1. Chapter 6 Data Communications

2. Wired vs. Wireless? What devices are needed? How much will it cost? Where to start? This Could Happen to You: “$175,000 to Hook Up a Computer?” 6-2 Scenario Video Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

3. Q1 What is a computer network? Q2 What are the components of a LAN? Q3 What are the alternatives for connecting to a WAN? Q4 What are the fundamental concepts you should know about the Internet? Q5What happens on a typical web server? Q6 How do organizations benefit from Virtual Private Networks (VPNs) How does the knowledge in this chapter help FlexTime and you? Study Questions 6-3 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

4. Network Collection of computers Communicate with one another over transmission line Major types of network topologies Q1: What Is a Computer Network? 6-4 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

5. Q2: What Are the Components of a LAN? 6-5 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

6. Connects computers across metropolitan, state, regional, national areas Uses communication networks from vendors Licensed by government WANs 6-6 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

7. Switch Special purpose computer that receives and transmits messages Gateway Network interface cardNetwork interface card (NIC) UTP (unshielded twisted pair) Optical fiber cable Wired Connectivity 6-7 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

8. LAN Protocol 6-8 IEEE 802.11 Protocol Wired LAN 10/100/1000 Mbps EthernetEthernet Protocol specifies hardware characteristics, cables, and how messages are packaged and processed Wireless LAN Most popular 802.11g (2010) Bluetooth Common wireless protocol for transmitting data over short distances—wireless mice and keyboards, cell phones Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall IEEE 802.3 Protocol

9. Summary of LAN and WAN Networks 6-9 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

10. WANs connect computers at separate sites Use routers and public communications links between siteslinks Cable connections made through licensed public telecommunications companies Internet service provider (ISP) A company that provides customers access to the Internet Provides legitimate Internet address Serves as gateway to Internet You pay for Internet access Q3: What Are the Alternatives for a WAN? 6-10 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

11. DSL and Cable Internet Access 6-11 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

12. Digital Subscriber Line (DSL) Operates over telephone lines Data signals do not interfere with voice telephone service Faster data transmission than dial-- up 256 kbps to 6.544 Mbps DSL modems use their own protocols Download and upload speeds differ Asymmetric digital subscriber lines (ADSL)ADSL Symmetrical digital subscriber lines (SDSL)SDSL DSL Modems 6-12 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

13. Network Collection of computers Communicate with one another over transmission line Basic types of Network Topologies Q1: What Is a Computer Network? 6-13 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

14. Provide high-speed data transmission Use cable television lines High-capacity optical fiber cable to neighborhood Optical fiber cable connects to regular cable-television cables run to subscribers home or business. Does not interfere with television transmission. Up to 500 users share facility  Performance varies based on number of people connected Download speed up to 50 Mbps, upload up to 512 kbps Cable Modems 6-14 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

15. Amazon’s Kindle uses a Sprint wireless network to provide wireless data connections Variety of WAN wireless protocols exist. Sprint and Verizon use EVDO; AT&T supports iPhone and T-Mobile use HSDPA; WiMax by Clearwire EVDOHSDPAWiMax Clearwire WAN wireless provides average performance of 500 kbps, with peaks of up to 1.7 Mbps, as opposed to the typical 50 Mbps for LAN wireless Narrowband lines transmission speeds less than 56 kbps Broadband lines speeds in excess of 256 kbps WAN Wireless Connection 6-15 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

16. Using the Internet for a Hotel Reservation Q4: What Are the Fundamental Concepts You Should Know About the Internet? 6-16 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

17. TCP/IP Architecture 6-17 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

18. Hyper Text Transport Protocol (HTTP) Protocol used between browsers and web servers. Simple Mail Transfer Protocol (SMTP) Used for email transmissions. File Transfer Protocol (FTP) Used to move files over Internet. Web-Internet-based network of browsers and servers that process http or https. When you use ftp or smtp, you are using Internet, not web. Application Layer Protocols 6-18 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

19. TCP or Transmission Control Protocol Breaks traffic up into pieces and send each piece along its way IP (Internet Protocol) Specifies routing of pieces of data communication through networks that comprise any Internet Packet is a piece of a message that is handled by programs that implement IP Router is a special purpose computer that moves packet traffic according to rules of IP protocol TCP and IP Protocols 6-19 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

20. Public IP Addresses Identify a particular device on public Internet Public IP Addresses must be unique, worldwide Assignment controlled by ICANN (Internet Corporation for Assigned Names and Numbers)ICANN Private IP Addresses Identify a particular device on a private network, usually on a LAN IP Addressing 6-20 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

