I think there is a world market for maybe five computers. Exploring the Internet. ENIAC Circa Vannevar Bush c1945

Transcription

1 Exploring the Internet I think there is a world market for maybe five computers. January 26, 2006 Thomas Watson Senior, Chairman of IBM, 1943 There will always be plenty of things to compute... With millions of people doing complicated things. memex stores all his books, records, and communications, and... can be consulted with speed and flexibility Matchbook sized, $.05 encyclopedia Speech to text Head mounted camera, dry photography ENIAC Circa 1947 Vannevar Bush c1945

2 ENIAC Circa 1947 ENIAC Characteristics Physical Characteristics 19,000 vacuum tubes, 1,500 relays 60,000 pounds, 16,200 cubic feet 174 kilowatts 5 kflops (~ same as Intel 4004) Future Prediction (1949 Popular Mechanics) 1,500 vacuum tubes 3,000 pounds 10 kilowatts There is no reason anyone would want a computer in their home. Ken Olsen President, Chairman and founder Digital Equipment Corporation 1977 Internetters growth World Population TVs & Phones PCs Internetters 1 Gp by 2000 Negroponte

3 Internetters growth y World Population extrapolated at 1.6% per year Internet Growth extrapolated at 98% per year Actual US Internet Usage New England: 66% Mid-Atlantic Region: 58% Capital Region: 64% Southeast Region: 57% South: 48% Industrial Midwest: 56% Upper Midwest: 59% Midwest: 55% Border States: 60% Mountain States: 64% Pacific Northwest: 68% California: 65% (Percentages apply to the proportion of adults, 18 years old and over.) From Pew Internet and American Life Project. Cyberspace: A Network of... Networks of... Cyberspace: one, two or three networks? Continent World Region/ Intranet Campus Body Home Data Telephony Television

4 Cyberspace: A spiraling quest in 3D real space Computation The Information Age ushered in by new powerful methods of computing and communication Communication Cyberization Gutenberg s invention of the printing press took books out of the monasteries and put them, for the first time, into the hands of people The telephone allowed people to communicate information directly to one another in real time synchronous communication. The Information Age The Internet Introduced a new dimension: an electronic, virtual world in which time and space lose much of their meaning and constraints A loose amalgam of thousands of computer networks reaching millions of people all over the world. Geographic distance, time zone differences,equipment differences no longer prevent people from communicating 24 hours a day from thousands of locations

5 The Internet The Internet : What is it? Any two connected computers can be considered a network. (intranet) Any two connected networks become an internet (small i). Technological advancements over the last few years have enabled virtually all computers to be networked together, giving birth to today s Internet (capital I). A network of networks based on the TCP/IP protocols A community of people who use and develop networks A collection of resources that can be reached from those networks The Internet Originally designed to provide researchers with access to expensive hardware resources Remote login File sharing Its speed and effectiveness as a communications medium has transcended the original mission Instant Messaging World Wide Web e-commerce Implications are staggering Instantaneous broadcast (tv/radio) available for decades filtered by others users had no role in selection Internet provides thousands of sources of information unedited unvalidated users chooses what, when and where to receive information

6 The Internet - the beginnings Began as one network (Research Project Agency NET) in 1973 at UCLA - a Defense Dept. project. This network split in the early 80 s merging with non military networks (UUCP, USEnet, CSnet,BITnet) to connect to one another ( primarily university C.Sc., Eng. & Science) In 1986, a government funded network joining supercomputer centers was created( NSFnet) accelerated growth and cooperation in the US. Across the globe the broader Internet community also began to experience rapid growth. Early 90 s global cooperation congeals and Internet becomes a reality The Internet - now Has been and continues to be a key part of the R&D community However, it now counts among its users people from all walks of life and age groups Journalists obtain background info. and on-line updates for stories Communities use bulletin boards to communicate and to announce events Businesses communicate internally and with external clients and partners... Provides access to more people and more information faster than any other medium What kind of information is available? weather reports, travel information, recipes news updates ( CNN scripts and transcriptions,...), video conferencing capability, newsgroups & bulletin boards traffic info.( bottlenecks to avoid in rush hour); GIS - ship/truck/car location sports and entertainment-schedules, ticket prices, seating locations, ordering info college viewbooks, library catalogs millions of background and research documents ; many of the non-copywritten classics ( Project Gutenberg = complete texts),... Challenges and Problems Organizing the information Accessing the information Productive use of your time and of the network s resources in identifying the information that you for which you are really looking Legal and Cultural Issues Social Interactions and the dramatic changes this medium provides Privacy, Cultural conflict, Pornography,... How democratic should and can the Internet remain? Bandwidth Cost

7 The Internet - now Why does it work? Universal use of agreed upon standards ( TCP/IP,...) Focus on interoperability Who runs the Internet? No one organization runs it. No particular group or organization owns the Internet. It is actually a worldwide network that links approximately 20,000 other networks together. Volunteer groups of individuals do set some standards for Internet technologies, but there is no central body that governs the structure. There a some large organizations that set some policies for the backbone operations ( NSF, regional backbone operators-for New England area it is NEARnet) The Internet - What is it? Internet, to the user, looks like one big, seamless network The Internet is a network of networks The Internet NOT just one big network it is thousands of different interconnected networks that are providing interoperability Consists of LAN s - Local area networks, WAN s -Wide area networks connecting computers for organizations all over the world Connections Networks are hooked together using a wide variety of technologies: dial-up lines high-speed dedicated leased lines ( 56kb, T-1, T-3,...) satellite links microwave links fiber optic links Computers on the networks also need to use some common protocols and standards if they are to communicate correctly

8 Standards Standards play a large part in our everyday lives Why does camera film always fit your camera? Electrical plugs fit in sockets and transmit current? CD s work in any brand of player? Standards are critical in networks and computers Internet : protocols + standards The protocol TCP/IP is the language of the Internet TCP/IP = Transmission Control Protocol/ Internet Protocol to actually communicate two computers must be using the same protocol at the same time TCP/IP- developed in the 70 s, used 1st time in 1983 and at UC Berkeley in their UNIX development project and distributed at little or no cost to universities. Developed with public funds so no one company can own it - hence no one company or group of companies can control access to the Internet What s a protocol? human protocols: what s the time? I have a question Format of a letter Surgical procedures Introductions, Film, light bulbs, specific msgs sent specific actions taken when msgs received, or other events network protocols: machines rather than humans all communication activity in Internet is governed by protocols protocols define : format, order of messages sent and received among network entities, actions taken on message transmission, receipt What s a protocol? a human protocol and a computer network protocol: Hi Hi Got the time? 2:00 Q: Other human protocols? time TCP connection req. TCP connection reply. Get <file>