Wireless networking

Overview

Recall questions on the adapter and the access point, the SSID, why wireless needs encryption when wired does not, and how far hiding the SSID actually protects.

What you need to know

Answer each one before you reveal it.

Questions from this subtopic

Each one with the model answer underneath.

1. 1

   Explain the purpose of WiFi.

   Model answer

   WiFi is a wireless local area network technology based on international standards. Its purpose is to let devices connect to a network, and through it to other devices and to the Internet, without a physical cable — using radio waves instead. Because it is built on agreed international standards, equipment from different manufacturers can interoperate.

2. 2

   What two components are required for wireless networking?

   Model answer

   A wireless network adapter in each device, and a wireless access point.

3. 3

   What does a wireless network adapter do?

   Model answer

   It is the hardware inside a device that lets it join a wireless network. It converts the device's data into a radio signal for transmission and converts received radio signals back into data, and it holds the MAC address by which the device is identified on the local network.

4. 4

   What does a wireless access point do?

   Model answer

   It is the device that creates the wireless network. It receives radio transmissions from wireless devices and passes them on, and it broadcasts to them in turn, acting as the central point through which wireless devices communicate and providing the bridge between the wireless network and a wired network or the Internet.

5. 5

   Describe three ways in which a wireless network can be secured.

   Model answer

   First, strong encryption of the transmitted data using WPA or WPA2 (WiFi Protected Access), so that although the radio signal can be picked up by anyone in range, the data it carries cannot be read without the key. Second, disabling SSID broadcast, so the network name is not advertised and a user must know it in advance in order to connect. Third, a MAC address allow list, so the access point only accepts connections from devices whose MAC addresses have been entered on its list of permitted devices.

6. 6

   Why does a wireless network need encryption in a way that a wired network does not?

   Model answer

   Because the transmission medium cannot be physically restricted. Radio waves spread beyond the walls of the building, so anyone within range can receive every frame without touching the equipment or being detected. On a wired network an intruder would first have to gain physical access to a cable or port. Encryption means that intercepting the signal is not enough — without the key the captured data is unintelligible.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.