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Introduction to Information
Technology
2nd Edition
Turban, Rainer & Potter
© 2003 John Wiley & Sons, Inc.
Chapter 7:
The Internet, Intranets, and Extranets
Prepared by:
Roberta M. Roth, Ph.D.
University of Northern Iowa
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Introduction to Information Technologies
Lecture Preview
• In this lecture, we will study:
– The evolution, operations, and services of the
Internet
– The segment of the Internet called the World
Wide Web
– Organizational applications of Internet
technology (intranets and extranets)
– Specialized Internet applications
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Introduction to Information Technologies
What is the Internet?
• The largest computer network in the world (a
network of networks)
• Information exchange is seamless using
open, non-proprietary standards and
protocols, within interconnected networks
• A true democratic communications forum
producing a democratization of information
• Spirit of information sharing and open access
underlies the Internet.
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Introduction to Information Technologies
The Internet Today
• The Internet is international, with users on all
continents
• The cost of personal computers and Internet
connections are prohibitively high for most of the
world’s population
• Political, cultural, and regulatory barriers have
slowed the rate of Internet adoption internationally
• The vast majority of sites are in English
• The vast majority of content is generated in the
United States
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Introduction to Information Technologies
The Infrastructure of the Internet
• Commercial communications companies are
primary providers of the physical network
backbone of the Internet
• The U.S. government contributes some funds to
essential administrative processes
• The Internet infrastructure is supplied by network
service providers
• Connections between and flow of information
between backbone providers has been open and
free of charge
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Introduction to Information Technologies
Future Internet Initiatives
• Internet2
– A collaboration among more than 180 U.S. universities
to develop leading-edge networking and advanced
applications for learning and research.
– A group of very high bandwidth networks on the
Internet.
– Partnership between universities, industry, and
government.
• Next Generation Internet (NGI)
– Federal government led initiative to advance Internet
technology and applications.
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Introduction to Information Technologies
The Operation of the Internet
• Packets of information flow between machines governed by
common rules (protocols):
– Internet protocol (IP)
– Transport control protocol (TCP)
• Internet is a packet-switching network
– Messages are decomposed into packets, containing part of the
message, plus information on the sending and receiving machines
and how the packet relates to the other packets
– Packets travel independently and possibly on different routes
through the Internet
– Packets are reassembled into the message at the receiving machine.
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Introduction to Information Technologies
The Operation of the Internet
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(continued)
Each computer on the Internet is identified by an
IP address
Most computers also have domain names
Network Solutions, Inc. had a monopoly on
domain name registration until 1999.
Today, some 82 companies can register domain
names.
Cybersquatting – purchase of domain name with
intent to resell it. Legislative action resulted in
Nov. 2000
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The Operation of the Internet
(continued)
• New top-level domain zones: In November 2000,
the first addition of a global top-level domains to
the Internet since the 1980s occurred.
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.aero (for the air-transport industry)
.biz (for businesses)
.coop (for cooperatives)
.museum (for museums)
.name (for individuals)
.pro (for professions).
Introduction to Information Technologies
The Operation of the Internet
(continued)
• Accessing the Internet
– Connect via LAN Server
– Connect via Serial Line Internet
Protocol/Point Protocol (SLIP/PPP)
– Connect via an Online Service (AOL,
MSN)
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Introduction to Information Technologies
Internet Services Communications
• E-mail – electronic messaging
• USENET newsgroups –
• Instant messaging – instant
forums that collect groups of
messages from users based on
common themes
• Telnet – user on one computer
• LISTSERV – distributes
email messages to all
subscribers
• Chatting – live, interactive,
written conversations based on
topic groups
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text messaging between Internet
users
doing work on another
computer
• Internet telephony –
conducting voice conversations
over the Internet
• Internet fax – real time
document transmittal
• Streaming audio and video
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Internet Services – Information
Retrieval
File Transfer Protocol (FTP) – electronic transfer of
files from one computer to another
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Archie – tools to enable searching for files at FTP sites
Gophers – menu-driven information search tool
Veronica – text search through Gopher sites
Wide Area Information Servers (WAIS) – database
search tool
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Introduction to Information Technologies
Internet Services – Web Services
• Delivery of software components via a web
site rather than through traditional means
(disks, CDs)
• .NET – Microsoft’s new platform for XML Web
services. Integrates web sites and programs to
deliver applications.
