What Is Pay As You Go Internet?

Internet access is a Chinese vocabulary. Internet access refers to the operation of an electronic computer or mobile phone to access the Internet, search information on the network, query (including chatting, watching videos), etc., as long as the network is used during use, it is called Internet access.

Internet

Implementation method

One of the main functions of shared Internet access is for internally connected enterprises. Let all networked computers share Internet accounts and lines together, which not only meets work needs but also saves a lot of money. Some people may ask, if you use 56K dial-up to access the Internet, Will a few people be slow with a single phone line? The answer is not absolute. In fact, a person using a telephone line to access the Internet wastes a lot of resources. For example, when you are reading a webpage, the line is actually very idle. Also, when you visit some slow websites, the speed of the line transmission is far less than the speed of the MODEM connection. So there is no need to worry. If you use a broadband connection such as ADSL, even multiple people sharing a line will come faster than independent 56K dial-up.

To achieve shared Internet access, you must first understand whether you have the conditions to do so. First of all, the computer is indispensable, and all computers must be connected to the Internet, that is, the local area network is working normally. Generally, each computer on the local area network needs to have the TCP / IP network protocol installed, followed by a line connecting the Internet, 56K or ISDN dial-up, and ADSL. Yes, dial-up and ADSL are usually cost-effective. In addition, the connection equipment (MODEM, ISDN TA, etc.) of this line also needs to be prepared. A computer in the local area network can normally access the Internet through this line. From the perspective of technical implementation, shared Internet access is divided into: hardware shared Internet access and software shared Internet access.

Hardware shared Internet access: A shared Internet access router is usually used. In addition to the functions of shared Internet access, this type of device also has the function of a HUB. They use the built-in hardware chip to complete the exchange and management of data packets between the Internet and the local area network. In fact, the shared Internet access software is solidified in the chip. Of course, large powerful routers are not included in this list. Because the hardware work does not depend on the operating system, it has good stability, but the updateability is relatively poor compared to the software, and it requires additional investment to purchase. According to the author, the average shared Internet router is about 2,000 yuan, and the cost is not Great.

Software sharing and Internet access: Software sharing and Internet access is to install the Internet sharing software on a computer with an Internet connection line in the office LAN to realize the Internet sharing of the entire LAN. The advantage of software sharing and accessing the Internet lies in the low cost, and some shared Internet access software is even free, and the software is updated quickly, which can quickly adapt to the new Internet access technology and application protocols. The disadvantage is that a dedicated computer is required as The shared Internet server provides Internet access for other computers, and the performance of this computer cannot be too low. In addition, it depends on the operating system and is a standard application. Therefore, the stability is slightly worse than the hardware method. Whether it is software or hardware, its working principle is to convert the network request inside the local area network to the Internet and then send the data received from the Internet to the internal computer that issued the request after processing. The basic network structure is shown in the figure below.

Because the software method only needs to add a piece of software to the existing office LAN, it does not require additional capital investment, so it is the mainstream shared Internet access method.

Software classification

Software method The software used to share the Internet is divided into two major categories, namely the proxy server type and the NAT network address translation type, of which the NAT network address translation type is also commonly referred to as the gateway type.

The full English name of a proxy server is Proxy Server, and its function is to proxy network users to obtain network information. It is like a relay station for network information. In general, when we use a web browser to directly connect to other Internet sites to obtain network information, we send out a request signal, and then the other party transmits the requested information back.

A proxy server is a server between the client network application and the corresponding Internet server. For example, if the client is a browser, the Web server responds on the Internet. With a proxy server, the browser does not go directly to the Web server to retrieve the webpage, but sends a request to the proxy server. The proxy server retrieves the information required by the browser from the web server and transmits it to your browser. In addition, most proxy servers have a cache function. It has a large storage space. It continuously stores newly acquired data on the local storage. If the data requested by the browser already exists on the local storage and Is the latest, then it does not get data from the Web server, but directly transfers the data on the memory to the user's browser, which can significantly improve browsing speed and efficiency. Because there are multiple application protocols such as Web, FTP, and POP3 on the Internet, proxy servers generally have the ability to support multiple applications simultaneously.

The method of using a proxy server in a local area network has the following points: The proxy server has a cache function to speed up access to the network. Since the proxy server independently performs proxy work for each network application, it has strong control and management capabilities for users. However, this is also the shortcoming of the proxy server method. It cannot support emerging network applications. Every network application needs to be properly configured. Each client needs to configure each network application software.

