Networks

Networks

1. Advantages

   • Share files between computers
   • share resources between computers
   • Share logins between computers
     • same username and password can be used on every computer

2. Disadvantages

   • Viruses can spread quickly through the computers
   • It can be expensive to set up
   • Expertise is needed to set up and maintain a network

3. Types on networks

   • LAN
     • Local Area Network
     • A network in a small area or single organisation
   • WAN
     • Wide Area Network
     • A network that spans a large area or multiple organisations

4. Topologies

   • BUS
     • Advantages
       • Cheap to install
     • Disadvantages
       • High chance of catastrophic failure
       • Lots of collisions
       • Slows down as more computers are added
   • STAR
     • Advantages
       • Low chance of failure
       • No Collisions (fast)
     • Disadvantages
       • Expensive
       • Depends on a switch
   • RING
     • Disadvantages
       • High chance of catastrophic failure
       • Difficult to expand
     • Advantages
       • Cheap to install
       • No collisions (fast)

5. IP Address

   • Messages on a network have an IP Address attached
     • This is used to identify it
     • How the computer knows whether or not to keep the message
   • The internet is a huge network with more devices that it is possible to assign a unique address to.
   • Unique addresses are assigned to businesses and houses
     • These houses and businesses run their own mini-network inside with different IP Addresses
   • There are over 4 Billion IP Addresses in the world

6. The Internet

   • A giant mesh of computers
   • Impossible to break the internet
   • A cost is assigned to each connection
   • Route-finding algorithms are uses
     • Find the lowest cost route between two nodes
   • Data is split into small chunks called packets
   • Each packet is sent along the lowest cost route
     • The packets are re-assembled on the other side