Internet:
Yesterday, Today and Tomorrow
September 2005
Prof. James Won-Ki Hong
Dept. of Computer Science & Engineering
POSTECH
jwkhong@postech.ac.kr
http://dpnm.postech.ac.kr/~jwkhong
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Outline
Overview of Internet
Internet Services
The Future of Internet
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Overview of Internet
What is Internet?
History
Internet Statistics
TCP/IP
Internet address
Client-Server architecture
Peer-to-Peer architecture
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What is Internet ?
Internet is not a single network but a
network of networks connecting millions of
computers around the world
No single organization owns it but
administered cooperatively by various
organizations around the world
It uses the standard TCP/IP protocol for
exchanging information
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Internet History (1)
Internet was started in 1969 by connecting four
geographically separated computers in US, called
APRANET for military purpose
In 1971, 23 computers were added to the
ARPANET
In 1973, UK and Norway were connected
In 1982, TCP/IP was selected as the standard
protocol for the network and the name Internet was
used since
Read the classical article, “A Brief History of the
Internet” by Leiner, Cerf, Clark, Kahn, Kleinrock,
Lynch, Postel, Roberts, Wolff
(http://www.isoc.org/internet/history/brief.shtml)
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Internet History (2)
Internet Users
1995 – 40 Million, 1998 – 160 Million, 2000 – 407
Million, 2002 – 605 Million, ….
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Internet Map in Korea (1995.5)
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Internet Map in Korea (1999.3)
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Internet Map in Korea (2000.8)
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Growth of Internet Users in Korea
Unit: Million
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TCP/IP
When two people from different countries try to
communicate, what language should they use?
What happens if they try to use their own
languages?
For computers, they must also use a common
protocol in order to communicate as well
TCP/IP (Transmission Control Protocol/Internet
Protocol) is the common/standard communication
protocol for Internet hosts and devices
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Internet address
We must be able to identify computers when we
try to connect or send messages. Internet (or IP)
addresses are used for this purpose
4 integer numbers (using 32 bits) separated by .
(dot) are used for each IP address. For example,
141.223.1.2 is a computer at POSTECH
Each computer must have unique IP address
(what happens if two or more computers have the
same IP address?)
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Host Names
However, remembering 4 digit numbers for each computer
is very difficult. Thus, we (humans) use host names instead
For example, we use www.postech.ac.kr for 141.223.5.10
In www.postech.ac.kr, ac means academy, kr means Korea
Frequently used name notations are
co (company), re (research), or (organization)
go (government)
uk (United Kingdom), ca (canada), fr (france),
cn (China), jp (Japan)
com (company), edu (education), net (network
company)
What organization in which country is for
www.bluehouse.go.kr?
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Internet Service Architectures
(Client-Server)
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Internet Service Architectures
(Peer-to-Peer)
Peer
Peer Peer
A peer can act both as a
server and client
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Internet Services
Traditional Internet Services
Web, FTP, Email, Telnet, etc.
Emerging Internet Services
Online games, shopping, banking, stock trading,
network storage
VOD, EOD, VoIP, IPTV
P2P applications – instant messaging, file sharing
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Online game VoIP VOD
Your Internet Usage
What do you currently use Internet for?
What do you think you can use Internet for in
the future?
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Future of Internet
BcN (Broadband Convergence Network)
Data + Voice + Video + TV broadcasting
IPv6
4G (4th Generation Mobile Network)
All IP network and services
Network Security
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The Future of Internet
is up to you!
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