NAT is an abbreviation of Network Address Translation. Using network address translation technology, "illegal Internet IP addresses" inside a local area network can be converted into "legal Internet IP addresses" through NAT, enabling legitimate access to external networks such as the Internet. The essence of NAT can be understood in this way. It is a proxy proxy at the bottom of the data packet. It no longer acts as a proxy for each Internet application protocol such as http, ftp, telnet. It does each TCP / IP data packet. Proxy.

Using address translation technology, NAT checks and translates each IP packet address sent by the internal client, records and repackages the IP address data of the requesting end in the packet into a legitimate Internet external IP address and sends it to the Internet. Then NAT reassembles the data packet obtained from the Internet according to the record of the requesting end, and reassembles the destination IP address inside the data packet, so that it is converted into the IP address of the LAN client and then sent to the client.

The advantage of NAT shared Internet access is that the internal machine only needs to set the address of the shared server as the gateway of the client machine, and the service software completes all the conversion work. The client is like a machine with real Internet connection capability. One data packet conversion, there is no need to proxy and process different network application protocols, users do not need to consider the configuration of connection proxy according to each network application, use it freely. So sometimes it is called "transparent proxy". Because NAT is completely transparent and works at the bottom layer, the control and management capabilities of network applications used by clients are worse than those of the Proxy type. However, as development companies deepen their research on IP packets, control management Capabilities are also gradually being enhanced. The ability to control and manage NAT shared Internet access software is much stronger than when it first came out. Whether using Proxy or NAT type shared Internet access, another advantage is that it has a firewall function. When the outside world actively connects to the local area network, because the local area network has only a valid IP address, the outside world only connects to the proxy server used for shared Internet access. The other internal clients are inaccessible. Of course, if they are not accessible, they cannot invade. Therefore, comparing the independent Internet access methods of each computer, sharing the Internet access greatly improves the data security of the computer.

LAN sharing

There are many softwares used in LAN shared Internet access. Below we will introduce some of them according to the working method, which is convenient for everyone to choose in the work. The software introduced below can run on Windows 9x, NT and Windows 2000 as shared Internet server.

(1) Proxy type

1 WinGate: The old Proxy type shared Internet access software. Because NAT is flexible and transparent, NAT function has been added to the original Proxy service function to support more network software. Currently the latest version is 4.3. Existing network application protocols can support it. , T1-T3, DSL, Cable, ISDN and other Internet connection methods.

2 Winproxy: Standard proxy-type proxy software developed by ositis software company, supporting most of the existing network application protocols, such as HTTP, FTP, POP3, Socks4, Socks5, etc. It also has network virus monitoring capabilities to prevent outside computer viruses from invading and has strong management and control capabilities. The latest version also adds NAT functionality to support more Internet application protocols.

3 AnalogX Proxy: Proxy-type proxy server software supporting multiple protocols such as FTP, HTTP, HTTPS, POP3, NNTP, and SMTP. CProxy Server: Supports multiple protocols, providing virus scanning, website and content filtering, fast caching, etc.

(2) NAT type

1 WinrRoute: Super powerful, with the good name of a software router, supporting various protocols and networking methods, providing routing functions for external access to internal web, mail and other servers, and management control capabilities are also very common in NAT-type shared Internet service software Strong. It also comes with Proxy service and cache acceleration, SMTP and other functions. Download URL please see extended reading

2 Sygate: The well-known NAT shared Internet access software, supports all network application protocols, supports various networking methods, and its Office Professional version can also control the network bandwidth used by each client. More Home versions are used, which is simple to set up and use Convenient, weak control and management capabilities. Download URL please see extended reading

3 Internet GateWay Server: The NAT service software developed by Vicom supports multiple network protocols and connection methods. The most distinctive feature is the built-in PPPoE protocol, which directly supports ADSL virtual dial-up Internet without installing PPPoE software. Can keep track of bandwidth usage. Download URL please see extended reading

4 Windows 2000 & Windows 98se / me comes with ICS (Internet Connection Share), which is also a set of NAT-type shared Internet access software. After installing the above version of Windows, you can add this component to implement shared Internet access, but the function is relatively simple and management There is almost no control ability, and there are many problems in cooperating with ADSL.

