Modern methods of accessing the Internet offer several connection options: using a coaxial cable, optical fiber and twisted pair. Let us dwell on the characteristics of the twisted cable and how the pinout of the twisted pair cable is made, what is necessary for this and what rules should be followed.
Twisted pair called wires that are twisted and covered with insulation. One twisted cable may contain 2 or 4 twisted pairs of wires placed in a dielectric sheath. The wires are in different voltages, an information signal is supplied through them. There are several types of twisted pairs. They are unshielded, foil with an external screen, foil with a pair of external screens, protected and shielded protected. Twisted pair has one drawback. During its operation, there is a risk of interception of information transmitted via cable. Shielding it is necessary in order to avoid unauthorized listening. On the other hand, shielded wires are quite expensive and therefore less commonly used.
Cables in which twisted pair cable is used are divided into several categories. The first is a telephone cable designed for voice transmission. A cable of category 2 can transmit information in a frequency band of up to one megahertz, 3 categories - up to sixteen megahertz, 4 categories - up to twenty megahertz. The latter is rarely used, because it almost does not differ from category 3 cable.
The most perfect cable at the moment is the fifth category cable, designed to transmit information in frequencies up to one hundred megahertz. Twisted pair of category 5 has at least twenty-seven turns per meter of length. Usually there are several of them, up to twenty-five pairs. The cable is suitable for connecting computers to the Internet and creating local networks. There are also cables of categories 6 and 7, which are respectively designed for 200 and 600 megahertz. Category 6 cable is used to connect to Ethernet networks.
When connecting to a local area network of at least two computers, difficulties arise. To overcome them and make the connection the most optimal, computer network cards and twisted pair cables belonging to the fifth category, as well as RJ-45 connectors, will be required.
Since cables consisting of twisted pairs are difficult to cut into sockets, they need to be crimped, which is carried out according to standards and using special tools so that the quality of information transfer is not affected. If the cable has eight cores, twisted pair pinout for Ethernet and Gigabit Ethernet is performed. Due to the fact that category 5 and 6 cables show themselves well in twisting and bending, they are successfully used for the manufacture of patch cords that connect peripherals to sockets.
Let us dwell on two options that are used when connecting computers to a network or to connect one PC to network equipment (patch cord). Moreover, the entire local area network can use only one option, through which the twisted pair pinout will be carried out. The cable must be prepared for insertion into the connector. It is worth noting that both RJ-45 connectors must be crimped the same way. There are two types of crimping that apply to twisted pair. The first (direct order) has the direction of "workstation-hub". The second is a cross, cross-link.
To connect the network cards of two computers directly, you need to separate the cable so that the pairs (for example, orange and green) are swapped. Thus, the pinout of the twisted pair cable is carried out, as a result of which one of the connectors will be crimped in the first embodiment, and the second in the second. The cable will be called a crossover in this case. It is also called nullhab.
Thus, the advantage of twisted pairs is the ease of installation and low cost. Stranded wires have a large signal attenuation and are most common for connecting to the Internet, twisted pair pinout is used to improve the quality of the process, which allows you to adapt the cable for connections with a computer and peripheral devices.