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Chapter 4: File Management, Virus Protection, and Backup

Chapter 4: File Management, Virus Protection, and Backup. Chapter 1: Computer, Internet, Web, and E-Mail Basics. 1. 1. 1. 1. Chapter 5 Preview. After this chapter, you should be able to: Describe the characteristics of various networks Diagram Shannon’s model of a communications network

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Chapter 4: File Management, Virus Protection, and Backup

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  1. Chapter 5: Internet and LAN Technology Chapter 4: File Management, Virus Protection, and Backup Chapter 1: Computer, Internet, Web, and E-Mail Basics 1 1 1 1

  2. Chapter 5 Preview After this chapter, you should be able to: • Describe the characteristics of various networks • Diagram Shannon’s model of a communications network • List types of cables • List network devices • Describe the role of communications protocols and list some protocols associated with the Internet and LANs • Explain packet switching and circuit switching • Explain packet switching and circuit switching • Recount the history of the Internet Chapter 5: Internet and LAN Technology

  3. Chapter 5 Preview After this chapter, you should be able to: • Draw a conceptual diagram illustrating the Internet backbone, NAPs, NSPs, routers, and ISPs • Explain Ping and Traceroute • Explain the differences between permanent IP addresses, dynamic IP addresses, private IP addresses, and domain names • Describe the advantages and disadvantages of dial-up, cable modem, DSL, ISDN, T1, T2, and wireless Internet access • Explain when and why it is important to implement security measures such as antivirus software, firewalls, and Network Address Translation Chapter 5: Internet and LAN Technology

  4. Chapter 5 Outline • Section A • Network Building Blocks • Section B • Local Area Networks • Section C • Internet Technology • Section D • Internet Access Chapter 5: Internet and LAN Technology

  5. Chapter 5Internet and LAN Technology Section A: Network Building Blocks Computer Concepts 8th EditionParsons/Oja

  6. Why is networking computers advantageous? • Reduce costs • Provides access to a wide range of services and specialized peripheral devices • Sharing data on a network is easy • Networks enable people to work together regardless of time and place Page 226 Chapter 5: Internet and LAN Technology

  7. Do networks have disadvantages? • Primary disadvantage is their vulnerability to unauthorized access • More vulnerable than standalone computers to malicious code Page 226 Chapter 5: Internet and LAN Technology

  8. How are networks classified? • Geographical scope • Organizational structure • Physical topology • Network links • Bandwidth • Communications protocols Page 226 Chapter 5: Internet and LAN Technology

  9. Why is geographic scope important? • Wide Area Network • Metropolitan Area Network • Local Area Network • Neighborhood Area Network • Personal Area Network Page 228 Chapter 5: Internet and LAN Technology

  10. What is the difference between a client/server network and a peer-to-peer network? • Client/server – contains servers and clients • Peer-to-peer (P2P) – every computer is considered an equal Page 229 Chapter 5: Internet and LAN Technology

  11. How are devices on a network physically arranged? Star Topology Tree Topology Ring Topology Bus Topology Mesh Topology Page 230 Chapter 5: Internet and LAN Technology

  12. Network Links: What connects the nodes of a network? • Data can travel from one network device to another over a cable or through the air • A communications channel is a physical path or a frequency for a signal transmission • Wired network • Networks use different types of cables • Wireless network Page 231 Chapter 5: Internet and LAN Technology

  13. What are popular network cabling options? • Today’s networks use twisted-pair cables • UTP (unshielded twisted pair) • STP (shielded twisted pair) • Looks similar to telephone cable • Has square plastic RJ-45 connector Page 232 Chapter 5: Internet and LAN Technology

  14. What are popular network cabling options? • Another option is coaxial cable • Resembles cable-TV cable • Round, silver BNC or F-type connector Page 232 Chapter 5: Internet and LAN Technology

  15. What are popular network cabling options? • Fiber-optic cable is a bundle of extremely thin strands of glass • Each optical fiber (strand) is thinner than a human hair • USB, serial, parallel, SCSI, and Firewire connections Page 232 Chapter 5: Internet and LAN Technology

  16. What are the options for wireless networks? • Data can also travel airways in form of RF signals sent and received by a transceiver • Microwaves provide another option for transporting data • Radio and microwave transmissions cannot be bent around the surface of the earth to reach far-flung towers • Communications satellites play an important part in long-distance communications • A transponder on the satellite receives the signal, amplifies it, and retransmits the signal back to a ground station on earth Page 233 Chapter 5: Internet and LAN Technology

  17. What’s the difference between analog and digital signals? • Digital signals are transmitted as bits using a limited set of frequencies • Analog signals can assume any value within a specified range of frequencies Page 233 Chapter 5: Internet and LAN Technology

  18. What’s bandwidth? • The transmission capacity of a communications channel • High-bandwidth communications systems are sometimes referred to as broadband • Systems with less capacity are referred to as narrowband Page 234 Chapter 5: Internet and LAN Technology

  19. How does data travel over a network? • In 1948, Claude Shannon published an article that described a communication model Page 234 Chapter 5: Internet and LAN Technology

  20. How does data travel over a network? Page 234 Chapter 5: Internet and LAN Technology

  21. What is a protocol? • A set of rules for efficiently transmitting data from one network node to another • The best-known protocol is probably TCP/IP Page 235 Chapter 5: Internet and LAN Technology

  22. What’s a packet? • When you transmit data, it is broken up into small pieces called packets • A packet is a parcel of data that is sent across a network • Has the address of its sender • Has the address of the destination • Has some data • When they reach the destination, they are put back together into original form Page 235 Chapter 5: Internet and LAN Technology

