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First question

First question

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First question

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  1. First question What is the Internet?

  2. What is the Internet? • A global network of networks

  3. What is the Internet? • A global network of networks, including their wires, fibers, and routers (switches)

  4. What is the Internet? • A global network of networks, including their wires, fibers, and routers (switches)

  5. What is the Internet? • A global network of networks, including their wires, fibers, and routers (switches) • The computers connected to each network

  6. What is the Internet? • A global network of networks, including their wires, fibers, and routers (switches) • The computers connected to each network • A book of “IP” addresses that tells each computer where all the others are

  7. Techno-Alphabet Soup, pt 1 • IP = Internet Protocol – routes the packets • TCP = Transmission Control Protocol arrives in reliable order TCP/IP describes the rules for transmitting small packets of bits (0s and 1s) from one computer to another.

  8. Techno-Alphabet Soup, pt 2 Each computer on the Internet is uniquely identified so that it can be addressed.

  9. Techno-Alphabet Soup, pt 2 Each computer on the Internet is uniquely identified so that it can be addressed. It may have: • a name – for example, the Web server for this university is www.albany.edu…

  10. Techno-Alphabet Soup, pt 2 Each computer on the Internet is uniquely identified so that it can be addressed. It may have: • a name – for example, www.albany.edu But it must have: • an IP address – 169.226.1.110

  11. Techno-Alphabet Soup, pt 3 The translation or resolution of the name to the address is done by a “domain name server” (DNS)…

  12. Techno-Alphabet Soup, pt 3 The translation or resolution of the name to the address is done by a “domain name server” (DNS), which is like the white pages of the Internet, translating names to IP addresses.

  13. Techno-Alphabet Soup, pt 3 The translation or resolution of the name to the address is done by a “domain name server” (DNS), the white pages of the Internet. There are thousands of DNSs around the world…

  14. Techno-Alphabet Soup, pt 3 The translation or resolution of the name to the address is done by a “domain name server” (DNS), the white pages of the Internet. There are thousands of DNSs around the world, and they all know that: 169.226.1.110 = www.albany.edu and vice versa.

  15. Techno-Alphabet Soup, pt 4 Notice that the IP address is hierarchical, like a phone number or street address : 169.226.1.110 = www.albany.edu

  16. Techno-Alphabet Soup, pt 4 Notice that the IP address is hierarchical, like a phone number or street address : 169.226.1.110 = www.albany.edu 518-442-3300…

  17. Techno-Alphabet Soup, pt 4 Notice that the IP address is hierarchical, like a phone number or street address: 169.226.1.110 = www.albany.edu 518-442-3300, or 415-442-3300, x. 118

  18. Techno-Alphabet Soup, pt 4 Notice that the IP address is hierarchical, like a phone number or street address: 169.226.1.110 = www.albany.edu 518-442-3300, or 415-442-3300, x. 118 But notice that the domain name is a different kind of hierarchy…

  19. Techno-Alphabet Soup, pt 4 Notice that the IP address is hierarchical, like a phone number or street address: 169.226.1.110 = www.albany.edu The domain name has 2 parts – the host and top level domain (TLD). albany = host (really University at Albany) .edu = TLD (top level domain)= education

  20. Domain categories Original top level domain categories in the U.S.: • .com – businesses • .edu – educational institutions • .gov – government agencies • .mil – military units • .net – networks • .org – non-profit organizations

  21. Other domains New Top-Level Domains: • .aero, .biz, .info, .name, .pro, etc.

  22. Other domains New Top-Level Domains: • .aero, .biz, .info, .name, .pro, etc. Other government sites within U.S.: • state.ny.us

  23. Other domains New Top-Level Domains: • .aero, .biz, .info, .name, .pro, etc. Other government sites within U.S.: • state.ny.us Country codes: • .at, .au, .ca, .de, .fr, .uk, etc.

  24. Other domains New Top-Level Domains: • .aero, .biz, .info, .name, .pro, etc. Other government sites within U.S.: • state.ny.us Country codes: • .at, .au, .ca, .de, .fr, .uk, etc.

