For laying computer networks use a special Ethernet cable (Lan cable). There are several main types of such wires: twisted pair, coaxial and fiber. The first type is considered the cheapest and simplest, so it is used by more than 90 percent of all local area networks.
Types of Twisted Pair
This ethernet cable is the most common and famous. It consists of eight copper conductors that are intertwined in pairs. As an insulating material, PVC compound 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 a 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 greater cost. There are also several types of twisted pair, which are indicated by the marking "CA", which determines the category of wire. There are seven types of this parameter. The higher the category number, the greater the cable throughput , i.e. more conductors are used. So, the seventh category of twisted pair (the last to date) allows you to transfer information at a speed of 40 Gbit / s. To ensure this speed without distorting the signal, each pair of conductors in the cable must have a wave impedance of 100 ohms.
Ethernet Coaxial Cable
This type of wire consists of a shield and a conductor having a common axis of rotation. The cable contains a conductor, an insulator, a PVC sheath, a 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 impedance of 50 Ohms - for computer networks - and 77 Ohms - for transmitting a television signal. The maximum data transmission capacity is 10 Mbps. In addition, it is impractical, as 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 transmitting data over long distances, they are not susceptible 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 is needed to connect. This type is rarely used for laying networks in an apartment or office, because, in addition to sophisticated equipment, it has a rather high price.
Ethernet cable pinout
A standard four-pair twisted pair cable for building local networks is crimped with an RJ-45 type connector. The connection diagram has the following order: white-green, green, white-orange, blue, white-blue, orange, white-brown and brown wires. Crimping patterns differ depending on the purpose of the connecting lines, technologies, and information transfer standards . Sometimes use the forward and reverse (cross) crimp connector.