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Electronic commerce fundamentals ch2

Chapter 2

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The Internet and the Web:
Infrastructure for
Electronic Commerce

Electronic Commerce

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Objectives
General structure of the network of
networks supporting the Internet and ecommerce
◆ Protocols that move commerce across
the Internet and send/receive e-mail
◆ Internet utility programs to trace, locate,
and verify the status of Internet host
sites



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Objectives
Popular Internet applications, including
e-mail, Telnet, and FTP
◆ History and use of Web markup
languages, including SGML, HTML,
and XML
◆ HTML tags and links
◆ Web client and server architectures and
the messages they send to each other


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Objectives
Differences and similarities between
internets, intranets, and extranets
◆ Options for connecting to the Internet,
their cost and bandwidth tradeoffs


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Technology Overview
Internet is the most obvious technology
needed to conduct e-commerce
◆ Other technologies are also required



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● Database

software
● Network switches and hubs
● Encryption hardware and software
● Multimedia support


Potential for business volume to double
in less than a year
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Packet-Switched Networks
Local and long distance telephone
companies were early models in the
1950s
◆ Single paths were created to connect
two parties together, called circuit
switching


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Packet-Switched Networks


The Internet uses Packet switching
● Files

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and messages are broken down into
packets, which are electronically labeled
with their origin and destination
● The destination computer collects the
packets and reassembles the data from
the pieces in each packet
● Each computer the packet encounters
decides the best route towards its
destination
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Packet-Switched Network
and Message Packets
Figure 2-1

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Open Architecture
Independent networks should not
require any internal changes in order to
be connected to the network
◆ Packets that do not arrive at their
destination must be retransmitted
◆ Router computers do not retain
information about the packets
◆ No global control exists over the
network


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The TCP/IP Internet Protocol


Set of protocols developed by Vincent
Cerf and Robert Kahn
● Transmission

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Controls the assembly of a message into
smaller packets before transmission, and
reassembles them once received

● Internet




Control Protocol (TCP)

Protocol (IP)

Rules for routing packets from their source to
their destination

Replaced NCP as used by ARPANET
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TCP/IP Architecture
Figure 2-2

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IP Address and Domain Names


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Appears as a series of up to four
separate numbers delineated by a
period, often referred to as a “Dotted
Quad”
● Each

of the numbers range from 0 to 255
● First four numbers identify the network
● Following numbers identify a node
● Sample IP address: 126.204.89.56
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IP Address and Domain Names


Uniform Resource Locator (URL)
● Easier

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to remember than IP address
● Consists of names and abbreviations
● Contains at least two parts
First part contains the protocol used
◆ Second part contains the location of the
resource


● http://www.adobe.com

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Top-Level Domain Names
Figure 2-3

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Other Internet Protocols


Hypertext Transfer Protocol (HTTP)
● Responsible

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for transferring and displaying

Web pages


Simple Mail Transfer Protocol (SMTP)
● Specifies

the exact format of a mail

message


Post Office Protocol (POP)
● Responsible

for retrieving e-mail from a

mail server
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Other Internet Protocols


Interactive Mail Access Protocol (IMAP)
● Latest

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protocol, may replace POP
● Defines how a client program asks a mail
server to present available mail
Download only selected messages, instead of
all messages
◆ View headers only
◆ Create and manipulate mailboxes on the
server


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Other Internet Protocols


File Transfer Protocol (FTP)
● Transfers

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files between TCP/IP-connected
computers
● Uses client/server model
● Transfers both binary and ASCII text
● Displays and manipulates remote and
local computer file directories

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Internet Utility Programs


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Finger
● Runs

on UNIX computers and allows
users to obtain limited information about
other network users

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Finger Program Output
Figure 2-4

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Internet Utility Programs


Packet InterNet Groper (Ping)
● Tests

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the connectivity between two
Internet hosts
● Determines if the host is active


Sends a packet and waits for a reply

● Determines

number of hosts (hops)
between two specified hosts

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Tracert and Other Route-Tracing
Programs
TRACE RouTe (Tracert) traces the
round trip path between a user’s
computer and another computer on the
Internet
◆ Incorporates a Graphical User Interface
(GUI) for a visual representation of the
route


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Tracing a Path Between Two Computers
Figure 2-5

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Internet Applications:
Electronic Mail
Began in the 1970s for use on the
ARPANET
◆ Most popular form of business
communication
◆ Can send documents, pictures, movies,
worksheets, or other important pieces
of information


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Sending E-Mail Attachments
Figure 2-6

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Internet Applications: Telnet
Allows users to log on to a remote
computer that is attached to the
Internet
◆ Type commands to run on the remote
host computer by using terminal
emulation
◆ Client software is available, and users
can access Telnet through most Web
browsers


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