networks

networks

1. disadvanteges

   • 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

2. ADVANTIGES

   • Networks allow computers to: Share files, so the same files are available whichever computer you use Share resources such as printers and Internet connection. Share Logins, so the same username and password can be used on every computer on the network.

3. Lan

   • local area network

4. Wan

   • Wide area network

5. Topologies

   • bus
     • The network consists of a single cable that runs through the network All devices attach to this single cable
     • disadvanteges
       • 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
     • Advanteges
       • Cheap to install (only one wire needed)
   • ring
     • 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
     • Advanteges
       • Cheap to install (one cable per computer) No collisions - only one computer is transmitting on each cable
     • Disadvanteges
       • High chance of catastrophic failure (if any cable breaks or any computer goes down, the entire network fails Difficult to add new computers
   • star
     • All computers are connected to a central switch. The switch directs the traffic to the appropriate computer

6. Star

   • All computers are connected to a central switch. The switch directs the traffic to the appropriate computer Question: Why is this the most common type of network?

7. internal IP

   • Addresses therefore range from 0.0.0.0 to 255.255.255.255.

8. IP address

   • Computers on a network also need an address to identify them
   • When a computer is added to a network it is assigned an IP Address (Internet Protocol Address) The IP Address is unique value assigned to each computer on a network

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