2. Welcome to CMPE003 Personal Computer Concepts: Hardware and Software Winter 2003 UC Santa Cruz Instructor: Guy Cox

3. January 19, 20032 Assignments No late assignments will be accepted 2 nd Homework Due Now!!

4. The Internet: A Resource for All of Us Chapter 8 Part A

5. January 19, 20034 Objectives Describe some of the history of the Internet Explain what is needed to get on the Internet Describe generally what an Internet service provider does Describe the rudimentary functions of a browser Describe how to search the Internet List and describe the non-Web parts of the Internet Explain some of the ongoing problems associated with the Internet

6. January 19, 20035 History of the Internet Government and Universities over 30 years Who’s connected today?  Individuals  Educational institutions  Government/Military/Police  Research  Medical  Businesses  Everyone!

7. January 19, 20036 The Early Years 1969 – US Department of Defense and Rand Corporation Origins  Cold War – fear that a bomb could demolish computing capabilities  Several computers, geographically dispersed, networked together  Plan – if one computer was disabled, others could carry on using alternative communication routes

8. January 19, 20037 The Early Years Many WANs and LANs were installed, but machines on the WANs could not access information on the LANs..  Remote access was separated from local access A single cohesive network was desirable.

9. January 19, 20038 The Early Years US Department of Defense had a similar scenario – lots of autonomous networks that could not interoperate The DoD funded network research in the early ’70s through (D)ARPA creating various network technologies, including a research WAN called ARPANET.

10. January 19, 20039 The Early Years ARPANET allowed researchers the opportunity to build a working test-bed for networking ideas.  Solved incompatibility issues  Solved interoperability issues  Created an internetwork of LANs and the WANs The Internet is born

11. January 19, 200310 The Early Years ARPANET Backbone UCLA LAN UCLA LAN MIT LAN MIT LAN UCB LAN UCB LAN DARPA LAN DARPA LAN G1 G2 G4 G3

12. January 19, 200311 The Early Years… Internet Software  Internet Protocol (IP) Provides basic communication Handles the addressing and routing  Transmission Control Protocol (TCP) Provides services for applications to communicate Packetizes message, reassembles message at the destination  The “TCP/IP Internet Protocol Suite” aka TCP/IP

13. January 19, 200312 The Early Years ARAPA placed the research and software into the public domain.  All information was freely available to any person or vendor, allowing them to create devices or networks that would interoperate with the Internet technology.  Improvements were documented and made publicly available.  This philosophy is called an Open System

14. January 19, 200313 The Early Years Internet documentation  On-line and accessible from the Internet  Reports for improvements to the Internet were initially a two step process Request for comments (RFC) went out first Internet Engineering Note came out with the comments as the final report.  Today the RFC remains as the definitive documentation for the Internet On-line at www.faqs.org/rfcs/www.faqs.org/rfcs/  Also www.ietf.org/rfc.htmlwww.ietf.org/rfc.html

15. January 19, 200314 The Early Years The UNIX operating system  Built at Bell Labs in the early ’70s  UNIX given to universities to study  UC Berkeley team added LAN software Distributed to others via the Berkeley Software Distribution (BSD) and became known as BSD UNIX (The ancestor of today’s Free BSD)

16. January 19, 200315 The Early Years ARPA negotiated with UCB to add the TCP/IP suite to the BSD UNIX release.  Gave large number of universities access to study networking, and deploy it in their departments. 1982 the US Military chose the Internet as its primary communication system. 1983 the ARPANET began running TCP/IP exclusively.

17. January 19, 200316 The Early Years Incredible growth from day one..  In 1982 ~200 machines were connected  By 1983 the number had doubled  With growth comes the problems.. Static lists of machines need updated Limited memory space … Software updates..

18. January 19, 200317 The Early Years The Computer Science Network (CSNET)  Sponsored by NSF in early `80s Goal was to connect every Computer Scientist in the country over one network. CSNET was deployed using TCP/IP and the Internet By mid 1980s most major university and research labs were connected to the Internet Graduate students began to investigate the details of these new technologies, and include them in their research topics.  Developed new applications  Extended the technology

19. January 19, 200318 The Early Years The IAB (Internet Activities Board) (Now known as the Internet Architecture Board)  Original controlling body to coordinate TCP/IP research and Internet development. Chairman – Internet Architect RFC Editor Formed volunteer task forces to solve problems  Task forces generated new RFCs

20. January 19, 200319 The Early Years The IETF (Internet Engineering Task Force)  Originally chartered for short-term Internet development.  Now is responsible for most of the Internet technical development Working groups meet and create the RFCs  Manet, ipsec, tcp…

21. January 19, 200320 The Early Years NSFNET  NSF recognized the importance of the Internet to the scientific community.  Interconnected the supercomputer centers around the US with a TCP/IP WAN Proved useful, but small NSF looked for ways to improve the ARPA Internet

22. January 19, 200321 The Early Years The NSFNET Backbone  1988 WAN established as main backbone of the Internet MCI – long distance transmission lines IBM – dedicated computers and software MERIT – network operation

23. January 19, 200322 The Early Years The ANS Backbone (Advanced Networks and Services)  Consortium of MCI, IBM & MERIT Allowed the government to begin privatization of the Internet  1992 – WAN was built to serve as the Internet backbone ANSNET, 30 times NSFNET capacity

24. January 19, 200323 The Early Years Exponential growth …….

25. January 19, 200324 The Early Years By 1999, the Internet was growing so fast that, on average, a computer was added to the Internet every second – and the rate continues to increase. An interesting fact:  At any time from 1983 through 1999, approximately half the growth of the Internet occurred in the previous 12 months… So, after you have been “on” the Internet for only one year, you will have had more experience than half the other users….

