What are the network access methods?

1. dial-up connection

(1) Normal dialing mode

(a) Dialing up the Internet in this way requires a device: a modem.

It's the abbreviation of English modem. Chinese is commonly known as "cat". Because the ordinary telephone network transmits analog signals, while the computer processes digital signals. If the process of converting digital signals into analog signals is called modulation, then the opposite process is demodulation. Modems play this role. There are two types: built-in and external. The built-in modem is a card inserted into the computer motherboard; Many brands of computers are pre-installed with built-in modems. If it is added later, many people will choose an external modem. Pre-installed built-in modems usually have drivers installed. Just connect the telephone line connector (commonly known as crystal head, because it is white and transparent) to the interface provided by the modem behind the main chassis. The external modem is to plug the telephone line into the modem, and the accessory comes with the connecting cable between the modem and the computer. One end of the connecting cable is connected to the modem, and the other end is connected to the serial interface on the computer host. You can refer to the instruction manual of the accessories. As for installing drivers, MODEM are all so-called PnP devices (plug and play), and windows will automatically detect the installation. In short, you don't need any professional knowledge, and novices can do it.

(2) Single-wire communication (ISDN)

ISDN (Integrated Services Digital Network), whose Chinese name is Integrated Services Digital Network, is commonly known as "One Line Communication" by China Telecom. It is a new way of communication that rose in the international arena in the late 1980s. Only one telephone can be connected to the same pair of ordinary telephone lines, so the original dial-up internet access means that you can't make a phone call at this time. After applying for ISDN, you can use several terminals at the same time through a conversion box called NT. You can surf the Internet while making phone calls or communicating with other data. Although it is still an ordinary telephone line, NT's converter box provides users with two standard 64KB/S digital channels, namely the so-called 2B+D interface. The TA port is connected to the telephone, and the NT port is connected to the computer. The maximum transmission rate it allows is 128KB/S, which is three to four times that of ordinary MODEM. Therefore, its popularity is, in a sense, a major innovation in the traditional concept of communication. Installation and communication costs are similar to ordinary telephones. It has only been opened in major cities in China in the past year or two. You can also apply at the business outlets of the Telecommunications Bureau. Of course, this has become the first way to dial up the Internet at present.

3.ADSL:

ADSL is the abbreviation of English Asymmetric Digital Subscriber Loop. ADSL technology is a new high-speed broadband technology running on the original ordinary telephone line. It uses a pair of existing telephone copper wires to provide users with asymmetric uplink and downlink transmission rates (bandwidth).

The asymmetry is mainly reflected in the asymmetry between the uplink rate (up to 640Kbps) and the downlink rate (up to 8Mdps). Uplink (from user to network) is a low-speed transmission, which can reach 640Kbps；; Downlink (from network to user) is high-speed transmission, which can reach 8Mbps. At first, it was mainly developed for video-on-demand services. With the development of technology, it has gradually become a more convenient broadband access technology, which has attracted the attention of telecom departments. Through the IPTV set-top box, many network applications that could not be realized at low rate before can be realized.

4.DSL:

DSL (Digital Subscriber Line Digital Subscriber Loop) technology is a broadband access technology based on ordinary telephone lines. It transmits data and voice signals on the same copper wire, and the data signals do not pass through the telephone exchange equipment, thus reducing the load of the telephone exchange. And you don't have to dial, always online. It's a private internet mode. DSL includes ADSL, RADSL, HDSL, VDSL, etc.

5.VDSL:

VDSL (Very High Bit Rate Digital Subscriber Loop) is a high-speed digital subscriber loop. Simply put, VDSL is a fast version of ADSL. Using VDSL, the maximum download rate can reach 55Mbps in a short distance, and the upload rate can reach 19.2Mbps, or even higher. ......& gt& gt

What are the connection methods of the network?

There are three main types:

First, direct fiber-to-the-home, which is the most advanced method, has high speed and less dropped calls, which may cost more.

Second, the local area network (LAN) is an optical fiber to a residential area or a building, and then after photoelectric conversion, operators use LAN lines (a six-core line) to reach users there, forming a small LAN in this residential area or a building. This method is also relatively stable and fast. They all have fixed IP addresses.

Thirdly, ADSL is a method for Netcom or telecom companies to access the Internet for users by using the telephone lines of existing fixed telephones. Its characteristic is that when users need to access the Internet, PPPoE is used to assign users a dynamic IP address. The network speed can basically reach the speed of local area network, and the network speed is fast, so there is no need to cross the line to get home alone. Compared with optical fiber and LAN, the stability is slightly worse. The cost is cheap.

Fourth, dial-up Internet access, which is slow and unstable, is basically not used now.

Either way, you need to go through the formalities with the operator. Netcom or Telecom?

