Post on 31-Dec-2015
SC ICT CertificationLevel 1
SC ICT CertificationLevel 1
09 What Is The Internet?
By Ross Parker
The Internet• wikipedia.org: “The Internet is a global
system of interconnected computer networks that interchange data by packet switching using the standardized Internet Protocol Suite (TCP/IP). It is a ‘network of networks’...”
The Internet is not IM, The Internet is not P2P, The Internet is not Chat, The Internet is not Email,
The Internet is not The Web:
The Internet is simply a communications channel!
The Internet facilitates these applications
Visualise It!
Partial map of the Internet based on the January 15, 2005 data found on opte.org. Each line is drawn between two nodes, representing two IP addresses. The length of the lines are indicative of the delay between those two nodes. Lines are colour-coded as follows: * Dark blue: net, ca, us * Green: com, org * Red: mil, gov, edu * Yellow: jp, cn, tw, au, de * Magenta: uk, it, pl, fr * Gold: br, kr, nl * White: unknown Source: Matt Britt, Wikimedia Commons
Simplify It!
PC PC
PrinterPC
Switch &
Firewall
The InternetWhy a cloud?
LAN
Switch &
Firewall
LAN
Server
1945Vannevar Bush
publishes paper on Memex machine
1957USSR launches
Sputnik
1958USA forms
ARPA
1960J.C.R. Licklider publishes "Man-
Computer Symbiosis"
1961Leonard Kleinrock
publishes “Information Flow in Large
Communication Nets"
1966 Larry Roberts publishes "Towards a Cooperative Network of Time-Shared
Computers"
1969ARPAnet
commissioned by USA DoD: 4 nodes
1971ARPAnet: 15
nodes w/ 23 hosts
1973ARPAnet extends to
England and Norway
1973 Vint Cerf and Bob
Kahn propose “internetwork”
1976Queen Elizabeth II sends an email
1979 USENET
established
1982 TCP/IP
established
1983IP-capable UNIX
workstations available
1984DNS Introduced1,000+ hosts
1986Internet
Engineering Task Force (IETF) born
1988 Internet Relay Chat (IRC) developed by
Jarkko Oikarinen
1989100,000+
hosts
1991World-Wide Web
(WWW) released by CERN; Tim Berners-Lee
19921,000,000+
hosts
1993 Mosaic breaks! WWW grows at
341,634% per annum
1995 Commercial
access via dial-up
1997 Browser wars
199940,000,000+
hosts
2005350,000,000+
hosts
History of the Internet
Theory
Development
Growth
Explosion!
Important Strands• Move from single machines to networked
machines– WAN first, then LAN
• Move from isolated networks to internetworks• Move from academic to commercial use• Move from organisational to personal use• Growth in range and richness of applications
Astounding GrowthCan you imagine a bridge that can handle this growth in traffic? This is robust engineering. And it was a largely open process…
Licensing• All original work used here is licensed under the Creative Commons Attribution-Share
Alike 3.0 Unported license. For more details please look at http://creativecommons.org/licenses/by-sa/3.0/.
• This license has been chosen to permit a high degree of sharing, whilst protecting the author’s control as to how the content is used.
• Please respect this license and use accordingly!• Recycled and borrowed works from other sources are used under appropriate
licenses, which are not affected by this license. The original source is always given. • All original work created by Ross Parker (Sha Tin College, English Schools
Foundation, Hong Kong), except where specified.