Types of twisted pair cables and their applications. Twisted pair (network cable)

Twisted pair refers to cable systems with its own structure, used for transmitting information in telecommunications networks. Connection to network devices is made using an 8P8C connector. Let's consider the technical data of twisted pair cables taken into account when creating computer networks.

The great popularity of using twisted pair is due to the fact that it is compatible with different types of equipment, is easy to install, and has a low cost for forming a network. Crimping is done using special crimping pliers.

Twisting of wires is done for a specific purpose. Interweaving wires with a certain weaving pitch forms a pair of wires, with the help of which the quality of communication is improved. Interference from electromagnetic waves has a uniform effect on the wires in a pair, reducing mutual interference during signal transmission and external factors during operation.

Device

Twisted pair has various technical data. It depends on the category. It consists of many copper conductors forming a pair. Conductors can be insulated from polyvinyl chloride or polypropylene. High quality cables are equipped with Teflon or polyethylene insulation. Such insulation guarantees low dielectric losses and protects conductors from increased heating. Conductors can be made of one or more cores that make up a bundle.

To make it convenient to cut the cable, the sheath contains a nylon thread for breaking. The outer shell is made of polyvinyl chloride, as well as fire-resistant polymers.

In our country, twisted pair cables are marked:

ng(A) - HF; ng(B) - HF; ng(C) - HF; ng(D) - HF;

The outer shell is made of hydrophobic polyethylene. It is applied over the PVC shell. The empty area in the cable is filled with hydrophobic helium, and can also be armored with a special tape.

The use of different colors is used to identify and assign the cable sheath. The black color indicates that the cable is protected from moisture; the orange cable is resistant to combustion. Light gray network cable is used inside offices and residential buildings.

Types

Communication cables are multi-core and single-core, as well as with a shielded sheath and without a shield.

Twisted pair with a single core is used to conduct a line in the wall, and is not connected directly to devices. Termination equipment is connected to the cable, for example, a socket (termination). This cable has wires that break easily.

Twisted pair with several cores is used for switching digital devices. This cable is suitable for bends and has thin cores. Multicore cable has a significant attenuation signal, so its maximum length should not exceed 100 m.

Shielding types:

• UTP– without screen.
• FTP- foil screen.
• STP– the screen of each pair and the general grid.
• S/FTP– foil screen for couples and outer screen.
• U/STP– there is no common screen, each pair has a screen.
• SF/UTR– two external screens.

Categories by transmission speed

Categories of twisted pairs are divided into categories based on the frequency interval of the signal transmission. This is achieved by the number of turns. The higher the transmission frequency and the number of turns, the higher the category.

Features of using twisted pair

There has been a lot of progress in science recently, but many inventions were made back in the 19th century. Today twisted pair cable is widely used:

• Video signal data transmission.
• Local networks.
• Telephone lines.
• Transmission of electronic signals.

Advantages of connection using twisted pair

If we compare coaxial cord and twisted pair, then twisted pair has the best protection for the data flow from interference, due to its structural features. This is especially noticeable at a distance of about 2 kilometers. The signal is clear and clean, especially if a grounded wire with a shield is used. Such a wire is relevant in places with high electromagnetic radiation.

The line can simultaneously transmit several signals: sound, video, telemetry data. There is one limitation: the number of pairs in the cable. To prevent these pairs from influencing each other in the cable, the twisting steps are different. The more accurate the balancing, the lower the negative impact of couples on each other will be.

The costs of installing and connecting a local network of computers or video surveillance with different monitors and cameras are reduced, since a shorter cable length is required. If a twisted pair cable is laid over a distance of more than two kilometers, the signal frequency is noticeably attenuated. Therefore, network cable is more often used in short networks. It is better to choose a cable made of copper conductors rather than copper-plated steel.

Twisted pair crimping

Let's figure out how to crimp the twisted pair cable needed to connect computers to each other on a local network, or connect a TV to a hub, or another media device.

We have the cable, connectors and crimping pliers needed to crimp the twisted pair cable itself. Let's look at how two different connectors are crimped. One is two-component, the other is one-component. The two-piece connector consists of two parts and has an additional insert that supposedly makes it easier to assemble the wires in the connector. The one-piece connector does not have any inserts.

