

There are two main types of twisted pair cables:

Unshielded twisted pair (UTP) is a cable consisting of two or four pairs of wires. This type of cable functions solely due to the mutual compensation effect created by the pairs twisted wires, which limits signal distortion resulting from electromagnetic and radio interference. NVP is most often used as cable wiring in networks. NVP cables have a range of 100 m (328 ft).

Shielded twisted pair (ESP) - each pair of wires is braided with metal foil to better shield the wires from noise. In addition, four pairs of wires are wrapped in metal braid or foil. EVP reduces electrical noise from inside the cable. In addition, it reduces electromagnetic and radio interference from outside the cable.

Despite the fact that EVP reduces interference better than NVP, it is more expensive due to additional shielding and more difficult to install due to its greater thickness.

In addition, the metal shield must be grounded at both ends. If not properly grounded, the shield acts like an antenna, picking up unwanted signals.

EVPs are used primarily outside of North America.

number of wires in the cable,

number of turns in these wires.

Category 5 and 5e cables consist of four pairs of wires with a data transfer rate of 100 Mbps. Category 5e wires have more turns per foot than Category 5 wires. These extra turns prevent interference from external sources and other wires within the cable.

Category 5 and Category 5e cables look the same, but Category 5e cable is manufactured to more high standards in order to provide higher data transfer rates. 6e cable is built to even higher standards than Category 5e. A Category 6e cable may even have a central separator that separates the pairs within the cable.

The most common cable used on a network is Category 5e cable. It fits standard Fast Ethernet, and its length is up to 100 m. In some offices and homes, 6e cable is installed so that in the future it is possible to increase the bandwidth without problems. Some applications, such as video, video conferencing, and games, require a lot of bandwidth.

The latest type of twisted pair cable is Category 6A cable. It can transmit Ethernet signals at a speed of 10 Gbit/s. The abbreviation for 10 Gigabit Ethernet over twisted pair cable is the 10GBase-T specification, which is described in the IEEE 802.3an-2006 standard. Customers who require large networks throughput, can benefit from installing a cable that supports the Gigabit Ethernet or 10 Gb Ethernet standard.

Twisted pair cables

Depending on the presence of protection - an electrically grounded copper braid or aluminum foil around the twisted pairs, the types of this technology are determined: unprotected twisted pair

(UTP - Unshielded twisted pair) - absent protective screen around a single pair;

foiled twisted pair (FTP - Foiled twisted pair) - also known as F/UTP (see: Screened Shielded Twisted Pair (S/STP)), there is one common external screen in the form of foil;

protected twisted pair (STP - Shielded twisted pair) - there is protection in the form of a screen for each pair and a common external screen in the form of a mesh;

foil shielded twisted pair (S/FTP - Screened Foiled twisted pair) - an external screen made of copper braid and each pair in a foil braid;

unprotected shielded twisted pair (SF/UTP - Screened Foiled Unshielded twisted pair) - double external shield made of copper braid and foil, each twisted pair without protection.

Shielding provides better protection from electromagnetic interference, both external and internal, etc. The entire length of the screen is connected to a non-insulated drain wire, which unites the screen in case of division into sections due to excessive bending or stretching of the cable. Depending on the structure of the conductors, the cable is used single-core or multi-core. In the first case, each wire consists of one copper core, and in the second - of several. A single-core cable does not require direct contact with connected peripherals. That is, as a rule, it is used for installation in boxes, walls, etc., followed by termination with sockets. This is due to the fact that copper strands are quite thick and with frequent bending they quickly break. However, for “cutting” into the connectors of socket panels, such conductors are ideally suited. In turn multi-core cable does not tolerate “cutting” into the connectors of socket panels (thin wires are cut), but behaves well when bent and twisted. In addition, stranded wire has greater signal attenuation. Therefore, multicore cable is mainly used for making patch cords.(English patchcord), connecting the periphery with sockets.

Standards for color placement

There are two most common standards for arranging colors in pairs:

On the RJ45 connector (correct 8P8C) the colors of the conductors are arranged as follows:

How to properly crimp a twisted pair cable?

The UTP cable is crimped in accordance with established color marking standards 568A and 568B. The connector is an RJ-45 connector with 8 pins.

Only 4 of them are actually used: 1 and 2 - transmitting (Tx) and 3 and 6 - receiving (Rx).

In practice, there were cases when some devices with POE power supply refused to work with twisted pair cable crimped according to the EIA/TIA -568A standard. Since most manufacturers focus on EIA/TIA -568B standard, we recommend using it.

MDI, MDIX, Auto-MDIX

Medium Dependent Interface (English interface depending on the transmission medium) or MDI - Ethernet port subscriber device(for example, PC network cards). Allows devices such as network hubs or switches connect to other hubs without using a crossover cable or null modem. MDI differs slightly in pin connections from its variation MDIX. Pins 1 and 2 are used for transmitting (Tx) information (signals), 3 and 6 are used for receiving (Rx).

