Networks

LANs

• A local network
• -Covers a small geographical area
• -All of the hardware is owned by the organisation that uses it
• -Either wired (Ethernet cables) or wireless (wifi)
• -You could find LANs in businesses, schools and universities.

Why use a LAN?

• - Sharing files is easier, network users can access and copy the same files and work collaboratively on them.
• - You can share the same hardware on a LAN (such as a printer)
• -The internet connection can be shared between every device connected to the LAN
• -You can install and update software on all computers at once.
• -You can communicate with LAN users cheaply and easily (eg. instant messages)
• -User accounts can be stored centrally so that users can log in on any device on the network.

WANs

• - A network that connects LANs
• - 'Wide Area Network'
• -Connects to LANs that are in different geographical locations
• - Organisations hire infrastructure ( eg. communication lines) from telecommunications companies who own and manage the WAN. This makes it much more expensive to set up
• -WANs may be connected using fibre or copper telephone lines, satellite links or radio links.
• - The internet is the biggest WAN.

Factors that affect performance of NWs

• -Bandwidth is the amount of data that can be transferred at a given time. The greater the bandwidth, the better the network can perform
• -Available bandwidth is shared between users of a network, too many users or heavy use may slow down the network.
• - Wired connections are faster and more reliable than wireless. Fibre optic cables can give much better performance than copper cables. Wireless performance depends on signal quality so is affected by the range of the device, the amount of interface from other devices and physical obstructions like thick walls in buildings
• - Choice of hardware other than cables and network topology also have a big effect.