Twisted pair has four twisted pairs of eight conductors. This means there are eight wires, separated by color. Of these, every two wires are twisted together, thereby forming a twisted pair.

For a home network, a category 5E cable is suitable. It is intended for installation indoors. There is a cheaper version of the cable, where instead of eight conductors there are only four wires. That is, the cable has only two twisted pairs.

There are many schemes for crimping local network connectors. One standard is direct connection, the second is cross connection.

A direct connection is used to connect a computer to a hub, and connect other devices to the hub. The second is used to connect two computers, or to connect a computer to a hub. It is recommended to crimp the cable using the second option. If you connect a computer to a hub, you can connect two computers with the same cable. You will not have to pinch the cable that was crimped in the first option.

The picture shows that some wires are crossed. This means that on one connector there is one numbering, on the second connector the numbering of the same wires will be completely different.

There are standards for crimping wires by color. Only four wires are used to transmit data. These are 1, 2, 3, and 6 conductors. They are the most important wires. They intersect as follows: first - third, second - sixth. The remaining wires run in parallel.

Let's look at the connector according to the second scheme. First we must cut the end of the wire using pliers. They have a special knife for this.

We straighten the wires, and unwind the pairs, straighten the conductors. We distribute them by color, as shown in the figure. We level them so that they fit snugly against each other.

Once again we check the arrangement by color. Now we take the crimping pliers and, using the knife they contain, cut off the conductors 1.5 cm long from the edge of the outer insulation.

After trimming there is a smooth, neat edge. Now let's take the connector. If the connector is turned towards you, the first contact will be located on the right, and the eighth on the left. Now we insert the conductors into the connector. At the same time we press them against the plane of the comb and against the bottom wall of the connector.

There are special guides, each wire has its own guide channel. Insert until the end. Every wire should shine. This indicates that it rested against the plastic case and was inserted all the way.

Now you need to clamp the connector using pliers. We insert the connector into the special groove of the pliers and clamp it.

This clamps the comb of contacts on the wires, and on the other side the insulation is clamped. This is a properly crimped RJ-45 connector, done correctly. Now it is almost impossible to remove it.

Crimping a two-piece connector

Now let's look at how a two-piece connector is crimped. We also clean the insulation, straighten the wires, and straighten them. If the nylon thread located in the insulation interferes, then it can be cut off.

The first wire should not be white-orange, but white-green. All wire colors are selected according to the above diagram. All operations are the same, just different colors. Another difference is that to make it easier to crimp the contacts, there is a plastic insert. It has a small ledge that we place upward. We cut the wires straight and insert the wires into this insert.

The peculiarity of this connector is that it is difficult to insert the wires into the insert. But it’s convenient because it holds the wire, keeps the order and numbering of the wires. Now we cut the wires again, making a smooth edge at a distance of 5 mm from the insert.

Now we also put on the connector, but there is no need to press the plastic.

Insert the wires with the insert all the way. Now we insert the connector with the wires into the crimping pliers and also clamp it.

Our connector is crimped. We received a small patch cord for connecting two computers, or connecting a computer to a hub.

Despite the intensive development of wireless technologies, cable data transmission 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 of 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 transfer 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 at high frequencies of the 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 values ​​close to those 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 way.

Shielded twisted pair

When twisted pair cables are laid near power lines, powerful sources of electromagnetic radiation, or equipment that creates strong electromagnetic interference, factors such 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 EMI sources, it is recommended to use 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 the UTP cable will be completely protected from external EMI.
• 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 will suit the specific laying conditions, and that it will be of the 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. A droplet forms on the copper wire, but the wire itself does not deform. 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) is an American system for marking the thickness of wires, and the XX value 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 network operation. 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, water will get under the insulation, which sooner or later may end up in the 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 operation of the network, minimization of losses, and maximum network service life. 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 office networks, it is also preferable to use UTP, since when using shielded cable there are additional difficulties with grounding the shield: according to ANSI/TIA/EIA-568-A standards and the international standard ISO/IEC 11801, the shield must be grounded at both ends on the bus telecommunications grounding system. 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 the Larex, Sofetec and Hortex brands allow you to optimize the budget for laying cable lines and guarantee high quality products, which allows you to use the cable to solve a wide range of problems.