5 i.Share: a set of all-in-one fools and special NAT software, which is converted through the IPX protocol of the local area network. It only needs to be set up after the server and client are installed to work, and the control and management capabilities are average. Download URL please see extended reading

Broadband router is also a shared Internet access device, similar to the routing ADSL Modem. It also has the function of "routing", which can replace the location of the proxy server and become the "gateway" of the client. Clients access the Internet through this "gateway". In addition, most broadband routers also have 4-port or 5-port switches. Clients only need to plug the network cable into the switch port of the broadband router, and then perform simple configuration to access the Internet. Its networking mode is shown in Figure 1.

Broadband routers support sharing of multiple Internet access methods, such as ADSL, FTTB + LAN (fiber-to-the-floor + LAN-to-home), closed-line broadband (ie, Cable Modem), and ordinary 56Kbps Modem dial-up Internet access. However, for the ADSL access method, it only supports the Ethernet ADSL Modem.

Below, we still take the Windows 2000 platform as an example, and take ASUS AAM6000EV non-routed Ethernet ADSL Modem and TP-Link (Pure Air) TL-R400 broadband router as examples to explain the method of sharing ADSL by broadband routers (other The branded broadband routers will be different on the setting interface, but the places to be set and the specific settings are almost the same).

First, make sure that the ADSL Modem is working properly, that is, we can already access the Internet through it. Then, we cut off the power of the computer and the ADSL Modem and connected the TL-R400 broadband router.

TL-R400 Broadband Router is shown in Figure 2. It is a shared Internet access device specially developed for home users and small offices. It integrates a 4-port 10 / 100Mbps switch for connecting users' computers that need to access the Internet. The WAN port on the back panel is used to connect to network access equipment such as ADSL Modem. First, we connected the straight-through twisted pair cable that came with AAM6000EV to the RJ-45 port of the Modem and the WAN port of TL-R400 (the original straight-through twisted pair was used to connect the Modem to the computer), Then use straight-through twisted pair to connect the RJ-45 port of the computer network card and the switch port (LAN port) of the TL-R400. After connecting, plug in the modem and TL-R400 and turn on the computer.

First, the configuration of the broadband router

We need to make a simple configuration for the TL-R400 Broadband Router so that it can auto-dial instead of a computer.

Router (12 photos)

Like most Ethernet ADSL Modems, the TL-R400 Broadband Router also has an IP address and uses Web page management. We can enter "http://xxx.xxx.xxx.xxx" in the address bar of Internet Explorer to enter the management page to set it. When the TL-R400 is shipped from the factory, the default IP address is "192.168.123.254" and the subnet mask is "255.255.255.0". We should note that entering the "http://192.168.123.254" directly into the address bar of the IE browser of the computer cannot access the management page. The reason is simple: the IP address must be on the same network segment to be accessible. So we first need to modify the IP address of the computer's local connection.

Right-click the "Network Neighborhood" icon on the system desktop, and select "Properties" from the pop-up shortcut menu. The "Network and Dial-up Connection" dialog box appears. Select "Local Area Connection" in the dialog box, right-click, and select "Properties" from the pop-up menu to enter the "Local Area Connection Properties" dialog box. In this dialog box, select the "Internet Protocol (TCP / IP)" item and click the "Properties" button to enter the "TCP / IP Properties" dialog box. In this dialog, set the IP address to "192.168.123.x" (x is a natural number from 1 to 253) (for example, "192.168.123.200" in this example) and set the gateway to "192.168.123.254" (image 3). After OK twice in a row, the setting will take effect immediately. We can enter "http://192.168.123.254" in the IE address bar to enter the management page of TL-R400.

Enter the default password "admin" in the login box on the left of the login page that appears to enter the administration page. In the menu on the left side of the management page, select the "Primary Setup" item and the dialog box shown in Figure 4 appears. In this dialog box, the default IP address of the TL-R400 and the type of WAN (Wide Area Network) are displayed. The default is "Dynamic IP Address". Click the "Change" button to enter the dialog box shown in Figure 5. In this dialog box, we need to click "PPP over Ethernet" to change the WAN type to "PPPoE" (point-to-point protocol on the local area network). This is because ADSL dial-up uses this protocol. After clicking, click the "Save" button to enter the next dialog box. Here, we need to set the ADSL account and password (that is, the ADSL user name and password provided by your ISP). After that, the task of dialing will be left to the TL-R400. After filling it out, we need to save the settings. But slow! !! We think carefully about the process of transmitting data on the Internet to the user's computer. It is from Internet ADSL Modem Broadband Router Local. We have seen that in order to access the Broadband Router, we must connect the IP address segment of the local connection and the IP address of the Broadband Router. The address segments can be unified. Then, think of ADSL Modem-ASUS AAM6000EV Ethernet ADSL Modem's default private IP address is "192.168.1.1" (most Ethernet ADSL Modem's factory default IP address is "192.168.1.1" ), The subnet mask is "255.255.255.0". Obviously, it is not on the same network segment as "192.168.254.x", that is, the TL-R400 cannot access the ADSL Modem at this time, and the data cannot be transmitted. Only when the IP address segments of the ADSL Modem, Broadband Router, and Local Connection are unified, can mutual access and data transmission be achieved! Therefore, we also need to modify the IP address of the TL-R400. We recommend that the IP address be changed to the same network segment as the ADSL Modem. 6). Finally, click the "Save" button to save the settings, and click "Reboot" to immediately restart the TL-R400 broadband router for the settings to take effect.

