Fundamentals of Information Systems International Edition 4Th Edition by kxz77453

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									Fundamentals of Information
       Systems
     Fourth Edition
             Chapter 4
 Telecommunications, the Internet,
      Intranets, and Extranets
     Principles and Learning Objectives
• The effective use of communications technology is
  essential to organizational success by enabling
  more people to send and receive all forms of
  information over greater distances at faster and
  faster rates
     – Define the term telecommunications and describe
       the components of a telecommunications system
       including media and hardware devices
     – Identify several network types and the uses and
       limitations of each
     – Define the term communications protocol and
       identify several common ones

Fundamentals of Information Systems, Fourth Edition      2
     Principles and Learning Objectives
                 (continued)
• The Internet and the Web provide a wide range of
  services, some of which are effective and practical
  for use today, others that are still evolving, and still
  others that will fade away from lack of use
     – Briefly describe how the Internet works, including
       alternatives for connecting to it and the role of
       Internet service providers
     – Describe how the World Wide Web works and the
       use of Web browsers, search engines, and other
       Web tools
     – Identify programming languages and tools used to
       create Web content

Fundamentals of Information Systems, Fourth Edition          3
     Principles and Learning Objectives
                 (continued)
• Because the Internet and the World Wide Web are
  becoming more universally used and accepted for
  business use, management, service and speed,
  privacy, and security issues must continually be
  addressed and resolved
     – Identify and briefly describe several applications
       associated with the Internet and the Web
     – Define the terms intranet and extranet and discuss
       how organizations are using them
     – Identify several issues associated with the use of
       networks

Fundamentals of Information Systems, Fourth Edition         4
Why Learn About Telecommunications, the
   Internet, Intranets and Extranets?
 • Need to access data wherever it resides
      –   Fast, reliable communications
      –   Exchange messages
      –   Upload/download data and software
      –   Route business transactions
      –   Connect to remote databases
      –   Send output to printers




 Fundamentals of Information Systems, Fourth Edition   5
Why Learn About Telecommunications
          and Networks?
• Need to access data wherever it resides
     –   Fast, reliable communications
     –   Exchange messages
     –   Upload/download data and software
     –   Route business transactions
     –   Connect to remote databases
     –   Send output to printers




Fundamentals of Information Systems, Fourth Edition   6
  An Overview of Telecommunications

• Telecommunications: the electronic transmission
  of signals for communications
• Telecommunications medium: anything that
  carries an electronic signal and interfaces between
  a sending device and a receiving device




Fundamentals of Information Systems, Fourth Edition     7
  An Overview of Telecommunications
             (continued)




            Figure 4.1: Elements of a Telecommunications System

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                       Channel Bandwidth

• Telecommunications professionals consider the
  capacity of the communications path or channel
  when they recommend transmission media for a
  business
• Channel bandwidth: the rate at which data is
  exchanged over a communication channel
     – Usually measured in bits per second (bps)




Fundamentals of Information Systems, Fourth Edition   9
                  Communications Media




                  Table 4.1: Guided Transmission Media Types

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    Communications Media (continued)




                          Table 4.2: Wireless Technologies

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         Telecommunications Hardware




               Table 4.3: Common Telecommunications Devices

Fundamentals of Information Systems, Fourth Edition           12
                                     Services

• Digital subscriber line (DSL):
  telecommunications service that delivers high-
  speed Internet access to homes and small
  businesses over the existing phone lines of the
  local telephone network
• All major long distance carriers offer wireless
  telecommunications services that enable you to
  place phone calls or access the Internet



Fundamentals of Information Systems, Fourth Edition   13
  Networks and Distributed Processing

• Computer network: the communications media,
  devices, and software needed to connect two or
  more computer systems and/or devices
• Network nodes: the computers and devices on the
  networks




Fundamentals of Information Systems, Fourth Edition   14
                             Network Types

•   Personal area network (PAN)
•   Local area network (LAN)
•   Metropolitan area network (MAN)
•   Wide area network (WAN)
•   International networks
•   Mesh networking




