Transcript T1-lecture

CSC 330 E-Commerce
Teacher
Ahmed Mumtaz Mustehsan
GM-IT CIIT Islamabad
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Virtual Campus, CIIT
COMSATS Institute of Information Technology
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T1-Lecture-3
The Internet and The Web
Chapter-2
Part-I
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Objectives
Define the origin and evolution of the Internet.
 Identify the key technology concepts behind the
internet
 Describe the role of Internet protocols and utility
programs
 Explain the current structure of Internet.
 Understand the limitations of todays internet
 Describe the potential capabilities of Internet II
 Understand how the world wide web works
 Describe how internet and web features and services
support e-commerce.

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The Internet: Technology Background
Internet

Interconnected network of thousands of networks and
millions of computers

Links businesses, educational institutions, government
agencies, and individuals
World Wide Web (Web)
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One of the Internet’s most popular services
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Provides access to around billions, possibly trillions, of
Web pages
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The Evolution of the Internet 1961 - Present

Innovation Phase, 1964 -1974

Institutionalization Phase, 1975 -1994

Commercialization Phase,1995 - present
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The Evolution of the Internet 1964 - 1974
Innovation Phase: (1964 -1974)

The basic building blocks were introduced such as;
packet-switching hardware, client/server computing, and
a communications protocol called TCP/IP

The original purpose of the Internet, was to link large
mainframe computers on different university/college
campuses.

This kind of one-to-one communication between
campuses was previously possible only through the
telephone system or postal mail.
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The Evolution of the Internet 1975 -1994
Institutionalization Phase: (1975 -1994)
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Large institutions such as the US Department of
Defense (DoD) and the National Science Foundation
(NSF) provided funding to legitimate for the fledging
invention called the Internet.

DoD contributed $1 million to further develop the
network into a robust military communications system so
that it could withstand during nuclear war.

In 1986, the NSF assumed responsibility for the
development of a civilian Internet (NSFNET) and began
a ten-year-long $200 million expansion program.
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The Evolution of the Internet (1995- Present)
Commercialization Phase: (1995 – present)

Government agencies encouraged private
corporations to take over and expand both the
Internet backbone and local services to ordinary
citizens who were not students.

