History of the Internet and Internet Basics

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History of the Internetand Internet Basics

• AGED 4143
• Electronic Communications
• in Agriculture

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History

• (1969) The U.S. DOD wanted a non-centralized
  network over phone lines that would survive power
  outages (ARPANet -- Advanced Research Projects
  Agency Network)
• J.C.R. Licklider was the primary developer
• He informally referred his idea as the
  intergalactic network, (later reduced to
  internet)
• Defense research programs at UCLA and Stanford
  were the first two nodes

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History

• (1972) NCSC developed telnet, allowing for remote
  log in
• (1973) FTP was introduced, allowing easy
  transfer of files among remote computers
• (1977-83) A standard method of packaging messages
  was developed (TCP/IP-Transmission Control
  Protocol/ Internet Protocol), and more
  supercomputers (nodes) were added

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History

• (1983) MILNET split from ARPANET
• (1983) Desktop computers with UNIX operating
  systems appeared
• (1985) The NSF got involved by linking a major
  network (NSFNET) to the internet for use by
  academic researchers

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History
1993 NSFNET Backbone
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History

• (1989) The backbone network was upgraded with
  help from IBM to "T1" (1.5 million bits of data
  per second, or about 50 pages of text per second)
  
• 1990 ARPANET was dissolved
• 1993 NSFNET was upgraded to T3
• (1994) Internet use exploded due to the advent of
  the the University of Minnesotas Gopher Server
  and CERNs World Wide Web.

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History
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History

• The Web was a project developed by CERN (Conseil
  Européen pour la Recherche Nucléaire), a European
  organization energy research
• The Web was built with the use of hypertext in
  mind (term coined in 1968)
• (1979) Charles Goldfarb invented SGML, which led
  to HTML (Tim Berners-Lee)

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History

• (1994) Netscape was founded Web servers on the
  internet grew from 250 to 2500 in one year
• (1993-94) Web browsers Mosiac and Netscape
  Navigator were introduced
• (1995) Servers grew to 73,500 in one year
• (1998) 72.6 million Americans had internet access

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History

• WYSIWYG, icon-driven programming is commonplace
• Real-time and interactive communication is
  prevalent, with the advent of CGI programming and
  video and audio streaming
• 64 of Americans 12 and older used the internet
  in 2001

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History

• Projections
• 2005 300 million people will be connected

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How the Web Works

• http//www.howstuffworks.com/web-server1.htm

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How the Web Works

• http//www.howstuffworks.com/web-server1.htm
• The Web is only a part of the internet
• Some of the servers connected to the internet
  are web servers
• Special software to handle http (hypertext
  transfer protocol)

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How the Web Works

• Servers have their own domain name, which is a
  human conversion of an IP (internet protocol)
  address
• E.g., www.howstuffworks.com 209.116.69.66
• The domain name is a part of the URL (uniform
  resource locator), which is the web address

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How the Web Works

• Servers have their own domain name, which is a
  human conversion of an IP (internet protocol)
  address
• E.g., www.howstuffworks.com 209.116.69.66
• The domain name is a part of the URL (uniform
  resource locator), which is the web address
• Web browsers request documents from web servers
  using the URL

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How the Web Works

• URLs contain the following elements
• access method (usually hypertext transfer
  protocol -- http//)
• location or domain name (www.uark.edu)
• directories and HTML file (/depts/aeedhp/index.htm
  l)
• So, the address for the AEED home page is
• http//www.uark.edu/depts/aeedhp/index.html
• Organizations like InterNIC, working with the
  World Trade Organization, register domain names
  for 35 and up

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How the Web Works

• Modems convert digital information to analog
  information that can travel over the physical
  lines that make up the internet
• These lines include phone lines (twisted pair and
  optical fiber), coaxial cable, satellite
  airwaves, then they convert incoming analog
  signals back to digital
• Digital conversion takes time and slows download
  speeds

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How the Web Works

• Information requested by the browser on your lab
  computer from a Web server in India, for example,
  probably follows this route
• Server in India Regional network in Asia
  backbone network regional network in U.S. U
  of A server PC in computer lab
• All the files related to a Web site are stored in
  a directory on a web server (usually owned by an
  ISP/OSP or by a large company or organization)

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How the Web Works

• Each web site is a collection of pages linked by
  hypertext that can be read with a web browser,
  like Netscape Navigator or Microsoft Internet
  Explorer
• The browser reads the HTML tags for the page
  requested and represents them on the monitor as
  graphics and text.
• When you open a web site, your computer
  downloads each individual file associated with
  each page to its RAM and displays the visual
  images on your monitor