1. Advanced Diploma of Information Technology
MIT Nguyễn Hữu Phát
Kent International College
80 hours

3. In this chapter, you will learn about:
 The origin, growth, and current structure
of the Internet
 How packet-switched networks are
combined to form the Internet
 How Internet protocols and Internet
addressing work
 The history and use of markup languages
on the Web, including SGML, HTML, and
XML
E-Commerce: The Second Wave, Fifth Annual Edition 3

4.  How HTML tags and links work on the
World Wide Web
 The differences among internets,
intranets, and extranets
 Options for connecting to the Internet,
including cost and bandwidth factors
 About Internet2 and the Semantic Web
E-Commerce: The Second Wave, Fifth Annual Edition 4

5.  Computer network
› Any technology that allows people to
connect computers to each other
 The Internet
› A large system of interconnected computer
networks spanning the globe
 World Wide Web
› A subset of computers on the Internet
E-Commerce: The Second Wave, Fifth Annual Edition 5

6.  Early 1960s
› U.S. Department of Defense funded research
to explore creating a worldwide network
 In1969, Defense Department researchers
› Connected four computers into network
called ARPANET
 Throughout 1970s and 1980s
› Academic researchers connected to
ARPANET and contributed to its technological
developments
E-Commerce: The Second Wave, Fifth Annual Edition 6

7.  1972
› E-mail was born
 Mailing list
› E-mail address that forwards any message
received to any user who has subscribed
to the list
 Usenet
› Started by group of students and
programmers at Duke University and the
University of North Carolina
E-Commerce: The Second Wave, Fifth Annual Edition 7

8.  In 1991, NSF
› Eased restrictions on commercial Internet
activity
› Began implementing plans to privatize the
Internet
 Network access points (NAPs)
› Basis of new structure Internet
 Network access providers
› Sell Internet access rights directly to larger
customers and indirectly to smaller firms
and individuals through ISPs
E-Commerce: The Second Wave, Fifth Annual Edition 8

9. http://www.internetworldstats.com

10. E-Commerce: The Second Wave, Fifth Annual Edition 10

11. The $23.4 billion in annual internet advertising spending exceeded advertising on cable
TV for the first time (which was $21.4 billion), and took the No. 3 spot behind national
and local TV ads ($29.8 billion) and newspaper ads ($34.4 billion).

12. Internet advertising is almost twice as large as broadcast TV advertising was in its 14th
year ($13.3 billion) and nearly four times as large as cable TV ($6.5 billion).

13.  The Web
› Software that runs on
computers connected to
the Internet
 Vannevar Bush
› Speculated that engineers
would eventually build a
memory extension device
(the Memex)
 In the 1960s
› Ted Nelson described a
similar system called
hypertext

14.  Tim Berners-Lee
› Developed code for
hypertext server program
 Hypertext server
› Stores files written in
hypertext markup language
› Lets other computers
connect to it and read files
 Hypertext Markup Language
(HTML)
› Includes set of codes (or
tags) attached to text

15.  Local area network (LAN)
› Network of computers
located close together
 Wide area networks (WANs)
› Networks of computers
connected over greater
distances
 Circuit
› Combination of telephone
lines and closed switches that
connect them to each other

16.  Circuit switching
› Centrally controlled, single-connection model
 Packets
› Files and e-mail messages on a packet-switched network that are
broken down into small pieces
› Travel from computer to computer along the interconnected
networks until they reach their destinations

17.  Routing computers
› Computers that decide how
best to forward packets
 Routing algorithms
› Rules contained in programs
on router computers that
determine the best path on
which to send packet
› Programs apply their routing
algorithms to information
they have stored in routing
tables

18. E-Commerce: The Second Wave, Fifth Annual Edition 18

19.  Protocol
› Collection of rules for
formatting, ordering, and error-
checking data sent across a
network
 Rules contributing to success of
Internet
› Independent networks should
not require any internal
changes to be connected to
the network
› Packets that do not arrive at
their destinations must be
retransmitted from their source
network
› Router computers act as
receive-and-forward devices
› No global control exists over the
network

