Transcript What is the Internet?

What is the Internet?
So What is the Internet?
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The Internet, in simplest terms, is the
large group of millions of computers
around the world that are all connected
to one another. These computers are
connected by phone lines, fiber optic
lines, coaxial cable, satellites, and
wireless connections.When you log on
to the Internet you are given access to
many of the other computers that are
connected around the world.
Where did the Internet come from
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The Internet was “born” in the late
1960s when the Advanced Research
Projects Agency (ARPA) of the US
Department of Defense linked
together mainframe computers to
form a communications network.
Where did the Internet
come from…
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The Agency’s main objectives were
to create a communications system
that could survive a nuclear attack or
natural disaster.
This communications network would
also provide links to its users in
remote locations.
Why was the USA so worried?
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By strapping four
military rockets
together, in October
1957 the USSR
launched Sputnik I (a
70 kgs bleeping
sphere the size of a
medicine ball) into
Earth orbit.
This was the very first
satellite ever launched
into our space!
Why was the USA so worried?
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One of the immediate reactions
was the creation of the
Advanced Research Projects
Agency within the Dept. of
Defence (ARPA).
Its mission was to apply stateof-the-art technology to US
defence and to avoid being
surprised (again!) by
technological advances of the
enemy.
Why was the USA so worried?
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In 1962 ARPA opened a computer
research program and appointed to its
head an MIT scientist with the following
concept... a vision where computers would
be networked together and would be
accessible to everyone
In a 1965 experiment, computers in
Berkeley and MIT were linked over a low
speed dial-up telephone-line to become
the first "wide area network" (WAN) ever
created.
The inadequacy of the telephone network
for running programs and transferring
data was revealed in this experiment.
Use of ARPANet
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Users of ARPANet used the network
to share information, and discovered
other uses – the most popular was
email!
And today email is by far the most
used internet application/service!
It is second only to the telephone as
per the number of users worldwide.
The number of emails sent per day?
Progression of ARPANet
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Because of the growth, in 1983,
ARPANet split into two parts:
• 1.
• 2.
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ARPANet and
MILNet
ARPANet was primarily used for
research and development and
MILNet was used for military
purposes.
NSFNet
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With more and more users on
ARPANet, in the late 1980s, a new
high-speed network was developed
• NSFNet (National Science Foundation)
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Also during the 1980s a number of
companies began providing Internet
Service, known as Internet Service
Providers (ISPs)
Some Interesting Facts
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1.3 billion – number of email users
worldwide
210 billion – number of emails sent per
day (wow… that’s 2.4 million per second)
70% – percentage of emails that are spam
53.8 trillion –number of spam emails sent
in 2008 (assuming 70% are spam)
Internet in the home…
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This move to ISPs began the move
towards a commercial use.
During the early 1990s, internet service
was moving into the homes of many
Canadians via dialup service over
telephone lines.
In the late 1990s, internet service was
being provided over many mediums.
Canada has over 22 million internet users
today, with a population of 32 million –
probably the most wired nation per capita!
Tools
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http://www.yougetsignal.com/tools/v
isual-tracert/
http://network-tools.com/
http://www.whois.net
http://www.speedtest.net/
Homework
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Define the following (in your notes):
•Router
•Switch
•Uplink
•WAN
•LAN
•Protocol
•HTTP
•SMTP
•FTP
•UDP
•TCP/IP