What is Network Cable?

A network cable is essential for connecting to a local area network. Commonly used network cables in LANs are twisted pair, coaxial cable, and optical cable. Twisted pair is a data transmission line consisting of many pairs. Its characteristic is that it is cheap, so it is widely used, such as our common telephone lines. It is used to connect with RJ45 crystal head .

There are two standards for twisted pair termination: T568A and T568B, and there are two main methods for connecting twisted pair: straight-through cable and crossover cable. Both ends of the crystal head of the straight-through cable follow the T568B standard. Each set of twisted-pair wires corresponds one-to-one at both ends. The same color remains in the corresponding slots of the crystal head at both ends. It is mainly used on the switch (or hub) Uplink port to connect the switch (or hub) common port or the switch common port to the computer network card. And cross cable

Twisted pair: Horizontal cables are used for data transmission with a permanent link not exceeding 90 meters and the channel not exceeding 100 meters.

Coaxial cable : 75-7 coaxial cable is about 200-250 meters, 75-5 is about 100-150 meters.

The twisted-pair wires on the market are not the same, and are mainly expressed in the material of the line (the following materials have a decreasing degree of quality from top to bottom):

Texture	description
Pure copper	This type of network cable is the best network cable, and copper has the second smallest resistance under the same conditions, so it can be used as a high-quality cable. And it is suitable for POE power supply. The small resistance can avoid electricity loss during transmission.
Aluminum wire	The quality of this type of network cable is inferior to that of copper cable, but there is no big problem in short-distance use, so the terminal of the home or small office-the switch line can choose this type of cable. This type of wire is only suitable for short-distance POE power supply because the resistance is greater than copper wire.
Copper clad aluminum wire	This type of network cable has a layer of copper plated on the outside of the aluminum wire. Due to the skin effect, the electrical conductivity of the aluminum wire has been improved. However, this type of cable is also only suitable for short-distance POE power supply, also because of its large resistance.
Copper-clad iron wire	This type of network cable has a layer of copper plated on the outside of the iron wire. Due to the skin effect, the conductivity of the iron wire is improved to a certain extent. But this kind of line is not suitable for POE power supply, because the resistance is large.
Core wire	This type of network cable has a large resistance and is only suitable for transmission in short distances and with low network speed requirements. This type of wire is not suitable for POE power supply, also because of the large resistance.
Mixed wire	Some of these network cables use copper and some aluminum. They are only suitable for short distances and can be used for POE power supply. However, when making crystal heads, they must be made strictly according to the wire sequence. Otherwise, copper wires cannot be used for power supply, which will increase resistance. , Affecting the power supply effect.

The identification of the third category line is "CAT3", and the bandwidth is 10M, which is basically eliminated for ten trillion networks. The identification of the fifth category line is "CAT5", and the bandwidth is 100M, which is suitable for networks below 100M. The identification of the super five category line is "CAT5E", with a bandwidth of 155M, is a mainstream product; the identity of the category 6 line is "CAT6", with a bandwidth of 250M, which is used to set up a Gigabit network

In addition to fake lines, there are many cases in the market where Category III lines are used to impersonate Category V lines and Super Category V lines. The following is the identification method of the network cable:

• Lines in the third category are two to four, and lines in the fifth category are four to eight.

• The outer rubber of the real thread is not easy to burn, while the outer rubber of the fake thread is mostly flammable.

• Under the higher temperature (above 40 ), the outer rubber will become soft, but it will not.

• The copper core material inside the real wire is relatively pure, soft, tough and not easy to be broken.

• The twist direction of the network cable is twisted counterclockwise instead of clockwise. Clockwise winding will affect speed and transmission distance.

• The number of turns in the network cable when the pair is wound is different, because if the number of turns is the same, the transmission signals between the two pairs of wires will interfere with each other, making the transmission distance shorter.

• There is a layer of metal mesh and insulation between the shielded twisted pair wire and the rubber, and the crystal head is also covered by metal.

• If conditions permit, you can find a 100-meter twisted pair cable and use the "Network Monitor" or "Resource Monitor" in Windows to conduct field tests. Category 5 cables can reach 100 Mbps, and category 3 cables have only 10 Mbps.

• Standard cable length 1000 feet / box (approximately 305 meters)

• The magnet core can be used to identify the core wire. If the network cable can be attracted by the magnet (even if it is slightly attracted), it indicates that the core wire is a core wire. Because the core wire has a large resistance, it seriously affects the transmission efficiency and the transmission distance. It is not recommended to buy it. High-quality network cables generally use copper as the core. Even if the wire is worse, aluminum should be used as the core.

• Peel off a little network cable and look at the thickness of the core. A thin core will also affect the transmission efficiency. So you should choose a relatively thick wire core.