This article help you identify the network cable in your home.Most of the network cables used in our daily homes are still twisted-pair cables.
Whether it is transmitting analog signals or transmitting digital signals, twisted-pair cables are commonly used transmission methods.
When we make a crystal head for a twisted pair, we will find that it is composed of two, four or eight insulated wires arranged in a regular spiral structure. A pair of wires can be used as a communication wire.
The purpose of the spiral arrangement of each wire pair in the twisted pair is to minimize the electromagnetic interference between each wire pair.
The twisted pair used in the local area network mainly has two levels of shielded twisted pair (STP) and unshielded twisted pair (UTP).
Unshielded twisted pair has no shield, and only consists of an outer protective layer and multiple twisted pairs, as shown in the figure below.
The network cables we use in the local area network are several of the many twisted pairs, and the network cables are usually four pairs of eight-core twisted pairs.
As early as the early 1990s, the TIA/EIA568 standard, the two standardization organizations of the American Telecommunications Association (TIA) and the Electronic Industries Association (EIA), specified the specification of twisted pair cables.
This description divides the unshielded twisted pair (UTP) into five categories. Later, with the development of network communication technology, Category 5e and Category 6 cables appeared.
For network cables, the commonly used unshielded twisted pair (UTP) cables are Category 5e and Category 6 cables.
For Category 5 wire, it is also widely used in current local area networks, and its transmission rate can reach 100Mbit/s; for Category 5e wire, it usually uses high-quality copper wire with higher winding, which is used in the production process Advanced manufacturing processes can reduce crosstalk.
It can support the rate of up to 200Mbit/s for the Super Category 5 cable, which is twice the capacity of the conventional Category 5 cable.
It can be seen that the quality of the network cable is one of the key factors in determining the LAN bandwidth.
For Category 6 wire, it includes four wire pairs. Each pair of wires is wrapped by a foil insulator, another layer of foil insulator is wrapped around all pairs, and a layer of fire-resistant plastic wrap is wrapped around the second layer of foil.
The foil insulator in Category 6 cables is very good for crosstalk. Resistance, so that Category 6 cables can support six times the throughput of conventional Category 5 cables.
Therefore, most of the network cables used now include Category 5 cables, Category 5e cables and Category 6 cables.
If we want to distinguish them, we can identify them from the appearance characteristics and logos of the network cables.
For example, we can see the information marked on the outer skin of the network cable. If the word “CAT5” is printed, it means that the network cable is a Category 5 twisted pair cable. If an “e” letter is added after CAT, it means that it is a super five It is a Category 6 network cable; if “CAT6” is printed, it is a Category 6 network cable, as shown in the figure below.
When we use the network cable, we will also find that the letter “CATEGORY 5” is sometimes printed on the outer foreskin of the network cable, which also means that it is a Category 5 network cable.
In addition, we can also judge the type and quality of the network cable from other appearances of the network cable.
For example, when we make the crystal head for the network cable, we can observe whether the copper core in the network cable has good toughness.
The brighter the color of the copper, the better the toughness. It means that the level of the network cable is higher, because the quality of the network cable is one of the key factors that determine the bandwidth of the local area network.
In addition to looking at the quality of the copper core, we can also observe the manufacturing process level of the network cable.
For example, we can see the winding density and direction of the wire pairs inside the network cable.
We know that in order to reduce the interference of communication signals, each wire pair in the network cable is composed of two Insulated copper wires are wound with each other.
The winding density of all pairs in the network cable should be the same, and the winding direction should be counterclockwise.
Under normal circumstances, in the five types of UTP, the winding degree of the pair is denser than that of the four types; the super type five is denser than the five types.
Finally, we can also see that the network cable is not easy to bend, and the high-quality network cable should be bent naturally so that it is convenient for wiring; we can also see whether the outer sheath of the network cable is flame-retardant, in order to avoid the cable damage caused by high temperature or fire , the outermost layer of the twisted-pair cable should not only have good tensile properties, but also have flame retardancy. We can use a lighter to test it and know that the rubber will become soft when heated. Will not catch fire.
For the “Category 5e” network cable, it has two categories: Unshielded Twisted Pair (UTP) and Category 5e Shielded Twisted Pair (STP). The unshielded twisted pair cable is composed of multiple pairs of twisted pairs and a plastic sheath. The outside of the Category 5 shielded twisted pair (STP) is wrapped with a layer of metal material to reduce radiation and prevent information from being eavesdropped.
At the same time, it has a high data transmission rate, but the price is high and the installation is more complicated; the unshielded twisted pair (UTP) price is relatively cheap and the networking is flexible. Except for some special occasions, such as the use of shielded twisted pair (STP) for wiring in places with severe electromagnetic radiation and high requirements for transmission quality, we generally use unshielded twisted pair (UTP).
The UTP currently used can be divided into three categories, four categories, five categories, super five categories, six categories, and six categories. Now Category 5 UTP has become the first choice for Fast Ethernet 100Mbps because of its high quality and low price; Category 5 UTP cable can support Gigabit Ethernet.