One, modem dial-up Internet access There are many types of modems, the cheapest and most common of which is the use of telephone lines as a transmission medium for audio modems.
Two, cable modem, also known as cable modem, with it, you can use the cable network for data transmission, high-speed access to the Internet through the cable TV cable.
Three, ISDN access that is, Integrated Services Digital Network. Users only need a communication line, an ISDN number, a terminal adapter with ISDN standard interface can realize high-speed, high-quality Internet access.
Four, ADSL dedicated line access that is, asymmetric digital subscriber line access. This way of accessing the Internet does not have to pay the phone bill, can be online 24 hours a day, is a dedicated line to access the Internet, and answer the phone, make a phone call does not affect each other.
At present, ADSL is the fastest, but the highest cost of equipment; ISDN speed, access equipment costs cheaper than ADSL; cable modem hardware investment and charges higher, easy to install and use; dial-up Internet access is simple, but slower.
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Service Providers Provide Services
1, Dial-up Internet Access
Up 163 Required Equipment and Access Methods
Required Equipment
Have a 586 computer, have the relevant software, have a MODEM, have a telephone line, and then carry a valid document that can prove your identity to the local telecommunications department to register an account - your "network ID card. After the account is opened, you will become a formal "Internet users", start your "online life". We wish you good luck!
What are the ways to access CHINANET?
1. Ordinary telephone dial-in.
2, through the ISDN, through the ISDN Internet, you will have the feeling of a dedicated line;
3, and 163 dedicated phone dial-in. 163 dedicated phone will be comrades of the networms to save a lot of telephone expenses.
Dial-Up Network Opening Fee
(yuan) Basic Fee Network Usage Fee Communication Fee
CHINANET
(163) CHINFO
(169)
Dial-Up Registration Class A Business 100 0 3 yuan/hour 1.8 yuan/hour 0.02 yuan per minute
One time
Dial-Up Registration Class A Business 100 0 3 yuan/hour 1.8 yuan/hour
One time
One time
One time
Category B business 0 50 yuan/month 2 yuan/hour 1.5 yuan/hour
100 yuan/month 2 yuan/hour 1 yuan/hour
Internet card
(stored value card) 0 0 0.05 yuan/minute 0.03 yuan/minute
Domestic roaming business 0 0 3 yuan/hour 3 yuan/hour
Dial-up registration A, B and Internet card service users are charged half of the network usage fee from 0:00 to 24:00 (all day) on legal holidays and rest days, and from 23:00 to 8:00 the next day on non-holidays. There is no preferential period for domestic roaming service.
2. ISDN
Introduction of the service
The "one line through" service, also known as the Narrowband Integrated Services Digital Network (N-ISDN), is a comprehensive service that integrates voice, data, and image communications developed on the existing telephone network. "N-ISDN users can obtain integrated telecommunication services by utilizing a pair of ordinary telephone lines: up to eight different terminals can be connected, and two terminals are allowed to communicate at the same time. Access to the Internet via ISDN is more convenient and faster, and it is also possible to make phone calls while surfing the Internet.
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Service Advantages
(1) Compared with traditional MODEM, the rate of ISDN is much faster than that of MODEM is much faster, the minimum rate of an ISDN line is 64KB/S, and the maximum rate can be up to 128KB/S.
(2) All-digital line, short call setup time, good quality and high stability. digital transmission of ISDN can effectively reduce noise and crosstalk, and make the data communication more secure and reliable.
(3) High line efficiency, a line with multiple machines, and can realize the two machines communicate at the same time without interfering with each other.
(4) can meet the user's business requirements in various aspects: computer networking, remote communication, image transmission.
(5) through the ordinary telephone, fax machine, computer and other existing analog equipment can be realized voice, video, data and other multimedia communications, just add an ISDN TA adapter, you can achieve high-speed Internet access.
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ISDN Applications
(1) 128K line bandwidth, to solve the problem of user Internet access speed .
(2) Similar to the speed of the private line, but the charges are comparable to ordinary telephone.
(3) The best choice for data circuit backup in the financial securities industry.
(4) Office, school LAN access to the INTERNET ideal method.
(5) The new choice for the installation of local telephone users, the Internet at the same time you can also call or send and receive faxes, while enjoying a variety of telecommunications services.
