Chapter 18 Practical ADSL Techniques
18.1 Internet ADSL connection of A Computer
ADSL is short for Asymmetric Digital Subscriber Line. It accomplishes quickly bilaterally transmitting digital signals for voice and data on a pair of ordinary telephone line by nowaday advanced digital codings、the modulation and demodulation technologies such as FDM
(Frequency-Division Multiplexing) and DMT (Discrete Multiaudio Technology).Its effective transmitting range is 3~5 kilometers, with upper speed 640kbps, the top lower speed 6~8Mbps.
The device used in Internet ADSL connection is called ADSL modem. ADSL modems are now mainly divided into three kinds: the one with a PCI port, the next one with a USB port, another one with a RJ-45 port, of which the ADSL modem with a PCI port is cheap, but complex to install, therefore it is sparsely used; the ADSL modem with a USB port is popular without dismantling the computer for installing it; the ADSL modem with a RJ-45 port needs no installing the drives, but runs with a Ethernet Networking Interface Card(NIC).Next comes introducting how to accomplish Internet connection of a computer with ADSL modem.
18.1.1 Installing the ADSL modem with a RJ-45 port
(1) TO connect the RJ-45 port of a NIC and E port(Ethernet 10BaseT/MDI-X) of the modem with accessary straight-through linking line, PWR port and a transformer.
Fig. 18.1 A method to connect them Fig. 18.2 The other method to connect
(2) TO connect the modem and ADSL splitter. There are two connecting methods(according to Fig.18.1 and Fig.18.2), of which the first is held to by Chinese Telecommunication, while the other method is requested to held in the manual. As a result of the fact, they are both feasible.
(3) To turn on the power of the ADSL modem, which will come into working state half a minute later.Then the synchronal light begin to aglow.
18.1.2 Installing and configuring the software
The steps lie below: The first thing is to configure Microsoft Internet Explorer(IE).An user can click the item “Internet options” in the tool menu, and click the item “connecting”,and then
cross out the item "automatically to seek the proxy server. The other thing is to install the relative
protocols and dialing software. The familiar dialing softwares for ADSL include WinpoET、
EnterNet and RASpppoE. During their installings the relative protocols will be automatically added to the computer. Because installing EnterNet and WinpoET is quite easy, the user can accomplish it by clicking the button“Next”or “Finish”. After WinpoET has been installed, the
dial-up window will automatically pop up(according to Fig. 18.3), then what the user has to do is to fill the window with a correct account and the password, thus the computer can be connected to Internet.
Fig. 18.3 The dialing dialog box of WinpoET Fig. 18.4 The main window of EnterNet
While EnterNet requests that the user has to create the connection by himself. The user ought to open the window according to Fig.18.4 by doubly clicking the icon of EnterNet, in the window the user should click the item “Creat New Profile” and fill it with the connecting symbol by the
prompts, and then fill it with the account and password. Next pops up the dialog box demanding the user to select devices, the user can click the button “Next” after clicking the symbol of the
NIC connected to the ADSL modem in the popped menu. Then EnterNet demand the user to select a protocol, he should choose PPPoE(according to Fig. 18.5).Finally the user can make the computer to be connected to Internet by doubly clicking the created connection(according to Fig. 18.6).