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  1. 1. EC3007 Internet for Business Economists (IfBE) Lecture 2 The growth and development of the Internet: history, infrastructure, institutions and protocols.The Internet for Business Economists: Guy Judge, September 2008 1
  2. 2. Todays objectives to inform you about the important stages in the development of the Internet, the applications that run on it and the associated protocols to familiarise you with some key points about the technical infrastructure of the Internet to highlight the role of some key people and organisations to look at the growth of the Internet and consider factors (especially economic ones) that can account for this growth The Internet for Business Economists: Guy Judge, September 2008 2
  3. 3. Reading 1. Rohlfs, J H (2003) Bandwagon effects in high-technology industries. MIT Press, Cambridge, MA,especially chapters 5, 13 and 14. 2. Rohlfs, J H (2001) Bandwagon effects and theInternet. Strategic Policy Research Inc.http://www.spri.com/pdf/reports/its2001/jhrbandwagonpaper.pdf 3. Varian, H R, Farrell, J and Shapiro, C (2004) TheEconomics of Information Technology: AnIntroduction. Cambridge 4. Odlyzko, A (no date) The current state and likelyevolution of the Internet. http://www.research.att.com/~amo 5. Greenstein, S (2003) Jumping on bandwagons.http://www.kellogg.northwestern.edu/faculty/greenstein/images/columns.htmlThe Internet for Business Economists: Guy Judge, September 2008 3
  4. 4. Follow up work for the weekPractical 2 1 explanation of some key terms and consideration of theirrelevance to our understanding of the growth anddevelopment of the Internet 2 identification of the role of some key people 3 identification of the role of some key organisations 4 Internet metrics issuesThe Internet for Business Economists: Guy Judge, September 2008 4
  5. 5. Some points from last week the Internet and the World Wide Web are not the same thing the importance of protocols - the standards or set of rules that enable computers to communicate with each other the adaptable nature of the Internet and its institutions The importance of network externalities and complementary bandwagon effects for the take off of the Internet The Internet for Business Economists: Guy Judge, September 2008 5
  6. 6. The InternetThe Internet is an interconnected set of computer networks across the globe that work together under a common set of rules or protocols (the TCP/IP suite).The name Internet refers to the global seamless interconnection of networks made possible by the protocols devised in the 1970s, the Internet protocols, still in use today. Vint Cerf, 1995 The Internet for Business Economists: Guy Judge, September 2008 6
  7. 7. Internet backbone networks, ISP etc. The Internet for Business Economists: Guy Judge, September 2008 7
  8. 8. From ARPANET to Internet 1969 ARPANET - a single network with 4 nodes (funded from US Defense budget) 1973 work began on linking networks Internetting; first n international links to UCL and Norway 1985 NSF takes over the backbone for interlinking networks (still government funded but by now more academic than military) 1995 NSF funding stops - commercial companies take over the Internet - by then it consists of over 50,000 networks connecting over 5 million computers The Internet for Business Economists: Guy Judge, September 2008 8
  9. 9. The original ARPA network The Internet for Business Economists: Guy Judge, September 2008 9
  10. 10. Internet traffic (2005) as depicted by TeleGeography Inc.The Internet for Business Economists: Guy Judge, September 2008 10
  11. 11. A more detailed depiction of Internet traffic from TeleGeography Inc. (2006)The Internet for Business Economists: Guy Judge, September 2008 11
  12. 12. http://www.telegeography.com/maps/internet/images/europe_map_large.gif The Internet for Business Economists: Guy Judge, September 2008 12
  13. 13. JANET - the Joint Academic Network in the UK The Internet for Business Economists: Guy Judge, September 2008 13
  14. 14. Source: The Guardian Friday 1st February 2008 http://image.guardian.co.uk/sys-files/Guardian/documents/2008/02/01/SEA_CABLES_010208.pdfThe Internet for Business Economists: Guy Judge, September 2008 14
  15. 15. ProtocolsA protocol is an agreement (set ofrules) between the communicatingparties (peers) on how communicationis to proceed. The Internet for Business Economists: Guy Judge, September 2008 15
  16. 16. The TCP/IP suite Q Why is it important?A It enables computers on different networks,designed by different vendors, to work together indelivering various applications; e.g. e-mail, filetransfer, remote login (telnet), use of the web etc.TCP/IP was the key to turning the Arpanet into theInternetThe Internet for Business Economists: Guy Judge, September 2008 16
