When building a network, most people will pay attention to equipment such as switches, routers, and network cards, but they are generally not too picky about network cables. However, with the expansion of network scale and the increase in demand for network cables, the importance of network cables has become increasingly obvious. So what types of network cables are there, what are the differences between different network cables for data transmission, and how to choose a network cable when building a network?
1、Network cable type
network cable mainly divide into three kinds, “twisted pair”,”coaxial cable”,”fiber optical”
Twisted pair
Twisted pair (TP) is one of the most commonly used transmission media in integrated wiring projects. It is generally formed by two 22-26 gauge insulated copper wires entwined with each other. The name “twisted pair” is also derived from this . 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 headTwisted pair cable can be divided into unshielded twisted pair (UTP) and shielded twisted pair (STP). The outer layer of the shielded twisted pair cable is wrapped with aluminum platinum to reduce radiation, but it cannot completely eliminate the radiation. The price of shielded twisted pair cable is relatively high, and installation is more difficult than that of unshielded twisted pair cable. Unshielded twisted pair cable has the following advantages:
Unshielded jacket, small diameter, saving space occupied; light weight, easy to bend, easy to install; stringing the proximal end
Disturbance is minimized or eliminated.
Twisted pair cables are from category 1 to category 7, and the positioning network is different, and the transmission rate is also different.
Coaxial cable
Coaxial cable refers to a cable with two concentric conductors, and the conductor and the shielding layer share the same axis. It is a kind of network cable. The most common coaxial cable consists of a copper conductor isolated by an insulating material. Outside the inner insulating material is another layer of ring conductor and its insulator, and then the entire cable is covered by a polyvinyl chloride or Teflon material sheath. .
Optical Fiber
Optical cables are manufactured to meet optical, mechanical or environmental performance specifications. It is a communication cable assembly that uses one or more optical fibers placed in a sheath as a transmission medium and can be used individually or in groups. An optical cable is a communication line in which a certain number of optical fibers compose a cable core in a certain manner, and are covered with a sheath, and some are also covered with an outer sheath to realize the transmission of optical signals.
What is the difference between a network cable and a telephone line? Can they be shared?
- different roles
1、The telephone line uses ADSL to modulate the computer’s digital signal into an analog line number and spread it through the telephone line. After reaching the opposite end, which is the telecommunications side, the analog signal is demodulated into a digital signal. The network cable access to the Internet lacks the step of modulation and demodulation.
2、Bandwidth issues. The telephone line is affected by the physical bandwidth, and generally the bandwidth is not too high (the maximum bandwidth is
8M), the physical bandwidth of the network cable is relatively high (a good network cable can reach 1000M or more).
（2）Different interface：
Why is the phone interface connected with the cat, but the network cable interface has no response when it is connected? This is because the signal from the phone line needs to be converted and processed by the cat to be forwarded to the network equipment, such as forwarding to the computer, router, Hubs and switches, etc. If it is connected directly, it is an unrecognizable analog signal, which is equivalent to no signal. In other words, the role that the cat plays in the middle is signal conversion and simple processing. Specifically, it converts the analog signal from the telephone line into a digital signal to the network device, and converts the digital signal sent by the network device into an analog signal. The phone line goes out.
（3）Sharing is not recommended. The method of choosing a network cable and a telephone line to share a network cable is common in the network systems of small and medium-sized enterprises, especially small enterprises. Some network managers have neutralized the telephone and network for the consideration of saving the funds of the integrated wiring for the enterprise, and chose the method of sharing the same network cable with the network cable as the solution to the current situation. In order to avoid later management, maintenance and troubleshooting considerations, it is not recommended that the telephone and the network share a network cable.
3、Enterprise networking is to choose the super five or six network cable
There is no difference between the use of Category 5 and Category 6 networks, and the connection scenarios and costs used are different.
The recognition is “CAT6”, attracting 250M, Category 6 unshielded twisted pair can support Ethernet implementation very well, and the transmission distance of 100m is upgraded. Six types of functional systems are widely used in the design of sub-machine rooms and floors that retain the six types of non-intrusive capabilities. Category 6 non-intrusive twisted pair cables are expensive, but because they have very good advantages over Category 5 systems and can support 1000Base-T very well, they have slowly become the new favorite of integrated pets.
If you consider the future application requirements of the network, theoretically the most advanced wiring products should be installed, because it is often difficult to update and replace after the installation of cables. Basically, a wiring system must be used as a standard for at least 10 years and can support 4 to 5 generations of networks The performance of the equipment is updated, if the future network equipment needs better cables to increase the data speed. So, it is inevitable to use Category 6 cables to replace Category 5e cables.
However, these cable re-assembly projects are very expensive, so even if the price of Category 6 products is slightly more expensive than Category 5 products, in order to reduce future network upgrade problems, Category 6 products are still worth considering.