First-recognized twisted pair Cable | category 5, Category 5, Category 5

Communication Media is a physical media used to transmit information. Different communication media have different attributes and should be used for different purposes in different occasions to exert the best efficiency of different communication media.

Twisted pair cables (twisted pair cables) are a transmission medium formed by encapsulating one or more twisted pair cables in an Insulating Coat. They are currently the most commonly used cabling materials in local area networks. In order to reduce the signal interference degree and minimize the electromagnetic radiation and external electromagnetic interference), each pair of twisted wires in the cable is generally twisted by two insulated copper wires, each line is marked with an insulating layer and a color mark, hence the name of twisted pair wires. Twisted Pair wires are classified based on their electrical characteristics. They are generally divided into two categories: unshielded twisted pair UTP and shielded twisted pair STP, in Lan, unshielded twisted pair wires are divided into three categories, four categories, five categories, and five categories. shielded twisted pair wires are divided into three categories and five categories.

Currently, twisted pair wires commonly used in Lan are non-shielded cables of Category 5, 4 pairs, that is, 8 wires. The transmission rate of these twisted pair cables can reach 100 Mbps. With the development of transmission media, over five twisted pair wires have appeared in LAN in recent years. Category 5 twisted pair wires are unshielded twisted pair wires. Compared with common category 5 twisted pair wires, Category 5 twisted pair wires have lower attenuation and stronger anti-interference capabilities during signal transmission. In a m network, the interference level of your device is only 1/4 of that of common 5-class cables. Therefore, it is considered as a "solution for future network applications", but it is rarely used in shared Ethernet.

Twisted pair wire is generally used for star network cabling, the two ends of the installation with a RJ-45 head crystal head), the network adapter and Hub Connection workstation, the maximum network cable length is 100 meters, if you want to increase the network range, A repeater can be installed between two twisted pair wires, but up to four reconnections can be installed, that is, up to four reconnections can be connected to five CIDR blocks, and the maximum range can be 500. When the twisted pair cable is connected to the HUB and network card, how can we determine whether the connection is established? First of all, when installing the RJ-45 head, the twisted pair wire cabling sequence of the two RJ-45 heads should be fixed and unified; the second is to check whether the LED on the HUB and Nic is shiny, because a pulse signal is sent between the hub and the network card every 16 milliseconds. when the two sides can receive the signal, the LED will shine, indicating that the physical connection is normal.