21. Use of Private IP Addresses 6-21 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall Source: http://www.broadband-help.com/articles/networking/networking-guide-part2-tcpip-explained#b10

22. IPv4IPv4 Supports (2 32 ) or 4,294,967,296 addresses Four decimal dotted notation like 165.193.123.253 IPv6IPv6 - Supports 2 128 addresses Public IP Addresses and Domain Names 6-22 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall Domain name Unique name affiliated with public IP address URL (Uniform Resource Locator)

23. Sonos is a company leveraging technology to provide entertainment. Uses wireless technologies, to develop easily installed, high- quality wireless audio systems. Customers hook one of several different Sonos devices into home LAN device using a wired Ethernet connection to link up to 32 other Sonos audio devices around home. Each device can independently play its own music or other audio; some or all can play same audio program. Each Sonos device includes a small computer running Linux. Those computers communicate wirelessly using a proprietary Sonos protocol. Experiencing MIS InClass Exercise 6: Opening Pandora’s Box 6-23 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

24. 1. Assume you want to play audio and music in your office, your living room, and your bedroom. a. Go to www.Sonos.com and select and price the equipment you will need.www.Sonos.com b. Go to Sonos’ competitors at www.LogitechSqueezeBox.com and http://Soundbridge.Roku.com and select and price equipment you will need.www.LogitechSqueezeBox.comSoundbridge.Roku.com c. Recommend one of the selections you identified in your answers to parts a. and b. and justify your selection. d. Report your findings to the rest of the class. 2. Visit www.Pandora.com. Using free trial membership, build a radio station. Base your station on whatever song or music your group chooses.www.Pandora.com Experiencing MIS InClass Exercise 6: Opening Pandora’s Box (cont’d) 6-24 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

25. 3. Sonos equipment does not have on/off switch. You can mute each station, but to turn a station off, you must unplug it. Sonos equipment is still on, it will continue downloading packets over Internet to a device that no one is listening to. a. Describe the consequences of this situation on the Internet. b. You pay a flat fee for your Internet connection. In what ways does such a fee arrangement discourage efficiency? c. It turns out that if you pause the music, rather than mute the device, Sonos device will stop downloading packets. Do you think this design is appropriate? If not, how would you change it. Experiencing MIS InClass Exercise 6: Opening Pandora’s Box (cont’d) 6-25 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

26. 4. Using your group’s imagination and curiosity, describe the consequences of Internet-based audio on: a. Existing radio stations b. Vendors of traditional audio receivers c. Audio entertainment d. Cisco (a vendor of Internet routers) e. Your local ISP f.Any other companies or entities you believe will be impacted by wireless audio systems 5. Report your conclusions to the rest of the class. Experiencing MIS InClass Exercise 6: Opening Pandora’s Box (cont’d) 6-26 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

27. 6. Using history as a guide, we can assume that audio leads the way for video. a. Explain how you could use a wireless video system in your new condo. b. In the opinion of your group, is having multiple wireless video players in your condo more or less desirable than wireless audio? Explain your response. c. Answer parts a. through f. in step 4, but use wireless video rather than audio as the driving factor. Report your answers to the rest of the class. Experiencing MIS InClass Exercise 6: Opening Pandora’s Box (cont’d) 6-27 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

28. 7. Considering all of your answers to steps 1 through 5: a. What industries are the winners and losers? b. What companies are the winners and losers? c. How does your answer to parts a. and b. guide your job search? 8. Use the knowledge you have gained in answering steps 1 through 6 to prepare a 1-minute statement that you could make in a job interview about the emerging opportunities in Internet-based audio and video. Assume that with this statement you want to demonstrate your ability to think innovatively. Experiencing MIS InClass Exercise 6: Opening Pandora’s Box (cont’d) 6-28 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

29. Q5What Happens on a Typical Web Server? 6-29 Three-Tier Architecture Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

30. Programs that run on a server tier computer Manage HTTP traffic by sending and receiving web pages to and from clients Web servers Application programs that run on a server tier computer Receives requests from users via web server, takes some action, and returns a response to users via the web server Commerce servers Web Farm Servers 6-30 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

31. Hypertext Markup Language (HTML) 6-31 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

32. XMLXML (eXtensible Markup Language) FlashFlash and Silverlight Silverlight HTML 5.0 Fixes several HTML deficiencies Program-to-program interaction over web Add-ons to browsers Provides animation, movies, other advanced graphics inside a browser New version of HTML supports animation, movies, and graphics XML, Flash, Silverlight, HTML 5 6-32 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

33. Virtual private network Uses Internet or private network to create appearance of point-to-point connections Uses public Internet to create appearance of private network Q6 How Do Organizations Benefit From Virtual Private Networks (VPNs) 6-33 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

