Networks

Networks

1. Types of Network

   • WAN
     • wide area network
       • a network that spans a large area or multiple organisations
   • LAN
     • local area network
       • a network in a small area or single organisation

2. Disadvantages

   • Difficulty
     • expertise is needed to set up and maintain a network
   • Increased risk
     • problems such as viruses can effect every computer on the network
   • Cost
     • networks are expensive to set up

3. Advantages

   • Share resources
     • such as prints and internet connections
   • Share logins
     • so the same username & password can be used on every computer
   • Share files
     • so the same files are available whichever computer you use

4. Topologies

   • bus topology
     • advantages
       • cheap to install
     • disadvntages
       • high chance of catastrophic failure
       • lots of collisions
       • slows down as more computers are added
   • ring topology
     • diadvantages
       • high chance of catastrophic failure
       • difficult to expand
     • advantages
       • cheap to install
       • no collisions
   • star topology
     • disadvantages
       • expensive
       • depends on a switch
     • advantages
       • low chance of failure
       • no collisions

5. IP Adress

   • a unique value assigned to every computer on a network, used to identify it.
   • messages on a network have an IP adress attached, which is how a computer knows whether or not to keep the messages

6. the internet

   • the internet is a giant mesh of computers
   • it is impossible to break the internet since another route can always be found
   • a cost is assigned to each connection mesh
   • route-finding algorithims are used to find the lowest cost route between two nodes

7. packets

   • 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