20.  TCP
› Controls disassembly of a message or a file
into packets before transmission over
Internet
› Controls reassembly of packets into their
original formats when they reach their
destinations
 IP
› Specifies addressing details for each packet
E-Commerce: The Second Wave, Fifth Annual Edition 20

21.  Internet Protocol version 4/6 (IPv4/6)
› Uses a 32-bit number to identify
computers connected to the Internet
 Base 2 (binary) number system
› Used by computers to perform internal
calculations
 Subnetting
› Use of reserved private IP addresses within
LANs and WANs to provide additional
address space
E-Commerce: The Second Wave, Fifth Annual Edition 21

22.  Private IP addresses
› Series of IP numbers not
permitted on packets that
travel on the Internet
 Network Address Translation (NAT)
device
› Used in subnetting to convert
private IP addresses into
normal IP addresses
 Internet Protocol version 6 (IPv6)
› Protocol that will replace IPv4
› Uses a 128-bit number for
addresses

23.  Sets of words assigned to
specific IP addresses
 Top-level domain (or TLD)
› Rightmost part of a domain
name
 Internet Corporation for
Assigned Names and Numbers
(ICANN)
› Responsible for managing
domain names and
coordinating them with IP
address registrars

24. E-Commerce: The Second Wave, Fifth Annual Edition 24

25.  Web client computers
› Run software called Web
client software or Web
browser software
 Web server computer
› Runs software called Web
server software
 Client/server architecture
› Combination of client
computers running Web
client software and server
computers running Web
server software

26.  Hypertext Transfer Protocol
(HTTP)
› Set of rules for delivering
Web page files over the
Internet
 Uniform Resource Locator (URL)
› Combination of the protocol
name and domain name
› Allows user to locate a
resource (the Web page) on
another computer (the Web
server)

27.  Electronic mail (e-mail)
› Must also be formatted
according to common set
of rules
 E-mail server
› Computer devoted to
handling e-mail
 E-mail client software
› Used to read and send e-
mail
› Example: Microsoft
Outlook, Netscape
Messenger

28.  Simple Mail Transfer Protocol (SMTP)
› Specifies format of a mail
message
 Post Office Protocol (POP)
› POP message can tell the e-mail
server to
 Send mail to user’s computer
and delete it from e-mail
server
 Send mail to user’s computer
and not delete it
 Simply ask whether new mail
has arrived
› Provides support for
Multipurpose Internet Mail
Extensions (MIME)

29.  Text markup language
› Specifies set of tags that are inserted into text
 Standard Generalized Markup Language (SGML)
› Older and complex text markup language
› A meta language
 World Wide Web Consortium (W3C)
› Not-for-profit group that maintains standards for the Web

34.  Offers a system of marking up documents
that is independent of any software
application
 Nonproprietary and platform independent
 Offers user-defined tags
 Costly to set up and maintain

35.  Prevalent markup language used to
create documents on the Web today
 HTML tags
› Interpreted by Web browser and used by it
to format the display of the text
 HTML Links
› Linear hyperlink structure
› Hierarchical hyperlink structure
E-Commerce: The Second Wave, Fifth Annual Edition 35

36.  Scripting languages and style sheets
› Most common scripting languages
 JavaScript, JScript, Perl, and VBScript
› Cascading Style Sheets (CSS)
 Sets of instructions that give Web
developers more control over the format of
displayed pages
 Style sheet
 Usually stored in a separate file
 Referenced using the HTML style tag
E-Commerce: The Second Wave, Fifth Annual Edition 36

37.  Uses paired start and stop tags
 Includes data management capabilities
that HTML cannot provide
 Differences between XML and HTML
› XML is not a markup language with defined
tags
› XML tags do not specify how text appears
on a Web page
E-Commerce: The Second Wave, Fifth Annual Edition 37

38. E-Commerce: The Second Wave, Fifth Annual Edition 38

39.  Intranet
› Interconnected network
that does not extend
beyond organization that
created it
 Extranet
› Intranet extended to
include entities outside
boundaries of organization
› Connects companies with
suppliers, business partners,
or other authorized users

40.  Public network
› Any computer network or
telecommunications
network available to the
public
 Private network
› A private, leased-line
connection between two
companies that physically
connects their intranets
 Leased line
› A permanent telephone
connection between two
points

