Networks

• LAN usage

  • Businesses
  • Schools
  • Universities
  • Homes
• LAN


  All hardware is owned by the organisation that uses it
• WAN


  WANs connect many different LANs that are in different geographical locations
• Types of LAN connections

  • Wired- Ethernet
  • Wireless- WIFI
• Benefits of LAN

  • Sharing files is easier
  • You can share the same hardware
  • Internet connection can be shared between every device on LAN
  • Install and update software on all computers at once
  • Communicate with LAN users cheaply and easily
  • User accounts can be stored centrally. Users can log in from any device
• Types of networks

  • LAN
  • WAN
• LAN


  Covers a small geographical area on a single site
• WAN


  Organisations hire infrastructure from telecommunication companies that own and manage the WAN as they are more expensive to set up than LANs
• The Internet is one big WAN
• WAN connection methods

  • Fibre or copper telephone lines
  • Satellite links
  • Radio links
• Factors affecting network performance

  • Wired vs wireless networks: Wired networks are usually faster and more reliable. Wireless performance depends on signal strength but is rarely better than wired connections
  • Bandwidth: Higher bandwidth means higher network performance. Bandwidth is shared between users, so performance can decrease with many users
  • Choice of hardware: The choice of cabling and networking hardware impacts network speed
• Hardware components of LANs

  • Network interface card (NIC): Enables computer connection with a device, laptops/mobiles have wireless NICs, NICs have a MAC address
  • Wireless access point (WAP): Connects wireless devices on an LAN without physical cables, broadcasts data to every device on a WiFi network
  • Switch: Connects wired devices on a LAN, sends data between computers
  • Router: Connects different networks, crucial role on the Internet directing data in packets towards their destination
  • Transmission media: Wired-cables (Ethernet copper cables, Fibre optic cables, Coaxial cables), Wireless-radio signals (Bluetooth, WiFi)
  • Server: Centralised device managing access to resources across a network, fulfills requests from clients on the network