Client configuration

When the TL-R400 restarts, a dialog box with the words "System is restarted Please reconnect manually" will pop up. Let us reconnect to the management page. At this time, you can no longer access the management page by entering "http://192.168.123.254" in the IE address bar, because the IP address segment of the TL-R400 has been modified, and the IP address of the existing local connection is no longer available. It's on a paragraph. So we need to reconfigure the client.

Enter the dialog shown in Figure 4. Here, change the IP address to "192.168.1.x" (x is a natural number from 3 to 255) ("192.168.1.3" in this example), and the subnet mask is still "" 255.255.255.0 ". Since the TL-R400 replaces the proxy server and acts as a" gateway ", here we set the" gateway "to the IP address" 192.168.1.2 "of the TL-R400. Since the" gateway " ", The client's DNS server should also point to the" gateway ", that is," 192.168.1.2 "(Figure 7) (about this, we have already mentioned when using SyGate to share the network).

Third, the broadband router dials up to connect to the Internet

The ADSL Modem, broadband router, and locally connected private IP addresses are all on the same network segment, enabling data transmission.

Enter "http://192.168.1.2" in the IE address bar, then enter the management password to enter the TL-R400 management page, and click the "Connect" button in the lower right corner for dial-up connection. After waiting for about 5 seconds, the connection is successful, and at the same time, the TL-R400 will display the obtained public IP address, ISP's DNS server address and other information (Figure 8).

The client can go online. Open IE and enter the URL-Go !!

To access the Internet in the future, as long as the ADSL Modem and TL-R400 are powered on, the TL-R400 will automatically dial and connect to the Internet. At this time, after the computer logs in, you can directly access the Internet without any additional operations. If you don't want to go online, just turn off the power of the TL-R400.

TL-R400 supports 4 computers to share Internet access. If there are more than 4 computers, a hub (or switch) can be added. The networking method is shown in Figure 9.

Pros and cons

Some readers may say, I don't want to share the Internet, and it doesn't matter if the route is not. Indeed, if it is not important for users to access the Internet on a single machine, routing is not very important, but for users who need to share, there is a relatively intuitive difference between routing and not. Finally, we summarize the advantages and disadvantages of the routing mode. You can decide whether to use the routing method based on your actual situation.

advantage

1. Convenient networking and does not require a separate computer as a proxy server, which can reduce losses and save electricity costs ^ __ ^.

2. Once set, the computer can be connected to the Internet after booting up, no need to install dial-up software for dialing, which is very convenient and saves effort.

3. All computers are not exposed to the public network and are relatively secure. If the firewall function of the broadband router is enabled, the Internet security will be further guaranteed!

Disadvantage

1. All computers have no public IP address, and the exposed ADSL Modem or Broadband Router is exposed. Some applications that require public IP addresses (such as peer-to-peer information sharing, such as P2P; various server setups, such as streaming media servers, mail servers, etc.) need to be implemented by port mapping. Although most ADSL modems and broadband routers support port mapping, they need to be set up separately, which is not so convenient.

2. The number of shared computers supported is limited, which is inferior to the sharing method using a separate proxy server / gateway computer. The general routing ADSL Modem can stably support 5 to 12 units, and a broadband router (without a switch, which also needs to purchase a switch or hub separately) that can stably support 60 computer sharing needs more than 2,000 yuan, and the price is not cheap.

wireless online

What is wireless Internet access?

The so-called wireless Internet access is divided into two types. One is to enable the data function through a mobile phone. A computer can use a mobile phone or a wireless network card to achieve wireless Internet access. The speed is only about 33K, which can only be regarded as an emergency response. Another wireless Internet access method is a wireless network device, which is a wireless Internet access method based on a traditional local area network and a wireless AP and a wireless network card.