To connect one hub with an MDI port to the MDIX port of a computer or other hub, use a regular cable. However, to connect an MDI port to the MDI port of another device, you need a crossover cable (the same as to connect two MDIX ports).

Some network equipment manufacturers (Planet, Danpex, Level One, Zelax, etc.) use the designation MPR and DTE, which corresponds to MDI and MDI-X

And what can arbitrary crimping lead to?

In principle, a twisted pair can be crimped arbitrarily, as long as the contacts on both sides match. However, this is not recommended. According to the standard, the wires in the cable are crimped in such a way that the transmitting and receiving wires are twisted together (orange with orange stripes and green with green stripes) to protect against interference. At a distance of 5-6 meters the difference will not be felt, but at a greater distance, a cable not crimped to the standard will be unusable. When finishing, the main thing is that the pairs are arranged in order:

Contacts 1 and 2 are the second pair. 3 and 6 contacts - third pair 4 and 5 contacts - first pair 7 and 8 contacts - fourth pair

The accepted color sequence is:

Blue - first pair Orange - 2 Green - 3 Brown - 4

Although changing colors will change absolutely nothing.

If you under-crimp or crimp incorrectly (the wires are not from the right pairs), then the data transfer speed drops noticeably. When using a hub, performance drops across the entire network when accessing a given station. The hub is a broadcast repeater - any call is heard by all network stations connected to the hub. Accordingly, re-sent packets that do not reach their destination intact load traffic.

Crossover cable

Crossover cable- intended for connecting equipment of the same type (for example, computer-to-computer). However, most modern network devices is able to automatically detect the cable crimping method and adapt to it ( Auto MDI/MDI-X), and the crossover cable has lost its relevance today.

Fiber optic cable

Fiber optic cable (Optic fiber) is a glass or plastic conductor that transmits information using light waves. A fiber optic cable consists of one or more optical fibers enclosed in a braid or jacket. Due to the fact that the fiber optic cable is made of glass, it is not subject to electromagnetic or radio interference. At the input to the cable, all signals are converted into light pulses, and at the output they are converted back into electrical signals. This means that the signals transmitted over fiber optic cable are clearer, can travel longer distances, and have greater capacity than cable made from copper or other metals.

A fiber optic cable can be several kilometers long before the signal needs to be regenerated. Fiber optic cable is usually more expensive to use compared to copper cable, and the connectors are also more expensive and more complex to assemble. Most common for fiber optic networks are connectors SC, ST and LC. These three types of fiber optic connectors are half duplex, which allows data to move in only one direction. Therefore, two cables are required.

There are two types of fiber optic cables:

Multimode is a cable whose core is thicker than single-mode. It is easier to make and can be used for more simple sources light (LEDs), and it works well at distances of no more than a few kilometers. Multimode fiber has a larger diameter - 50 or 62.5 microns. This type of optical fiber is most often used in computer networks. The higher attenuation in multimode fiber is due to the higher dispersion of light in it, due to which its throughput is significantly lower - theoretically it is 2.5 Gbps.

Single-mode - a cable with a very thin core. It is harder to manufacture, uses lasers as a light source, and the signal can easily be transmitted over distances of tens of kilometers. Single-mode fiber is very thin, its diameter is about 10 microns. Thanks to this, the light pulse passing through the fiber is less often reflected from its inner surface, which ensures less attenuation. Accordingly, single-mode fiber provides longer range without the use of repeaters. The theoretical throughput of single-mode fiber is 10 Gbps. Its main disadvantages are high cost and high installation complexity. Single-mode fiber is mainly used in telephony.

Installing connectors on a fiber optic cable is a very responsible operation that requires experience and special training, so you should not do this at home without being a specialist. If you really want to build a network using fiber optics, it is easier to purchase cables with connectors. However, given the cost of the cable, connectors, as well as active equipment for optics, it can be assumed that this equipment will not be used in home and small LANs for a long time.

Since our site is about Wi-Fi routers, and other network equipment, then I just had to prepare an article about twisted pair - the cable that connects network equipment to each other. With the help of which computers and other devices are connected to routers and modems. Also, with a cable called twisted pair, most likely you have an Internet connection from the provider’s equipment to your router, or directly to your computer. Also, almost all router manufacturers include it with their devices network cable short length. It is needed to connect to the router different devices (PC, laptop, TV, game console etc.).

IN modern world The development of data transmission technologies is occurring at a truly rapid pace. It is quite possible to say “at the speed of light”, because no one will be surprised by the transmission of information flows using optical fiber. But with all the positive functional characteristics of such communication cables, they have several serious drawbacks. The key ones are high cost and fragility.