To organize most data networks, computer or telephone, cables are used. Such networks are called wired. In recent years, they are most often laid using a special type of cable called “twisted pair”. The name reflects the type of arrangement of the conductors relative to each other. A twisted pair is two insulated conductors twisted together with a certain twist pitch. Typically, these two wires have another layer of insulation.

There are cables that have two, four, eight pairs of conductors under one sheath. And still, such a cable is called “twisted pair”, although there are several pairs themselves. Depending on the type of protection, there are unshielded and Shielding reduces the influence of external and internal interference, increases the reliability of the connection, and reduces the number of errors. To ensure integrity in case of excessive bends and breaks, the screen along the entire length of the cable is connected with a special non-insulated drain wire. Shielded twisted pair cable provides higher transmission speeds and partially eliminates influence and interference from other objects.

Screens can be in the form of mesh, braid, or continuous foil covering. There are cables with double protection, with foil wound over the mesh braid. According to international practice, this type of conductor has the following designation: unshielded twisted pair - UTP, shielded - STP. If a cable has an overall protective shield, but individual pairs are not shielded, then such a wire is also classified as unshielded. Terminal equipment uses different types of cables. Which one do you need, look in the passport or description.

Depending on the structure of the conductors used, a twisted pair can be single-core or multi-core. consists of a single wire of large diameter, multi-core is a bundle of thin wires. The scope of their application is different. Single-core wires have greater rigidity, do not bend well, and can break if bent repeatedly. Their

used for laying in walls, pipes and boxes with subsequent insertion into an outlet. Multicore twisted pair has good flexibility, but does not tolerate connection to sockets. This type of cable is used to connect terminal devices to sockets.

The outer shell of the conductors serves to protect them from moisture and mechanical damage. It has different thicknesses and is made from different materials. According to European standards, only those cables that do not emit smoke or burn are suitable for external installation.

To make work easier, different colors are used for conductors for various purposes. For example, the outer sheath color of a cable for external installation is black, orange means that the sheath material does not burn, and the color of internal conductors is usually gray. Cables consisting of twisted pairs can have different shapes: round or flat (for laying under the floor covering).

Which cable should I use for IP CCTV cameras when designing local area networks or integrated security systems?

Purpose.

You need to choose a UTP twisted pair cable depending on your purpose. Each cable has its own purpose and will do its job better.
What kind of cable can be laid underground? Which one to use outdoors? Which one can you “start” on? Which one can be used in children's institutions/hospitals? Which one to use in crowded places: shopping centers, airports, train stations?

Explanation of twisted pair cable designations.

Please note that the wire may have several markings in different combinations, for example: FRLSLTx.

Questions, comments and suggestions write to: samohvalov@site

It is becoming more and more difficult to understand the accelerating modern flow of goods and technologies provided. First of all, this concerns computer equipment and accessories for it. The latter also includes various types of information cables, the names of the markings of which are easy to get confused even for a specialist. In the article below, a study will be conducted, the purpose of which is to identify the main distinctive properties of UTP, FTP, STP and other twisted pairs.

The meaning of information cable markings

In the modern market of structured cabling systems (SCS), there are many names of twisted pairs that are obscure to buyers: UTP, S/UTP, F/UTP, FTP, ScTP, STP, S/STP... The list goes on. And in order not to get confused in the multitude of labels when choosing the necessary product, you should find out the meaning of English abbreviations.

International classification of information cables

However, there is confusion among manufacturers regarding LAN cable encodings. And the problem arises when it is necessary to clarify the location of the shielding layer. The latter can be located in two places. The one on top of a separate pair is called individual. Located around pairs isolated from each other ( twisted pair ftp) is usually called general. To avoid confusion, an international classification of LAN cables was created. When compiling it, the following were taken into account:

• presence of a shared screen;
• a layer of insulation over a separate pair of conductors;
• twisting method.

