For those who forgot: CSIS-116: Survey of Information Technology

1. For those who forgot:CSIS-116: Survey of Information Technology Dr. Eric Breimer

2. Recap of last class • Course Topics • Internet • Web meets DB • E-commerce • Syllabus • Come to lecture • Don’t miss exams • Don’t cheat • Other non-sense

3. Agenda • The books • Info. Tech (IT) inside and out • WPI nerds • Dreamweaver MX • Reference manual • Chapter 2: IT pages 15-33 • The Internet and the WWW (what’s the difference?) • History of The Internet • What exactly is the World Wide Web

4. The Books • I’ll call it “IT” • Written by two Electrical/Computer Engineers • Covers the basics of how things work • Why I picked it? • Covers exactly the topics I think are important

5. The Books • I’ll call it “Dreamweaver” • Reference manual • Will come in handy during lab. • This is an awesome book. • Don’t sell it.

6. Chapter 2: The World Wide Web • A Unique Product of the Information Age • Whatever that means? • Exam Question #2: What EXACTLY is the difference between the Internet and the World Wide Web? • Stupid Question #1: Why is it important to know the difference?

7. The Internet • Computers can be connected in a variety of different ways. • Ethernet, Token-ring, Wireless, Ports (Serial, Parallel, USB). These are all communication subtrates. • Two or more connected computers form a Network • The CS Dept. has its own Ethernet Network • Different types of networks can be connected • Bridges, gateways, etc. • Two or more connected networks can be called an inter-network • Siena had a very complex Inter-Network until recently. • Wanna see it?

8. The Internet • Inter-networks can obviously be connected • At some point in history, inter-networks became connected across the entire USA • The entire nation-wide collection of connected networks became known as The Internet. • Eventually, inter-networks became connected across the entire world

9. The Internet • The text book doesn’t mention this… • Most experts in the “Network World” think of The Internet as both • The physical infrastructure (wires, routers, hubs, switches, satellites, optical cables, receivers, transmitters, etc.) that form the inter-connections. • And, the actual collection of computers (and devices) that are “inter-connected.”

10. The World Wide Web (WWW) • Most experts think of The WWW as • HTML documents that are accessible via a URL (very narrow definition), or • All the data, information, and services that are widely available via The Internet (more general definition) • Thus, The Internet is the physical hardware that makes the connections possible and • The World Wide Web is the content and services that are widely available over this massive collection of connected computers.

11. The World Wide Web (WWW) • While the two terms are somewhat synonymous to the non-expert, • You should appreciate the subtle difference in the two terms. • Some examples and history might help…

12. The World Wide Web (WWW) Examples: Content & High-level Protocols • Content: WebPages • Hypertext Transfer Protocol (http) • URL (Universal Resource Locator) • Content: Documents & Programs • File Transfer Protocol (ftp) • Content: Music & Videos • Gnutella Protocol

13. The World Wide Web (WWW) More examples • Content: Email • SMTP (Simple Mail Transport Protocol) • IMAP (Internet Message Access Protocol) • POP (Post-Office Protocol) • DNS (Domain Name System) • MIME (Multipurpose Internet Mail Extensions) • Content: Peer to Peer messaging • AOL IM Protocol • Multi-player gaming (various protocols)

14. The Internet Examples: Hardware & Low-Level Protocols • Hardware • Computer, Ethernet card • CAT-5 cable, fiber optic cable • Router, Hub, Switch, Bridge, Gateway • Low-Level Protocols/ Concepts • TCP/IP (Transmission Control Protocol/Internet Protocol) • Packet Switching

15. What is the Internet? • The largest network of networks in the world. • Uses TCP/IP protocols and packet switching . • Runs on any communications substrate. From Dr. Vinton Cerf, Co-Creator of TCP/IP

16. Brief History of the Internet • 1968 - DARPA (Defense Advanced Research Projects Agency) contracts with BBN (Bolt, Beranek & Newman) to create ARPAnet (Advanced Research Projects Agency) • 1970 - First five nodes: • UCLA • Stanford • UC Santa Barbara • U of Utah, and • BBN • 1974 - TCP specification by Vint Cerf • 1984 – On January 1, the Internet with its 1000 hosts converts en masse to using TCP/IP for its messaging

17. A Brief Summary of the Evolution of the Internet Age of eCommerce Begins 1995 Mosaic Created 1993 WWW Created 1989 Internet Named and Goes TCP/IP 1984 TCP/IP Created 1972 ARPANET 1969 Hypertext Invented 1965 Packet Switching Invented 1964 First Vast Computer Network Envisioned 1962 1962 1995

