CPSC 441 Computer Communications

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CPSC 441Computer Communications

• Ajay Gopinathan
• ajay.gopinathan_at_ucalgary.ca
• http//www.cpsc.ucalgary.ca/agopinat/441
• Office ICT 626A
• Phone [phone]

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History of the Internet
Slides created by Ajay Gopinathan. Content
adapted from previous slides by Emir Halepovic as
well references found at the end of this
presentation
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Communication Networks...

• Telecommunication networks are 100 years old
• Circuit-switched, connection oriented
• Intelligent core, dumb edge terminals

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In the beginning... ARPA

• 1957 Russians launch Sputnik. Eisenhower saw the
  need for the Advanced Research Projects Agency
  (ARPA)
• ARPA becomes a technological think-tank for
  American defence
• Several years later, ARPA starts looking into
  computer communication and networking
• 1962 ARPA appoints John Licklider to head its
  computer research program

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Packet Switching

• Data traffic is bursty intervals of activity
  followed by periods of inactivity.
• E.g. Think of a web browsing session
• Circuit switched networks would be inefficient

Image Source CEFRIEL, Milan
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Packet Switching

• 1961 Leonard Kleinrock uses queuing theory,
  proposes packet switched networks
• More bandwidth efficient
• Robust not reliant on single route

Image Source Leonard Kleinrock's homepage,
http//www.cs.ucla.edu/lk/
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ARPANET

• 1967 Leonard Roberts of ARPA publishes plan for
  the first computer network system the ARPANET
• Packet switches were needed. Called Interface
  Message Processors (IMP), the contract was
  awarded to BBN
• Oct 1969 IMPs installed in UCLA, Stanford, UCSB
  and Utah

Interface Message Processor
Image Sourcehttp//aleph.llull.net/wp-content/fil
es/imp.jpg
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ARPANET

• 1969 At UCLA Kleinrock attempts the first ever
  remote login at Stanford
• "We set up a telephone connection between us and
  the guys at SRI...," Kleinrock said in an
  interview "We typed the L and we asked on the
  phone,
• "Do you see the L?"
• "Yes, we see the L," came the response.
• "We typed the O, and we asked, "Do you see the
  O."
• "Yes, we see the O."
• "Then we typed the G, and the system crashed"...

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Early 70s...

• ARPANET, with 40 nodes, goes public in 1972
• Ray Tomlinson writes email program for ARPANET
• First computer to computer chat takes place
  between Stanford and BBN
• 1972 Telnet protocol RFC published
• 1973 FTP protocol RFC published

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Ethernet

• ARPANET Each node able to only talk to the
  other node on the other end of wire
• First medium access control ALOHANet by Norman
  Abramson
• 1973-75 Bob Metcalfe's dissertation leads to the
  Ethernet protocol
• Medium access control protocol for wired networks
  based on Abramson's ALOHA.
• Dissertation initially rejected by Harvard for
  not being analytical enough, but won acceptance
  when a few more equations were added!

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A little off topic...

• I came to work one day at MIT and the computer
  had been stolen, so I called DEC to break the
  news to them that this 30,000 computer that
  they'd lent me was gone. They thought this was
  the greatest thing that ever happened, because it
  turns out that I had in my possession the first
  computer small enough to be stolen!
• - Robert Metcalfe

Image Sourcehttp//electronicdesign.com/Articles/
Index.cfm?AD1ArticleID2855 Quote SourceThe
History of the Ethernet, Mary Bellis,
http//inventors.about.com/library/weekly/aa111598
.htm
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Proprietary Networks

• ARPANET was a standalone network. Other
  proprietary, standalone networks were created in
  the 70s
• ALOHANET Linking Hawaiian universities, using
  microwave as transmission medium
• Telenet by BBN, commercial
• Cyclades French packet switching network
• Number of networks was growing!

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Fathers of the Internet

• At DARPA, Vinton Cerf and Robert Kahn are working
  on an architecture to create a network of
  networks - internetting!

Vinton Cerf and Robert Kahn
Image Source http//www.adeptis.ru/vinci/kan_cerf
.jpg
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Internetting principles

• Decentralized control
• Stateless routers
• Autonomy - networks should be independent,
  require no modification to participate in the
  Internet
• Best Effort Service Model - Packets would be
  routed through the fastest available route

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NCP, TCP and UDP

• First host-to-host protocol on ARPANET Network
  Control Program (NCP)
• Early versions had in sequence delivery combined
  with forwarding
• It was soon apparent that unreliable, non-flow
  controlled service was important, e.g. packetized
  voice
• This led to separation of TCP and IP and creation
  of the UDP protocol.

TCP over IP
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1980s

• Time of growth
• Linking universities together
• BITNET email and ftp (Northeast)
• CSNET linking universities without access to
  ARPANET
• NSFNET provide access to NSF supercomputing
  resources
• 1983 TCP/IP replaces NCP as universal host
  protocol on Jan 1.
• By the end of the 80s, there were 100,000 hosts

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1990s...

