Coaxial cable can be divided into two basic types, baseband coaxial cables and broadband coaxial cable. At present, baseband is a commonly used cable, the shielding line is made of copper mesh, characteristic impedance of 50 (such as RG-8, RG-58, etc.); the shielding layer of cable used in broadband coaxial cables is usually made of aluminum, and the characteristic impedance is 75 (such as RG-59).
Coaxial cable According to its diameter can be divided into: coarse coaxial cable and fine coaxial cable. The coarse cable is suitable for the large local network, its standard distance is long, the reliability is high, because the installation does not need to cut off the cable, therefore may flexibly adjust the computer's network position according to the need, but the thick cable network must install the transceiver cable, the installation difficulty is big, therefore the overall cost is In contrast, the installation of fine cables is relatively simple, low cost, but because the installation process to cut off the cable, both ends must be fitted with the basic network connection Head (BNC), and then connected to the T-type connector at both ends, so when the joint is prone to bad hidden trouble, this is the current operation of the Ethernet is one of the most common failure.
Whether it is a rough or fine cable is a bus topology, that is, a cable connected to multiple machines, this topology is suitable for a machine-intensive environment, but when a contact failure, the failure will cascade affect all the machines on the entire root cable. Fault diagnosis and repair are cumbersome, so it will gradually be replaced by unshielded twisted pair or cable.