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Business tariffs
(1) Initial installation fee: 1,116 yuan for Type A, 1,216 yuan for Type B, and retrofitting 316 yuan.
(2) Monthly fee: 1.5 times of the fixed line.
(3) Calling fee: according to the standard implementation of the ordinary fixed-line telephone, the use of dual-channel (2B) when the use of two phones at the same time call calculation.
(4) New service fee: same as ordinary fixed-line telephone.
3, ADSL
What is the super one line through
Super one line through the ATM broadband technology as the core, to provide users with high-speed real-time set of data, voice, image, video in one of the broadband integrated services digital network (B-ISDN). It adopts asymmetric digital signaling technology (ADSL), making full use of the existing telephone lines to realize high-speed user access with uplink 1M bit/s and downlink 7M bit/s. Telephone conversations and high-speed multimedia data transmission can be carried out simultaneously on a single telephone line.
Super One Line Service Function
＊Telemedicine Broadband network provides high-definition medical information transmission, consultation and exchange of off-site, remote program development, and collaborative surgical treatment, allowing you to enjoy the most modern medical care without leaving your home.
＊Conference TV Real-time information interaction, clear video guarantee. The application of broadband interactive conference TV system, so that the traditional wide range of meetings without the need for cumbersome centralized arrangements, not only to ensure that the effect, but also to save money, and can enhance efficiency.
＊Remote Teaching Famous teachers guide, interactive teaching, broadband network for you to network around the master teacher, to provide lively multimedia teaching, to take you into the network school, to realize the dream of learning in your heart.
＊Virtual commercial building Broadband network will take you into the realistic three-dimensional supermarket, through the three-dimensional picture to show you all aspects of the goods, to provide all kinds of information on the goods, let you enjoy shopping for the items you need. Let you enjoy the real fun of online shopping without leaving home.
＊Video on Demand High bandwidth ensures that users can play high-quality video in real time, and a large-capacity video disc warehouse enables you to order movies to your liking. By entering the broadband multimedia information network, you will have your own online theater!
＊3D Entertainment The high-speed real-time broadband network will provide users with 3D chat rooms, simulated field trips, real-time network games, live TV broadcasts, and other colorful online entertainment projects, which will add luster to your life.
＊Internet access ADSL access can reach downlink rates of 6-8 Mbps, more than 200 times faster than ordinary MODEM dial-in, and at the same time, it can realize collective **** enjoyment within the company LAN.
How to use Super One
Installing ADSL is quick and easy. To install ADSL on an existing telephone line, you only need to install an ADSL communication terminal (ADSL modem, etc.) on the user's end without making any changes to the existing line. Users can enjoy high-speed access services by dialing up, and can make normal phone calls while surfing the Internet. There are two ways to access broadband network through ADSL:
1. ADSL modem way. Users add a network card (10M Ethernet card or ATM 25M network card) on the microcomputer or a STB (set-top box) on the TV, and then connect the network card or STB to the ADSL modem, and then access the host computer of the bureau through the telephone line to realize high-speed communication.
2. PC NIC card method. PC NIC card is installed on the user's host, connected to the telephone line through the PC NIC card and accessed to the host of the bureau, you can enter the broadband network and realize high-speed communication.
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The most critical factor in surfing the Internet is the bandwidth. Nowadays, most people still use the traditional 56K MODEM to connect to the phone line this combination of Internet, often need to have enough patience, because it surfing rate is too slow is the most headache of many users. In order to solve this problem from various aspects, in the past few years in the network has put forward the following programs, you can compare and see which is better or worse.
1. ISDN program
ISDN full name is Integrated Service digital Network, the Chinese name for the integrated service digital network, which is based on the integrated digital telephone network as the basis for the development of a new, able to provide end-to-end digital connections. Ordinary analog telephone network adopts digital transmission and switching after becoming IDN, but in IDN, from the user terminal to the telephone exchange is still analog transmission, need to be equipped with modems to transmit digital signals.ISDN will be from a user terminal to another user terminal between the transmission of all the digital, including the user part of the digital form of the unified processing of various services, so that the user can get digital superior performance. can obtain the excellent performance of digitization. However, ISDN can provide data transfer rate up to 128kbps, which is still its optimal operating frequency, and now users use ISDN is after all a narrow-band network, and the network has been to the bandwidth era, so the ISDN program is still not able to meet the needs of Internet users.