Fundamentals of Information Systems, Fourth Edition   15
              Network Types (continued)




                               Figure 4.4: A Typical LAN

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              Network Types (continued)




                          Figure 4.5: A Wide Area Network
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                    Distributed Processing

• Centralized processing: all processing occurs in a
  single location or facility
• Decentralized processing: processing devices
  are placed at various remote locations
• Distributed processing: computers are placed at
  remote locations but connected to each other via a
  network




Fundamentals of Information Systems, Fourth Edition   18
                    Client/Server Systems

• Client/Server system: multiple computer platforms
  are dedicated to special functions, such as
  database management, printing, communications,
  and program execution




Fundamentals of Information Systems, Fourth Edition   19
     Client/Server Systems (continued)




                        Figure 4.8: Client/Server Connection

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          Communications Software and
                  Protocols
• Communications protocol: a set of rules that
  govern the exchange of information over a
  communications channel
• Protocols govern several levels of a
  telecommunications network, such as:
     – Hardware device level
     – Application program level




Fundamentals of Information Systems, Fourth Edition   21
          Communications Software and
             Protocols (continued)




              Table 4.4: Common Telecommunications Protocols

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   Wireless Communications Protocols

• Wireless communications protocols are still
  evolving as the industry matures
• The Institute for Electrical and Electronic Engineers
  (IEEE) has been instrumental in defining numerous
  telecommunications standards




Fundamentals of Information Systems, Fourth Edition   23
   Wireless Communications Protocols
              (continued)




      Table 4.5: Wireless Networks Based on IEEE 802.xx Standards
Fundamentals of Information Systems, Fourth Edition                 24
               Communications Software

• Network operating system (NOS): systems
  software that controls the computer systems and
  devices on a network and allows them to
  communicate with each other
• Network-management software: software that a
  manager uses on a networked desktop
     – Monitors the use of individual computers and shared
       hardware (such as printers)
     – Scans for viruses
     – Ensures compliance with software licenses

Fundamentals of Information Systems, Fourth Edition      25
    Use and Functioning of the Internet

• Internet: a collection of interconnected networks,
  all freely exchanging information
• ARPANET
     – The ancestor of the Internet
     – A project started by the U.S. Department of Defense
       (DoD) in 1969
• Internet Protocol (IP): communication standard
  that enables traffic to be routed from one network
  to another as needed


Fundamentals of Information Systems, Fourth Edition      26
                   How the Internet Works

• The Internet transmits data from one computer
  (called a host) to another
• If the receiving computer is on a network to which
  the first computer is directly connected, it can send
  the message directly
• If the receiving computer is not on a network to
  which the sending computer is connected, the
  sending computer relays the message to another
  computer that can forward it


Fundamentals of Information Systems, Fourth Edition   27
    How the Internet Works (continued)

• Data is passed in chunks called packets
• Transmission Control Protocol (TCP): widely
  used transport-layer protocol that is used in
  combination with IP by most Internet applications
• Uniform Resource Locator (URL): an assigned
  address on the Internet for each computer




Fundamentals of Information Systems, Fourth Edition   28
    How the Internet Works (continued)

• Accessing the Internet
     – Connect via LAN server
     – Connect via Serial Line Internet Protocol
       (SLIP)/Point-to-Point Protocol (PPP)
     – Connect via an online service
     – Several other ways to connect
           • Example: WAP




Fundamentals of Information Systems, Fourth Edition   29
    How the Internet Works (continued)




                Figure 4.11: Routing Messages over the Internet

Fundamentals of Information Systems, Fourth Edition               30
    How the Internet Works (continued)




                Figure 4.12: Several Ways to Access the Internet

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                Internet Service Providers

• Internet service provider (ISP): any company that
  provides individuals or organizations with access to
  the Internet
• Most charge a monthly fee
• Many ISPs and online services offer broadband
  Internet access through digital subscriber lines
  (DSLs), cable, or satellite transmission