41.  Extranet that uses public
networks and their protocols
 IP tunneling
› Effectively creates a
private passageway
through the public Internet
 Encapsulation
› Process used by VPN
software
 VPN software
› Must be installed on the
computers at both ends of
the transmission

42.  Bandwidth
› Amount of data that can
travel through a
communication line per unit of
time
 Net bandwidth
› Actual speed that information
travels
 Symmetric connections
› Provide same bandwidth in
both directions
 Asymmetric connections
› Provide different bandwidths
for each direction

43.  POTS, or plain old telephone
service
› Uses existing telephone
lines and analog modem
› Provide bandwidth
between 28 and 56 Kbps
 Digital Subscriber Line (DSL)
› Connection methods do
not use modem
 Integrated Services Digital
Network (ISDN)
› Offers bandwidths
between 128 Kbps and
256 Kbps

44.  Operate at speeds of greater than 200
Kbps
 Asymmetric digital subscriber (ADSL)
› Transmission bandwidth is from 100 to 640 Kbps
upstream and from 1.5 to 9 Mbps downstream
 Cable modems
› Provide transmission speeds between 300 Kbps
and 1 Mbps
 DSL
› Private line with no competing traffic
E-Commerce: The Second Wave, Fifth Annual Edition 44

45.  DS0 (digital signal zero)
› Telephone line designed to carry 1 digital signal
 T1 line (also called a DS1)
› Carries 24 DS0 lines and operates at 1.544 Mbps
 Fractional T1
› Provides service speeds of 128 Kbps and upward in 128-
Kbps increments
 T3 service (also called DS3)
› Offers 44.736 Mbps

46.  Bluetooth
› Designed for personal use over
short distances
› Low-bandwidth technology,
with speeds of up to 722 Kbps
› Networks are called personal
area networks (PANs) or
piconets
› Consumes very little power
› Devices can discover each
other and exchange
information automatically

47.  Most common wireless connection
technology for use on LANs
 Wireless access point (WAP)
› Device that transmits network packets
between Wi-Fi-equipped computers and
other devices
 Has potential bandwidth of 11 Mbps and
range of about 300 feet
 Devices are capable of roaming
E-Commerce: The Second Wave, Fifth Annual Edition 47

48.  802.11a protocol
› Capable of transmitting data at speeds
up to 54 Mbps
 802.11g protocol
› Has 54 Mbps speed of 802.11a
› Compatible with 802.11b devices
 802.11n
› Expected to offer speeds up to 320 Mbps
E-Commerce: The Second Wave, Fifth Annual Edition 48

49.  One version uses system of repeaters to
forward radio signal from ISP to customers
 Repeaters
› Transmitter-receiver devices (transceivers)
 Mesh Routing
› Directly transmits Wi-Fi packets through
hundreds, or even thousands, of short-range
transceivers

50.  Third-generation (3G) cell phones
› Combine latest technologies available
today
 Short message service (SMS)
› Protocol used to send and receive short text
messages
 Mobile commerce (m-commerce)
› Describes the kinds of resources people
might want to access using wireless devices

51.  Internet2
› Experimental test bed for new networking
technologies
› Has achieved bandwidths of 10 Gbps and
more on parts of its network
› Used by universities to conduct large
collaborative research projects
E-Commerce: The Second Wave, Fifth Annual Edition 51

52.  Semantic Web
› Project by Tim Berners-Lee
› If successful
 Would result in words on
Web pages being
tagged (using XML) with
their meanings
 Resource description
framework (RDF)
› Set of standards for XML
syntax
 Ontology
› Set of standards that
defines relationships
among RDF standards
and specific XML tags

53.  TCP/IP
› Protocol suite used to create and transport
information packets across the Internet
 POP, SMTP, and IMAP
› Protocols that help manage e-mail
 Languages derived from SGML
› Hypertext Markup Language (HTML)
› Extensible Markup Language (XML)
E-Commerce: The Second Wave, Fifth Annual Edition 53

54.  Intranets
› Private internal networks
 Extranet
› Used when companies want to collaborate
with suppliers, partners, or customers
 Internet2
› Experimental network built by a consortium
of research universities and businesses
E-Commerce: The Second Wave, Fifth Annual Edition 54