In the network hardware, there is a class that can not be ignored is the network transmission media, and we usually call the network cable. At present, the more common network cable sub-twisted pair, fiber optic cable, coaxial cable and coarse coaxial cable.

Fiber optic cable

Fiber-optic cable is a new generation of transmission media, compared with copper media, fiber, whether in terms of security, reliability or network performance has been greatly improved. In addition, the bandwidth of optical fiber transmission beyond the copper cable, and its support for the maximum connection distance of more than two kilometers, is the inevitable choice for the formation of larger networks. As the optical fiber cable has good anti-electromagnetic interference, confidentiality, speed, transmission capacity, etc., so its price is more expensive, rarely used in domestic occasions. At present, there are two different types of optical fibers commonly used, namely single-mode optical fibers and multi-mode optical fibers. The so-called "mode" means a beam of light that enters the optical fiber at a certain angle. Multimode fiber is typically used for network connections in the same office building or in relatively close area. The single-mode optical fiber to transmit data of higher quality, longer transmission distance, is usually used to connect office buildings or geographically dispersed networks. If the use of optical fiber and cable as a network transmission medium, the need to increase optical transceivers and other equipment, so the cost of investment greater, less commonly used in the application.

Twisted pair

Twisted pair is a flexible communications cable, containing pairs of insulated copper wire, which is characterized by cheap, it is widely used, such as our common telephone line. According to the different maximum transmission rate, twisted pair can be divided into Category 3, Category 5 and Category 5. Category 3 twisted pair speed of 10mb / s, 5 up to 100mb / s, while the ultra-Category 5 up to 155mb / s or more, can be suitable for future multimedia data transmission needs, it is recommended to use Category 5 or even Category 5 Stranded. Twisted pair can also be divided into shielded twisted pair (stp) and unshielded twisted pair (utp). stp twisted pair Although the rate is low (only 4mb / s), but the anti-interference than utp twisted pair, so the price is much more expensive, and now a few dollars a meter of such twisted pair, expensive thing More than ten yuan to buy a meter. In contrast, utp twisted pair is generally about one meter in price, more affordable. In addition, the commonly used 10m and 100m unshielded twisted pair popular name is 10base-t and 100base-t, we can often see in the market. And supporting the use of twisted pair rj45 crystal head, used to make twisted pair and network card connector between the rj45 interface, the quality of the network is directly related to the stability of the quality can not be ignored.

3. Coaxial cable

Coaxial cable is familiar to many friends of a class of transmission medium, which is a layer of insulated wire wrapped around the center of the copper conductor cable, its most important feature is the anti-interference ability, the transmission data is stable, and the price is cheaper , It was once widely used, such as closed-circuit television lines. However, the previous coaxial cable was mainly used because the cost of a bus network composed of coaxial cables is relatively low. However, the damage of a single cable may cause the entire network to be paralyzed and be difficult to maintain. This is the biggest drawback. Coaxial Ethernet applications are mainly divided into coarse coaxial cable (10base5) and fine coaxial cable (10base2) two. Rough coaxial cable is now running out of small, thin coaxial cable there are some markets. Thin coaxial cable general market price of a few dollars a meter, not too expensive. In addition, the coaxial cable is used to connect with the bnc head, coaxial cable sold on the market are generally finished with the bnc head connected, we can directly use.