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  • 1. Networking
    • Define what a network means
    • List the basic components of a data communication system
    • Explain the different types of network configurations or topologies
    CHAPTER 7 Objectives:
  • 2. Communications
    • Process in which two or more computers transfers data, instructions, and information
  • 3. Communication
    • What is needed for successful communications?
    Communication Device Communication Device Sending device — initiates instruction to transmit data, instructions, or information Receiving device — accepts transmission of data, instructions, or information Communications channel — media on which data, instructions, or information travel
  • 4. Communication Communication Device Sending Device Receiving Device Communication channels
  • 5. Networks
    • Network is a collection of computers and devices connected by communication channels
      • To facilitate communications, share hardware, data and information, software, etc
  • 6. Networks TYPES OF NETWORKS:
  • 7. Type of Networks
    • 1. Local Area Network (LAN)
    • Privately owned communication network
    • Home, school computer laboratory or office building
  • 8.
    • 2. Metropolitan Area Network (MAN)
    • Network that covers geographical area
    • Connects LANs in city or state
    Type of Networks
  • 9.
    • 3. Wide Area Network (WAN)
    • Network that covers large geographical area - country.
    • Consists of 2 or more LANs/MANs
    • Internet is world’s largest WAN
    Type of Networks communications satellite
  • 10. How data travel ? Analog Signal is a continuous electrical signal in the form of a wave and it is called as a carrier wave .
    • Frequency – how many times it completes a cycle in a second
    • Amplitude – the height of a wave within a given period of time
    Volts Analog Signal 5 0 -5 (sec) 2 complete cycles in 1 sec. Frequency = 1Hz, Amplitude = 10v
  • 11.
    • Digital signal consists of individual electrical pulses that represent bits grouped together into bytes.
    • On/off - present/absent electrical pulses in discontinuous wave
    • Represents 0s/1s. ( two state binary language)
    How data travel ? 0 5 (sec) 1 1 0 1 1 0 1 0 Volts Digital Signal 2 states On - 5v - 1 and OFF - 0v – 0
  • 12. Communication Devices
    • Function of a communications devices
    • Capable to transmit data, instruction and information between sending and receiving devices.
  • 13.
    • Example of communications devices
    Communication Devices Common types are dial-up modems, ISDN and DSL modems, cable modems, wireless modems, network cards, wireless access points, routers, and hubs
  • 14. Communication Devices Modem ( Mo dulate/ dem odulate)
    • Transmission speed
      • speed at which modem transmit data
      • measurement - bits per second (bps) or kilobits per second (kbps)
    • Computers use digital signal and some communication channel uses analog signals.
    • Convert digital signal to an analog signal and vice versa
  • 15. Communication Devices MODULATION DEMODULATION MODEM To convert a digital signal into an analog signal To convert an analog signal into a digital signal
  • 16.
    • Type of Modem
      • External Modem
      • Internal Modem
      • PC Card Modem
      • Wireless Modem
    Communication Devices
  • 17. Communication Devices Network cards
    • Adapter card, PC Card or flash card that enables a computer or device to access network.
    • called network interface card (NIC)
  • 18. Communication Devices Wireless Access Point
    • Allows computers and devices to transfer data wirelessly among themselves or wirelessly to a wired network.
  • 19. Communication Devices Router
    • connects multiple computers and transmits packet of data to its correct destination.
  • 20. Communication Channels
      • Bandwidth amount of data that can travel over a communications channel
      • Transmission media on which data, instructions or information travel in a communication system
    • Type of transmission media
        • Physical
        • Wireless
  • 21. Communication Channels
    • Wire, cable and other tangible materials used to send communications signals
    Physical transmission media
  • 22. Communication Channels
    • Twisted - Pair cable
      • the wires are twisted together to reduce “noise” - electrical disturbance
      • suitable for short distances
      • used for telephone systems and network cabling
    Physical transmission media
  • 23.
    • Coaxial cable
      • produce high quality transmission
      • often used for cable television wiring
      • advantages:
        • less affected by electrical interference “noise”
    Communication Channels Physical transmission media
  • 24.
    • Fiber optics cable
      • Consist thin strand of glass  send data through light beams
      • Advantages:
        • carry more data signals
        • faster data transmission
        • less affected by “noise”
        • smaller size
      • Disadvantages:
        • more expensive
        • difficult to install and modify
    Communication Channels Physical transmission media
  • 25. Communication Channels
  • 26.
    • Used when inconvenient, impractical, or impossible to install cables
    Wireless transmission media Communication Channels
  • 27.
    • Infrared
    • Sends signal using infrared light waves.
    • Suitable for short distances
    • Mobile devices such as handphone, notebook and PDA.
    Wireless transmission media Communication Channels
  • 28.
    • Broadcast Radio
    • distributes radio signal through the air over some distance.
    • It need transmitter (send signal) and receiver
    • E.g: Bluetooth, HomeRF, Wi-Fi technology
    Wireless transmission media Communication Channels
    • Cellular Radio
    • Form of broadcast radio – mobile communication
    • Transmit voice and digital data messages
    • Categories of cellular transmission : 1G, 2G, 3G
  • 29.
    • Microwave transmission
      • used radio waves that provide a high-speed signal transmission
      • Line-of-sight transmission
    Wireless transmission media Communication Channels Microwave station
  • 30.
