Multimedia Communication
Multimedia and the Internet
CP586 © Peter Lo 2003
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The Internet
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The key to Internet operation is Client Server model in
which computers, called clients, can simultaneously access
a server.
Internet Backbone: Provides connectivity and services
between servers.
It relies on high speed communication lines to rapidly
move information and commands between servers and
individual work stations.
DNS, TCP/IP, Internet functions, origin of the WWW and
web authoring.
HTML overview.
CP586 © Peter Lo 2003
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Some services found on the Internet
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e-mail
Web
File transfer
Chat
Message board
Instant messaging
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How did the Internet originate?
ARPANET
Goal:
To allow
scientists at
different
locations to share
information
Networking project
by Pentagon’s
Advanced Research
Projects Agency
(ARPA)
Goal:
Became
functional
September
1969
To function if
part of network
were disabled
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Who provides the Internet’s
structure today?
Networks from
corporations,
commercial
firms, and other
companies
Telephone
companies
Cable
companies
Government
Satellite
companies
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How has the Internet grown?
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Today
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1984
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More than 100 million host nodes
More than 1,000 host nodes
1969
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Four host nodes
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Who controls the Internet?
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Nobody; it is public, cooperative, and an independent
network
Several organizations set standards
World Wide Web Consortium
(W3C)
• Oversees research, sets
standards and guidelines
• Tim Berners-Lee, director
Internet2 (I2)
• Internet-related research
and development project
• Develops and tests
advanced Internet
technologies
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What are ways to access the
Internet?
1 Regional
ISP
2 National
ISP
3 OSP
(Ex. AOL)
4 Wireless
Internet
Service
Provider
1
2
local
call
long-distance local
call
CP586 call
© Peter Lo 2003
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local
call
toll-free
call
4
local
call
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How can you connect to the Internet?
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Very high-speed connection
Digital subscriber line (DSL) and cable modem
Dial-up access
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What are three parts of an
Internet connection?
Client
Backbone
CP586 © Peter Lo 2003
Server
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How might data travel the Internet using a
telephone line connection?
1: RHow
equest
data
from
the the Internet using a telephone line connection?
might
data
travel
a server on Internet.
2: Modem converts digital
signals to analog signals.
3: Data travels through
Regional
ISP
Step 3
Step 5
Step 1
telephone lines to a
local ISP.
4: Data passes
through routers.
Step 2
Step 4
National
ISP
5: Regional ISP uses
leased lines to send
data to a national ISP.
6: National ISP routes
data across the
country.
7: National ISP passes
data to local ISP.
8: Server sends
data back to you.
Local ISP
Step 6
Internet
backbone
Step 8
Step 7
National ISP
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Internet protocol (IP) address
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Number that uniquely identifies each computer or
device connected to Internet
IP address
199.95.72.10
first part
identifies
network
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last part
identifies
specific
computer
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Domain name
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Text version of IP address
IP address
Domain name
199.95.72.10
scsite.com
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What is a URL?
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Unique address for Web page located on Web server
protocol
domain name
path
http://www.nationalgeographic.com/travel/index.html
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The Internet
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The Internet is a vast network of interconnected
computers that can share and exchange
information.
Started in 1960’s & was called “ARPAnet”
The Internet is often called the Information Super
Highway and the World Wide Web.
Web pages are based on the HTML standard.
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Internet Basics
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HTTP: is a connection orientated protocol
designed for the rapid transport of files.
HTTP uses a simple protocol that supports
negotiation between the client and server.
This negotiation allows web browsers and servers
to be developed independently of emerging
technologies.
Eg. Get, put, checkout, delete, text search.
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Internet Naming Structure
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INS uses labels separated by periods.
It uses a hierarchical structure where organisations
are grouped into primary domain names.
com : Commerce, gov : Government, edu :
Educational, mil : Military, Net : Internet Network
Support Centres, org : Another Organisation, au :
Australia.
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Standardised Addressing
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TCP/IP : Transport Control Protocol / Internet
Protocol.
The Internet uses TCP/IP.
Each node on the Internet has an associated IP
address X.W.Y.Z and a physical address of the
form XX:XX:XX:XX. (MAC)
X,W,Y,Z are integer values ranging 0-255.
IP is to postcode as MAC is to address.
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Reference
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Discovering Computers World 2003 (Ch. 2)
Multimedia, Technology and Applications (Ch.10)
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