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Networking and Telecommunications

9. Networking and Telecommunications. Chapter Outline. “Any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clarke. Linking Up: Network Basics Electronic Mail, Teleconferences, and Instant Messages: Interpersonal Computing

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Networking and Telecommunications

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  1. 9 Networking andTelecommunications

  2. Chapter Outline “Any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clarke • Linking Up: Network Basics • Electronic Mail, Teleconferences, and Instant Messages: Interpersonal Computing • ConvergingCommunicationTechnologies: From Messages to Money  2001 Prentice Hall

  3. Linking Up: Network Basics Why is networking important? • Cost • allows people to share hardware • Efficiency & Productivity • allows people to share data and software • Opportunity • allows people to work together in ways that are otherwise difficult or impossible  2001 Prentice Hall

  4. Basic Network Anatomy • A computer network is anycomputer system that linkstwo or more computers • There are three essentialcomponents in a network: • Hardware • Software • People  2001 Prentice Hall

  5. The Network Interface • A Network Interface Card (NIC): • Is needed to connect directly to a network • Adds an additional port to the computer • Controls the flow of data between the computer’s RAM and the network cable • Converts the computer’s digital signals into the type required for the particular network  2001 Prentice Hall

  6. Communication á la Modem • A modem is needed to connect a computer to a phone line • The computer communicates with digital signals • The telephone system was designed to transmit voice signals, which are analog  2001 Prentice Hall

  7. How a Modem Works The word modem comes from theterms modulation and demodulation Modulation Demodulation  2001 Prentice Hall

  8. Communication á la Modem A modem: • Converts the digital stream of information from a computer to an analog stream in order to send a message on the telephone network  2001 Prentice Hall

  9. Communication á la Modem A modem: • Converts the analog stream of information received over the telephone network into the digital form that the computer understands  2001 Prentice Hall

  10. Networks Near and Far There are two general types of computer networks: • LAN(Local Area Network) • WAN(Wide Area Network)  2001 Prentice Hall

  11. LAN (Local Area Network) A LAN is a network in which the computers are physically close to each other • They typically share peripherals (printers and servers) • Each computer and shared peripheral isa node on the LAN  2001 Prentice Hall

  12. WAN (Wide Area Network) A WAN is a network in which the computers are a great distance from one another • Connections are made via telephone lines, satellites, and/or microwave relay towers • Each network site is a node  2001 Prentice Hall

  13. WAN (Wide Area Network) WANs are often made up of LANs  2001 Prentice Hall

  14. Communication Software Communication software includes: • Software that allows the hardware to interact with various networks • A network operating system (NOS) which controls information shared between the dedicated server andclient machines  2001 Prentice Hall

  15. Client/Server Model Client software sends requests from the user to the server Server software responds to client requests by providing data  2001 Prentice Hall

  16. Peer-to-Peer Model • The peer-to-peer model allows every computer on the network to be both client and server • Peer-to-peer networking is built into some operating systems • Many networks use a hybrid of client/server and peer-to-peer  2001 Prentice Hall

  17. The Network Advantage Networks allow people to: • Share computer resources (hardware and software) • Share data • Work togetherin new ways  2001 Prentice Hall

  18. E-Mail, Teleconferences, & IM: Interpersonal Computing • Electronic mail, teleconferencing, and Instant messaging (IM) allow communication between two or more computer users • People can communicate in real time or delayed time  2001 Prentice Hall

  19. Real-Time vs.Delayed Communication Real-time communication (synchronous): • participants meet in real time • participants see each other’s typedmessages as they are typed • examples: Talk and Chat  2001 Prentice Hall

  20. Real-Time vs.Delayed Communication Delayed communication (asynchronous): • Participants type, post,and read messages attheir convenience • Participants share an electronic mailboxrelated to the group’spurpose • Examples: email and Newsgroups  2001 Prentice Hall

  21. The Postal Alternative • Speed • Accessibility • Facilitates group communication • Allows messages to be edited and combined with other documents • Less intrusive than the telephone  2001 Prentice Hall

  22. Advantages of E-mail and Video/Teleconferencing • Allows decisions to evolve over time • Emphasizes the message, not the messenger • Makes long-distance meetings possible through video and tele-conferencing  2001 Prentice Hall

  23. Disadvantages of E-mailand Teleconferencing • Vulnerable to machine errors, human errors, and security breaches • Can pose a threat to privacy • Can be faked  2001 Prentice Hall

  24. Disadvantages of E-mailand Teleconferencing • Works only if the recipient responds • Can be overwhelming • Both filter out many human components of communication  2001 Prentice Hall

  25. Rules of Thumb: On-line Survival Tips • Work offline unless you must be connected • Avoid peak hours • Let the system simplify and streamline your work • Store names and addresses in an on-line address book • Protect your privacy • Cross-check on-lineinformation sources • Be aware of the amount of time youspend on-line • Avoid informationoverload  2001 Prentice Hall

  26. Converging Communication Technologies: From Messages to Money Alternative Technologies: “Never in history has distance meant less.” Alvin Toffler • On-line Information Services • AOL, CompuServe, MSN, Prodigy • Members pay a fee for these services • Fax Machines and Modems  2001 Prentice Hall

  27. Alternative Technologies • Voice Mail and Computer Telephony • Global Positioning System • Video Teleconferencing • E-Money  2001 Prentice Hall

  28. Building Bandwidth The quality of information transmitted through a communication medium depends upon bandwidth. • Increased bandwidth means faster transmission speed • Bandwidth is affected by the amount of network traffic, software protocols, and type of network connection  2001 Prentice Hall

  29. Fiber Optic Cables • Fiber optic cables are replacing aging copper lines • They use light waves to carry information • They provide data rates over one billion bits per second • They offer extremely low error rates  2001 Prentice Hall

  30. Digital Communication Comes Home Digital communication lines will soon be available in homes. They will provide us: • Multi-person video phone conversations • Universal e-mail • Customized digital newspapers • Automatic utility metering • A variety of entertainment options  2001 Prentice Hall

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