Computer Concepts – Illustrated Introductory, Seventh Edition

1. Computer Concepts – Illustrated Introductory, Seventh Edition UNIT E: Networks and the Internet

2. Objectives Introduce networks Classify networks Explore network hardware Explore data transport Compare wireless and wired technology Install a LAN Computer Concepts – Illustrated Introductory, Seventh Edition

3. Objectives Share network resources Introduce Internet technology Explore IP addresses and domain names Connect to the Internet with wires Connect to the Internet without wires Computer Concepts – Illustrated Introductory, Seventh Edition

4. Objectives Talking points: Why pay for Internet access if you can get it for free? Computer Concepts – Illustrated Introductory, Seventh Edition

5. Introducing Networks Communications network -combination of hardware, software, and connecting links that transport data Allow users to share resources – hardware, software, and data Computer Concepts – Illustrated Introductory, Seventh Edition

6. Introducing Networks • Ethernet • Significant network idea conceived by Bob Metcalfe in 1976 • Transfers data between computers • Key element in nearly every computer network • Including Internet Computer Concepts – Illustrated Introductory, Seventh Edition

7. Introducing Networks • Computer is on network if: • computer can access other computers or share hardware with other computers • Networks in home • Access surveillance and monitoring devices • Control media devices • Share hardware and software Computer Concepts – Illustrated Introductory, Seventh Edition

8. Introducing Networks • Sharing networked hardware • Reduce costs • Expand access • Sharing networked software • Reduce costs • Facilitate data sharing • Enable collaboration Computer Concepts – Illustrated Introductory, Seventh Edition

9. Introducing Networks • Disadvantages of network connection • Vulnerability to unauthorized access • Susceptibility to malicious code • Most computer owners believe that advantages far outweigh disadvantages Computer Concepts – Illustrated Introductory, Seventh Edition

10. Introducing Networks • Network is like spider web with many interconnecting points • Node - each connection point • Network nodes typically contain computers, networked peripherals, or network devices • Server • Computer connected to network that distributes resources to network users Computer Concepts – Illustrated Introductory, Seventh Edition

11. Introducing Networks Network connects computers and peripherals Computer Concepts – Illustrated Introductory, Seventh Edition

12. Classifying Networks • Networks - classified according to size and geographic structure • PAN (personal area network) • LAN (local area network) • NAN (neighborhood area network) • MAN (metropolitan area network) • WAN (wide area network) Computer Concepts – Illustrated Introductory, Seventh Edition

13. Classifying Networks Networks Technologies Computer Concepts – Illustrated Introductory, Seventh Edition

14. Classifying Networks • Client / server network • Must have at least one server and one or more clients • Network computers can serve as clients or servers Computer Concepts – Illustrated Introductory, Seventh Edition

15. Classifying Networks • Server • Computer that provides services to other computers the network (clients) • Application server • Runs application software for network workstations • File server • Stores files and supplies them to workstations on request Computer Concepts – Illustrated Introductory, Seventh Edition

16. Classifying Networks • Print server • Handles jobs sent to network printers • Workstation • Network client, usually personal computer Computer Concepts – Illustrated Introductory, Seventh Edition

17. Classifying Networks • Peer-to-peer structure • Does not have a server • Workstations serve as both clients and servers Computer Concepts – Illustrated Introductory, Seventh Edition

18. Exploring Network Hardware • Network device • Any electronic device that broadcasts network data, boosts signals, or routes data to destination • Modems, network interface cards, hubs, switches, routers, gateways, bridges, repeaters Computer Concepts – Illustrated Introductory, Seventh Edition

19. Exploring Network Hardware • Modem • Converts digital signals into signals that can travel over network • Network interface card (NIC) • Network circuitry needed to connect to network • Ethernet card (Ethernet adapter) • NIC designed to support Ethernet protocols Computer Concepts – Illustrated Introductory, Seventh Edition

20. Exploring Network Hardware If computer does not have Ethernet adapter,can purchased and installed Computer Concepts – Illustrated Introductory, Seventh Edition

21. Exploring Network Hardware USB and PC Ethernet adapters plug into ports on outside of system unit Computer Concepts – Illustrated Introductory, Seventh Edition

22. Exploring Network Hardware • Network hub • Links two or more nodes of wired network • Network switch • Sends data only to network devices specified as destination • Network router • Transmits data from one network to another • Used to connect LANs and WANs Computer Concepts – Illustrated Introductory, Seventh Edition

23. Exploring Network Hardware Network Router Computer Concepts – Illustrated Introductory, Seventh Edition

24. Exploring Network Hardware • Special hardware for wireless networks • Transceiver • Used to send and receive wireless data • MIMO (multiple-input multiple-output) technology Computer Concepts – Illustrated Introductory, Seventh Edition

25. Exploring Network Hardware • Networked peripheral • Any device with built-in network circuitry • Can connect directly to network • Network attached storage (NAS) • Storage device that directly connects to network Computer Concepts – Illustrated Introductory, Seventh Edition

26. Exploring Data Transport • Communications channel (network link) - physical path or frequency for signal transmission • Used for transporting data Computer Concepts – Illustrated Introductory, Seventh Edition