2. Cable MODEM program
Cable MODEM is based on the original cable network. Previously, the cable television industry is only the transmission of television signals, but now the use of the original has established a closed set of cable transmission lines, after the transformation to achieve Internet access and communications. Because cable TV uses coaxial cable, so its data capacity is quite large, the use of coaxial cable downlink rate can be up to 30Mpbs. but it is also obvious that the problem, because cable TV coaxial cable is designed according to the one-way mode, so only allows the signal from the cable TV station to the user's home, and does not allow the signal from the user's home back to the cable TV station. Internet networking, on the other hand, is a two-way transmission method, i.e., the user not only has to press to receive online information, he also has to transmit the information to the Internet. It can be said that the solution for cable TV is also to modify the basic wiring so that it can reach the point of two-way transmission of information. This is likely to cost Cable TV a lot of money, plus the user has to connect and install a high-speed Cable MODEM on his computer to browse the Internet. In addition Cable MODEM uses the HFC scheme, which uses a hierarchical numbered structure, in which several nodes are simply connected together. Therefore, it is actually a rough bus-type network, which means that users have to enjoy a limited bandwidth with their neighbors, so when the number of people surfing the Internet at the same time is large, the speed of Cable MODEM's Internet browsing will be slowed down. Because of the inherent unreliability of bus-type networks, LAN technology began to phase out bus-type structures in favor of star-type structures a few years ago. The information shows that in the present situation, the HFC solution must take into account the cable TV program, it is important that this cable TV solution is in the pilot stage.
3. DDN leased line access program
DDN is the abbreviation of "Digital Data Network", the Chinese name of the digital data network. It is a digital channel to provide a semi-permanent connection circuit, data signaling based on the digital transmission network. It will provide users with 64Kbps-2Mbps rate. But its expensive access fee and monthly fee discourage the majority of ordinary users. It can be said that DDN is more suitable for business users, the use of DDN services provided by the construction of a private communications network is an ideal choice, but it is expensive to promote it difficult to make the general public accept.
4. ADSL Solution
ADSL solution does not need to modify the telephone signal transmission line, it only requires the user to have a special MODEM, that is, ADSL MODEM. it is connected to the user's computer, and the other end of the telecom department connected to the ADSL network, the user and the telecom department connected to the ordinary telephone line. Generally speaking, the transmission speed of ADSL program is about 50 times faster than that of ISDN program, and at the same time, it does not need to change the line of the broadband network, so ADSL is a more feasible acceleration of Internet access program.
Because of the expensive access cost of DDN, it is definitely not suitable for general home users. Cable MODEM is currently used in a very small range, in Shanghai so far only a small number of neighborhoods in the pilot, it is estimated that to launch there is still a long time. From the above introduction, we can see that ADSL program has very significant advantages, and will undoubtedly be a good choice for future families. So let's introduce ADSL in more detail:
I. Definition of ADSL
The definition of ADSL is that it is a networked network. Definition of ADSL
ADSL (Asymmetrical Digital Subscriber Line), also known as asymmetric digital subscriber line, is a kind of xDSL. xDSL is the collective name of DSL (Digital subscriber Line), which means digital subscriber line, is a combination of transmission technologies that uses copper telephone lines as the transmission medium. XDSL is a collective term for DSL (Digital Subscriber Line), which means digital subscriber line, a combination of transmission technologies using copper telephone lines as the transmission medium, where "x" stands for different types of digital subscriber line technologies, including ADSL, HDSL, VDSL, SDSL, and so on. The differences between the various digital subscriber line technologies are mainly in the transmission rate and distance of the signal, as well as the difference between symmetric and asymmetric.
ADSL uses ordinary telephone lines as the transmission medium. Although the traditional MODEM is also transmitted using the telephone line, but it only uses the 0KHz-4KHz low-frequency band, while the telephone line theoretically has a bandwidth of nearly 2MHz, ADSL is precisely the use of 26KHz after the high-frequency in order to provide such a high speed. The specific workflow is: the signal encoded by the ADSL MODEM passes through the telephone line to the telephone office and then through a signal recognition/separator, if it is a voice signal on the channel switch, if it is a digital signal on the Internet access.
