networks

networks

1. disadvantage

   • cost
     • network are expensive to set up
   • increased risk
     • problems such as viruses can affect every computer on the network
   • difficulty
     • expertise is needed to set up and maintain a network

2. types of networks

   • WAN
     • wide area network
       • a network that spans a large area or mutiple organations
   • LAN
     • local area network
       • a network in a small area or single organation

3. advantages

   • share logins
     • so the same files are available whichever computer you use
   • share resources
     • such as printers and internet connection

4. topologies

   • bus
     • advatages
       • cheap to install
     • disadvantages
       • high chance of failure
       • collisions
       • slow if more computers are added
     • the network consists of a single cable that runs through the network
   • star
     • advantages
       • low chance of failure
       • no collisions
     • disadvantages
       • exspensive
       • depends on switch
     • computer connected to a switch in the centre
   • ring
     • advantages
       • cheap
       • no collisions
     • disadvantages
       • high chance of failure
       • difficult to exspand
     • computers are connected to each other in a ring

5. IP address

   • definition
     • an IP address is a unique value assigned to every computer on a network ,use to identified it
   • what is it for
     • it is to identify every device
   • how many IP address are there
     • there are 4,228,250,625 IP address
       • they look like 86.188.242.210

6. internet

   • mesh topolgy
     • 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
   • packets
     • Big file is broken down into smaller packets and the packets are reassembled at the end
   • how is a route chosen
     • cost is assigned to each connection in a mesh .Route finding algorithms are used to find the lowest cost route