27. Exploring Data Transport • Wired network • Data travels from one device to another over cables • Wireless network • Data travels through air, no need for cables Computer Concepts – Illustrated Introductory, Seventh Edition

28. Exploring Data Transport • Types of cables • Twisted pair • Shielded twisted pair (STP) • Coaxial (coax) • Fiber-optic Computer Concepts – Illustrated Introductory, Seventh Edition

29. Exploring Data Transport • Buying cable - choose Category 5 (Cat 5) or Category 6 (Cat 6) • Rating indicates capacity • Higher number, higher capacity • Cables can be purchased in variety of lengths Computer Concepts – Illustrated Introductory, Seventh Edition

30. Exploring Data Transport Ethernet network cables terminated at each end with RJ45 connector Computer Concepts – Illustrated Introductory, Seventh Edition

31. Exploring Data Transport • Bandwidth • Transmission capacity of communications channel • High-bandwidth systems include cable and DSL (broadband) • Systems with less capacity include dial-up, referred (narrowband) Computer Concepts – Illustrated Introductory, Seventh Edition

32. Exploring Data Transport • Other cables can be used to transport data over wired network • USB, serial, parallel, SCSI, and FireWire • Wireless networks transport data via • RF (radio frequency) signals • Microwaves • Infrared lights Computer Concepts – Illustrated Introductory, Seventh Edition

33. Comparing Wireless andWired Technology • Wired networks • Fast, secure, reliable, simple to configure • Wireless • Provide mobility • No unsightly wires or cables to tangle • No need to run wires through walls, ceilings, floors Computer Concepts – Illustrated Introductory, Seventh Edition

34. Comparing Wireless andWired Technology • Wired network is best choice if you need speed • Wired networks more secure than wireless networks • Wireless signals pass through air and can be intercepted more easily Computer Concepts – Illustrated Introductory, Seventh Edition

35. Comparing Wireless andWired Technology Signal strength of wireless network • Range limits • Wired network - defined by longest cable in configuration • Wireless network - depends on type of signal, transmitter strength, and physical environment Computer Concepts – Illustrated Introductory, Seventh Edition

36. Comparing Wireless andWired Technology • Prices have equalized between wired and wireless networks • May need some additional equipment for wireless • Wi-Fi card • Wireless access pointor router Computer Concepts – Illustrated Introductory, Seventh Edition

37. Installing a LAN Place router in central location,plug into surge protected outlet Run cables from router toEthernet adapter in each workstation Run cable from Internet deviceand router’s WAN port Turn on devices, computershould recognize andestablish connection Computer Concepts – Illustrated Introductory, Seventh Edition

38. Installing a LAN Before using network, adjust router configuration settings Computer Concepts – Illustrated Introductory, Seventh Edition

39. Installing a LAN • Other ways to set up wired network • HomePNA network uses telephone wiring in home • Power-line network uses existing electrical wiring Computer Concepts – Illustrated Introductory, Seventh Edition

40. Installing a LAN • Power-line networks form infrastructure of LAN using existing electrical wiring • Special NIC to connect computer to standard electrical outlet Computer Concepts – Illustrated Introductory, Seventh Edition

41. Sharing Network Resources • Wireless and wired devices can be connected to same network • Most wireless routers include ports for Ethernet cables and WAN port for cable to Internet device Computer Concepts – Illustrated Introductory, Seventh Edition

42. Sharing Network Resources • Access network by clicking workgroup name • May also have to enter password and user ID • SSID (service set identifier) • Helps log into correct network in places where networks may overlap Computer Concepts – Illustrated Introductory, Seventh Edition

43. Sharing Network Resources • To add workstations • Turn on computer with wireless capabilities • Choose correct network • Enter network key or passphrase • Workstation owners can specify whether files and locally attached printers can be accessed from other workstations on network Computer Concepts – Illustrated Introductory, Seventh Edition

44. Sharing Network Resources File Sharing Computer Concepts – Illustrated Introductory, Seventh Edition

45. Sharing Network Resources • Three ways to connect printer to network using Windows Control Panel • Connect it to one workstation in network • Network print server • Connect printer directly to hub or router Computer Concepts – Illustrated Introductory, Seventh Edition

46. Introducing Internet Technology • Internet backbone • Consists of high-speed fiber-optic cables connecting high-capacity routers that direct network traffic • Provide main high-speed routes for data traffic • Network service providers (NSP) maintain backbone links and routers • NSP equipment and links are tied together by network access points (NAPs) Computer Concepts – Illustrated Introductory, Seventh Edition

47. Introducing Internet Technology Connecting computer to Internet Computer Concepts – Illustrated Introductory, Seventh Edition

48. Introducing Internet Technology • ISP equipment offers variety of services • e-mail, chat groups, IM capabilities, music file sharing, FTP, and more Computer Concepts – Illustrated Introductory, Seventh Edition

49. Introducing Internet Technology • Upstream speed • Rate of data transmitted from computer to Internet • Downstream speed • Rate of data arriving at computer Computer Concepts – Illustrated Introductory, Seventh Edition

50. Introducing Internet Technology • Internet uses variety of communications protocols • Support basic data transport and services • TCP • Breaks message or file into packets • IP • Addresses packets so they can be routed to destinations Computer Concepts – Illustrated Introductory, Seventh Edition