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Internet Technologies
CSC457
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Internet
• Internet is a communication technology.
• Like telephone it enables people to
communicate.
• Telephones enabled voice communication.
Internet enables data communication.
• Because it spans many countries Internet is
called the global network.
• Other networks were: BITNET, FIDONET,
JANET, EARN.
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Information Infrastructure
• Internet provides a new infrastructure for
communications like postal system, telegraph,
and telephone did earlier.
• New infrastructure makes new industries and
application possible, some of which cannot be
foreseen.
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Evolution of the Internet
• There are many different LAN technologies:
Ethernet, Token Ring, ATM, etc.
• Each has different ways to connect computers,
format data packets, data transmission rates,
etc and thus incompatible.
• Desirability of a single network to enable
resource sharing.
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Evolution of the Internet
• US DoD starts funding research on how to
interconnect the networks.
• 1969 ARPANET was developed this was the first
Internet.
• E-mail was adapted for ARPANET in 1972.
• 1972 First public demonstration of ARPANET.
• The telnet protocol, enabling logging on to a
remote computer started in 1972.
• The ftp protocol, enabling file transfers between
Internet sites, started in 1973.
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Evolution of the Internet
• The first networking protocol used on the
ARPANET was the Network Control Program.
• In 1983, it was replaced with the TCP/IP
protocol.
• In 1993 first graphical browser Mosaic was
developed.
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GROWTH OF THE INTERNET
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The Underlying Technologies
What is inside the Internet? Or What are the key
underlying technologies that make it work so
successfully?
– Packet Switching
– Routers/Packet Switches
– TCP/IP
– Clients + Servers = Distributed Computing
– Computer Names.
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Applications
• Some applications of the Internet:
– World Wide Web (WWW)
– Electronic Mail (Email)
– Bulletin Boards (Newsgroups)
– Audio & Video Services
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Internet Topology
Backbone Network
Network Access Provider
(NAP)
Internet Service Provider
(ISP)
Users
Users
Users
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Internet Topology (Detailed)
Backbone Network
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NAP1
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ISP
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The Way It Works
• A typical user dials into an ISP using
telephone to send a message.
• The ISP routes the call to the internet
through NAP.
• It may cross the backbone network to reach
the final destination.
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A Typical ISP
Subscribern
modemn
Subscriber3
modem3
Subscriber2
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Subscriber1
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Remote
Access
Server
(RAS)
Internet
ISP Setup
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