1. CE80N Introduction to Networks & The Internet Dr. Chane L. Fullmer UCSC Winter 2002

2. January 15, 2002CE80N -- Winter 2002 -- Lecture #42 New Session Hours Jack’s Lounge (1 st floor BE) –Thursdays – 7:30 -> 8:30 PM TA Office Hours –Tuesdays – 6:30 -> 7:30 PM –Fridays – 1:00 -> 2:00 PM

3. January 15, 2002CE80N -- Winter 2002 -- Lecture #43 Homework Must be turned in during – –Class lecture –Session –TA Office Hour

4. January 15, 2002CE80N -- Winter 2002 -- Lecture #44 Today’s Reading Chapter 8, Internet: The Early Years; Chapter 9, Two Decades of Incredible Growth; Chapter 10, The Global Internet; Chapter 11, the Information

5. January 15, 2002CE80N -- Winter 2002 -- Lecture #45 The Early Years… A Multitude of Local Area Network (LAN) technologies exist -- –Combinations of : Speed, reliability, cost, platform, etc.. –Performance determines cost High speed costs more –Platform dependency of Network Interface Card (NIC) –Not all technologies are available across all platforms, restricting interoperability among certain platforms

6. January 15, 2002CE80N -- Winter 2002 -- Lecture #46 The Early Years Many autonomous groups installing independent networks –Allowed them to control access, policies, etc.. –Resulted in a proliferation of LAN technologies from various vendors.

7. January 15, 2002CE80N -- Winter 2002 -- Lecture #47 The Early Years… LAN technologies are basically incompatible –Electrically: Voltage, frequency, speed –Protocol Encoding –Other LAN limitations distance

8. January 15, 2002CE80N -- Winter 2002 -- Lecture #48 The Early Years… Wide Area Networks (WAN) –First WANs used dialup technology to form a set of long-haul transmission lines –Uses a dedicated machine at each local site to unify the transmission lines into a coordinated system

9. January 15, 2002CE80N -- Winter 2002 -- Lecture #49 The Early Years  A WAN differs from a disjoint set of transmission lines because of the inclusion of a special computer (Gateway) at each site that connects to the transmission lines and keeps communication independent of the computers that use the WAN

10. January 15, 2002CE80N -- Winter 2002 -- Lecture #410 The Early Years WAN G1 G2 G3

11. January 15, 2002CE80N -- Winter 2002 -- Lecture #411 The Early Years WANs are expensive to install and maintain –Leased transmission lines –Dedicated hardware Again, many WAN and LAN technologies were developed, and incompatibilities continued to exist. WANs are not compatible with LAN technology, and cannot directly interoperate.

12. January 15, 2002CE80N -- Winter 2002 -- Lecture #412 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.

13. January 15, 2002CE80N -- Winter 2002 -- Lecture #413 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.

14. January 15, 2002CE80N -- Winter 2002 -- Lecture #414 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

15. January 15, 2002CE80N -- Winter 2002 -- Lecture #415 The Early Years ARPANET Backbone UCLA LAN UCLA LAN MIT LAN MIT LAN UCB LAN UCB LAN DARPA LAN DARPA LAN G1 G2 G3

16. January 15, 2002CE80N -- Winter 2002 -- Lecture #416 The Early Years… Internet Software –Internet Protocol (IP) Provides basic communication –Transmission Control Protocol (TCP) Provides services for applications to communicate –The “TCP/IP Internet Protocol Suite” aka TCP/IP

17. January 15, 2002CE80N -- Winter 2002 -- Lecture #417 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

18. January 15, 2002CE80N -- Winter 2002 -- Lecture #418 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

19. January 15, 2002CE80N -- Winter 2002 -- Lecture #419 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)

20. January 15, 2002CE80N -- Winter 2002 -- Lecture #420 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.

21. January 15, 2002CE80N -- Winter 2002 -- Lecture #421 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..

22. January 15, 2002CE80N -- Winter 2002 -- Lecture #422 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

23. January 15, 2002CE80N -- Winter 2002 -- Lecture #423 The Early Years The IAB (Internet Activities 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

24. January 15, 2002CE80N -- Winter 2002 -- Lecture #424 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…

25. January 15, 2002CE80N -- Winter 2002 -- Lecture #425 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

26. January 15, 2002CE80N -- Winter 2002 -- Lecture #426 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

27. January 15, 2002CE80N -- Winter 2002 -- Lecture #427 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

28. January 15, 2002CE80N -- Winter 2002 -- Lecture #428 The Early Years Exponential growth …….

29. January 15, 2002CE80N -- Winter 2002 -- Lecture #429 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….

30. January 15, 2002CE80N -- Winter 2002 -- Lecture #430 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.

31. January 15, 2002CE80N -- Winter 2002 -- Lecture #431 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

32. January 15, 2002CE80N -- Winter 2002 -- Lecture #432 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.

33. January 15, 2002CE80N -- Winter 2002 -- Lecture #433 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

34. January 15, 2002CE80N -- Winter 2002 -- Lecture #434 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

35. January 15, 2002CE80N -- Winter 2002 -- Lecture #435 GlossaryGlossary ARPA –Abbreviation for Advanced Research Projects Agency. Backbone Network –Used to refer to a central network to which many routers connect.

36. January 15, 2002CE80N -- Winter 2002 -- Lecture #436 GlossaryGlossary Internet –The collection of networks and routers that use the TCP/IP protocol suite and function as a single, large network. Open System –A non-proprietary technology or system: any vendor can use the specifications of an open system to build products and services.

37. January 15, 2002CE80N -- Winter 2002 -- Lecture #437 GlossaryGlossary RFC –Abbreviation for Request For Comments. TCP/IP –Literally, the name of protocols that specify how computers communicate on the Internet.