At the moment, you have to try very hard to find a person who has absolutely no idea what the Internet is or has never used it. U huge amount people are at home personal computer with access to the World Wide Web. But in order to “connect” the Internet to your home PC, you need to use a convenient, reliable, and most importantly strong cable. This is where a cable has come to the rescue for many years, given an incomprehensible, at first glance, name - twisted pair.

What is twisted pair?

Twisted pair is a special type of network cable. It is based on one or more pairs of insulated and twisted conductors. (the cable category depends on their number). The number of turns per certain unit of length is minimal, but sufficient to significantly reduce mutual guidance during signal transmission. The top of the twisted pair is usually covered with a protective plastic sheath.

IN lately this type of communication cable has become the most common when creating local and structured cabling networks. This happened due to its low cost and ease of installation.

The main disadvantage of twisted pair cables is significant signal attenuation (to the level of unrecognizability) at distances over 100 meters. But this drawback is easily eliminated with the help of repeaters.

Species

Depending on whether there is protection or not, as well as its quality, there are several types of cables created using this technology:

• unshielded twisted pair (UTP) – no additional protective devices are used;
• shielded twisted pair (STP) – copper mesh is used;
• foil twisted pair (FTP) - aluminum foil is used;
• Shielded Foil Twisted Pair (SFTP) - uses copper mesh and aluminum foil.

However, some types of shielded cable may use protection around each pair. This type of shielding provides significantly better protection against various types of guidance, both internal and external.

Twisted pair cable categories

In total, there are currently about 15 categories of twisted pair cables. They are numbered from CAT 1 to CAT 8.2. In most cases, the category has a direct dependence on the number of pairs used to transmit information, as well as on the number of turns that are used per unit length. Cable categories are clearly described in American standard wiring in commercial buildings.

Let's briefly describe each of the categories:

• CAT 1 is a well-known telephone cable. It uses only one pair. Applicable exclusively for voice transmission and creating connections using a modem.
• CAT 2 is an outdated type of cable, consisting of 2 pairs of conductors. It supported data transfer at speeds less than 4 Mbit/s. It was often used in token ring networks. Now rarely used in some telephone networks.
• CAT 3 is an improved version of the previous 2-pair cable. Designed to provide data transmission at speeds up to 10 Mbit/s. Now it continues to be found very often in telephone networks.
• CAT 4 is another type of cable that is not used today. Consists of 4 pairs, has a transmission speed of up to 16 Mbit/sec.
• CAT 5 – it is the cables of this category that are most often called “twisted pair” in its classical sense. Consists of 4 pairs. The transfer speed varies from 100 Mbit/s (2 pairs are used) to 1000 Mbit/s (4 pairs are used).
• CAT 5e is an improved version of the usual 5th category. Also consists of 4 pairs. The cable has the same speed characteristics as the twisted pair cable of the previous category. Now this category is the most common.
• SAT 6 – 4 pairs are used for transmission, which allows you to increase the transmission speed to 10,000 Mbit/s.
• SAT 6a - 4 pairs are used for transmission, which allows you to increase the transmission speed to 10 Gbit/sec.
• SAT 7 - 4 pairs are used for transmission, which allows you to increase the transmission speed to 10 Gbit/sec. The cable of this category must be shielded.
• CAT 8 is currently in development. Presumably will allow you to transmit information flow with speeds up to 40 Gbit/sec. Must have shared screen or a screen for each pair.

Methods and schemes for crimping twisted pair cables

Obviously, to connect the cable to various computer technology or to switches and routers, the twisted pair cable must be terminated in convenient and standardized connectors. This type of communication cable uses an RJ-45 connector (the correct name is 8Р8С, but we will use the usual one).

In order for a network built on twisted pair to work correctly, it is necessary to connect the contacts in the RJ-45 connectors in the appropriate order. This must be done from both one and the other end of the cable. For ease of crimping, all wires are marked with standardized colors. Naturally, if you have sufficient knowledge, you can crimp the cable at your own discretion, but in order to avoid confusion when connecting networks, it is better to use standard crimping schemes. There are only two of them: direct crimping order and cross crimping order (crossed).

1. The first crimping scheme (direct) is used when connecting different types of equipment, for example, a laptop network card and a switch.
2. The second crimping scheme (crossover, or cross) is used when connecting equipment of the same type, for example, two laptops (sometimes to connect a computer to some older types of switches and hubs).

To crimp the cable, use a special device - a crimper (pliers). I wrote about this in the article: .

And now directly about the crimping procedure. Let's consider crimping circuits for twisted pair cables of category 5, as the most common at the moment.

Straight Cable Crimping Diagram

This cable is the most common. It is suitable for connecting computers, laptops, TVs, etc., to routers and other network devices.