18. Ideas 1940s to 1969 We will prove that packet switching works over a WAN. Hypertext can be used to allow rapid access to text data Packet switching can be used to send digitized data though computer networks We can accomplish a lot by having a vast network of computers to use for accessing information and exchanging ideas We can do it cheaply by using Digital circuits etched in silicon. We do it reliably with “bits”, sending and receiving data We can access information using electronic computers 1945 1969

19. Ideas 1970s to 1995 Great efficiencies can be accomplished if we use The Internet and the World Wide Web to conduct business. The World Wide Web is easier to use if we have a browser that To browser web pages, running in a graphical user interface context. Computers connected via the Internet can be used more easily if hypertext links are enabled using HTML and URLs: it’s called World Wide Web The ARPANET needs to convert to a standard protocol and be renamed to The Internet We need a protocol for Efficient and Reliable transmission of Packets over a WAN: TCP/IP Ideas from 1940s to 1969 1970 1995

20. Vannevar Bush • Summary: Vannevar Bush established the U.S. military / university research partnership that later developed the ARPANET. He also wrote the first visionary description of the potential use for information technology, inspiring many of the Internet's creators. • From 1946 to 1947, Bush served as chairman of the Joint Research and Development Board. Out of this effort would later come DARPA, which would later do the ARPANET Project. Source: Livinginternet.com

21. Claude Shannon • The Father of Modern Information Theory • Created the idea that all information could be represented using 1s and 0s. Called these fundamental units BITS. • Won a Nobel prize for his master’s thesis in 1936, titled, “A Symbolic Analysis of Relay and Switching Circuits”, it provided mathematical techniques for building a network of switches and relays to realize a specific logical function, such as a combination lock. Source: http://www.research.att.com/~njas/doc/ces5.html

22. Paul Baran • Summary: Paul Baran developed the field of packet switching networks while conducting research at the historic RAND organization. • RAND (a contraction of the term research and development) is the first organization to be called a "think tank.“ • Baran's architecture was well designed to survive a nuclear conflict, and helped to convince the US Military that wide area digital computer networks were a promising technology. Source: Livinginternet.com

23. Leonard Kleinrock Lawrence Roberts • Summary: Leonard Kleinrock is one of the pioneers of digital network communications, and helped build the early ARPANET. • Summary: Lawrence Roberts was the ARPANET program manager, and led the overall system design. Source: Dr. Kleinrock’s Homepage

24. Vinton Cerf • Summary: Vinton Cerf is co-designer of the TCP/IP networking protocol. • Cerf worked on several interesting networking projects at DARPA, including • the Packet Radio Net (PRNET), and • the Packet Satellite Network (SATNET). • In the spring of 1973, he joined Bob Kahn as Principal Investigator on a project to design the next generation networking protocol for the ARPANET. Source: Livinginternet.com

25. Robert Kahn • Summary: Bob Kahn is co-designer of the TCP/IP networking protocol. • He set four goals for the TCP design: • Network Connectivity. Any network could connect to another network through a gateway. • Distribution. There would be no central network administration or control. • Error Recovery. Lost packets would be retransmitted. • Black Box Design. No internal changes would have to be made to a computer to connect it to the network. Source: Livinginternet.com

26. Tim Berners-Lee • The inventor of HTML. Graduate of Oxford University, England, Tim is now with the Laboratory for Computer Science (LCS)at the Massachusetts Institute of Technology (MIT). • He directs the W3 Consortium, an open forum of companies and organizations with the mission to realize the full potential of the Web. Source: w3c.org

27. Internet Growth Trends • 1977: 111 hosts on Internet • 1981: 213 hosts • 1983: 562 hosts • 1984: 1,000 hosts • 1986: 5,000 hosts • 1987: 10,000 hosts • 1989: 100,000 hosts • 1992: 1,000,000 hosts • 2001: 150 – 175 million hosts • 2002: over 200 million hosts • By 2010, about 80% of the planet will be on the Internet

28. Important Milestones September 2002 > 200,000,000 IP Hosts > 840,000,000 Users Netsizer.com – from Telcordia

29. Sept. 1, 2002 Dot-Com Bust Begins Chart by William F. Slater, III The Internet was not known as "The Internet" until January 1984, at which time there were 1000 hosts that were all converted over to using TCP/IP.

30. Statistics from the IITF Report The Emerging Digital Economy * • To get a market of 50 Million People Participating: • Radio took 38 years • TV took 13 years • Once it was open to the General Public, The Internet made it to the 50 million person audience mark in just 4 years!!! • http://www.ecommerce.gov/emerging.htm • Released on April 15, 1998

31. Questions?

32. Sources of Statistical Information • Netsizer.com – from Telcordia • CAIDA • Network Wizards Internet Domain Survey • RIPE Internet Statistics • Matrix Information and Directory Services • Growth of the World Wide Web • The Netcraft Web Server Survey • Internet Surveys • The Internet Society