▷ Types of twisted pair cable: utp cables, stp cables and ftp cables

Who does not have Internet today? Even you will be using a UTP cable, or an STP cable or an FTP cable. They are all twisted pair cables, if you do not know what these types of cables are, we will immediately see what they are, how they are manufactured and which are better and worse.

Index of contents

In the updated we are totally surrounded by the world of the Internet, a world that has undoubtedly changed our lives completely, with its good things and also its bad things. To connect to the Internet we always use an electronic device that can be our mobiles, tablets or our desktop computers.

Technology advances and more and more devices are using the wireless medium called Wi-Fi to establish this Internet connection. The advantages are obvious, greater mobility and good speed, and of course we can be almost anywhere. Especially now that the first routers with the 802.11ax protocol are being introduced, which provides very important advantages in wireless connections, reaching speeds in internal networks of more than 2.5 Gbps.

But we have not yet talked about cables, and the truth is that these are very important today, and will continue to be due to important advantages over the wireless connection: higher bandwidth at least until now, much lower latency and higher connection distances. In 90% of cases, when we contract an Internet connection service at our home, our router will be connected via an Internet cable, either a twisted pair cable or a fiber optic cable. Twisted pair cables will be the protagonists in this article so, without further delay, let's start.

What is a twisted pair cable

Twisted pair cable is the cable most commonly used to establish data communications over a network. It gets its name because it has two isolated and in turn interlaced electrical conductors to cancel the interferences caused by external electrical sources and electromagnetic waves.

Today a twisted pair cable not only has two of these interlocked cables, but has a larger number of them. Of course, always in even numbers and always twisted two by two in a helical fashion. The inventor of this type of cables was a certain Alexander Grahan Bell in 1881, Bell discovered that the waves that travel by two independent and helically interlaced cables are canceled, causing a reduction in the interferences that occur, thereby improving transmission. of data.

And the most interesting thing without a doubt, is that if we group a set of interwoven cables two by two we will also be making sure that each of these groups have less interference from themselves and from the groups around them, and even from external actions. such as higher voltage cables or microwaves that cross this physical medium.

Each of these twisted pairs will be identified by an insulating material and a color to differentiate each of the pairs and each of the conductors. In each of these pairs, the electrical signal is configured in differential mode, that is, one is the inverse of the other. In this way the noise of both signals cancels, otherwise what it would do is add up.

When did you start using this type of cables?

The first telephone communication networks used a telegraph network based on an open wire and a ground connection, but this system would soon cease to be feasible due to the increased frequency of communications and the construction of trams near them. networks. Being a single cable, the noise greatly affected these facilities, worsening the quality of the transmissions considerably.

With the evolution of electricity grids in cities, the use of balanced grids that had been designed to avoid the noise of trams were not enough either, mainly due to their high voltage and the magnetic field they generated around them. It was then that the invention of Graham Bell made sense and twisted pair systems began to be used to unite large cities by aerial laying with repeaters every certain distance. Furthermore, this system allowed for greater bandwidth and transmission capacity, making it also one of the main reasons why the evolution of telecommunications has advanced so much.

Of course, this cable is still used today in many places, and not just for local area network connections. Traditional ADSL overhead lines are based on twisted pair cables. With the evolution of telecommunications and the great need for ever faster systems, it has led to the replacement of many of the twisted pair cables with much faster fiber optic cables, with greater bandwidth and capable of reaching much more. away without interference as they rely on an optical rather than an electrical signal.

Advantages and disadvantages of twisted pair cables

In general, these cables provide very good performance for local area networks and ultimately for medium and long distance links, as long as there are signal repeaters about 2 or 3 kilometers away. The highest specifications of these cables have a capacity of up to 40 Gbps, but at reduced distances and in well-protected environments. These cables are not totally immune to noise as fiber optic cables can be, despite the fact that they are shielded and shielded in the highest categories, the noise element will always say present.

Main advantages:

• Possibility of feeding connected equipment PPPoE Ease of use and installation Low cost of manufacturing and acquisition High capacity for data transmission in local area networks Fast connectivity and upgradeable Good latency in LAN networks

Main disadvantages:

• Not immune to noise Limited bandwidth vs. fiber cables Limited distance and need for repeaters Error rates to consider at high speeds

Twisted pair cable types: UTP, STP and FTP

Currently, there are different twisted pair cable configurations. Depending on their construction method, they are oriented to domestic, industrial use or to transmit several data signals simultaneously. The basic difference of all these types is the form of insulation they implement, since the basic configuration is always the same: two conductors with helical braiding.