• First option (type T586A): one side has the following order of contacts (from 1 to 8) - white-green, green, white-orange, blue, white-blue, orange, white-brown, brown. The other side has the same contact order. It is best to use this option.
• Second option (type T568B). One side has the following order of contacts (from 1 to 8) - white-orange, orange, white-green, blue, white-blue, green, white-brown, brown. The other side has the same contact order.

Crossover cable: crimp pattern

• One side has the following order of contacts (from 1 to 8) - white-green, green, white-orange, blue, white-blue, orange, white-brown, brown.
• The other side has the following pin order (from 1 to 8) - white-orange, orange, white-green, blue, white-blue, green, white-brown, brown.

For the manufacture of gigabit crossover cable (supports speeds up to 1 Gbps), you need to use a slightly different scheme:

• One end of the cable: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown.
• Other end of the cable: white-green, green, white-orange, white-brown, brown, orange, blue, white-blue.

The development of data transmission technologies does not stand still. It is theoretically possible that twisted pair cable will soon become an obsolete type of cable, but at the moment it is the most used, reliable and cheap look network cable.

Despite the intensive development wireless technologies, cable data lines still remain the most reliable, noise-resistant, and relatively inexpensive solution for organizing scalable computer networks with access control. Choosing a twisted pair when designing and installing such networks is one of the main tasks. Despite the apparent simplicity of wired technologies, the difficulties that arise when choosing a twisted pair can confuse many, since they can save money and at the same time ensure the operability of the network long time it will be quite difficult to guarantee a stable connection of its active components. Moreover, the intensive development of data transmission technologies leads to the fact that equipment operating at a speed of 100 Mbits is gradually being replaced by equipment of 1000 Mbits; accordingly, when designing an SCS it is necessary to include a certain safety margin, because increased speed requires increased attention to line quality. Therefore, when choosing a twisted pair, you need to consider the following factors:

1. Budget allocated for network laying (selection of optimal parameters)
2. Cable laying conditions(resistance to natural conditions, rodents, corrosion, electromagnetic radiation)
3. Line length(longer distance means higher requirements for cable quality and laying conditions)
4. Data transfer rate. For a painless transition to a speed of 1 Gbits in the near future, it is worth paying more attention to the quality of lines, and buy twisted pair with some “margin of safety”.

The twisted pair parameters that must be taken into account when designing SCS are as follows:

• Category. According to telecommunications cabling standards EIA/TIA 568 and ISO 11801, there are ten of them: categories 1-4 do not meet modern requirements and are not currently used, and categories 7 and 7a are inferior in practicality to optical cable. Therefore, we will talk about categories 5, 5e, 6, 6a.
• Core material. Copper, or copper-plated aluminum. Plus, you should pay attention to copper plating technology: CCA, CCAA, CCAG, or CCAH
• Outer shell type: for external or internal installation
• Shielding type: for installation near strong sources electromagnetic radiation
• Availability of cable or armor for air laying, or laying in a room infested with rodents

The main difference between the categories of twisted pair cables is the frequency of the transmitted signal, which, in turn, determines the quality and speed of data transfer. Categories 5 and 5e operate in the frequency band up to 100 MHz. Using category 5e cable, the data transfer speed can be up to 1 Gbit/s, so cable of this category is currently the most common for laying computer networks.

Categories 6 and 6a apply to signals with frequencies of 250 and 500 MHz, respectively. This signal allows you to organize data transmission at speeds of up to 10 Gbit/s over distances of up to 50 meters. In the future, it is planned to use it to transmit data at speeds of up to 40 Gbit/s. However, such speed parameters are highly specialized, and the use of category six cable for laying networks can hardly be called an economically optimal option.

Twisted pair core material

The twisted pair wires can be copper or copper-plated. The difference, as usual, is in price and quality. The conductivity of copper is higher, but cables with copper cores are also more expensive. Copper plating of cores is carried out with the skin effect in mind. Its essence is that when high frequencies transmitted signal, most of the current flows through the surface layer of the conductor. However, despite the fact that copper-clad cable has many opponents, few people take into account that copper plating is different from copper plating, and Hortex clad aluminum cable can be a good alternative to copper cable. High-quality cladding allows you to achieve performance close to the parameters of a copper conductor. It's all about production technology and the percentage of copper in the cable conductor. While most twisted pair manufacturers use CCA (copper clad aluminum) technology, cable manufacturer Hortex uses CCAG (Copper Clad Aluminum and Argentum Powder) technology. This technology makes it possible to achieve higher quality copper plating of aluminum compared to CCA, which significantly increases the conductivity of the twisted pair. But the price of such a cable, compared to copper analogues, differs in a pleasant direction.

Shielded twisted pair

When running twisted pair cables near power lines, powerful sources electromagnetic radiation, or equipment that creates strong electromagnetic interference, such factors as the quality of insulation and cable shielding take on additional importance. As a rule, to prevent interference and signal loss, the network cable is laid no closer than 15 cm from household electrical wiring, but for each specific case the distance is determined separately.

