1. Fiber optic 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 fiber transmission greatly exceeds the copper cable, and the maximum connection distance supported by it is more than two kilometers, which is an inevitable choice for building a large-scale network. Since the optical fiber cable has the advantages of good electromagnetic interference resistance, strong confidentiality, high speed, and large transmission capacity, it is also expensive and rarely used in household applications. At present, there are two different types of optical fibers, single mode fiber and multimode fiber (the so-called "mode" refers to a beam of light entering the fiber at a certain angle). Multimode fibers are typically used for network connections in the same office building or in relatively close proximity. Single-mode fiber delivers higher quality data and longer transmission distances, often used to connect between office buildings or geographically dispersed networks. If fiber optic cable is used as the network transmission medium, devices such as optical transceivers need to be added, so the cost is relatively large, and it is rarely used in general applications.
2. Twisted pair
Twisted pair is a flexible communication cable that contains pairs of insulated copper wires. It is characterized by its low price and is widely used, such as our common telephone lines. According to the maximum transmission rate, twisted pairs can be divided into 3 categories, 5 categories and 5 categories. The rate of Category 3 twisted pair is 10mb/s, Class 5 can reach 100mb/s, and Category 5 is up to 155mb/s, which can be suitable for future multimedia data transmission. Therefore, it is recommended to use Category 5 or even Category 5 Stranded wire. Twisted pair cables can also be divided into shielded twisted pair (stp) and unshielded twisted pair (utp). Although the stp twisted pair has a low speed (only 4mb/s), the anti-interference is stronger than the utp twisted pair, so the price is much more expensive. Now this kind of twisted pair is a few yuan cheaper than a meter. It is expensive. More than ten yuan can buy one meter. In contrast, the price of utp twisted pair is generally around one meter and one yuan, which is relatively low. In addition, the popular 10m and 100m unshielded twisted pair popular names are 10base-t and 100base-t, which are often seen in the market. Also used with the twisted pair is the rj45 crystal head, which is used to make the joint between the twisted pair and the network card rj45 interface. The quality is directly related to the stability of the whole network and cannot be ignored.
3. Coaxial cable
Coaxial cable is a kind of transmission medium that many friends are familiar with. It is a cable line of a central copper conductor wrapped by a layer of insulated wire. Its biggest feature is good anti-interference ability, stable transmission data, and low price. So it was once widely used, such as closed-circuit television lines. However, in the past, there were many coaxial cables, mainly because the bus structure composed of coaxial cables had lower network cost, but the damage of a single cable may cause the entire network to be paralyzed and difficult to maintain. This is its biggest drawback. The coaxial cable in Ethernet applications is mainly divided into two types: thick coaxial cable (10base5) and thin coaxial cable (10base2). Thick coaxial cables are not used much now, and there are some markets for thin coaxial cables. Thin coaxial cable is generally sold for a few yuan a meter, not too expensive. In addition, the coaxial cable is used to connect with the bnc head. The coaxial cable sold on the market is generally a finished product that has been connected with the bnc head, and can be directly used.