Sm1 Computer Networks

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    05-Dec-2014
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Network course

Transcript of Sm1 Computer Networks

  • 1.
    • Computer Networks
  • 2. Networks
    • A computer network is any system of two or more computers that are linked together.
  • 3. Networks
    • Why is networking important ?
    Networks enable people to share computer hardware resources, to share data and software and allow people to collaborate in ways that other wise difficult.
  • 4. Network Classification
    • LAN
    • WAN
    • MAN
    • PAN
  • 5. Network Classification
    • LAN (Local Area Network)
    • Computers are physically close to each other, usually in the same building.
  • 6. Network Classification LAN hardware Each computer or peripheral in a LAN is called a node ; nodes are connected through hubs or switches . Hubs broadcast messages to all devices connected to a network but one at a time. A switch broadcast the messages only to a destination node and it can carry multiple messages simultaneously.
  • 7. Network Classification
    • MAN (Metropolitan area network)
    • Links two or more LANs within a city
    • (WAN) Wide area network
    • Extends over a long distance.
    • Each network site is a node on the network.
    • WANs are possible thanks to telephone lines, microwave towers, satellites and fiber-optic cables
  • 8. Network Classification
    • Bridges : hardware devices that connect segments of a network. They often translate messages so they can be understood by networks that obey different protocols .
    • Routers : hardware devices or software programs that route messages as they travel between networks.
    MAN/WAN hardware
  • 9.
  • 10. Network Classification
    • It is a network that links a variety of personal electronic devices so they can communicate with each other,
    ( PAN) Personal Area Network generally through bluetooth technology.
  • 11. Wireless Technologies Is the transfer of information through the air rather than through cables. Wireless communication may be via:
    • radio frequency communication
    • microwave communication
    • infrared
  • 12. Modems
    • A modem is a device that converts digital signals from a computer's serial port to the analog signals required for transmission over traditional telephone lines, and vice versa.
    • Conversion is necessary because telephone lines were initially designed to handle the analog nature of the human voice, not data.
  • 13. Protecting the Network
    • The creation of bigger networks, has increased security risks
    • Firewalls : are hardware and software barriers that execute an access control policy among networks.