  23. How does a protocol initiate a transmission? • A synchronous protocol coordinates sending and receiving by using a clock signal • Asynchronous protocols require the transmitting computer to send a start bit that indicates the beginning of a packet • Handshaking Page 236 Chapter 5: Internet and LAN Technology

  24. How do protocols regulate the flow of data? • Simplex – signal travels in only one direction • Half duplex – signal travels in both directions, but only one direction at a time • Full duplex – signal travels in both directions at the same time Page 237 Chapter 5: Internet and LAN Technology

  25. Chapter 5Internet and LAN Technology Section B: Local Area Networks Computer Concepts 8th EditionParsons/Oja

  26. LAN Standards: What are LAN standards? • LAN technologies are standardized by the Institute of Electrical and Electronics Engineers • IEEE designation numbers help identify compatible network technologies • IEEE 802.3 Page 238 Chapter 5: Internet and LAN Technology

  27. What is ARCnet? • One of the oldest, simplest, and least expensive LAN technologies • Original ARCnet standard supported transmission rates of 2.5 Mbps • Later versions supported 20 and 100 Mbps transmission rates • Permits mixed transmission media Page 238 Chapter 5: Internet and LAN Technology

  28. What is Token Ring technology? • Defined by the IEEE 802.5 standard • Passes data around a ring topology using a signal called a “token” to control the flow of data Page 238 Chapter 5: Internet and LAN Technology

  29. What is the FDDI standard? • Offers 100 Mbps speeds over fiber-optic cables • Popular campus network technology Page 239 Chapter 5: Internet and LAN Technology

  30. How does Ethernet work? Page 239 Chapter 5: Internet and LAN Technology

  31. How does Ethernet work? Page 240 Chapter 5: Internet and LAN Technology

  32. How fast is an Ethernet network? Page 240 Chapter 5: Internet and LAN Technology

  33. What equipment is required for Ethernet installations? • An Ethernet card is a type of network interface card designed to support Ethernet protocols • A hub is used to connect more than two computers • Each network device requires one of the hub ports • You can add hubs using an uplink port Page 240 Chapter 5: Internet and LAN Technology

  34. What equipment is required for Ethernet installations? Page 240 Chapter 5: Internet and LAN Technology

  35. What is Wi-Fi? • Wireless LANs are slower but eliminate unsightly wires • Signals can be disrupted by large metal objects, cell phones, pagers, and other wireless devices • Most popular is 802.11 sometimes called WiFi for “wireless fidelity” • Range of up to 150 feet • Bluetooth • 1 Mbps, range of 30 feet Page 241 Chapter 5: Internet and LAN Technology

  36. HomePNA and HomePNC Networks • HomePNA uses a special NIC and cable to connect each computer to a standard telephone wall jack • Network frequency is usually different from voice • HomePLC uses special NIC to connect to standard electrical outlet Page 243 Chapter 5: Internet and LAN Technology

  37. HomePNA and HomePNC Networks Page 243 Chapter 5: Internet and LAN Technology

  38. LAN Installation: How do I set up a simple LAN? • First make sure every PC contains an Ethernet port • Next, attach each workstation to a hub • With all workstations connected, turn them on • Windows should automatically detect the Ethernet cards and establish a connection to the network Page 244 Chapter 5: Internet and LAN Technology

  39. How do I set up a simple LAN? Page 244 Chapter 5: Internet and LAN Technology

  40. How do I access network resources? Page 245 Chapter 5: Internet and LAN Technology

  41. How do I specify which resources can be shared by other workstations? • Each workstation can specify whether its files will be accessible to other workstations on the network • Drive mapping is Windows terminology for assigning a drive letter to a storage device that’s located on a different workstation Page 245 Chapter 5: Internet and LAN Technology

  42. Chapter 5Internet and LAN Technology Section C: Internet Technology Computer Concepts 8th EditionParsons/Oja

  43. Background: How did the Internet get started? • The United States created ARPA (Advanced Research Projects Agency). • To help scientists communicate and share valuable computer resources • In response to the Soviet Union’s launch of Sputnik in 1957, the first artificial satellite • The ARPANET, created in 1969, connected computers at four universities Page 246 Chapter 5: Internet and LAN Technology

  44. NAP NAP Links maintained by AT&T Links maintained by Sprint High-speed AT&T routers High-speed Sprint routers To ISP To ISP How is the Internet structured? Page 247 Chapter 5: Internet and LAN Technology

  45. Is it possible to track data as it travels over the Internet? • Using Ping or Traceroute, you can discover how long data is in transit • On average, data within the US usually arrives at its destination 110-120 ms (milliseconds) after it is sent • Overseas transmissions require a little more time Page 248 Chapter 5: Internet and LAN Technology

  46. Is it possible to track data as it travels over the Internet? Page 248 Chapter 5: Internet and LAN Technology

  47. What kinds of network devices are part of an ISP? • An ISP operates network devices that handle the physical aspects of transmitting and receiving data from your computer • Many ISPs operate e-mail servers to handle incoming and outgoing mail for their subscribers and Web servers for subscriber Web sites Page 248 Chapter 5: Internet and LAN Technology

  48. What kinds of network devices are part of an ISP? Page 249 Chapter 5: Internet and LAN Technology

  49. Internet Protocols: Why does the Internet use TCP/IP? • Provides a standard that is fairly easy to implement, public, free, and extensible • The Internet is not owned, operated, or controlled by any single entity • TCP/IP is glue that holds the Internet together Page 249 Chapter 5: Internet and LAN Technology

  50. Is TCP/IP the only Internet Protocol? Page 249 Chapter 5: Internet and LAN Technology

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