38. January 15, 2002CE80N -- Winter 2002 -- Lecture #438 GlossaryGlossary TCP/IP Software –The name of the software that implements the protocols. Wide Area Network (WAN) –Any network technology that can span long geographic distances.

39. January 15, 2002CE80N -- Winter 2002 -- Lecture #439 Glossary ANSNET – A major Wide Area Network that formed part of the Internet in the mid-1990s. Internet Architecture Board (IAB) –Set policy and standards for TCP/IP and the connected Internet. Internet Engineering Task Force (IETF) –Responsible for designing and testing new technologies for TCP/IP and the Internet.

40. January 15, 2002CE80N -- Winter 2002 -- Lecture #440 Glossary Internet Protocol (IP) –Specification for the format of packets computers use when they communicate across the Internet. National Science Foundation (NSF) –A U.S. government agency that has funded the development of a WAN for the Internet and helped scientists connect to the Internet.

41. January 15, 2002CE80N -- Winter 2002 -- Lecture #441 Glossary National Science Foundation NETwork (NSFNET) –The Wide Area Network that forms the backbone of the Internet in the United States. Operating System –Complex software that manages the computer, control I/O devices, and provides file storage on multi-user computers.

42. January 15, 2002CE80N -- Winter 2002 -- Lecture #442 Glossary Request For Comments (RFC) –Series of notes that contain the TCP/IP protocol standards. Transmission Control Protocol (TCP) –One of the two major TCP/IP protocols. TCP handles the difficult task of ensuring that all data arrives at the destination in the correct order.

43. January 15, 2002CE80N -- Winter 2002 -- Lecture #443 The Global Internet

44. January 15, 2002CE80N -- Winter 2002 -- Lecture #444 The Global Internet The Internet was originally sponsored by the US Government (through ARPA). –Efforts concentrated in the US –ARPA experimented with satellite connections to test the Internet Norway, England

45. January 15, 2002CE80N -- Winter 2002 -- Lecture #445 The Global Internet Email – the first “killer app” –Began with dialup networks UNIX – UUCP (Unix to Unix Copy) BITNET, FIDONET –Dialup software could be used from most locations in the world. Telephone systems interoperate globally –ITU (International Telecommunication Union) standards

46. January 15, 2002CE80N -- Winter 2002 -- Lecture #446 The Global Internet European development –Research networks JANET (Joint Academic Network) EARN (European Academic And Research Network) EBONE –1991 – cooperative formed in Europe to operate a WAN spanning Europe, and connecting to the US Internet

47. January 15, 2002CE80N -- Winter 2002 -- Lecture #447 Figure 10.2 The European Backbone

48. January 15, 2002CE80N -- Winter 2002 -- Lecture #448 The Global Internet 1997 – All seven continents are reached by the Internet – including Antarctica. 1998 – Total Globalization is achieved: –Every populated country in the world has Internet access.

49. January 15, 2002CE80N -- Winter 2002 -- Lecture #449 The Global Internet Infrastructure –New infrastructure makes new industries possible Shipping Railroads Interstate highway system Airlines

50. January 15, 2002CE80N -- Winter 2002 -- Lecture #450 The Global Internet Communication Infrastructure –Messengers on foot/horseback –Postal mail system Universal delivery –Any individual can send a letter to any other individual. –The scope of an infrastructure defines a closed community that shares the benefits it offers. –Telegraph system Introduced high-speed delivery.

51. January 15, 2002CE80N -- Winter 2002 -- Lecture #451 The Global Internet Communication Infrastructure (cont) –The Telephone system Extended instantaneous communication to individual homes and offices, and allowing interactive conversations. Wireless (cell) phones extend instantaneous communication to the individual directly, wherever they may be.

52. January 15, 2002CE80N -- Winter 2002 -- Lecture #452 The Global Internet The Internet Infrastructure –Basic communications facilities are general purpose Almost any network application can use the Internet –Most of the services available were not invented when the Internet was conceived. Web browsers, Real Audio, email…

53. January 15, 2002CE80N -- Winter 2002 -- Lecture #453 The Global Internet Internet Infrastructure –The TCP/IP Suite is the key General purpose Efficient Flexible Robust

54. January 15, 2002CE80N -- Winter 2002 -- Lecture #454 The Global Internet The Internet is a global information infrastructure. Although it offers many services, the Internet’s chief advantage lies in the design of the TCP/IP software that has accommodated changes in computers, networks and services. (And it has done so now, for 20 + years)

55. January 15, 2002CE80N -- Winter 2002 -- Lecture #455 The Global Internet Summary –Email was the first killer app. –EBONE brought Europe to the Internet –1997 – Every continent is connected –1998 – Every populated country is connected –The Internet is the new infrastructure –TCP/IP is the key to how the Internet works.

56. January 15, 2002CE80N -- Winter 2002 -- Lecture #456 Glossary EBONE –(European backBONE) The Wide Area Network facilities that interconnected many European countries to one another and to the Internet in the mid 1990s. BITNET –(Because It’s Time NETwork) An early network developed at City University of New York.

57. January 15, 2002CE80N -- Winter 2002 -- Lecture #457 Glossary ITU –Abbreviation for International Telecommunication Union. PTT –Abbreviation for Post, Telegraph, and Telephone.

58. January 15, 2002CE80N -- Winter 2002 -- Lecture #458 Glossary UUCP –(Unix to Unix Copy Program) Software developed in the mid 1970s that allows one computer to copy files to or from another over a (usually dial-up) connection.

59. January 15, 2002CE80N -- Winter 2002 -- Lecture #459 Glossary Infrastructure –A service or facility that is fundamental to society