About ADSL and dial up Internet access

Please don't talk nonsense if you don't understand! Who says ADSL doesn't have a distance limit?

ADSL theoretically transmits a distance of 5 km, but in practice, the effect of more than 3 km is very bad.

This 5 kilometers and 3 kilometers refers to the distance from the line to the switch (the switch, not the computer switch), at least a community in the city has a switch, generally a switch in several buildings, the length will never exceed 3 kilometers, so there is no problem, but the consumer living position in the township is relatively loose, and many times the signal needs to be transmitted over long distances. And then the question arises.

However, in response to your statement, 13 kilometers from your home to the town does not mean that there is no telecom switch near your home, and the 13 kilometers is not the length of the ** line. Specifically, you have to ask the local ** department. Hehe, you just ask them directly if you can install ADSL in your house, and if he says that he can come and install it, and the result is not good, you can go to court to sue him.

Khan, how did your supplementary question change and reply, I almost didn't see ......3 km refers to the length of the ** line. It is not a modem to the network cable of the computer.

It can be used, but it's not as good as it is in terms of speed

I still don't understand. ADSL is connected to the Internet by the computer through the cat, so this three kilometers is the distance of the **line or the distance between the cat and the computer??

I have experience in this, a branch of our company is in the countryside, and the broadband speed is very slow, and the connection is often dropped, and the Internet cannot be accessed, so it is recommended to consult the telecommunications department in detail whether the installation of ADSL will affect the speed, and record it when asking, if they say it will not, you will pretend, and if there is a problem, find them with the recording!!

**The line will definitely have a relationship! "When I used to work in Kashgar, Xinjiang, it was about 10 miles away from the city, and I connected to a telecom ADSL, and I often couldn't get on the line." Hehe!

Therefore, the ** line can't be long, too far away from the main line of the telecom or Netcom company, it will particularly affect the network speed!

ADSL is not limited, as long as you can lay the first line, you can install ADSL, and you can reach it all over the world.

ADSL dial-up refers to connecting to the Internet by dialing the access number of the ISP.

At present, users of dial-up Internet access in China basically use the full name of Point to Point Protocol over Ethernet based on PPPoE protocol, which is a protocol that combines Ethernet and PPP protocol.

PPPoE technology and broadband modems (e.g., ADSL modem) enable personal authentication access to high-speed broadband networks, creating a virtual dial-up connection for each user, so that they can connect to the Internet at high speeds.

Dial-up Internet access has been largely eliminated for a long time. Nowadays, home Internet access is basically broadband. Common ones are ADSL technology that uses ** lines, the latest fiber-to-the-home, cell fibers and so on.

Categories: Computer Internet >> Internet.

Analysis: ADSL technology is a technology for asymmetric digital subscriber lines to achieve broadband access to the Internet, ADSL as a transport layer technology, make full use of the existing copper line resources, and provide a bandwidth of 640kbps uplink and 8Mbps downlink on a pair of twisted pair cables, thus overcoming the traditional user in"The last mile"of"Bottlenecks", to achieve broadband access in the true sense.

The principle of ADSL:

Traditionally, ** systems use the low-frequency portion of the copper wire (band below 4kHz). ADSL uses DMT (Discrete Multi-Audio) technology to divide the original ** line from 0Hz to the frequency band into 256 sub-frequency bands with a frequency width. Among them, the frequency band below 4kHz is still used to transmit POTS (traditional ** service), the frequency band from 20kHz to 138kHz is used to transmit uplink signals, and the frequency band up to 138kHz is used to transmit downlink signals.

DMT technology adjusts the number of bits modulated on each channel according to the conditions of the line in order to make better use of the line. In general, the greater the signal-to-noise ratio of a sub-channel, the more bits are modulated on that channel. If a sub-channel has a poor signal-to-noise ratio, it is discarded.

Currently, ADSL can achieve data rates of 640kbps uplink and 8Mbps downlink.

As can be seen from the above, for the original ** signal, the original frequency band is still used, while the ADSL-based service uses a frequency band other than voice. Therefore, the original ** business will not be affected in any way.

Dial-up Internet access means that users use a personal computer, an external or built-in modem and a ** line, and then apply for their own account with the local ISP ** provider, or buy a network card, have their own username and password, and then connect to the Internet by dialing the ISP access number.

There is no strict definition of broadband. From a general point of view, it is the bandwidth that can meet the needs of various ** transmission on the network that people can feel, so it is also a dynamic and developing concept.

Dial-up Internet access:

Users have a personal computer, an external or built-in modem and a cable, apply for their own account with a local ISP, or buy a network card, have their own username and password, and then connect to the Internet by dialing the ISP's access number.

Wideband: In basic electronics and electronic communications, it describes a signal or electronic circuit that contains or is capable of simultaneously processing a wide range of frequencies.

The connection mode and bandwidth are different, dial-up is to use ** line, bandwidth 14kbps-56kbps (modem is different at different speeds), and broadband is connected to ADSL modem with a network cable, and then connected to ** line, you must apply to the operator, bandwidth 1 3mbps, bandwidth is fast.

In addition, dialing is an analog signal, that is to say, the computer converts the digital signal into an analog signal through the modem, and then transmits it through the ** line, and then converts it to a digital signal in telecommunications, while the broadband transmission is a digital signal.

Also, the frequency used for dial-up is the same as the frequency band of **, so when using dial-up to access the Internet, it is not possible to call, and the frequency of ADSL is much higher than the frequency band of **, so it is possible to call ** when accessing the Internet through broadband.