Four Methods for connecting networks to the Internet

We know that generally, a short-distance network connection mainly refers to a hundred megabytes) uses five types of lines, and the maximum connection distance of the five types of lines is 100 meters. If it is a quality network cable, it is estimated that it is only 50 meters; if it is a long-distance connection, optical fiber cables will be used. For example, the interconnection between man networks is measured by dozens of hundreds of kilometers. What if it is a medium-distance connection? For example, a campus or a factory may need several hundred meters of distance. How can this problem be solved?

This issue has aroused heated discussions on our forum. Next we will introduce and analyze the opinions of the hundreds of scholars one by one:

Opinion 1: Use Wireless Networks

This idea is actually inspired by the widespread popularity of wireless hotspots. It is also easy to implement in this way, saving the tedious wiring work. However, a typical Wireless AP does not have the bridging function and must use a professional Wireless Bridge. This product is a branch of a Wireless AP and works in a similar way as a Wireless AP, however, it supports more working modes. To solve the above problems, you can use the Wireless Repeater Wireless relay mode ):

Wireless Repeater Wireless relay Mode)

The relay mode is not supported by all APs. Generally, SOHO-level APS do not support this mode, while most high-end commercial APS support this mode. In this mode, an AP connected to a wired LAN is used as the central AP. The AP can adopt the "AP mode" as needed. The AP acting as a repeater is not connected to the wired network, but only connected to the power supply, use Repeater and enter the Remote ap mac address.

The relay AP can bridge with the central AP (note that the relay AP should be placed within the coverage of the central AP), and also provide client access within the coverage of its own signal, to extend the coverage. Generally, a central AP supports up to four remote relay AP connections. In this case, all APs must use the same SSID, Authentication mode, key and channel, and set the IP address of the AP to the same network segment without DHCP. The client will still think that this is a large range of AP, so the client settings are the same with the single AP.

Although this relay mode makes wireless coverage easier and more flexible, it requires support from high-end APs. If a problem occurs in the central AP, the entire WLAN will be paralyzed and redundancy will not be guaranteed.

If the distance between the two points to be connected is a little longer, you can use a targeted antenna to expand the signal. At this time, it is not necessary to relay the AP, the point-to-point bridging mode can be used because the oriented antenna can realize long-distance signal transmission.

WBridge Point to Point-to-Point bridging)

Its application signals that the two buildings each have a lan: LAN1 and LAN2, two APs: AP-A and AP-B are connected in Point-to-Point Bridge Mode. Each AP is connected to a local LAN switch. At this time, the two APS act as an "invisible network cable" and a bridge.

Both ap a and ap B are set in the same way. They both select "Bridge Mode" on the AP management interface and select "Remote Bridge MAC address (Remote Bridge MAC). Note that the IP addresses of the two APS must be in the same CIDR Block and the same channel can be used to achieve wireless connection and resource sharing between the two wired LAN networks, or expand the wired network. It should be noted that both APs adopt oriented antennas.

Opinion 2: Use optical fiber

Many netizens have agreed to this solution, because the current price of fiber optics is also more than 10 pieces per meter, and the cost of pulling fiber cables between two points is not too high; however, we also ignored a problem: when wiring optical fiber, the price for welding is relatively high.

It should be noted that the technical difficulty of adopting this scheme is relatively low and no complicated settings are required. However, note that there are many optical fiber transceiver categories, which are used in different scenarios, before purchasing the product, you must make it clear to avoid buying mistakes and causing unnecessary economic losses:

Optical Transceiver classification:

Categories by optical fiber properties:

Single-Mode Optical Transceiver: 20 km to 120 km

Multimode Optical Transceiver: 2 to 5 kilometers in transmission distance

Categories by required Optical Fiber:

Single-fiber optical transceiver: receives sent data transmitted on a single optical fiber

Dual-Fiber Optical Transceiver: receives sent data transmitted over a pair of Optical Fibers

Classification by work level/rate:

M Ethernet Optical Transceiver: working on the Physical Layer

10/100 M Adaptive Ethernet Optical Fiber Transceiver: working at the data link layer

By structure:

Table independent optical transceiver: independent client device

Rack-mounted modular) optical transceiver: it is installed in a sixteen-slot chassis and uses centralized power supply.

Categories by management type:

Non-network Ethernet Optical Fiber Transceiver: plug-and-play. The electrical port working mode is set through the hardware dial switch.

Network-managed Ethernet Optical Fiber Transceiver: supports carrier-level network management

By power supply:

Built-in Power Optical Transceiver: the built-in switch power supply is telecom-grade power supply.

External Power Optical Fiber Transceiver: External transformer power supply is mostly used on civil equipment [Page]

Opinion 3: Pull a wire and use VPN

This method is actually very practical. After all, the cost of pulling a single line is very low, and then the VPN function of the router can achieve the sharing of resources in two places, and the sharing security and manageability are also relatively high.

VPN technology has become popular in the past two years and has its unique advantages. Security and low cost are its biggest features. In this solution, some netizens have suggested using VPN, which is indeed unique, when I pull a line with the ISP, the charge is certainly lower than the pull line. However, for most users, how to establish a VPN still needs to turn to the system integration company, therefore, the overall cost should be included in the system integrator's charges.

There are too many things to talk about VPN. Here we will briefly introduce two mainstream VPN technologies:

SSL VPN

Secure Socket Layer (SSL) is a high-level security mechanism and is widely used in Web browser programs and Web server programs. In SSL, identity authentication is based on certificates.

Advantage: ssl vpn helps users access important enterprise applications through standard Web browsers. This makes it unnecessary for employees to carry their own laptops when they are on a business trip. They can access enterprise resources only through a computer connected to the Internet, which improves efficiency and convenience for enterprises.

Disadvantage: for non-webpage file access, application conversion is often required. Some ssl vpn products support a very small number of application converters and proxies, and some support FTP, Network File System, and Microsoft File Server application conversion. However, it is impossible to form a LAN application to form a large private network.

From the above analysis, the deployment and Application of ssl vpn will be very convenient. However, if you consider future enterprise applications, such as the use of some network-based collaborative development software, some non-Web-based applications within the LAN, and IP-based voice security applications, therefore, ssl vpn may not be able to provide good support.

IPSec VPN

IPSec is one of the standards supported by IETF. It is the layer-3 (IP layer) encryption. IPSec is not a special encryption algorithm or authentication algorithm, nor does it specify a Special encryption algorithm or authentication algorithm in its data structure. It is just an open structure, it is defined in the IP packet format. Different encryption algorithms can be implemented during network data transmission using the architecture defined by IPSec.

He baohong, an expert at the Institute of Communication Standards of the Ministry of Information Industry and the Institute of Telecommunications Research, once pointed out that IPSec is the most secure protocol so far. At the same time, IPSec VPN can truly solve the interconnection between LAN and form a real private network. In addition, from the perspective of development, IPSec VPN can also provide good support for future application development, not limited to the application situation based on web or other environments.

Opinion 4: Use the "Network extender"

This is the opinion of a device manufacturer, and it is more convenient to solve the problem of intercommunication between two locations within 700 meters. However, we do not know much about products such as "Network extender", and there are no well-known brands that have launched related devices. They are all developed by some small and medium network product manufacturers that are not well-known, the quality of this solution is completely unknown to everyone, so it has not been recognized by everyone on the forum.

This product is used as follows, similar to a vswitch.

1. How to build a network with over 100 meters
2. Analysis of differences between network interconnection devices for LAN Formation
3. You can also set up a home router to build a network.