Networks

Networks

1. Types of Networks

   • LAN
     • Local area network- a network in a small area or single organisation
   • WAN
     • Wide are network- a network that spans a large area or multiple organisations

2. Advantages

   • Save files no matter what computer you use
   • Share resources such as printers and internet connection
   • Use the same logins on every computer

3. Topologies

   • Bus
     • Advantages
       • Cheap to install
         • No collisions(fast)
     • Disadvantages
       • High chance of catastrophic failure
         • Lots of collisions
           • Slows down as more computers are added
   • Ring
     • Advantages
       • Cheap to install
         • No collisions(fast)
     • Disadvantages
       • High chance of failure
         • Difficult to expand
   • Star
     • Advantages
       • Low chance of failure
         • No collisions(fast)
     • Disadvantages
       • Very expensive
         • All depends on one switch
   • Mesh
     • Advantages
       • If one computer breaks the whole network is not affected
       • Lots of computers can be added without causing disruption
       • Manages high traffic
     • Disadvantages
       • Takes a lot of planing
         • There is quite a lot of complexity within this topology
           • A lot of power consumption is taken up

4. Disadvantages

   • Problems such as viruses can affect every computer on the network
   • Expertise are needed to set up and maintain a network
   • Networks are expensive to set up

5. IP Adresses

   • An IP address means internet protocol . Each IP address must be unique from others so that it can be identified directly.
   • An example of how an IP address can help with identifying a computer is when a message comes through to the computer it wil either keep the message or send it to another computer

6. Packets

   • All data is split into small chunks called packets
     • Each packet is sent along the lowest cost route
       • All packets are re-assembled on the other side

7. The internet

   • The internet is a giant mesh of computers
     • There are multiple different connections between any two nodes
       • Its impossible to break the internet as another can always be found

8. A cost is assigned to each computer in a mesh

   • Route- finding algorithms are used to find the lowest cost between any two nodes
     • All computers are connected together