Networks

Networks

1. Advantages

2. File Access everywhere

3. You can log onto a computer anywhere in the school!

4. You can:

   • Print
   • Use the internet
   • Email

5. Disadvantages

6. Expensive

7. Difficult - Technical expertise needed

8. More room for error

   • Every computer affected
   • Bad Malware
   • Viruses
   • Bad Software Spread

9. Network - A group of computers that are linked/connected together

10. LAN

    • Local Area Network
    • A network in a small are or a single organisation

11. WAN

    • Wide Area Network
    • A network that spans a large area multiple organisations

12. Bus Topologies

    • Disadvantages
      • High chance of catastrophic failure (a break in the central cable takes out the entire network)
      • High chance of collisions (multiple communications on the same cable that corrupt each other, slowing down the network
      • More computers means more collisions
    • Advantages
      • Cheap to install
      • Only one wire needed

13. Ring Topologies

    • Advantages
      • Cheap to installl
      • One cable per computer
      • No Collisions
        • Only one computer is transmitting on each cable
    • Disadvantages
      • Difficult to add new computers
      • High chance of catastrophic failure
        • If any cable breaks or any computer goes down, the entire network fails

14. Star Topologies

    • Advantages
      • Fast
        • Low chance of collisions
      • Easy to add new computers
      • Low chance of catastrophic failure
        • A broken cable only takes out one computer, the rest of the network is fine
    • Disadvantages
      • Expensive
        • Needs a lot of cabling, and a central switch, which is expensive
      • Failure of a switch will take down the network

15. IP Address

    • An IP Address is a unique value assigned to every computer on a network, used to identify it
    • Messages on a network have an IP Address attached, which is how a computer knows whether to keep the message or not.
    • Internal and External Networks
      • Each computer in the school has an internal IP Address, which the internet can not see
      • The School's main router uses the School's one external IP Address when communicating outside of school