Networks

Networks

1. types of networks

   • Lan
     • WAN
       • Wide Area Network A network that spans a large geographical area, or multiple organisations Often consists of multiple LANs networked together
     • Local Area Network A network contained in a single geographical location or organisation

2. Advantages

   • Consistent User Experience - You can log on to any computer in the school using the same username and password Your files are available on every computer you use, even if you created them on a different computer You can print, use the Internet, email and use the same software on any computer

3. Disadvantages

   • What disadvantages could there be to putting computers on a network? Expensive – extra hardware and wiring needed More room for error – if something goes wrong it can affect every computer Difficult – it requires a technical expertise Malware – viruses and other malicious software can spread through the network

4. Bus Topology

   • advantage
     • Cheap to install (only one wire needed)
   • disadvantages
     • High chance of catastrophic failure (a break in the central cable takes out the entire network) High chance of collisions (multiple communications on the same cable that corrupt each other, slowing down the network) More computers mean more collisions, so the network gets slower as it gets bigger

5. Ring Topology

   • Computers are connected to each other in a ring Communication only goes in one direction Each computer receives a message, and if it is not the intended recipient, passes it on to the next computer No central cable, each connection is between two computers Question: Which problem with bus networks does this solve?
   • disadvantages
     • High chance of catastrophic failure (if any cable breaks or any computer goes down, the entire network fails Difficult to add new computers
   • advantages
     • Cheap to install (one cable per computer) No collisions - only one computer is transmitting on each cable

6. star topolgy

   • All computers are connected to a central switch. The switch directs the traffic to the appropriate computer
   • advantages
     • Fast (low chance of collisions) Easy to add new computers Low chance of catastrophic failure (a broken cable only takes out one computer, the rest of the network is fine