NIC and WAP configuration of wireless clients

This article provides a detailed example of the NIC problem on the wireless client. The relationship between the wireless client and NIC, as well as the computer's wireless LAN and WAP, various related protocols. I hope this article will help you.

Wireless Client NIC Figure 1 wireless computer to computer mode

Wireless Networks require clients to use a wireless adapter or NIC) to connect to the network and communicate with other computers. There can be an access-end wireless router) to provide multiple users with Internet connections. A simple wireless LAN is composed of two or more computers connected via a wireless network. They do not require a cable or wired connection. Computers are connected by wireless NICs, which can send data through radio waves. Figure 9-1 is an example.

In fact, figure 1 shows that two computers are running through a wireless network in the computer Mode Ad hoc Mode. Wireless systems can run in computer-to-computer Mode or Infrastructure Mode. In computer-to-computer mode, no devices except wireless network adapters are required. In the computer-to-computer mode, point-to-point communication can be achieved, which provides excellent performance in small networks. The computer-to-computer mode is based on the node-to-node mode of communication. The Infrastructure mode uses a wireless access terminal WAP ). WAP is a central wireless device that controls traffic in the wireless network. Figure 9-2 shows an example of a wireless LANWLAN created using WAP.

In the Infrastructure mode, wireless devices communicate with WAP. Then, WAP forwards data packets to the appropriate computer. If you want to connect to WAP using your wireless device, your device must be configured to use the same service set IDSSID ). SSID is used to distinguish between different wireless networks. The SSID can be up to 32 characters long and case sensitive. However, it is easily sniffed during transmission. All in all, compared with the computer-to-computer mode and Infrastructure mode, we will find that the infrastructure mode is more scalable.

Wireless Client NIC Figure 2 wireless infrastructure Mode

Wireless Networks have issues that do not exist in wired networks. For example, in a wired network, it is easy for any device to find whether another device is transmitting data. In a wireless network, WAP listens to all wireless devices, but a single wireless device cannot listen to other wireless devices. This is the so-called node hiding problem. To solve this problem, you must use the CSMA/CA protocol. It monitors devices before they send data. If the wireless device finds another device is being transmitted, it will wait for a while before trying again. If the first wireless device finds that no other device is transmitting data, it will send a short message that is ready to be issued.