What is a wireless AP?

AP (Access Point) is actually an abbreviation, which basically has three types: 1. Wireless access point. 2. Wireless bridge. 3. Wireless router. One of them is equivalent to a wireless HUB, or a wireless receiver. The function of 2 is slightly stronger. In addition to the function of 1, it can also wirelessly bridge and wirelessly relay. And 3 is equivalent to an integrated product of 1 and a router.

What are the standards for wireless networks?

In order to solve the problem of interconnection of various wireless network devices, the Institute of Electrical and Electronics Engineers (IEEE) has introduced the IEEE802.11 wireless protocol notation. 802.11 mainly has three standards: 802.11b, 802.11a, and 802.11g. The first was 802.11b, which has a transmission speed of 11MB / s, with a maximum distance of 300 meters outdoors and about 50 meters indoors. Because of its relatively low connection speed, the 802.11a standard was subsequently introduced, and its connection speed can reach 54MB / s. However, because the two are not compatible with each other, some wireless network equipment that has already purchased the 802.11b standard cannot be used in the new 802.11a network, so the IEEE has officially launched 802.11g that is fully compatible with the 802.11b standard and compatible with the 802.11a rate In this way, through 802.11g, the original 802.11b and 802.11a standard equipment can be used in the same network. IEEE802.11g, like 802.11b, also works in the 2.4GHz frequency band, which is 5 times faster than the general 802.11b speed, and is fully compatible with 802.11. It is recommended to find out whether to support the protocol standard when purchasing equipment. Choose the one that suits you. The 802.11g standard has begun to spread.

What are the wireless networks?

Wireless Personal Network (WPAN): Wireless Personal Area Network stands for Bluetooth, with a characteristic transmission distance of <10m and a transmission rate of about 1Mbps, and the development of UWB speed is faster

Wireless Local Area Network (WLAN): Wireless Local Area Network represents the 802.11 series, with a characteristic transmission distance of <100m, a transmission rate of about 1M-54Mbps, and the development of 802.11n rates is faster

Wireless Metropolitan Area Network (WMAN): Wireless Metropolitan Area Network stands for WiMax, with a characteristic transmission distance of <5km and a transmission rate of about 70Mbps. Development is slowly in application

Wireless Wide Area Network (WWAN): The Wireless Wide Area Network stands for Mobile Unicom's wireless network, with a characteristic transmission distance of <15km, a transmission rate of about 3Mbps, and a faster development speed.

Generally speaking, wireless Internet refers to WLAN and WWAN.WLAN is to connect to Intelnet through a wireless access point; WWAN is to go to the mobile or China Unicom's business hall to handle related services.

With the popularization of the Internet, the safety of Internet access has attracted more and more attention.

At present, many browser software have advocated Internet security, including Firefox and Window of the World browsers.

V. China's domestic WWAN wireless Internet operators (3G)

China Mobile: operating TD-SCDMA networks, and EDGE and GPRS networks

China Telecom: operates CDMA2000 network (CDMA EV-DO), which is CDMA

China Unicom: Operating WCDMA Network (W-CDMA)

Forms of wireless Internet access

One is 802.11X, which is the connection between the wireless network card and the AP, which is typically Wi-Fi application. It is called wlan connection, and enters the local area network through the gateway. Generally use 802.1g, 54M connection speed. Generally hotels, companies will do wireless coverage in this area.

One is GPRS, which can directly dial CMNET or WAP to access the Internet through a GPRS mobile phone or card + SIM card, where dialing net can connect to the www website, and wap requires an agent. The net connection speed seems to be 115K, slow is slow, but convenient, you can use it on the phone where there is a signal.

One is CDMA, which is similar to GPRS, slightly faster than gprs, mostly through the card, and the connection speed is about 230K.

One is the latest 3G network, which is mobile TD-SCDMA, Telecom's CDMA2000, or China Unicom's WCDMA! The speed is comparable to broadband. The theoretical speed of mobile TD-SCDMA is 2.8M, the actual download speed is 100-200K / S, and the 3G-CDMA2000 (EVDO) of Telecom, the theoretical speed is 3.1M, and the actual download speed is 100-300K / S, China Unicom's WCDMA theoretical speed is about 7.2M-14.4M, and the actual download speed is 200-2M / S. Compared with broadband, it is better than that.