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Introduction to Information Technologies
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Internet Services – World Wide
Web
An application that uses
the Internet transport
functions
A system with universally accepted standards for
storing, retrieving, formatting, and displaying
information via a client/server architecture
Based on HTML - standard hypertext language
used in Web
Handles text, hypermedia, graphics, and sound
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Introduction to Information Technologies
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The World Wide Web (continued)
Home Page - a text and graphical screen display; first,
introductory page in a web site
Web Site - all the pages of a company or individual
Hyperlinks - ways to link and navigate around the pages
on a web site
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Webmaster - the person in charge of a Web site
Uniform Resource Locator (URL) - points to the
address of a specific resource on the Web
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Hypertext Transport Protocol (HTTP) communications standard used to transfer pages across the
WWW portion of the Internet
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Introduction to Information Technologies
The World Wide Web (continued)
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Browsers – graphical software that enables WWW users to request
and view web documents
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Offline Browsers – software that retrieves pages from Web sites
automatically at predetermined times
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Search Engines - programs that return a list of Web sites or pages
that match some user-selected criteria
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Metasearch Engines - automatically enter search queries into a
number of other search engines and return the results
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To be included in a search engine’s database
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Web Crawlers
Registration
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The World Wide Web (continued)
• Pull Technology - requires web user to actively
request information; traditional web mechanism
• Push Technology - automatically supplies
desirable information to users
– provides timely, prioritized distribution of
information over a corporate network in the
workplace
– enhances traditional Web advertising in the
consumer market
– used for software delivery and updates
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Introduction to Information Technologies
The World Wide Web (continued)
• Information Filters – automated methods of
sorting/screening WWW content
• Clipping Services – automated retrieval of articles and
news items from publications
• Personalized Web Services – ability to generate
personalized Web content
• Web Authoring (for page and site design)
– Standard HTML is the common denominator
– CompuServe Graphics Interchange Format (GIF) and Joint
Photographic Experts Group (JPEG) is the common format of
graphics files
– Browsers can be extended through software plug-ins
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Introduction to Information Technologies
Internet Challenges
• New Technologies
– Adopted by vendors more rapidly than users and
customers can implement them
– Web developers cannot assume that users can run their
innovations successfully
• Internet Regulation
– Technical organizations (e.g., World Wide Web
Consortium) develop standards governing the Internet’s
functionality
– These organizations are not formally charged in any
legal or operational sense with responsibility for the
Internet
– How to control controversial content on the Web?
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Introduction to Information Technologies
Internet Challenges (continued)
• Internet Expansion
– Tremendous Internet traffic growth has strained some
elements of the network
• Slower retrieval times
• Unreliable data transmission
• Denial of service by overloaded servers
– Approaches to overcoming this congestion include
• Improved hardware technology
• Improved Web management software
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Introduction to Information Technologies
Internet Challenges (continued)
• Internet Privacy - Web sites collect information with and
without consumers’ knowledge
– Cookie - small data file placed on users’ hard drives when a
site is first visited. Collects data on pages visited and content
viewed.
– Three potential approaches to the privacy issue
• Government lets groups develop voluntary privacy standards;
does not take any action now unless real problems arise
• Government recommends privacy standards for the Internet;
does not pass laws at this time
• Government passes laws now for how personal information can
be collected and used on the Internet
– Financial transaction security also a concern
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Introduction to Information Technologies
Intranets
• A private network that uses Internet
software and TCP/IP protocols
– Provide employees with easy access to
corporate information
– Used to deploy corporate applications
• Examples – policies and procedures manuals;
human resource forms; product catalogs
– Security is a concern
• Security measures include – public key security,
encryption, digital certificates, firewalls
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Introduction to Information Technologies
Extranets
• An extension of an intranet to selected outside
business partners, such as suppliers, distributors,
and key customers
– Provide business partners with easy access to corporate
information and easy collaboration
• Security
– Critical to prevent unwanted entry into internal systems
– Virtual private networks (VPNs) are often used to add
security to Internet communication
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Introduction to Information Technologies
Extranets (continued)
• Extranet configurations
– One company sets up a Extranet for its dealers,
customers, or suppliers
– Companies within an industry set up a collaborative
Extranet for mutual benefit
– Several companies collaborate over an Extranet for joint
venture
• Benefits include –
– Lower communication costs; better communication;
improved order entry and customer service;
improvement in business effectiveness
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Other Web-based Applications
• Enterprise Information Portals
– Users have single point of access to internal and external
stored information
• Mobile Internet
– Use of wireless communication telecommunication
devices to access Web-based applications
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Lecture Summary
• Internet is a network of network
• Internet provides communication and information
retrieval services, as well as the World Wide Web
• The World Wide Web enables a huge variety of
applications for businesses, including intranets and
extranets
• Many challenges exist when using the WWW,
including congestion, privacy, and security
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Introduction to Information Technologies