The classification scheme for information cables was presented in the form of the AA/BCC formula. The first 2 letters on the left indicate the presence of a common shield over all twisted conductors. For example, an S/FTP cable differs from an FTP cable in that all dual conductors have a common shield made of copper braid.
The third letter (B) carries information about the existence of an individual shield around each twisted pair of conductors. If there is one, then this is the one twisted pair ftp. The last two letters indicate the type of twist. Usually this is tp. However, recently the abbreviations “TQ” have become increasingly common. They mean that the conductors are twisted not in pairs, but in fours. Returning from “quads” to twisted pairs, the most tricky question should be clarified. If there is no shield around each individual twisted pair, and the protection is located only on top of all double conductors, then each of them is referred to as twisted pair utp, and the cable marking will look like this: F/UTP or S/UTP.

Features of the STP cable name

There is a lot of confusion when choosing the required cable, which is designated STP. This marking may refer to a different cable.

For example, shielded twisted pair cable (S/FTP, F/FTP, SF/FTP, or S/STP) is also called STP. In addition, the name STP indicates the material from which the cable screen is made - braid.

STP cable is widely used for data transmission using 10 GbE technology over twisted copper pairs.

UTP and FTP cables: main differences

Having understood a little about the international classification of twisted pair cables, we should consider the distinctive characteristics of UTP and FTP twisted pairs. In terms of information utp 4 cable, which has neither individual screens for twisted pairs nor a common screen, has one more difference. It does not have a drain wire, which is usually found in shielded LAN cables. For example, ftp cable 5e, the price of which is lower than the competitive one is equipped with this element. The drainage wire has no insulation and is connected along its entire length to a common aluminum screen. It is provided in case of sudden rupture of the aluminum sheath due to strong bends or excessive stretching of the cable. In this situation, the drainage wire becomes a kind of connecting clamp for the screen.
Aluminum or aluminum-polymer film is used for shielding in FTP cables. The latter is laid with the metal side inward, on the surface of pairs of twisted conductors. As a result
By adding additional elements, foil coaxial cable (FTP) becomes slightly thicker than unshielded twisted pair (UTP). In addition, FTP is somewhat less flexible than UTP.
Foil twisted pair cable has an advantage over unprotected twisted pair cable. The first is better protected from high-frequency interference. But for this purpose it’s vaporous ftp cable and the case of a computer or other electronic equipment must be grounded according to all rules. The situation with interference at low frequencies is even worse. Aluminum screens are not able to prevent low-frequency waves generated by powerful brushed motors. For this reason, FTP twisted pairs are not used in industrial production. In addition, foil LAN cables are characterized by low signal attenuation parameters.
When comparing the disadvantages and advantages of protected and unprotected twisted pairs, you should not forget about the price. For a low budget cable utp buy much more profitable, since its cost is much lower than a foil LAN cable.
Statistics show that ftp cable more often used in France. And a significant part of the computer networks in the United States and England is equipped based on UTP cables. Residents of Germany prefer twisted-pair cables with two shields: individual for each pair of conductors and a common one. You can buy twisted pair cables from AVS Electronics.

The meaning of some English abbreviations on LAN cables

When choosing an information cable for your needs, you need to carefully read the labels on it. Knowing the symbols of abbreviations, any buyer can easily select the right product. The letter combination LAN itself is translated as “local computer network”. And this term does not carry the technical characteristics of the product.

It is much more important to pay attention to the abbreviation CCA, which informs the buyer that this is a cable in which the conductors are made of aluminum and clad (covered on top) with a layer of copper. In Russian, the term “composite” is used instead of CCA. The latter indicates that cable - twisted pair ftp or utp - does not consist of copper conductors, but of aluminum clad with copper. The cost of these is several times less, however, their technical characteristics are significantly lower.
For example, twisted pair, the most common version of twisted pair.
Concluding the study, it should be noted that all information cables of the Cat5, Cat4 and Cat6 categories are equipped with 4 twisted pairs inside. The letter E after Cat5 indicates that the category is extended. And for the manufacture of FTP twisted pairs of the Cat5e class, it is mandatory to use not aluminum, but copper wires. You can buy UTP twisted pair cable from AVS Electronics. The company also has various varieties in its assortment.