Network cable knowledge

There are three types of cables used for network connection: coaxial cable, twisted pair cable, and optical cable.
There are two kinds of coaxial cables: coarse cables and fine cables. However, because the network topology of coaxial cables is ring-type, this network expansion card and related equipment are rare now, the connector is also required for connection and other reasons, so it is basically no longer used in general conditions.
There are many types of twisted pair wires, including three categories, five categories, and more than five categories. The cabling is relatively simple and the performance is good. It can be used in network connections of less than m, and is currently the most common network connection method.
Optical fiber connections are often used in backbone connections of enterprises or intercity networks because of their high equipment prices.

For twisted pair wires, the internal structure is formed by eight or four pairs of wires winding each other. The reinforced structure and insulation layer are encapsulated on the outer side, and some of the wires are shielded. This is the name of the twisted pair wires. wires are grouped by color after being wound. Different colors are defined according to the standard, and the winding distance of wires is also different. the reason for using a pair of wire winding is to offset the electromagnetic interference of the signal.

I don't know what you call a parallel network cable, because there is no such transmission medium in the network connection cable, and theoretically, using parallel wires, when a network signal is transmitted, it degrades seriously due to interference and reduces the communication rate. Therefore, regular Network cables cannot be parallel.

However, when the twisted pair wires suppress the crystal head of the RJ-45, the wiring method according to the standard, there is a crossover method and parallel connection method, that is to say, if both ends are installed according to 568a or 568b, it is called Parallel Connection method, if one end is 568a and the other end is 568b, it is called the crossover method. generally, the cross-connection method is used to connect two identical devices, such as two NICs and two switches. the parallel connection method is used to connect two different devices, such as a NIC and a hub. however, this is only the difference in the method of connection, and the standard twisted pair wires are used.