26. January 19, 200325 The Early Years Growth – Good and Bad  Good for vendors  Bad for the IETF Predictions of imminent collapse  March 1993, Summer ’97 Technology improvements have kept up with bandwidth and switching speeds required.

27. January 19, 200326 The Early Years The Hard limit – Address space  The IP protocol is limited to a number contained in 4 bytes (32 bits)… Byte 0Byte 1Byte 2Byte 3 This limits the number of possibilities to 2 32 = 4,294,967,296 There are solutions – IPv6, NAT

28. January 19, 200327 The Early Years Summary  The Internet began as an ARPA research project.  The TCP/IP protocol software was developed to make the Internet operational.  The Internet is an Open System, with the technology freely available to all.  The Internet documentation is available on-line in the form of reports known as RFCs.

29. January 19, 200328 The Early Years Summary (continued)  BSD UNIX distributed TCP/IP suite freely to universities in the early 80s  1982 US Military adopted TCP/IP as primary communication standard  Exponential growth from its inception  IAB formed to coordinate development  IETF - major technical development body Working groups

30. January 19, 200329 The Early Years Summary (Continued)  1988 – NSFNET Backbone  1992 – Privatization (ANSNET)  Exponential growth from its inception Half of the users today have been there less than one year……  IP Address 32 bit limitation

31. January 19, 200330 Tim Berners-Lee 1990 Perceived a spider’s web of computers with links from computer to computer CERN site  Dr. Berners-Lee’s physics laboratory  Birthplace of the World Wide Web Easy movement due to links  Hypertext  Hyper-region

32. January 19, 200331 Marc Andreessen 1993 Created browser software Mosaic – first graphical browser  Became Netscape (now owned by AOL) Provided attractive images and a graphical interface permitting users to click on pictures as well as text

33. January 19, 200332 Internet Explosion September 2002  Over 600 million users worldwide Part of our daily lives Four factors  TCP/IP standard  Ability to link from site to site  Ease of use of browser  Growth of PC and LANs that can connect

34. January 19, 200333 Global Internet Usage

35. January 19, 200334 URL Uniform Resource Locator Unique address of a web page or file on the Internet Case-sensitive http://domain-name.top-level-domain/last-section

36. January 19, 200335 http hypertext transfer protocol Protocol – rules Communication using links http://domain-name.top-level-domain/last-section

37. January 19, 200336 Domain name Address of the ISP Domain names are registered Ongoing fee is paid for each domain name http://domain-name.top-level-domain/last-section

38. January 19, 200337 Top-level Domain Represent the purpose of the organization of entity.com.gov.edu.org.net May be a two-letter country code

39. January 19, 200338 Last section Directories and file names that specify a particular web page http://domain-name.top-level-domain/last-section

40. January 19, 200339 Getting Started Computer with a modem or NIC Internet service provider (ISP) Browser client Other related software

41. January 19, 200340 Internet Service Provider Vehicle to access the Internet Provides  Server computers Email, News, etc..  Software to connect

42. January 19, 200341 Wireless Internet Access Supports mobile handheld devices  Text pagers  PDAs  Pocket computers  Web-enabled cellular phones Applications  E-mail  Checking weather  Making airline reservations

43. January 19, 200342 Wireless Internet Access Need  Account with wireless access provider  Cellular modem card or adapter Slow download speeds Wireless Application Protocol (WAP)  Convert web pages into format for mobile devices  Resized for limited display area  Fewer graphics transmitted

44. January 19, 200343 Browser Netscape Communicator Microsoft Internet Explorer Mozilla

45. January 19, 200344 Browser Used to explore the Internet Dials the ISP Display web pages

46. January 19, 200345 Browser Parts of the window Display Window Status Line Welcome Banner Browser Logo Bookmarks “Hot List” Menu Bar Buttons Control Panel Scroll Bar URL Textbox

47. January 19, 200346 Browser Functions and Features Browser display window  Displays contents of web page from each Internet site visited  Screen limits how much of the site you can view at a time. The page can be scrolled using the scroll bar to see its entire contents Status line – progress of data being transferred and other messages

48. January 19, 200347 Browser Functions and Features Welcome banner on title bar Browser logo – animation indicates you are in the process of moving to a new site Hot list  Bookmark  Favorites  Store your favorite URLs Browser control panel – menus and buttons

