Twisted pair,. The so-called twisted pair is a cable formed by twisting two copper wires (No. 22-26) with insulation protection layer at a certain density. The radio waves emitted by one of the wires during transmission will be offset by the radio waves emitted by the other wire, effectively reducing signal interference. The twisted pair (network cable) we see in daily life is made up of multiple pairs of twisted pairs wrapped in an insulated cable sleeve (consisting of 8 wires of different colors twisted in 4 pairs). Compared with other transmission media, twisted pair cables are not the highest in terms of transmission distance, channel width, and data transmission speed, but they are strong in terms of cost-effectiveness and can handle most connection scenarios.
① According to the joint sequence of twisted pair cables and the different connecting equipment, twisted pair cables are divided into straight line, cross line, and reverse line.
Also known as the main line or standard line. The wire sequence at both ends of the wire is the same, that is, if it is 568A standard, both ends are 568A; if it is 568B standard, both ends are also 568B standard. It will be mentioned in the introduction of the wire sequence after the 568A and 568B standards. Application scenarios: routers and switches, PCs and switches, etc.
One end of the wire adopts the 568A or 568B wire sequence standard, while the other end uses a wire sequence completely opposite to the former. Namely, if one end is: 1. White Orange 2, Orange 3, White Green 4, Blue 5, White Blue 6, Green 7, White Brown 8, Brown; On the other end are: 1. Brown 2, White Brown 3, Green 4, White Blue 5, Blue 6, White Green 7, Orange 8, White Orange. Application scenario: The reverse cable can be used to connect the host to the router console serial communication port (com), and an adapter needs to be used during the specific use process.
② The twisted pair cables are classified into shielded twisted pair (STP) and non shielded twisted pair (UTP) according to whether there is a shielding layer or not.