Components and functions of a Network

• Types of Wired Media

  • Twisted Pair
  • Coaxial
  • Fibre-optics
• Twisted Pair

  • Used for network cabling and telephone systems
  • Is a cheap cabling used to connect computers and peripherals
  • Cables consists of a pair of insulated copper wires twisted around each other
  • Does not allow very fast transmission, so it is not suitable for sending large amounts of data
  • It is used in small LANs transmission, so it is not for offices and homes
• Coaxial

  • It is a copper wire covered in a very thick layer of insulation
  • Provides faster transmission than twisted pair, so it is suitable for medium-sized LANs
  • Is more expensive than twisted pair
  • Can be used to transmit sound, voice and video across a network
  • Used for cable television wiring and in some networks
• Fibre - Optics

  • The most robust and efficient cable;
  • Can transmit signals over much longer distances than coaxial and twisted pair cables;
  • Is best for large WANs and MANs;
  • The data is transmitted as light pulses along clear glass fibres instead of as electrical signals along copper wires;
  • Can transmit signals over much longer distances than coaxial and twisted pair cables;

  It can carry information a vastly greater speeds which makes it possible for video conferencing and interactive services.
• Wireless Media

  • Infrared

  • Microwave

  • Satellite
• Infrared

  • Wireless medium that sends signals via short-wave electromagnetic radiation.
  • Used to transmit data fairly quickly over a short range. (remote controls)
• MICROWAVE

  Wireless signal that transmits data in a straight line; used in cellular phones
• SATELLITE

  • Wireless signals that allow computers to connect to the Internet. This vastly speeds up the transmission of large files from an internet server to the user’s computer
• SWITCH

  • A device that channels incoming data from any of multiple input ports to the specific output port that will take it toward its intended destination.
• Router


  A device that forwards data packets across multiple networks
• Router


  • Connects networks
  • Acts as a dispatcher as it decides which way to send each information packet
  • Located at any gateway (where one network meets another), including each point-of-presence on the internet
  • Is often included as part of a network switch
• MODEM

  • A combination of MOdulate and DEModulate

  • It is the most common communication equipment

  • It converts the digital signals of a computer to analog signals that can be transmitted over phone equipment and then back to digital so the signals can be received by another computer
• Network Interface Card/Network Adapter

  • Is a circuit board or card
  • Provides the computer with a dedicated, full-time connection to a network
• Network Interface Card/Network Adapter

  • Personal computers and workstations on a local area network (LAN) typically contain a network interface card specifically designed for the LAN transmission technology