1.4 Wired and Wireless Networks

Local Area Network

A computer network over a small geographical area. 

Wide Area Network

A network that connects separate LANs over a large geographical area.

The internet is a huge Wide Area Network. 

• Wires broken, signals interrupted.
• Different types of cables used.
• Multiple people using the network at the same time. Too much data trying to get through the network.
• Limited range (e.g. wifi signal.)
• Malware- Malware is made to stop your device from running properly and sometimes to steal your information. Your device can be harmed very quickly if it is infected by malware. It could crash, reboot or slow down. Your internet connection may also slow down as the virus or worm searches for other devices to infect, or transmits your data back to its maker.
• Denial of Service attacks

Needed to connect a stand-alone computer to a LAN. 

Allows wireless devices to connect to a wired network.

• They convert the data they receive through cables into a wireless signal (and vice versa)
• Commonly used in public buildings to proivde 'Internet Hotspots'
• Similar to hubs; they cannot direct messages to particular devices. 

Needed to connect a stand-alone computer to a LAN.

Switches

• Read messages passing through
• They can read the destination addresses and send them to only the intended computer. This is because they build up a table of all the MAC addresses on the network.
• Cut down on unecessary network traffic.
• Can send and receive information at the same time- therefore faster than hubs.

Routers

• Read the address info and forward messages to correct network. Switch does this on single network, router does it across several.
• Commonly used in the home to allow many computers to share an internet connection. Links the home network to a larger one (the internet)
• Can have both cable and wireless connections