From here, we will focus almost exclusively on the cables of four twisted pairs, which are the ones we use in our homes. It consists of 8 cables divided into 4 interlocking pairs. To know the category of a cable, we only have to look at the outer jacket.

UTP cable

They stand for " Unshielded Twisted Pair " or unshielded twisted pair cable. This type of cables contain their unshielded twisted pairs, that is, there is no separation means between each pair of cables that isolates them from the other pairs.

It is almost always used in local short-distance networks, since, as they are more exposed, the signal will degrade if a signal repeater is not introduced every so often. These cables are inexpensive and typically have a characteristic impedance of 100 Ω.

These cables have been used in the home telephone network, in two twisted pairs with an RJ11 connector. But they are also used in 4-pair configuration using the RJ45, DB25 or DB11 connector.

FTP cable

Acronym for “ Foiled Twisted Pair ” or shielded twisted pair cable. In this case we have a cable whose twisted pairs are separated from each other by a basic system based on plastic or non-conductive material. In this case, the shielding is not individual, but global, which covers the entire group of twisted pairs, and is made of aluminum.

It does not have as good benefits as STP cables, but they do improve UTPs in terms of distance and isolation. They are widely used and use the RJ45 connector, and their characteristic impedance is 120 Ω.

STP cable

We go to the next cable in this list, whose initials mean " Shielded twisted pair " or in Spanish, individual shielded twisted pair. In this case we already have each of the twisted pairs surrounded by a protection cover normally made of aluminum.

These cables are used in networks that require higher performance, such as the new Ethernet standards, where high bandwidth, very low latencies and very low bit error rates are required. They are more expensive cables than the previous ones and allow tracing greater distances without the need for a repeater. Its characteristic impedance is 150 Ω.

These sabers are generally used with RJ49 connectors.

SSTP cable

Screened Shielded Twisted Pair or individual shielded laminated twisted pair cable. The tongue twister is complicated here, now we have a cable with the structure of an STP cable, that is, with each of the pairs covered by aluminum. But in turn we also find a global lining around LSZH material.

This cable is the highest performance cable, with excellent protection against high frequencies and great transmission capacity over long distances. Your global screen will be generally connected to the equipment ground, to eliminate residual voltages. Of course it is the highest cost cable on the list.

Its resistance is 100 Ω, and it is compatible with RJ45 connectors.

SFTP cable

Screened Foiled Twisted Pair or individual shielded laminated cable. This cable is based on the construction of the FTP cable, but in the overall shield an LSZH metal mesh has been added around it to increase the isolation of this cable. Like the previous one, this sheet will be connected to the ground connection on devices that have it.

These improve the performance of an FTP cable, although they are still inferior to SSTP cables.

Twisted Pair Cable Categories

After knowing the different types of cables that exist in terms of their construction, these are also divided into categories, according to their transmission speed. This category division complies with specification 568A EIA / TIA (Electronic Industries Alliance / Telecommunications Industry Association).

	Bandwidth	Use	characteristics
Category 1	-	Telephony and modem	UTP cable
Category 2	4 Mbps	Old terminals (deprecated)	UTP cable
Category 3	10-16 Mbps 16 MHz	10 BASE-T / 100 BASE-T4 Ethernet	UTP cable
Category 4	16 Mbps 20 MHz	Token Ring	UTP cable
Category 5	100 Mbps 100 MHz	10 BASE-T / 100 BASE-TX Ethernet	UTP cable
Category 5e	1 Gbps 100 MHz	100 BASE-TX / 1000 BASE-T Ethernet	UTP / FTP cable
Category 6	1 Gbps 250 MHz	1000 BASE-T Ethernet	FTP / STP / SFTP / SSTP cable
Category 6e	10 Gbps 500 MHz	10GBASE-T Ethernet	FTP / STP / SFTP / SSTP cable
Category 7	Multi-transfer 600 MHZ	Telephony + television + 1000BASE-T Ethernet	FTP / STP / SFTP / SSTP cable
Category 7a	Multi-transfer 1000 MHz	Telephony + television + 1000BASE-T Ethernet	SFTP / SSTP cable
Category 8	40 Gbps 1200 MHz	40GBASE-T Ethernet or Telephony + television + 1000BASE-T Ethernet	SFTP / SSTP cable
Category 9	25000 MHz	In creation	8 Pair SFTP / SSTP Cable
Category 10	75000 MHz	In creation	8 Pair SFTP / SSTP Cable

These are basically the types of twisted pair cables that exist today.

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Did you know that all these types of cables and categories existed? What do you think is the cable that you have? If you have any questions or suggestions on the subject, write us.