  17. 17. TCP/IP key dates 1964 Paul Baran (RAND Corporation)publishes paper on packet-switchingnetworks 1974 Vint Cerf and Bob Kahn publish paperdescribing TCP 1978 Vint Cerf and others separate the TCPand IP functions The Internet for Business Economists: Guy Judge, September 2008 17
  18. 18. Internet applications and their protocols Early core applications File Transfer FTP (SSH is usually now preferred) Terminal access (remote login) Telnet Electronic mail (E-mail) SMTP Newsgroups Usenet The World Wide Web HTTPOther Internet applications include: chat systems, instantmessaging, Videoconferencing, Video and audio streaming,Voice over Internet, peer-to-peer file-sharing, IPTV etc.The Internet for Business Economists: Guy Judge, September 2008 18
  19. 19. The IP address Every computer on the Internet has a uniqueIP address - under the currently dominant IPv4system it consists of four numbers separated bydotse.g. 198.137.240.100identifies the main host computer at the WhiteHouse Because of the massive growth of the Internetthe new IPv6 system has been introducedThe Internet for Business Economists: Guy Judge, September 2008 19
  20. 20. Find your IP number The State University of New York at StonyBrook provides a service whereby youcan find out the IP number of the Internetcomputer you are connected to. Why not try it? (URL on my links page).The Internet for Business Economists: Guy Judge, September 2008 20
  21. 21. DNS - Domain Name System (1) DNS is the hierarchical domain-based namingscheme and distributed database system formapping host names and e-mail destinations to IPaddresses. Domain names are easy (for humans) toremember names for the computers on theInternet i.e. those that have been assigned IPnumbersThe Internet for Business Economists: Guy Judge, September 2008 21
  22. 22. DNS - Domain Name System (2)ICANN (Internet Corporation forAssigned Names and Numbers)coordinates the assignment of IPnumbers and Internet domain names.The Internet for Business Economists: Guy Judge, September 2008 22
  23. 23. DNS - Domain Name System (3) The top level domain covers twoidentifiers, separated by a dot generic type or group (gTLD)- e.g. .com,.ed (or .co and .ac) - recent additionsinclude .biz and .coop country codes (ccTLD) - e.g. .uk, .nl, .jp The Internet for Business Economists: Guy Judge, September 2008 23
  24. 24. DNS - Domain Name System (4) Sub-domains can then be created lower down thehierarchy by those responsible for that levele.g. userweb.port.ac.uk ICANN has recently (June 2008) announced arelaxation of the system of domain names The Internet for Business Economists: Guy Judge, September 2008 24
  25. 25. The Internet puts you in touch withresources and people Access to remote information (e.g.data sources, e-commerce, video ondemand) Person to person communication (e.g.e-mail, videoconferencing)synchronous and asynchronous links The Internet for Business Economists: Guy Judge, September 2008 25
  26. 26. Network connections via copper wires cable fibre optics microwaves (radio frequency) communication satellitesThe Internet for Business Economists: Guy Judge, September 2008 26
  27. 27. Network architecture architecture is a set of layers and protocols purpose of layer is to carry out services forthe higher layer in a way that is transparentto the higher layer layers communicate with their peersaccording to known protocols between layers there is an interfaceThe Internet for Business Economists: Guy Judge, September 2008 27
  28. 28. Design issues for layers layers need to identify senders and receivers have rules for communication (protocols) know about different available routes have conventions about speed identify and correct errorsThe Internet for Business Economists: Guy Judge, September 2008 28
  29. 29. Size classification of networks Local Area Networks (LAN) Wide Area Networks (WAN) internets Tanenbaum also distinguishes HomeNetworks, Wireless Networks andMetropolitan Area Networks (e.g. based oncable TV) The Internet for Business Economists: Guy Judge, September 2008 29
  30. 30. client-server modelbriefly mention differentsoftware models: fat client software thin client software Software as a Service (SaaS) The Internet for Business Economists: Guy Judge, September 2008 30
  31. 31. clients E-mail client software Outlook Pegasus Eudora also web based e-mail systems such asGmail, Hotmail, Yahoo!The Internet for Business Economists: Guy Judge, September 2008 31
  32. 32. SMTP Simple Mail Transport Protocolencodes every e-mail message as a sequenceof ASCII charactersUsed to send e-mail messages from oneserver to another. Messages can beretrieved with an e-mail client using POP orIMAP protocolsThe Internet for Business Economists: Guy Judge, September 2008 32
  33. 33. M IM E Multipurpose Internet Mail Extensionspecifies how non-text may be transmitted bySMTPThe Internet for Business Economists: Guy Judge, September 2008 33
  34. 34.