Ethernet cable: description, purpose, types of products

For laying computer networks use a special Ethernet cable (Lan-cable). There are several basic types of such wires: twisted pair, coaxial and fiber-optic. The first type is considered the cheapest and the most simple, therefore it is used by more than 90 percent of all local networks.

Types of twisted pair

This Ethernet cable Is the most common and famous. It consists of eight copper conductors, which are intertwined in pairs. As an insulating material, PVC plastic is used. There are many types of twisted pair, differing from each other by the type of protection or its absence. The protective function can be performed by aluminum foil wrapped around the wires, or copper braid of each pair. In addition, there are combined types of protection. Shielded Ethernet cable More resistant to external interference, but, accordingly, has a higher cost. Also, there are several types of twisted pair, which are identified by the "CA" marking, which defines the category of the wire. There are seven kinds of this parameter. The higher the category number, the greater the cable capacity , that is, more conductors are used. So, the seventh category of twisted pair (the last one for today) allows to transfer information with a speed of 40 Gbit / s. To ensure this speed without distortion of the signal, each pair of conductors in the cable should have a impedance of 100 ohms.

Coaxial Ethernet cable

This type of wire consists of a screen and a conductor having a common axis of rotation. The cable contains a conductor, insulator, PVC sheath, copper or aluminum braid. Today, this type of wire is used as a conductor for antennas. There are practically no local networks organized on coaxial cables. The most common wire with a wave resistance of 50 ohms - for computer networks - and 77 ohms - for the transmission of a television signal. The maximum data transmission capacity is 10 Mbit / s. In addition, it is impractical, since it is quite difficult to repair damaged areas, which subsequently leads to significant losses.

Optical fiber

These Ethernet cables are characterized by low attenuation, even when data are transmitted over long distances, they are not subject to interference. In addition, the optical fiber has a high translation speed. To repair the cable in question, specialized tools and equipment are required, and spectral equipment will be required for connection. This type is rarely used to build networks for an apartment or office, because, in addition to sophisticated equipment, it has a fairly high price.

Ethernet pinout

Standard four-pair twisted-pair cable for building local networks is crimped by a RJ-45 type connector. The connection scheme is as follows: white-green, green, white-orange, blue, white-blue, orange, white-brown and brown wires. Crimp schemes differ depending on the purpose of the trunks, technologies and standards of information transfer. Sometimes use a straight and reverse (cross) crimp the connector.