49. January 19, 200348 Browser Menus and Buttons Pull-down menu Buttons  Convenient shortcuts for commonly used functions  Click button rather than locate command from pull- down menu

50. January 19, 200349 Browser Support: Frames Divides page into rectangular sections Each section displays web pages independently Several small pages on one screen  Can be scrolled independently  Can be replaced with other pages independently Not all browsers support frames

51. January 19, 200350 Plug-ins Software that increases the functionality of a browser  Audio-video  Image viewing Download from web sites Install Example  Adobe Acrobat Reader  Shockwave

52. January 19, 200351 Programming Java Write software that is machine independent Programming language  Dancing icons  Sound clips  Flashing messages  Banners that scroll Applets – Permits dynamic web pages  Display animations  Receive input  Perform calculations

53. January 19, 200352 Programming ActiveX Controls Capabilities similar to Java Browser must be enabled to support applets / ActiveX Controls Security issues

54. January 19, 200353 Moving Between Sites Clickable categories in the browser  Sports  Weather  News  Technology  Comic strips Enter the URL in the address text box and press

55. January 19, 200354 URL Uniform Resource Locator Unique address of a web page or file on the Internet Case-sensitive http://domain-name.top-level-domain/last-section

56. January 19, 200355 Processing Requests URL User enters a URL User computer sends request to the ISP server ISP server sends request across networks of TCP/IP computers Destination site is reached Content is transmitted back to your computer (process in reverse)

57. January 19, 200356 Searching the Internet Search engine User specifies a search request Browser links to Search Engine Request returns matching pages based upon the Search Engine’s database Results presented

58. January 19, 200357 Processing Requests: Search Engine Database Search Engine builds database  Searchable terms  Related web sites Spider, robot, bot  Follows links across the web  Automatically indexes pages to a database One word All words Pages may be submitted by the owner

59. January 19, 200358 Request same search using different engines yields different results Databases built independently  Size  Content  Search methodology Metasearch – atomically puts the same request to several search engines Processing Requests: Search Engine Database

60. January 19, 200359 Processing Requests Directory vs. Search Engine Directory  Human involvement  Sites organized by content category  May concentrate on specific content areas  Subjective decisions regarding inclusion and importance Search Engine  Spider, robot, or bot automatically builds database  Index on a few keywords  Index on all words on web page

61. January 19, 200360 Processing Requests: Search Engine Limitations Index only a fraction of the Web Approximately 20% to 33% of sites More web pages added daily Solution  Same request to several search engines  Metasearch

62. January 19, 200361 Search Tools Directories Yahoo! NetGuide Metasearch Sites MetaCrawler Dogpile Search Engines AltaVista Excite Google HotBot Infoseek Lycos Northern Light

63. January 19, 200362 Refine the Search Add words Enclose words in “quotes” Use Boolean logic Examples  “World Trade Center”  Jordan AND NOT Michael

64. January 19, 200363 Other Uses of the Internet Newsgroups FTP Telnet E-mail Internet Relay Chat (IRC)

65. January 19, 200364 Newsgroups / Usenet Large bulletin board divided by category Posting and reading of messages that focus on specific topics Over 20,000 newsgroups Functions  Conversation  File download Newsreader software required (included with most browsers)

66. January 19, 200365 Newsgroup Operations Lurking Posting material  Inappropriate material Flame Flame war  Moderated newsgroup

67. January 19, 200366 FTP Client File Transfer Protocol Download files to your local computer Upload files to another computer Requirements to download file  Permission to download from a site  File is available for copying Anonymous FTP – do not need to identify yourself to the remote computer  (But we do know your IP address)

68. January 19, 200367 Public Archives Free files provided by educational institution or the government

69. January 19, 200368 Telnet/SSH Use your PC as a terminal providing remote access to another computer Permits  Log on to a host  Use as if you are sitting at a local terminal Need account on the host system Telnet software required (provided with most browsers) SSH available free on-line – must be installed

70. January 19, 200369 e-mail client Send/receive written messages Most used feature of the Internet Mail server – Collects and stores e-mail Mailbox – Assigned to each user E-mail address  User name  @  Domain of the mail server  bob@cruzio.com

71. January 19, 200370 e-mail Client Software Functions Retrieve Create Send Store Print Delete Address book Attach files Filters

72. January 19, 200371 IRC: Internet Relay Chat

73. January 19, 200372 Not Quite Perfect Yet Unregulated Useless web sites Misinformation and misstatements on web sites Concern over government censorship Security & Privacy Issues

74. January 19, 200373 Not Quite Perfect Yet: Social Issues Behavior problems  Who is out there?  What are they doing? Netiquette  Suggestions for appropriate behavior  Example: TYPING IN CAPS is shouting

75. January 19, 200374 Midterm #1 Wednesday – January 29  Chapters 1 – 4 and 8  ~50 questions  Multiple choice Bring Scantron form  #F-1712-ERI-L (big & pink) Bring #2 pencil  Bring your student ID Required to take exam