When laying cables outdoors, or near strong EMR sources, it is recommended to use a shielded cable. The shielded cable is marked as follows:

• FTP - common foil shield for all pairs in the cable
• STP - each pair is shielded, and the overall shield can be made in the form of a metal mesh
• S/FTP - each pair is shielded with foil, plus there is a copper braid for the entire cable.
• SF/UTP - this type uses double braiding of the entire cable (without separate shielding of pairs) of foil and copper braid.

Features of internal and external gaskets. Differences in insulation materials.

Having dealt with the various characteristics of twisted pair, it’s time to deal with the most important question - what, where, and how to lay it. Which cable to choose for laying a local network.

First of all, you should take into account the temperature regime. Initially, all conscientious manufacturers of twisted pair cables (such as, for example, Larex, Sofetec, and Hortex) use materials for the outer sheath that can withstand significant temperature changes. The most popular material is PVC. In almost all respects, including fire safety, it is suitable for indoor use, but is not suitable for outdoor use. This is explained by the fact that PVC, reinforced with plasticizers and various chemical additives, tolerates temperature changes, bending and stretching, but is a moisture-permeable and UV-unresistant material. For external laying, light-stabilized polyethylene is mainly used. This material is resistant to temperature changes, moisture-resistant, and light stabilization makes it resistant to ultraviolet radiation. The double sheath of the cables, Sofetec, and Hortex, provides increased strength and resistance to external factors.

For air laying, pay attention to the presence of an additional supporting element (cable or wire). It will take on all the loads and will not allow the cable to break.

When laying a home or small office network, you need to consider the following requirements:

• Twisted pair must be laid at a distance of at least 15 cm from household electrical wiring, while it is necessary to minimize the number and length of sections with parallel arrangement of power and information lines. For floor and interfloor trunk lines with a high concentration of information cables, the ideal option would be to lay power cables and twisted pair cables along opposite walls. Only in this case can we give a maximum, but not 100% guarantee that UTP cable will be completely protected from external EMR.
• The intersection of power supply wires and twisted pair wires must be strictly perpendicular.
• If the above requirements cannot be met for any reason, shielded cable must be used to reduce exposure. In this case, the cable must be grounded on both sides, otherwise, instead of protecting the twisted pair cores from EMI, the screen will become an antenna for interference.

How to choose a quality twisted pair cable

Everything is clear with the parameters and conditions of the external environment. How to choose and buy twisted pair , which is suitable for specific laying conditions, and that at the same time it will required quality? The easiest option is to take with you someone who knows what's what. Otherwise, you will have to rely on your own knowledge.

• First of all, make sure that you have a certified cable. Although it is somewhat more expensive than its homemade counterparts, it will last many times longer. And at the same time, you will be sure that you will get exactly what you pay for, because nameless manufacturers save on everything, violating the standards of conductor thickness and insulation, requirements for the quality of components, etc.
• Pay attention to the material of the cores. There are two ways to distinguish copper from clad cable:

1. Heat the end of the wire in the flame of a lighter. On copper wire a droplet is formed, but at the same time, the vein itself is not deformed. Copper-plated aluminum bends where it is heated, and can break off if it gets too hot.
2. Scrape off the top layer of the vein. The white shine of the metal will mean that this is copper plating. Type of copper plating (CCA or CCAG, unfortunately, cannot be determined in the field)

• Evaluate the cable visually and by touch. The insulation must be homogeneous, smooth, without any roughness or compaction, with a uniform color.
• Check the wire thickness. For this you will need a micrometer. The thickness of the cable cores is indicated in the cable marking as AWG XX. AWG (from English. American Wire Gauge) - American system marking the thickness of the wires, and the value XX will determine the thickness of the core. An AWG24 cable has a conductor thickness of 0.511mm, and an AWG25 cable has a conductor thickness of 0.455mm.

The result of choosing a low-quality or non-standard cable is only one: signal loss, and, as a result, unstable work networks. If the wires are thinner than standard ones, then the contact in the module (network connector) may be completely absent. Poor quality insulation can crack and/or crumble, and if the cable is laid outside the building, then water will get under the insulation, which sooner or later may end up in network equipment. If the cable is laid indoors, the destruction of the insulation will make the cable more vulnerable to mechanical damage. Poor-quality copper plating reduces the conductive properties of the conductors.

In order to be sure of the quality of the cable, we recommend paying attention to the brands Larex, Sofetec And Hortex. The core strictly complies with the thickness standard, double shell, high-quality cladding: all this distinguishes these brands from the products of other manufacturers. Despite the fact that Larex and Sofetec are clad using CCA technology, and the parameters of this cable are slightly lower compared to copper, if the standards and requirements for cable laying are met, the properties of the cable of these brands will provide a sufficient margin of strength and reliability of the SCS. The Hortex cable, clad using CCAG technology with a high percentage of copper, in turn, is closest in its electrical parameters to copper cables and has a core resistance of ≈140 Ohm/km. Also, cables of the Larex, Sofetec and Hortex brands have all the necessary certificates for compliance with quality standards and fire safety.