• MILNET and Defense Data Network began to carry
  most DoD traffic
• NSFNET began to serve as backbone, linking
  regional networks in US and networks abroad
• ARPANET was decomissioned
• NSFNET was decomissioned in 1995, most Internet
  backbone traffic carried by commercial ISPs
• Increased commercialization, advent of WWW, all
  lead to explosion of growth

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The Memex

• 1945 Vannevar Bush's essay, As We May Think,
  envisaged the memex, a device that was linked to
  books and films in the library
• Able to follow cross-references from one resource
  to another - hypertext!

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The World Wide Web

• Tim Berners-Lee marries hypertext to the
  Internet, and invents the WWW (1991)
• HTTP protocol, web browser, web server, web page

The historic NeXT computer used by Tim
Berners-Lee in 1990, on display in the Microcosm
exhibition at CERN. It was the first web server,
hypermedia browser and web editor.
Image Sourcehttp//www.w3.org/History/1994/WWW/Jo
urnals/CACM/screensnap2_24c.gif Image
Sourcehttp//info.cern.ch/
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TBL at WWW2007 in Banff
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Internet History
1961-1972 Early packet-switching principles

• 1961 Leonard Kleinrock - queueing theory shows
  effectiveness of packet-switching
• 1964 Paul Baran - packet-switching in military
  nets
• 1967 ARPAnet conceived by Advanced Research
  Projects Agency
• 1969 first ARPAnet node operational at UCLA,
  then called IMP (Interface Message Processor),
  soon joined by 3 more at UCSB, SRI and U of Utah

• 1969 first remote login from UCLA to SRI
• 1972
• ARPAnet demonstrated publicly
• NCP (Network Control Protocol) first host-to-host
  protocol
• first e-mail program
• ARPAnet has 15 nodes

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Internet History
1972-1980 Internetworking, new and proprietary
nets

• 1970 ALOHAnet satellite network in Hawaii, and
  others
• 1973 Metcalfes PhD thesis proposes Ethernet
• 1974 Vinton Cerf and Robert Kahn - architecture
  for interconnecting networks
• late70s proprietary architectures DECnet, SNA,
  XNA
• late 70s switching fixed length packets (ATM
  precursor)
• 1979 ARPAnet has 200 nodes
• Principles of TCP, UDP, IP

• Cerf and Kahns internetworking principles
• stateless routers
• decentralized control
• minimalism, autonomy - no internal changes
  required to interconnect networks
• best effort service model
• define todays Internet architecture

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Internet History
1980-1990 TCP/IP, DNS, more internetworks,
Minitel

• Several efforts to link universities into
  computer networks
• BITNET email and ftp
• CSNET links universities without ARPAnet access
• NSFNET becomes a primary backbone between
  regional networks
• ARPAnet
• 1983 TCP/IP deployed
• Later TCP extensions and DNS developed

• Minitel French project for data networks in
  homes
• Free terminal with modem
• Free and private sites
• 20,000 services at peak
• 20 of population
• 1B per year revenue
• End of 80s 100,000 Internet hosts

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Internet History
1990, 2000s commercialization, the Web, new apps

• Early 1990s ARPAnet decommissioned
• 1991 NSF lifts restrictions on commercial use of
  NSFnet (decommissioned, 1995)
• Commercial ISPs take over backbone traffic
• early 1990s Web emerges
• hypertext Bush 1945, Nelson 1960s
• 1991 Tim Berners-Lee HTTP, HTML,Web server and
  browser
• 1994 Mosaic, later Netscape

• Late 1990s 2000s
• commercialization of the Web
• killer apps email, webmail, web browsing,
  e-commerce
• more killer apps instant messaging, P2P file
  sharing
• network security to forefront
• est. 50 million host, 100 million users
• backbone links running at Gbps

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Internet Growth

• The Internet may not be full, but it has grown at
  a phenomenal rate!

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Internet Growth Hosts
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Internet Growth Domains
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Internet GrowthWWW sites
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Internet Growth Users
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The end

• Questions?

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References

• Internet History, Gregory Gromov,
  http//www.netvalley.com/cgi-bin/intval/net_histor
  y.pl?chapter1
• A Brief History of the Internet, Walt Howe,
  http//www.walthowe.com/navnet/history.html
• History of the Internet, Internet for Historians,
  Richard T. Griffiths, http//www.let.leidenuniv.nl
  /history/ivh/frame_theorie.html
• Hobbes' Internet Timeline, Robert Hobbes Zakon,
  http//www.zakon.org/robert/internet/timeline/
• CPSC 641 Lecture Slides - Introduction,
  Networking Terminology and Intenet Evolution,
  Carey Williamson, http//pages.cpsc.ucalgary.ca/c
  arey/CPSC641/
• CPSC 441 tutorial slides, Emir Halepovic