    • Satellite transmission
      • Space stations  send and receive signals from earth-based stations .
      • Geosynchronous orbit - the place that allows the satellite to remain positioned over the same spot on earth
    Wireless transmission media Communication Channels
  • 31.
    • Dial up lines
      • Temporary connection using telephone line for communications ( need to reestablish the connection )
      • Modem has to convert digital data into analog signal before it can travel through the telephone network.
    Communication Over the Telephone Line
  • 32.
    • ISDN lines
      • Digital transmission of data over standard copper telephone line
      • Needs ISDN modem
      • Advantages:
        • data transmission speed is faster than dial-up modem
        • the ISDN circuit has two phone lines
          • to connect to the Internet
          • to talk on the phone
    Communication Over the Telephone Line
  • 33.
    • T-Carrier Lines
      • Digital telephone line that carry multiple signals over a signal communication channel.
      • Provides very fast data transfer rates.
      • Used by large companies - expensive
      • T1 - Most popular T-carrier line
    Communication Over the Telephone Line
  • 34.
    • ADSL
      • Digital telephone line for small business and home user.
      • Can transmit at fast speed
      • An example of this service is the streamyx connection provide by TM bhd.
        • user who subscribed to this line need to have an ADSL modem.
    Communication Over the Telephone Line
  • 35. LAN
    • Network Topologies
    • Configuration, or physical arrangement, of devices in a communications network
    • Networks usually use combinations of three topologies
    bus ring star
  • 36.
    • Bus network
    • All computers and devices connect to central cable or bus
    • Inexpensive and easy to install
    LAN - Network Topologies
  • 37.
    • Ring network
    • Cable forms closed ring, or loop, with all computers and devices arranged along ring
    • Data travels from device to device around entire ring, in one direction
    LAN - Network Topologies
  • 38.
    • Star network
    • All devices connect to a central computer, called the hub
    • All data transferred from one computer to another passes through hub
    LAN - Network Topologies HUB printer
  • 39. LAN - Network Communication Standard
    • Specific combinations of hardware and software that allow different devices on several types of networks to communicate or connected
    Ethernet Token Ring TCP/IP Wi-Fi Bluetooth IrDa
  • 40.
    • Ethernet
    • LAN technology that allows personal computers to contend for access to network
    • Based on bus/ star technology
    LAN - Network Communication Standard personal computer personal computer personal computer personal computer personal computer
  • 41.
    • Token Ring
    LAN - Network Communication Standard Technology controls access to network by requiring devices to pass a special signal, called token Only device with token can transmit data over network at a time
  • 42.
    • TCP/IP
    • Define how data should travel through the Internet  data is sent to the right destination.
    • Transmits data by breaking it up into small pieces  packets
    LAN - Network Communication Standard Packets Data divided into small pieces TCP Breaks the message into data packets and reassembles them once reach their destination. IP Assign each packet a unique address .
  • 43.
    • Wi-Fi
    • Define how data should travel through the wireless network
    LAN - Network Communication Standard
    • Hot spots
        • provide users to connect to the internet wirelessly with their wireless mobile devices
  • 44.
    • Bluetooth
    • Define how two Bluetooth devices use short range radio waves to transmit data
    • Bluetooth devices contains small chip to allow it to communicate.
    LAN - Network Communication Standard IrDa
    • Define how data is transmitted via infrared light waves
    • Line-of-sight transmission
  • 45.
    • Connection and cabling system
      • Use either wire / wireless transmission.
    • Computer with NIC
    • Networking OS
    • Bridge
      • a combination of hardware and software that recognizes the messages on a network and passes on to the receiving nodes in another network.
      • To connect similar network. .
    LAN - Component
  • 46.
    • Router
    • Gateway
      • Allows a node to communicate with another node on a dissimilar network (eg : Star to Ethernet)
    LAN - Component
    • The design of computers, devices and media in a network.
    • LAN network categories:
      • Client/Server
      • Peer-to-Peer
      • Internet peer-to-peer
  • 48.
    • Client/server
    • Server – 1 or more computer that controls the network
    • Client – other computers that can request services from the server
    LAN - ARCHITECTURE client client client server laser printer
  • 49.
    • Peer-to-peer
    • Small network that shares hardware, data or information located on any computer in the network
    • Each computer is called peer
    LAN - ARCHITECTURE printer may be used by all computers on network network operating system and application software installed on each computer
  • 50.
    • Characteristics of peer-2-peer .
    • Each computer on the network communicate directly with one another without relying on server.
    • Each computer has same status, responsibilities, and capabilities.
    • Simple, inexpensive, suitable for very small businesses and home users.
    • Disadvantages – lack of speed
  • 51.
    • Internet peer-to-peer (P2P)
    • Enables users to exchange file directly from the hard disk over the Internet
    • Criteria :
        • use compatible software
        • connected to the Internet
  • 52. INTERNET
    • Internet is worldwide collection of networks that links millions of computers together
    • allows all of the computers to communicate with one another
    • E-mail
    • Information
    • Shopping
    • Meeting people
    • Entertainment
    • Internet Protocol (IP)
    • – language that computers use to communicate over the Internet Protocol Domain Name Path File Name IP Address - Unique identifying number - E.g.,,,