Features and specifics of cable selection for solving various problems

The main requirements set by the SCS designer boil down to: stable work network, minimizing losses, and maximizing network service line. The tasks, the solution of which requires the fulfillment of the above requirements, are different. For the most typical projects of small office or home networks, subject to the installation rules, it will be sufficient buy twisted pair UTP cable both when laying to the router, and from the router to the computer. For larger ones office networks It is also preferable to use UTP, since when using a shielded cable, additional difficulties arise with grounding the shield: according to ANSI/TIA/EIA-568-A and international standard ISO/IEC 11801 the shield must be grounded at both ends to the telecommunications grounding system bus. It is precisely due to the difficulties of grounding that FTP is recommended to be used when laying inter-server, intra-cluster lines within the general circuit of the information “ground”, or within different circuits, but with all the requirements for the grounding circuits of information circuits being met.

Twisted pair cable is also used to create video surveillance systems. It carries the video signal and it is recommended to use a shielded cable, especially if the video equipment is powered remotely.

Regardless of the types of tasks and requirements placed on the cable, first of all, it must comply with standards and have quality certificates, which guarantees its performance in any segments of structured networks and network protocols. Therefore, if your budget does not allow the use of copper cable, you should not use products from nameless manufacturers. Despite the fact that the cost of such a cable is significantly lower, the savings will be questionable if the cable has to be completely replaced after a year. Cables from Larex, Sofetec and Hortex brands allow you to optimize your installation budget cable lines, and guarantee high quality products, which allows the cable to be used to solve a wide range of problems.

All cables Ethernet local networks perform the same basic task - connecting devices to networks such as the Internet. However, not all cables are created equal. If you've ever needed a local cable Ethernet networks and you had no idea which one you should choose - you're not alone. Ethernet symbols, like many things in the modern technology world, are difficult to interpret and understand. Fortunately, you have contacted right place. Below is a description to find out which cable is suitable for your situation.

What does "CAT" mean?

If you've ever shopped for network cables online, you've probably noticed that they are almost always classified as "Cat 5", "Cat 6e" or similar. "CAT" simply stands for "Category" and the subsequent number indicates technical specifications, for which the cable was manufactured. General rule is that what more number, the higher speeds and higher frequencies (measured in MHz) they represent. As with most technologies, newer cables tend to support higher bandwidth and therefore increase download speeds and speed up connections.

Keep in mind that more long cables Ethernet will reduce data transfer speeds, although cables purchased for personal use rarely exceed the 100 meter mark, after which the speed usually begins to drop.

In 2016 The Institute of Electrical and Electronics Engineers (IEEE) released new standard Ethernet, which promises to significantly improve data transfer speeds over Cat 5 and Cat 6 cables. Unfortunately, it may be several years before the standard becomes available for ordinary users, unlike corporate users. Below are the characteristics of each cable type.

	Shielding	Maximum data transfer speed (up to 100m)	Maximum throughput frequency range
Cat 3	Unshielded (UTP)	10 Mbit/s	16 MHz
Cat 5	Unshielded (UTP)	10/100 Mbit/s	100 MHz
Cat 5e	Unshielded (UTP)	1 Gbit/s	100 MHz
Cat 6	Shielded (STP) Unshielded (UTP)	1 Gbit/s	250 MHz
Cat 6a	Shielded (STP)	10 Gbit/s	500 MHz
Cat 7	Shielded (SSTP)	10 Gbit/s	600 MHz
Cat 7a	Shielded (SSTP)	10 Gbit/s	1000 MHz

Cat 3 and Cat 5

Currently, Cat 3 and Cat 5 Ethernet cables are obsolete. Cat 5 cables aren't that hard to find, but don't even think about buying any of these LAN cables. They are slow and no one makes them anymore.

Cat 5e

“E” in Cat 5e stands for “Enhanced.” Physical differences There are no cables between Cat 5 and Cat 5e, but Ethernet 5e is built to more stringent testing standards to eliminate crosstalk, i.e. unwanted transmission of signals between communication channels. Currently, Cat 5e is the most common type of Ethernet, precisely due to its low production cost and ability to support higher speeds than original Cat 5 cables.

Cat 6

Cat 6 cables support much higher bandwidth than Cat 5 and Cat 5e cables, although they are also more expensive. The twisted pair in Cat 6 cables is more tightly wound than its predecessor cables and is always made with foil or braided shields. This shielding protects twisted pairs inside the Ethernet cable, helping to prevent electromagnetic interference and noise. Cat-6 cables can technically support speeds up to 10 Gbps, but only up to 55 meters.

