Wiring skills (I): network cable review and basics

Welcome to the network technology community forum and interact with 2 million technical staff. The focus of this series is the wiring method used by the current network. Currently, there are many different types of network cabling. In this article, I will only elaborate on the most common network cables, including UTPCAT5 express connect and crossover lines and Coaxial Lines. If you want to minimize network problems and bandwidth

Welcome to the network technology community forum and interact with 2 million technical staff> the focus of this series is the wiring method currently used by the network. Currently, there are many different types of network cabling. In this article, I will only elaborate on the most common network cables, including UTP CAT5 direct and cross lines and the same axis. If you want to minimize network problems and bandwidth

Welcome to the network technology community forum and interact with 2 million technical staff> enter

This series focuses on the current cabling methods used by the network. Currently, there are many different types of network cabling. In this article, I will only elaborate on the most common network cables, including UTP CAT5 direct and cross lines and the same axis.

Wiring is very important if you want to minimize network problems and bandwidth losses. When you try to design a network, there are some rules that cannot be violated-otherwise, you will encounter many computer communication problems. I have seen many cases where the network suffers from a large number of running problems due to incorrect initial design.

With the increasing popularity of wireless connections, in the near future, wired networks may become outdated and outdated. Even so, about 95% of companies still rely on wired networks.

Let's quickly review the wiring history, which helps us better understand the wired network.

Origin

We all tend to think that digital communication is a new technology, but as early as 1844, A new invention called Samuel Morse sent a message to Baltimore 37 miles from Washington D.C. Although this is far from today's computer networks, their principles are the same.

The Morse code is a binary system that uses vertices and bars in different sequences to represent letters and numbers. Modern data networks use 1 and 0 to achieve the same results. The biggest difference is that in the 19th century, the reporter may only transmit four or five verbs per second, and today's computer communication speed can reach 1 Gigabit, in other words, that is, the data can be transmitted for 1 and 0 for 1,000,000,000 times each second.

Although telegraph and telex typewriters are the pioneers of data communication, communication technology has developed rapidly in the past 35 years. This will inevitably lead to the continuous improvement of computer communication speed, and also drive the development of faster and faster network devices, more and more advanced network cables and connection hardware.

The development of new network technologies

In the middle of 1970, Xerox Corporation in California developed Ethernet at its Palo Alto Research Centre (PARC. In 1979, DEC and Intel and Xerox jointly standardized the Ethernet system to suit user needs. In 1980, the three companies released the first "Ethernet Blue Book" standard, which is known as the "DIX standard" abbreviated to the names of the three companies ".

This is a 10 MB (1010 Mbps = 10 million 1 and 0) system per second. It uses a large coaxial trunk network cable to connect the entire building, connect the workstation with a small coaxial network cable at an interval of 2.5 meters. Large coaxial network cables are often yellow, known as "coarse Ethernet" or 10 Base5-"10" refers to the speed (10 Mbps ), "Base" is because it is a baseband system (the baseband uses all bandwidth for transmission, while the bandwidth is divided into different channels for concurrent use ), "5" is the abbreviation of the system's maximum network cable length of 500 meters.

In 1983, Institute of Electrical and Electronic Engineers (IEEE) released an official Ethernet standard named IEEE 802.3 in the name of the Working Group responsible for development. 1985 versions (IEEE 802.3a) were released in 2nd ). This second version is usually called "thin Ethernet" or 10Base2. The maximum length of this version is 185 meters, although "2" indicates that it should be 200 meters.

Since 1983, due to higher bandwidth requirements, various standards have emerged, and now we have reached the Gigabit ratio.

Unshielded twisted pair wires

Unshielded twisted pair wires are currently the most popular network cable in the world. The UTP line is used not only in the network, but also in the traditional telephone network (UTP-Cat 1 ). There are six different types of UTP. You must select the network cable type that suits your needs. UTP-CAT5 is the most popular UTP cable. Since the previous Coaxial Lines could not adapt to the network's growing demand for faster speed and higher reliability, it was replaced by UTP-CAT5.

UTP features

UTP has excellent features and is very easy to operate, install, scale and fix. Now, we will consider how to create UTP direct connections, safe operation rules, and other useful things for different UTP layout charts!

Therefore, let's take a quick look at the various available UTP:

Category 1/2/3/4/5/6-specifications for a copper wire type (most telephone and network cables are copper) and sockets. The number (1, 3, 5, etc.) indicates the number of revisions to the specification, and the actual number of twists in the network cable (or the connection quality of the socket.

CAT1 is usually used in telephone lines. This type of line does not support computer network traffic and cannot be twisted. It is also used in telephone companies to support ISDN. CAT1 network cable is used in customer websites and telephone company networks.

CAT2, CAT3, CAT4, CAT5, and CAT6 are all network cable specifications. This type of line supports computer networks and telephone networks. CAT2 is mostly used to support the card ring network and supports a maximum speed of 4 Mbps. For a higher network speed (more than 100 Mbps), you must use CAT5 lines. For 10 Mbps, CAT3 is enough. CAT3, CAT4, and CAT5 cables are actually 4 pairs of double-plastic copper wires, while CAT5 is more twisted per inch than CAT3, so it can be used for higher speed and longer length. The impact of each pair on the network cable will lead to the disconnection of any network cable that appears/pick out the interference. Both CAT3 and CAT4 are used in the ring-the only difference is that CAT3 can be 100 meters in length, while CAT4 can only be 200 meters.

CAT6 was initially designed to support Gigabit Ethernet (although there is a standard that allows CAT5 lines to transmit Gigabit Ethernet, that is CAT 5e ). It is similar to CAT5 wire, but it is physically separated from 4 pairs to further reduce electromagnetic interference.