In the network hardware, there is a category that can not be ignored is the network transmission medium, we usually called the network cable. At present, the more common network cable is fine twisted pair, fiber optic cable, coaxial cable, and coarse coaxial cable. Fiber optic cable is a new generation of transmission media. Compared with copper media, optical fiber has greatly improved in terms of security, reliability, and network performance. In addition, the bandwidth of optical fiber transmission exceeds that of copper cables, and the maximum connection distance it supports is more than two kilometers. This is an inevitable choice for building larger networks. Because fiber optic cable has the advantages of good anti-electromagnetic interference, strong confidentiality, high speed, and large transmission capacity, its price is also relatively expensive, and it is rarely used in home use. Coaxial cable is a kind of transmission medium which many friends are familiar with. It is a cable with a central copper conductor wrapped by a layer of insulated wire. Its greatest feature is its good anti-interference ability, stable transmission data, and low price. , so it was widely used, such as closed-circuit television lines. However, more coaxial cables were used in the past, mainly because the cost of the bus structure network composed of coaxial cables is low, but the damage of a single cable may cause the entire network to collapse and maintenance is difficult, which is its biggest drawback. The above network cable will often be the one used in the fiber closure of optical fiber to enter homes and businesses. With the improved cable, fiber closure can better play its role, it can transmit information more quickly and accurately, without excessive losses in the middle of the process.