Cat 6a

The "A" in Cat 6a stands for "augmented". Compared to regular Cat 6 cables, 6a cables support twice the maximum bandwidth and can support higher transmission speeds as cable length increases. Cat 6a cables are always shielded and their jacket is thick enough to completely eliminate crosstalk. This makes the cable much denser and less flexible than Cat 6.

Cat 7

Cat 7 cables use the latest widely available Ethernet technology and support higher throughput and significantly more high speed transmission than Cat 6 cables. They are correspondingly more expensive than other Ethernet cables, although their performance matches their premium price. Cat 7 cables are capable of reaching up to 100 Gbps over a distance of 15 meters, making them great for connecting modems or routers directly to your devices. Cat 7 cables are also always shielded and use a modified GG45 connector (GigaGate45), which is backward compatible with regular Ethernet ports (RJ45).

Cat 8

Cat 8 cables are still in development. However, we can believe that they will appear on the market relatively soon, with higher maximum speeds and higher maximum bandwidth than Cat 7 cables.

How to choose such cables?

The easiest way to choose a cable is to choose the one that suits you. But what do you need?

Start with the speed of your home Internet connection. If you have Gigabit internet, old Ethernet cable will slow you down. But if you have a slow connection, say 10 or 20 megabits per second, Cat5 or newer cables will do the trick.

Next, consider the speed required for your network. This is simply not relevant for most home users. But if you often transfer large files between computers or you transfer video high definition, a better Ethernet cable can make a difference.

Finally, let's look at your router. Since cheap routers only support speeds up to 100 megabits per second, they will prevent data transfers higher than Cat 5. Even the best home routers rarely support more than Gigabit Ethernet, so the use of Cat 6a and Cat 7 is questionable.

All things considered, a Cat 6 cable is all you'll need; most home networks can easily use Cat 5e.

EthernetDictionary.

The differences between the different types of Ethernet cables are actually quite simple, but it's easy to get confused with the nomenclature. To help with this, we've put together short list the meanings of the different terms and what you should consider when purchasing a cable with these symbols.

AWG: . (Detailed Description via link)

TP: twisted pairs. This name means that the wires inside the cable are twisted together. Twisted Pair has been the industry standard for many years and is second only to fiber optic cables V maximum length and reducing speed.

UTP: Unshielded twisted pairs. Cables designated as UTP do not have shielding foil or braided shielding, making the cable cheaper to manufacture and more flexible. But you'll be sacrificing signal quality and increasing your vulnerability to crosstalk.

STP: shielded twisted pairs. Cables designated STP or SSTP are protected by braided shielding, which is usually made of copper or other conductive polymer. Shielding reduces interference and therefore improves communication quality.

FTP: foil twisted pairs. Cables marked FTP or SFTP are protected with shielding foil, which helps reduce interference and improve call quality.

Vention, especially for you!

The definition of a twisted pair cable category is based on the maximum transmittable frequency range. This is due to the number of turns per unit length of cable. That is, the higher the category, the greater the transmitted frequency range due to the increase in the turns of each twisted pair. Categories of twisted pair cables are described in international and domestic standards.

The categories (abbreviated CAT) of twisted pair cables determine the design data transfer rate. In addition, LAN cable is also divided into classes and they are also taken into account when building a structured cabling system. It should be remembered that higher-class twisted pair cables support lower-class technical capabilities. But twisted pair cables of a lower class do not support high-end technical applications. The higher the class the better transmission characteristics and higher than the maximum operating frequency of the cable line.

CAT1(frequency band - 0.1 MHz). It has one pair and is used to transmit voice and digital data using a modem. This is a standard telephone cable, which at one time was used in a “twisted” form in the USA, and in Russia it is still used without twists. Not suitable for modern systems and has a large interference effect.

CAT2(frequency band - 1 MHz). It has two pairs of conductors and has already outlived its usefulness. Sometimes used when building telephone networks. Previously seen in the Arcnet and Token Ring networks. Has data transfer speeds up to 4 Mbit/s. Not suitable for building modern networks.

CAT3 (frequency band - 16 MHz. Class "C"). There are 2-pair and 4-pair types of twisted pair. It is used not only to create telephone networks, but also local networks based on 10BASE-T. Supports data transfer rates from 10 to 100 Mbit/s using 100BASE-T4 technology over a length of no more than 100 meters. Unlike CAT1 and CAT2, it supports the IEEE 802.3 standard.

CAT4(frequency band - 20 MHz). At one time, this 4-pair cable was used in 10BASE-T and 100BASE-T4 technology. Data transfer rates up to 16 Mbit/s are possible. Not used these days.