Briefly describe how to access the Internet.

At present, there are several common access methods to choose from in China.

1.PSTN public telephone network

This is the easiest way to achieve and the cost is low. There is only one telephone line and one account that can connect to the ISP. But the disadvantages are low transmission speed and poor line reliability. It is suitable for offices and small enterprises with low reliability requirements. If there are many users, multiple telephone lines can work together to improve the access speed.

2. Integrated Services Digital Network

At present, it is rapidly popularized in China, and the price has dropped sharply. In some places, the installation fee is even free. 128 kbit/s dual-channel speed, fast connection and reliable line can meet the needs of small and medium-sized enterprises to browse and send and receive emails.

And enterprise VPN can be established through ISDN and Internet. This method is cost-effective, and most cities in China have ISDN access services.

3. Asymmetric digital subscriber line

Asymmetric digital subscriber loop can provide downlink transmission of 1.5 ~ 8 mbit/s and uplink transmission of 10 ~ 64 kbit/s on ordinary telephone copper cable, which can be used for video conference and video program transmission, and is very suitable for small and medium-sized enterprises. However, there is a fatal weakness: the line distance between the user and the switching room of telecommunications cannot exceed 4 ~ 6 km, which limits its application scope.

4.DDN special line

This method is suitable for applications with high bandwidth requirements, such as corporate websites. It also has a feature of high speed, ranging from 64 kbit/s to 2 mbit/s, but because the whole link is monopolized by enterprises and the cost is very high, SMEs have few choices.

This line has many advantages: fixed IP address, reliable line operation, permanent connection and so on. However, the cost performance ratio is too low, and this method is not recommended unless the user has sufficient funds.

5. Satellite access

At present, some Internet service providers in China have launched satellite access to the Internet. Suitable for users who need high bandwidth in remote places. Satellite users generally need to install a VSAT, including antennas and other receiving equipment. The downlink data transmission rate is generally around 1 Mbit/s, and the uplink is connected to ISP through PSTN or ISDN. Terminal equipment and communication costs are relatively low.

6. Optical fiber access

Some cities have built high-speed metropolitan area networks (MAN), with the backbone network rate reaching tens of Gbit/s, and broadband access has been promoted. The optical fiber can be laid on the user's roadside or in the building, and the access rate can reach more than 100 Mbit/s, which is suitable for large enterprises.

7. Wireless access

Due to the high cost of laying optical fiber, some cities provide wireless access for users who need broadband access. Users connect with ISP through high-frequency antenna, the distance is about 10km, and the bandwidth is 2 ~ 1 1 mbit/s, which is low in cost, but limited by terrain and distance, so it is suitable for users not far from ISP in the city. Very cost-effective.

8. Cable modem access

At present, China's cable TV networks are all over the country, and many cities provide cable modems to access the Internet, and the speed can reach more than 10 Mbit/s, but the working mode of cable modems is * * * to enjoy bandwidth, so the speed may drop in a certain period of time.

The above eight domestic access methods have their own advantages and disadvantages, and each has its own scope of application.

What are the common ways to surf the Internet?

1.PSTN dialing: the most widely used.

Public switched telephone network

2.ISDN dialing: Call the Internet correctly.

integrated services digital network (ISDN)

3.DDN special line: for group enterprises.

DDN is the abbreviation of English digital data network.

4.ADSL: personal broadband fashion

Asymmetric digital subscriber line

5.VDSL: high-speed broadband access

VDSL is faster than ADSL.

6. Cable modem: used for wired network.

cable modem

7. Passive optical network access

PON (Passive Optical Network) technology is a point-to-multipoint optical fiber transmission and access technology.

8.LMDS access: wireless communication

This is a wireless access technology that can be used for residential broadband access at present.

9. LAN: mature technology and low cost.

LAN access is to use Ethernet technology, using optical cable+twisted pair to comprehensively wire the community.

What are the four main ways to surf the Internet? 10.

1, ordinary dial-up access, convenient, as long as a telephone line and a modem can call, there is no need to apply, the price is one hour in our 4.5 yuan, the speed is poor, suitable for temporary internet access, send and receive some mail.

2, ADSL dial-up access, you need to apply for it, you need a telephone and ADSL modem, usually a monthly or annual service, ranging from 500 to 1000. Fast speed, suitable for people who surf the internet in fixed places for a long time, telecom, Netcom and other service providers.

3, residential broadband access, many service providers, first of all, optical fiber access to the community, the access fee seems to be 2000 yuan per month, pay attention to this trillion and ADSL trillion is not the same. Household, the more people who use the internet faster, the cheaper the price. Of course, the more speed points, the lower the relative speed will be.