34. WAN Using VPN Remote Access Using VPN; Actual Connections 6-34 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall Remote Client (Apparent connection) Actual connections (P2P leased lines)

35. Owners have to make decisions about data communications equipment for new building. Decisions fraught with risk. With knowledge, better chance of making good decisions. Kelly has no data communications knowledge, she cannot be a good partner. With knowledge in this chapter, you’re on road to having knowledge like Neil, and not being a passive bystander like Kelly. How Does the Knowledge in This Chapter Help FlexTime and You? 6-35 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

36. Ethics Guide: Personal Email at Work 6-36 Scenario A You email 12 pictures of your surfing skills from New Zealand to a friend who works at some company in Ohio. Each picture is 6.2 megabytes in size. Packets of email and picture transmitted to Ohio company router and from router to its email server. Your message consumed processing cycles on router and email serve. A copy of your pictures stored on that email server until your friend deletes them. Friend uses company LAN to download the pictures to his desktop computer. Friend reads his email during his working hours. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

37. Is it ethical for you to send the email and picture to your friend at work? Does your answer to question 1 change depending on size of pictures? Does your answer change if you send 100 pictures? If you send 1,000 pictures? If your answer does change, where do you draw the line? Once pictures are stored on company’s email server, who owns pictures? Who controls those pictures? Does Ohio company have right to inspect contents of its employees’ mailboxes? If so, what should managers do when they find your picture that has absolutely nothing to do with company’s business? What is greater cost to your friend’s company: Cost of infrastructure to transmit and store your email or cost of time your friend takes at work to read and view your pictures? Does this consideration change any of your answers above? Scenario A Questions 6-37 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

38. Scenario B Update: 2008: You use Facebook page with the photos. Friend use company computer to view your Facebook page. Scenario C Update: 2010: from his phone or iPad to view your Facebook page. Ethics Guide: Personal Email at Work 6-38 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

39. How does 2008 update change ethics of situation? Is it ethical for your friend to read and update Facebook using company’s computers? How does 2010 update change ethics of situation? Is it any of company’s business what your friend does with his iPhone or other device at work? Describe a reasonable policy for computer/phone/ communicating device use at work. Consider email, Facebook, and Twitter as well as 2008 and 2010 updates. Endeavor to develop a policy that will be robust in likely data communication changes in future. Questions for Scenarios B and C 6-39 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

40. Nathan Myhrvold claimed that humans: One cannot think exponentially Think of fastest linear change and extrapolate from there Was writing about growth of magnetic storage Applies to growth of computer network phenomena Ubiquitous and cheap connectivity is growing exponentially What are the threats and opportunities? Guide: Thinking Exponentially Is Not Possible, But… 6-40 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

41. Social progress occurs in small, evolutionary, adaptive steps Technology doesn’t drive people to do new things (?) Technology may enable a capability, but people may not want it People want to do what they are doing more easily They want to solve existing problems Respond by hedging your bets The more time involved, the more potential for error Guide: Thinking Exponentially Is Not Possible, But…(cont’d) 6-41 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

42. Q1 What is a computer network? Q2What are the components of a LAN? Q3What are the alternatives for connecting to a WAN? Q4What are the fundamental concepts you should know about the Internet? Q5What happens on a typical web server? Q6 How do organizations benefit from Virtual Private Networks (VPNs) How does the knowledge in this chapter help FlexTime and you? Active Review 6-42 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

43. Substantial portions of the knowledge you gain from this chapter will be obsolete within the first 5 years of your career. What is the problem of the last mile? The bottleneck on data communications into homes, and into smaller businesses, is the last mile. Problem with optical fiber infrastructure—it cannot be used by mobile devices WiMax standard includes two usage models: Fixed and mobile. Former akin to LAN wireless in existence today; latter for mobile access. Case Study 6: Keeping Up with Wireless 6-43 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

44. December 1, 2008, Clearwire merged with Sprint Nextel and received a $3.2 billion outside investment. Clearwire gained access to Sprint Nextel’s spectrum holdings List five possible commercial applications for mobile WiMax. Consider applications that necessitate mobility. Select the three most promising applications and justify your selection. Explain why Clearwire share price has dropped since 2007. Products are marketed as Sprint Xohm Case Study 6: Keeping Up with Wireless (cont’d) 6-44 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

45. Search the web for LTE vs. WiMax comparisons and compare and contrast these two technologies. Where will this end? On which of these technologies would you be willing to invest $100 million? Why? Case Study 6: Keeping Up with Wireless (cont’d) 6-45 Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

46. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall