1.3 - Computer Networks, Connections and Protocols

• LAN:

  • Operates on a single site or within a single organisation
  • Uses its own ethernet hardware and cabling to transmit data
  • Examples: Small company networks, home networks
• WAN:

  • Used to connect computers over much greater distances, often nationally/internationally
  • Uses third party or externa hardware such as satellites and the internet
  • Examples: Multi-national banking network, the Internet
• Number of devices that are connected to a network can affect performance.

  2 or more devices trying to transmit data at the same time along the same channel may cause data collisions to occur.
• Bandwidth can also affect the performance of a network since it affects how much data can travel at once.

  Higher bandwidth can transmit much more data simultaneously (e.g. fibre optic)

  Signal strength deteriorates with greater distance
• Wireless Access Point (WAP):

  • Creates a wireless network using radio waves
  • Wi-fi enabled devices can use this to connect to the internet or communicate with the network
• Router:

  • Sends and receives data packets
  • Assign IP addresses (public for the WAN, private for the LAN)
  • Local data passed onto the internet using this
• Switch:

  • Used to connect devices on a LAN
  • Receives data packets and forwards them to the correct device
  • Do this by using their MAC address
• NIC (Network Interface Card):

  • Required to connect any device to a network
  • Wired and wireless versions are available
  • All newer computers have a built in NIC