4, wireless Internet access, suitable for pen factory computers, with wireless Internet access, you need to buy Unicom CDMA or mobile GPRS card, which is slow and expensive. You can only browse simple information and send and receive some emails.

What are the ways to surf the Internet? What are their characteristics?

According to the forms of information source access, there are dial-up internet access, broadband access through account password, wired LAN internet access, wireless internet access and so on.

Four Common Ways to Access the Internet

1, ordinary dial-up access, convenient, as long as a telephone line and a modem can call, there is no need to apply, the price is one hour in our 4.5 yuan, the speed is poor, suitable for temporary internet access, send and receive some mail.

2, ADSL dial-up access, you need to apply for it, you need a telephone and ADSL modem, usually a monthly or annual service, ranging from 500 to 1000. Fast speed, suitable for people who surf the internet in fixed places for a long time, telecom, Netcom and other service providers.

3, residential broadband access, many service providers, first of all, optical fiber access to the community, the access fee seems to be 2000 yuan per month, pay attention to this trillion and ADSL trillion is not the same. Household, the more people who use the internet faster, the cheaper the price. Of course, the more speed points, the lower the relative speed will be.

4, wireless Internet access, suitable for laptops, with wireless Internet access, you need to buy Unicom's CDMA or mobile GPRS card, which is slow and expensive. You can only browse simple information and send and receive some emails.

What are the common network connection methods?

Because of different understanding, ambiguity is easy to occur.

First, computer surfing the Internet.

1. Wireless Internet access. Notebooks are very common.

2.ADSL Internet access. The mainstream Internet access mode of home computers in China.

3. Wired access. Large local area networks are connected with external networks.

4. Performing on the Internet. Mainly the connection between small LAN and external network.

5. others. For example, a computer has two network cards, one is a wireless network card and the other is a wired network card.

What do you mean by several network connection methods?

Compensation access mode Ordinary dial-up modem 56Kbps (in theory) is simple to install, and access can be realized by connecting the modem to the telephone line and dialing the ISP's access phone number; Low transmission rate and high communication line quality. When surfing the internet, the telephone line is monopolized and it is impossible to make calls at the same time. Family, people who don't have high requirements for internet access, time modem and telephone line.

The narrowband integrated services digital network ISDN 64Kbps/ 128Kbps provides two 64K channels for communication on ordinary telephone lines. Users can make phone calls and surf the Internet on a telephone line, or provide Internet access at the highest rate of 128Kbps. When a call comes in or out, it will automatically release a channel and connect the phone. 0.02 yuan/m per channel for families and people with low Internet access requirements; The monthly rent for additional modems and telephone lines is 3.00/hour.

Asymmetric digital subscriber line ADSL uplink: 640Kbps downlink: 8Mbps transmits data and voice signals on the same telephone line, allowing high-speed Internet access and simultaneous phone calls. The data signal does not pass through the telephone switching equipment, so there is no need to pay additional telephone charges. ADSL modem, voice separator, telephone line, network card, fixed/monthly network cable for families, enterprises and institutions.

Cable Modem downlink: 3~ 10Mbps uplink: 200k~2Mbps is connected to the Internet through cable TV coaxial cable (antenna), with high bandwidth, which does not affect watching cable TV programs, does not occupy telephone lines, and can surf the Internet indefinitely. Families, enterprises and institutions can access cable modems, cable TV lines, twisted pairs and network cards according to traffic/monthly subscription.

The digital data network below DDN 2Mbps is composed of optical fiber, digital microwave or satellite and digital cross-multiplexing equipment, which provides users with a fully digital and high-quality dedicated data transmission channel to transmit various data services. Can provide point-to-point private line, broadcast multi-point private line, two-way multi-point private line and voice private line. Computer networking communication departments such as banks, securities, meteorology, civil aviation, and intelligent communities rent network management control terminals (NMT) on a daily/monthly basis. DDN node machine; PCM equipment, etc. Transmission media include optical cable, digital microwave, satellite channel and common cable and twisted pair available to users.

Optical fiber access 100~ 1000Mbps, large enterprises, schools, * * * and military private networks, low loss, no electromagnetic interference, monthly supply of optical cables, optical fiber receivers, routers, switches, etc.

Wireless access WLAN GPRS: 1 15 kbps high-speed transmission, not limited by cables, mobile, can solve the problems caused by wired network wiring difficulties. Mobile office users charge by the volume, such as stations and wireless network cards.

LAN access mode LAN access LAN10m/100m/1000m high-speed Internet connection, saving money, smart community residents, schools, large enterprises monthly.

What are the computer network access methods? What is the difference between them? 10 point

At present, the most common access methods for individual users are: wireless WiFi access and wired broadband access. Enterprise users have fiber access and DDN access.

for reference only