Chapter 4

Chapter 4

1. Switches

   • Similar to hub but more efficient , Switches check the data packet recieved and works out destination address. (Directly) More efficient then Hubs. Only to appropriate computer.

2. Modem

   • Modulator demodulator
     • Converts a digital computer signal into an analog signal for transmission over telephone signal

3. Hubs

   • Devices to connect few devices/computers to form LAN.
     • take data packets received at one of its ports and broadcast it to every computer in the network (Cheaper than switch)
       • Network Issues and Communication
         • Network Security
           • Prevents illegal materials from being posted on websites.
             • People find it easier to find dangerous information
               • Prevent vulnerable groups of people from accesing undesireable websites
             • A risk of information overload
           • Why is it wrong?
             • Material published already available from other sources
               • Expensive
                 • Difficult to enforce
                   • It goes against freedom of information
                   • Laws already exist to deal with illegal material posted on the internet
         • Social Divide/Digital divide
           • Some people may not be able to access new technologies due to lack of skill, funding etc.
           • It is not a necesity to some people
         • Reliability of information
           • Information on internet more likely to be more up to date then books
             • Much easie to get information from websites
               • Easier to locate then books
                 • Information could be incorrect, inaccurate or biased because it doesn't go through a proper checking process
                   • Risk of information overload making it difficult to find relevant information

4. Each device/computer on a network has a MAC address that uniquely identifies it.

5. LAN

   • Local area network
   • WAN
     • MAN
       • PAN
         • Private Area Network (hotspot or bluetooth)
       • Metropolitan Area Network (Business eg.banks)
     • Wide Area Network (google, Internet)

6. Bridge

   • Devices connect LAN to another LAN that uses the same protocol
     • Often used to connect different LAN to become singular

7. Router

   • Enable data packets to be routed between the different network.
     • transmit internet and transmission protocols between 2 network and allow private networks to be connected together

8. Data Packets

   • Data is carried in the packet according to which protocol is used
     • When router receives packet it checks the address against the data.

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