The Internet at Home and in the Workplace

1. The Internet at Home and in the Workplace Chapter 8

2. Objectives • Briefly describe 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

3. Objectives • List and describe the non-Web services of the Internet • Describe the various types of e-commerce • Discuss e-commerce payments and taxes • Describe how advertising is done on the Internet • Describe what an intranet is and how a business uses it

4. History of the Internet • Government and Universities over 30 years • Who’s connected today? • Individuals • Educational institutions • Government/Military/Police • Research • Medical • Businesses • Everyone!

5. 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

6. 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.

7. 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.

8. 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

9. The Early Years ARPANET Backbone G2 MIT LAN G1 UCB LAN DARPA LAN UCLA LAN G3 G4

10. 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

11. 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

12. 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/ • Also www.ietf.org/rfc.html

13. 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)

14. 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.

15. 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..

16. 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

17. 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

18. 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…

19. 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

20. 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

21. 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

22. The Early Years • Exponential growth …….

23. Growth of Internet • Growth in host computers • 72 million in 2000 • 162 million in 2002 • Growth in users worldwide • 567 million in 2002 • 780 million projected in 2003

24. 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….

25. 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.

26. The Early Years • The Hard limit – Address space • The IP protocol is limited to a number contained in 4 bytes (32 bits)… Byte 3 Byte 2 Byte 1 Byte 0 • This limits the number of possibilities to 232 = 4,294,967,296 • There are solutions – IPv6

27. 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.

28. 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

29. 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

30. Tim Berners-Lee • Worked at CERN lab in Geneva • Thought his work would be easier if he could link to colleagues’ computers • Envisioned a network of computers much like a spider web • Used links to transfer data from one site to another location • CERN site considered the birthplace of the World Wide Web

31. Marc Andreessen • Developed the first graphical browser • Called Mosaic • Led to Netscape Navigator • Could display attractive images and a graphical interface permitting users to click on pictures as well as text

32. Internet Links • A link on a Web site is easy to see • Either underlined and colored text or an icon • Clicking the link transfers data from that site to the user’s computer

33. Browser • Interface software used to explore the Internet • Early browsers were text-only • Mosaic was the first graphical browser • Graphical browsers combine ease of links with attractive graphical interface

34. A Little About the Technology • A message sent over the Internet is divided into uniformly sized packets • Each packet labeled with its destination address • Transmission Control Protocol/Internet Protocol (TCP/IP) • TCP creates and reassembles packets • IP handles addressing • Ensures that packets are routed to their ultimate destination

35. The Internet Service Provider and the Browser • An Internet service provider (ISP) provides the server computer and software to connect to the Internet • Online service, such as America Online, includes Internet access, Internet service, and a browser • When you connect to the Internet, the browser displays a home page

36. Menus and Buttons • Menu – a series of choices normally laid out across the top of the screen • Called pull-down menus • Each initial choice gives lower-level choices • Buttons can be used to invoke commands • Screen tip – a small text message that appears when you rest the cursor over a button

37. Uniform Resource Locator (URL) • The complete, unique address of a Web page • Web page URL begins with http • HyperText Transfer Protocol – allows communication by using links to transfer data between sites • Domain name – address of site’s host computer • Last part of domain name is called a top-level domain • Identifies country or purpose of organization

38. URLUniform Resource Locator • Unique address of a web page or file on the Internet • Case-sensitive http://domain-name.top-level-domain/last-section

39. Processing RequestsURL • 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)

40. Plug-ins • Software that increases browser functionality • Most downloaded from their own Web sites • Once downloaded and installed, the browser can handle the new features • Most enhance a site’s audio-video experience • Shockwave permits viewing sites that include quality animation • Adobe Acrobat Reader displays and prints documents created in Portable Document Format (PDF) form

41. Web Page Programs • Small programs can be downloaded to run in your browser • Allow Web pages to perform many tasks • Allow dynamic interaction • Come in several forms • Scripting languages • Produce instructions to be interpreted and executed by your browser • JavaScript and VBScript are most common • Programs embedded in Web page • Java applets and ActiveX controls are most common

42. 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

43. Programming ActiveX Controls Capabilities similar to Java Browser must be enabled to support applets / ActiveX Controls Security issues

44. Wireless Internet Access • Use handheld devices such as pagers, PDAs, or pocket computers to access the Internet • Wireless Application Protocol (WAP) – convert Web pages into a format more compatible with limited capabilities of handheld devices

45. Wireless Internet Access • Supports mobile handheld devices • Text pagers • PDAs • Pocket computers • Web-enabled cellular phones • Applications • E-mail • Checking weather • Making airline reservations

46. Searching the Internet • Search Engine – lets a user specify search terms • Search engine builds database of sites that match those terms • Uses spider software (or bots) to build database • Metasearch – searches search engines and builds comprehensive list • Internet directory – database is developed by human researchers rather than spider

47. Processing Requests: Search Engine Database • Request same search using different engines yields different results • Databases built independently • Size • Content • Search methodology • Pages may be submitted by the owner • Metasearch – automatically puts the same request to several search engines

48. 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

49. Not Perfect • Unregulated • Useless web sites • Misinformation and misstatements on web sites • Concern over government censorship • Security & Privacy Issues

50. Newsgroups • Usenet – an informal network of computers • Allows posting and reading of messages • Typically focuses on specific topics • Requires a newsreader • Some are moderated • Messages sent to a moderator, who determines whether the message is appropriate • Prevents users from attacking other members and prevents inappropriate material from being posted