CAT5 (frequency band - 100 MHz. Class "D"). The cable was used to create telephone lines and construction of local networks 100BASE-TX, as well as Ethernet (LAN). Supports data transfer rates up to 100 Mbps.

CAT5e(frequency band 125 MHz). This is an advanced category 5 twisted pair cable. When using 2 pairs, it supports data transfer rates of up to 100 Mbit/s and up to 1000 Mbit/s in a 4-pair cable. As a rule, a 4-pair cable is used to build a local computer network. This is the most common type of twisted pair cable.

CAT6 (frequency band 250 MHz. Class "E"). This is a common cable type used in Fast Ethernet and Gigabit Ethernet networks. The cable structure has four pairs of conductors. Supports high data transfer rates up to 10 Gbit/s over a distance of no more than 55 meters.

CAT6a(frequency band 500 MHz. Class "E A"). The cable structure consists of four pairs of conductors. It is used in Gigabit Ethernet networks and supports speeds of up to 10 Gbps over a distance of up to 100 meters.

CAT7(frequency band 600 - 700 MHz. Class "F"). Supports data transfer rates up to 10 Gbps. The cable structure has a common outer shield and foil protection for each pair. The type is S/FTP (ScreenedFullyShieldedTwistedPair).

CAT7a(frequency band 1000 -1200 MHz. Class "F A"). Twisted pair speeds reach up to 40 Gbit/s over a distance of up to 50 meters and up to 100 Gbit/s over a distance of up to 15 meters.

trunk cable, design features
Twisted pair cables, which have three or more four-pair elements under a common sheath, are classified as multi-pair. The trunk cable is intended for use in main subsystems SCS for interconnection of cross-country premises. In the subsystem of external highways, usually most of the route is laid horizontally, in the subsystem of internal highways - vertically. In order to reduce the attenuation coefficient, the conductors are made of solid copper wire. Unlike horizontal cable, trunk structures contain more than four twisted pairs and are therefore often called multi-pair. Similar to horizontal cables, they vary in categories from 3 to 5, with trunk cables of category 4 being very rare in practice. The design of the cable depends on its capacitance. When the number of pairs is up to 25, they are placed in a common shell. In the case of a capacity of more than 25 pairs, they are divided into bundles of 25 pairs each, the totality of which forms the cable core.
Fig.4 Multi-pair trunk cables: a) 25-pair cable of category 5 b) 300-pair cable of category 3
Some designs use a central fiberglass core as the core. The wires of one bundle are fastened with polyethylene tapes. From the outside, the core is protected by a common dielectric shell. In addition to unshielded trunk cables, S/UTP structures are produced in limited quantities, in which under the outer dielectric sheath there is a screen covering the cable core. Similar to horizontal cables, markings are applied to their sheath, including the type, data on the diameter of the conductors and their number, the name of the testing laboratory, as well as foot or meter length marks. The linear weight of a 25-pair category 5 cable is usually ISO-190 kg/km, the operating temperature range is from -20 to +60°C. In addition to multi-pair cables, a number of companies offer so-called Multi Unit cables. They differ in that the cable core is formed not by individual twisted pairs, but by two- or four-pair elements, similar in design to a horizontal cable and equipped with an individual protective sheath. To increase strength and resistance to various mechanical influences, a central fiberglass rod can be used as the basis for the core of a multi-element cable. Trunk cables are divided into internal and external cables. The main difference between an external cable and an internal cable is the use of special measures and design solutions to protect the cable core from moisture ingress. Most often this problem is solved by using an outer polyethylene sheath. Some types of telephone cables have gel filling the internal voids of the core. Additional protection cable core from moisture and mechanical influences made with armor made of aluminum or steel corrugated tape.

Crimping twisted pair

Crimping a twisted pair cable is most often done with an 8P8C connector, more commonly called RJ-45 (RJ45) according to color scheme corresponding to the purpose of the cable.

RJ-45 connector (left - for twisted pair FTP/STP/SSTP, with shielded housing, right - UTP)

RJ-45 connector for twisted pair FTP STP SSTP and RJ-45 connector for UTP:

There are two main cable crimping schemes: T568A and T568B, but T568B is much more commonly used. To connect a computer to a switch or a computer to a hub, a straight cable is used, crimped on both sides equally; computer-to-computer or switch-to-switch (hub-hub) connections use a crossover cable - T568A on one side, and T568A on the other. T568B.

Crimping diagram for 4-pair cable:

Crimping diagram for a 2-pair cable (the color of the pairs may vary depending on the cable manufacturer):

If you connect computers directly to each other via Gigabit network cards, use the Gigabit Crossover scheme:

Gigabit Crossover:

If you decide to use FTP/STP and ground the shield - ground only in one place and only 100% grounded! If in doubt, it’s better not to do it at all; “grounding” it to a heating battery or electrical panel housing can only make things worse - not only for the computer, but also for you!