  25. The authority for domains… http://www.icann.org/ ICANN - Internet Corporation for Assigned Names and Numbers Newest : .mail – a site for anti-spam community .kid -?

  26. The authority for domains… • ICANN – Internet Corporation for Assigned Names and Numbers To the extent anyone is in charge, it’s ICANN.

  27. What’s in the packets… Here are the minimum things each needs:

  28. What’s in the packets… Here are the minimum things each needs: • An address (IP number)

  29. What’s in the packets… Here are the minimum things each needs: • An address (IP number) • An addressee, e.g., someone@…

  30. What’s in the packets… Here are the minimum things each needs: • An address (IP number) • An addressee, e.g., someone@… • Something to indicate order or sequence

  31. What’s in the packets… Here are the minimum things each needs: • An address (IP number) • An addressee, e.g., someone@… • Something to indicate order or sequence • A portion of the message (Why not all?…)

  32. What’s in the packets… Here are the minimum things each needs: • An address (IP number) • An addressee, e.g., someone@… • Something to indicate order or sequence • A portion of the message (Why not all?…) How would that work here?…

  33. Delivering the message… How would that work here in LC 25?… • We need an address: 25.2.9.7

  34. Delivering the message… How would that work here in LC 25?… • We need an address: 25.2.9.7 And right away we’re stuck. What does this mean? How do we find out?…

  35. Delivering the message… How would that work here in LC 25?… • We need an address: 25.2.9.7 And right away we’re stuck. What does this mean? How do we find out?… • We need a DNS server, which we’ll use in reverse… going from “number” to “name”

  36. The LC “DNS” server… Our hypothetical LC addresses, by analogy with IP addresses, are quadruples: LC (room) # . side of room . row # . seat # where left/right side (from front) is 1/2, row is from the front, and seat is from the aisle.

  37. The LC “DNS” server… Our hypothetical LC addresses, by analogy with IP addresses, are quadruples: LC (room) # . side of room . row # . seat # where left/right side (from front) is 1/2, row is from the front, and seat is from the aisle. So where is 25.2.9.7?…

  38. Splenda works As sugar switching Pieces of the message…

  39. Splenda works As well As sugar For packet switching Pieces of the message…

  40. Next question… When was the Internet?

  41. When was the Internet? • 1961 – Len Kleinrock (then at MIT, now at UCLA) developed theory of “packet switching,” describing how data could behave on a highway where collisions were not only allowed but expected!!

  42. When was the Internet? • 1961 – Len Kleinrock (then at MIT, now at UCLA) developed theory of “packet switching,” describing how data could behave on a highway where collisions were not only allowed but expected!! • 1964 – Paul Baran (RAND Corp.) used packet theory to develop idea of a network that could survive major outages….

  43. When was the Internet? • 1965 – Advanced Research Projects Agency (ARPA) in the Pentagon funded the first experimental connection between a computer at MIT and one in California… over a 1200 bps phone line.

  44. When was the Internet? • 1966 – Robert Taylor, an ARPA funding manager, got fed up. He proposed networking computers around the country… mainframes… four of them. His boss said “OK” and gave him $1M after a 20-minute conversation…. There was only one small problem: no one knew how to do this!

  45. When was the Internet? • 1966-69 – ARPA awarded a contract to Bolt Beranek and Newman (BBN), an architectural consulting firm in Boston to design and build “ARPANET,” the direct ancestor of today’s Internet, with a starting configuration of four nodes!

  46. When was the Internet? • 8/30/69UCLA • 10/1/69 SRI • 10/29/69 1st message, UCLA to SRI • 11/1/69 UCSB • 12/?/69 University of Utah… ski season…

  47. When was the Internet? • By 1971, there were 23 “hosts” (computers) at 15 “nodes” in CA, UT, IL, MI, PA, & MA

  48. When was the Internet? • 1972 – Ray Tomlinson chooses “@” as connector for userid and address

  49. When was the Internet? • 1972 – Ray Tomlinson chooses “@” as connector for userid and address • 1973 – 75% of all ARPANET traffic is email