Networks

Networks

1. Types of network:

   • 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.

2. Advantages:

   • You can share files so that they are available on every computer you use
     • You can share resources such as printers and internet connection.
       • You can share logins so the same username and password can be used on very computer on the networks

3. Disadvantages:

   • Networks are expensive to set up.
     • Problems such as viruses can effect every computer in the network.
       • Expertise is needed to set up and maintain a network.

4. Topologies:

   • Bus topology
     • Ring topology
       • Star topology
         • Mesh topology
   • Network topology is the arrangement of computers and other elements of a network.

5. Bus topology:

   • Advantages:
     • Cheap to install.
   • Disadvantages:
     • High chance of catastrophic failure.
       • Lots of collisions.
         • Slows down as more computers are added.

6. Ring topology:

   • Advantages:
     • Cheap to install.
       • No collisions.
   • Disadvantages:
     • High chance of catastrophic failure
       • Difficult to expand.

7. Star topology:

   • Advantages:
     • Low chance of failure.
       • No collisions
   • Disadvantages:
     • Expensive.
       • Depends on a switch

8. Mesh topology;

   • Advantages:
     • Multiple devices can be connected at once.
       • If one computer fails the rest will be fine.
         • Adding more devices doesn't affect the data transmissions on other devices.
   • Disadvantages:
     • More expensive than any other network topologies.
       • It takes time and genius to build and maintain.
         • The chance of redundant connections is high
           • This adds to the high cost to set up

9. IP Adress

   • An IP address is a unique value assigned to every computer on a network, used to identify it.

10. The Internet:

    • The internet is a giant mesh of computers.
      • There are multiple different routes between two nodes.
        • It is impossible to break the internet, since another route can always be found.

11. Internet:

    • Packets= The small chunks of data on the internet.
      • Routing= The process of selecting a path for traffic in a network or between or across multiple networks.
        • Mesh Topology=The layout in which each node is connected to one or more other nodes in an ad-hoc manner.

12. Data:

    • Data is split into small chunks called packets.
      • Each packet is sent across the lowest cost route.
        • The packets are re-assembled on the other side.

13. Cost of the internet:

    • A cost is assigned to each connection in a mesh.
      • Route-finding algorithms are used to find the lowest cost rote between two nodes.