II. ADSL Features and Standards
ADSL is designed for two purposes: high-speed data communications and interactive video. High-speed data communication capabilities can facilitate access on the Internet, management of remote computers in a company, or private network applications. Interactive video, on the other hand, includes video-on-demand, movies, games, and so on, which are implemented on high-speed networks. Undoubtedly, the wide application of interactive video will surely bring more colors to our poor lives.
ADSL has always had three common standards: QAM, CAP, and DMT. The DMT standard has been adopted by the national standards developed by the ANSI standardization group, and the CAP standard is based on the QAM standard, which can be said to be a variant of the QAM standard. Although CAP is not a standard, it was invented by AT&Tparadyne and has been widely used in communications. In addition to the above standard dispute, recently talked about a lot of G.Lite standard is also very much favored by the industry recently. It is because of the long-term standard inconsistency has also led to the delay in the popularity of ADSL. DMT and G.Lite two standards have their own strengths, respectively, applicable to different areas. DMT is a full-rate ADSL standard, support for high-speed downstream 8Mbps and 1.5Mbps upstream rate, but the DMT requires the user to install a POTS splitter, which is more complex, such as Ericsson The ADSL MODEM adopts is to support DMT standard. Although the G.Lite standard has a lower rate, i.e. 1.5Mbps downstream and 512Kbps upstream, it eliminates the complex telephone splitter, so users can buy it directly from the store and install it by themselves as they do with ordinary MODEMs. As far as areas of application are concerned, DMT is suitable for small or home offices, while G.Lite is used for regular home users.
III. Rate of ADSL:
After adopting ADSL solution, theoretically, ADSL supports upload rate of 640Kbps-1Mbps and download rate of 1Mbps-8Mbps on twisted copper wire, and the effective transmission distance is 3-5 kilometers. However, in practice, it can also dynamically adjust the user's access speed according to the quality of the twisted copper wire and the distance of transmission. The actual download rate we can enjoy is based on the use of different MODEM models, the user end to the communication center of the distance length, cable size, and interference and other factors to determine, from 10Kbps-640Kbps ranging. The increase in transmission rate brings the most direct benefit to users, saving a lot of time and money.
In addition, ADSL uses advanced algorithms to connect the ends of an existing twisted pair connection with its own unique modem hardware, and creates a pipe with three channels. The pipeline has a tell-tale downstream channel to the subscriber, a medium-speed duplex channel, and a POTS channel, which is used to allow voice communications to function even if the ADSL connection fails. Both the high-speed and medium-speed channels can be multiplexed to create multiple low-speed channels. In real-world use of high-speed and medium-speed channel rates, users can make voice calls or send faxes while downloading and uploading data without affecting the quality of the call or slowing down the download of Internet content, i.e., ADSL utilizes frequencies other than those used for telephone voice transmissions for data transmission.
IV. ADSL installation
ADSL installation does not need to change the telephone line, only in the original telephone line loaded with a multiplexing device, so users do not have to add a telephone line. When using ADSL, the user must use a special MODEM called endpoint, immediately after the MODEM, the user's computer needs to install an ordinary network card to connect to this MODEM, so this MODEM is like installing the same as the end of the network, and built-in plug-in cards do not need to connect to the network card.
In addition, there are many ADSL modems that combine these two functions into a single, internal multi-function card. Many traditional MODEM manufacturers such as Hayes, 3Com, globalBillage, ParGain, and so on, have produced this end point type of MODEM.
V. Disadvantages of ADSL
This is the first time that ADSL has been used in the United States. ADSL's shortcomings
Of course, ADSL is not perfect, it also has its own shortcomings. First of all, the existing ADSL modems are expensive, and then the establishment of a reasonable charging system is the most important problem faced by ADSL. Next, there is the fact that ADSL's performance on different quality lines varies greatly, for example, on poor quality lines, its downlink rate may only reach 1Mbps.
Well, that's all there is to know about ADSL. It is important to note that the range of ADSL is still very small, and is basically limited to a few major cities such as Shanghai, Shenzhen, etc. It seems to be very difficult to make ADSL available to everyone. It seems that it will take a while for everyone to enjoy the fast surfing experience of ADSL.
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