By 2000, the Internet’s use had expanded well
beyond military installations and research
universities and came into the public domain.
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An instance of internet - active nodes
Source: http://www.glossar.de/glossar/1frame.htm?
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The Internet: Key Technology Concepts
Network as Defined by NSF:
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Uses IP addressing
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Supports TCP/IP
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Provides services to users, in manner similar to telephone
system
Three important concepts:
1. Packet switching
2. TCP/IP communications protocol
3. Client/server computing
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Packet Switching
Packet Switching:
 Slices digital messages into packets
 Sends packets along different communication paths
as they become available
 Reassembles packets once they arrive at destination
Uses routers
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Special purpose computers that interconnect the
computer networks make up the Internet and route
packets.
Routing algorithms ensure packets take the best
available path toward their destination.
Less expensive, wasteful than circuit-switching.
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Packet Switching
Packet Switching Demo
http://www.pbs.org/opb/nerds2.0.1/geek_glossary/packet_switching_flash.html
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Key Concept Related to TCP/IP
Protocol
 A set of rules and standards for data transfer
 Transmission Control Protocol/Internet Protocol
(TCP/IP) the core communications protocol for the
Internet
TCP
 Protocol that establishes the connections among
sending and receiving Web computers and handles
the assembly of packets at the point of transmission,
and their reassembly at the receiving end
IP
 protocol that provides the Internet’s addressing
scheme and is responsible for the actual delivery of
the packets
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TCP/IP
Internet Protocol (IP):
 Provides the Internet’s addressing scheme.
Transmission Control Protocol (TCP):
 Establishes connections between sending and receiving Web
computers
 Handles assembly of packets at point of transmission, and
reassembly at receiving end
Four TCP/IP Layers (hourglass model)
1. Network Interface Layer
2. Internet Layer
3. Transport Layer
4. Application Layer
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The TCP/IP Architecture and Protocol Suite
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Key Concept Related to TCP/IP
Network Interface Layer:
 Responsible for placing packets on, and receiving
them from, the network medium.
Internet Layer
 Responsible for addressing, packaging, and routing
messages on the Internet
Transport Layer
 Responsible for providing communication with the
application by acknowledging and sequencing the
packets to and from the application
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Key Concept Related to TCP/IP
Application Layer
 Provides a wide variety of applications (HTTP, FTP,
SMTP ) with the ability to access the services of the
lower layers of TCP/IP.
 Internet address
 Internet address expressed a unique number that
appears as a series numbers separated with periods,
such as 64.49.254.91 carrying the address of an
individual machine on the internet.
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Internet (IP) Addresses
How 500 million people will be addressed?
The answer is IP addressing version 4 (IPv4) used
previously and IP addressing version 6 (IPv6) a new
version introduced lately to accommodate more clients.
IPv4
 32-bit number
 IPv4 can handle 4 billion.
 Expressed as series of four sets of separate numbers
marked off by periods e.g. 201.61.186.227 or
130.111.67.244
Class B address: (130.111.67.244) Network identified
by first two sets, computer identified by last set
Class C address: (201.61.186.227)
Network identified by first three sets, computer
identified by last set
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Internet (IP) Addresses
IPv6
A newer version of the IP protocol, called IPv6, has
been developed. IPv6 provides for 128-bit addresses,
or about 1 quadrillion
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(10 to the power15)
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Checking your IP
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From start menu click Run
Type cmd in dialogue box
Type ipconfig
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Routing Internet Messages:
TCP/IP and Packet Switching
The Internet uses packet-switched networks and the TCP/IP
communications protocol to send, route, and assemble messages.
Messages are broken into packets, and packets from the same
message can travel along different routes.
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Domain Names, DNS, and URLs
Domain Name
 IP address expressed in natural language
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comsats.edu.pk  203.124.43.105
Domain Name System (DNS)
 Allows numeric IP addresses to be expressed in natural
language
Uniform Resource Locator (URL)
 Address used by Web browser to identify location of
content on the Web
e.g., http://www.azimuth-interactive.com/flash_test/potocol/server/file
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How to Pick a Domain Name
Pointer for picking domain names
 If you sell bricks, pick a domain name containing a
word like brick
 Consider name length and ease of remembering the
name
 Hyphens to force search engines to see keywords in
your domain name
 Make sure the domain name is easy for Web users to
remember and find
 The domain name should suggest the nature of your
product or service
 The domain name should serve as a trademark
 The domain name should be free of legal conflicts
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Some memorable Internet names
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Good names
◦
◦
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Amazon.com
Ebay.com
Yahoo.com
Google.com
Alibaba.com
Hotmail.com
qwerty.com
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Bad names
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Yadayada.com
Doggles.com
ePet.com
Teacherstalk.com
“anything”online.com
llanfairpwllgwyngyllgog
erychwyrndrobwyllllantysiliogogogoch.co
m
◦ Close to an existing
name
 Gooogle.com
 Goggle.com
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How to Register a Domain Name
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if you are interested a domain In Pakistan (.pk )
You may use :
https://nexus.pk/pknic.php
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If you want to register an international domain .com
you may try :
http://www.register.com/
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How to Register a Domain Name in Pakistan?
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How to Register a Domain Name in Pakistan?
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How to Register an international Domain Name ?
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How to Register an international Domain Name ?
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The Internet Today
Internet growth has boomed without disruption because
it is based on some powerful applications using the
following architecture:
1. Client/server computing model
2. Pear to Pear P2P Model
3. Cloud Computing
4. Hourglass, layered architecture
◦ Network Technology Substrate
◦ Transport Services and Representation Standards
◦ Middleware Services
◦ Applications
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Client/Server Computing
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Powerful personal computers (clients) connected in
network with one or more servers
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Servers perform common functions for the clients,
such as Storing files, software applications, etc.
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Client Server
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The New Client: The Emerging Mobile
Platform
Within a few years, primary Internet access will be
through:
 Netbooks
◦ Designed to connect to wireless Internet
◦ Under 2 lbs, solid state memory, 8” displays
◦ $200–400
 Smartphones
◦ Disruptive technology: Processors, operating systems
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Cloud Computing
Obtain Software and hardware as Service
 Firms and individuals obtain computing power
(hardware) and software over Internet
◦ E.g., Google Apps
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Fastest growing form of computing
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Radically reduces costs of:
◦ Building and operating Web sites
◦ Infrastructure, IT support
◦ Hardware, software
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Cloud Computing
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Cloud Computing Model
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Other Internet Protocols and Utility
Programs
Internet protocols
 HTTP
 E-mail: SMTP, POP3, IMAP,
 FTP, Telnet, SSL
Utility programs
 Ping
 Tracert
 Pathping
 NSlookup
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Other Internet Protocols and Utility Programs
HyperText Transfer Protocol (HTTP)
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is the Internet protocol used to transfer Web pages
HTTP was developed by the World Wide Web Consortium (W3C).
HTTP runs
in the Application Layer of the TCP/IP model
An HTTP session begins by the client’s browser requesting a
resource, such as a Web page, from a remote Internet server.
When the server responds by sending the page requested, the
HTTP
session for that object ends.
Web pages may have many objects such as graphics, sound or
video files, frames, so each object must be requested by a
separate HTTP message.
The most common HTTP request message is Get, used to request
a resource
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Other Internet Protocols and Utility Programs
Simple Mail Transfer Protocol (SMTP)
 Is an Internet protocol used to send e-mail to a
server.
 SMTP is a relatively simple, text-based
protocol that was developed in the early
1980s.
 SMTP handles only the sending of e-mail.
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Other Internet Protocols and Utility Programs
To retrieve e-mail from a server, The client computer
uses
Post Office Protocol 3 (POP3)
 A protocol used by the client to retrieve mail from an
Internet server and then delete the
 messages on the server, or retain them on the
server.
Internet Message Access Protocol (IMAP).
 IMAP is a more current e-mail protocol supported by
all browsers and most servers and ISPs.
 IMAP allows users to search, organize, and filter
their mail prior to downloading it from the server.
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Other Internet Protocols and Utility Programs
File Transfer Protocol (FTP)
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One of the original Internet services. Part of the TCP/IP
protocol that permits users to transfer files from the server to
their client computer, and vice versa.
The files can be documents, programs, or large database files.
FTP is the fastest and most convenient way to transfer files
larger than 1 megabyte, which some e-mail servers will not
accept
Telnet
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A terminal emulation program that runs in TCP/IP.
The term Telnet also refers to the Telnet program, which
provides the client part of the protocol and enables the client to
emulate a mainframe computer terminal.
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Other Internet Protocols and Utility Programs
Secure Sockets Layer (SSL) is a protocol that
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operates between the Transport and Application Layers of
TCP/IP and secures communications between the client and
the server.
SSL helps secure e-commerce communications and payments
through a variety of techniques such as message encryption
and digital signatures
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P2P Class Discussion

How does P2P networking differ from client/server
networking?
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Why is P2P networking a potential money-saver for
corporations and other organizations?
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What are some illegal uses of P2P networking?
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What are some legal uses of P2P networking?
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What other alternatives are there for streaming large
video files?
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End
The Internet and The Web
Chapter-2;
Part-I
T1-Lecture-3
For Lecture Material/Slides Thanks to:
Copyright © 2010 Pearson Education, Inc