Fundamentals of Information Systems, Fourth Edition   32
 Internet Service Providers (continued)




       Table 4.7: A Representative List of Internet Service Providers


Fundamentals of Information Systems, Fourth Edition                     33
                     The World Wide Web

• The Web, WWW, or W3
• A menu-based system that uses the client/server
  model
• Organizes Internet resources throughout the world
  into a series of menu pages, or screens, that
  appear on your computer
• Hypermedia: tools that connect the data on Web
  pages, allowing users to access topics in whatever
  order they want


Fundamentals of Information Systems, Fourth Edition   34
      The World Wide Web (continued)

• Hypertext Markup Language (HTML): the
  standard page description language for Web pages
• HTML tags: codes that let the Web browser know
  how to format text - as a heading, as a list, or as
  body text - and whether images, sound, and other
  elements should be inserted




Fundamentals of Information Systems, Fourth Edition   35
      The World Wide Web (continued)




               Figure 4.13: Sample Hypertext Markup Language
Fundamentals of Information Systems, Fourth Edition            36
                             Web Browsers

• Web browser: software that creates a unique,
  hypermedia-based menu on a computer screen,
  providing a graphical interface to the Web
• The menu consists of graphics, titles, and text with
  hypertext links
• Popular Web browsers: Microsoft Internet Explorer,
  Netscape Navigator, Mozilla Firefox, Apple
  Computer’s Safari



Fundamentals of Information Systems, Fourth Edition   37
   Search Engines and Web Research

• Search engine: Web search tool
     – Examples: Yahoo.com, Google.com
• Most search engines are free
• Searches can use words, such as AND and OR to
  refine the search
• Meta-search engine: submits keywords to several
  individual search engines and returns results from
  all these search engines



Fundamentals of Information Systems, Fourth Edition   38
   Search Engines and Web Research
              (continued)




                         Table 4.10 Popular Search Engines

Fundamentals of Information Systems, Fourth Edition          39
          Web Programming Languages

• Java
     – An object-oriented programming language from Sun
       Microsystems based on C++
     – Allows small programs (applets) to be embedded
       within an HTML document




Fundamentals of Information Systems, Fourth Edition   40
                 Developing Web Content

• Products that greatly simplify the creation of a Web
  page
     – Example: .NET platform
• Other Web publishing packages include Bubbler,
  Homestead QuickSites, and JobSpot




Fundamentals of Information Systems, Fourth Edition   41
                              Web Services

• Standards and tools that streamline and simplify
  communication among Web sites for business and
  personal purposes




Fundamentals of Information Systems, Fourth Edition   42
Internet and Web Applications: E-Mail,
     Instant Messaging, and Push
              Technology
• E-mail is no longer limited to simple text messages
     – Sound and images can be embedded in messages
     – Files that contain text documents, spreadsheets,
       graphs, or executable programs can be attached
• Instant messaging: allows two or more individuals
  to communicate online using the Internet




Fundamentals of Information Systems, Fourth Edition       43
    Internet Cell Phones and Handheld
                 Computers
• Some cell phones can be connected to the Internet
  to:
     – Search for information
     – Buy products
     – Chat with business associates and friends
• Handheld computers and other devices can be
  connected to the Internet using phone lines or
  wireless connections, such as Wi-Fi



Fundamentals of Information Systems, Fourth Edition   44
Career Information and Job Searching

• Internet is an excellent source of job-related
  information
• Most medium and large companies have Internet
  sites that list open positions, salaries, benefits, and
  people to contact for further information
• Some sites can help you develop a good résumé
  and an effective cover letter, apply for jobs online,
  prepare for a job interview, and negotiate a good
  employment contract


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Web Log (Blog), Video Log (Vlog), and
            Podcasting
• Web log (blog): Web site that people can create
  and use to write about their observations,
  experiences, and feelings on a wide range of topics
• Video log (vlog): video content placed on the
  Internet using the same overall approach as a blog
• Podcast: audio blog, like a personal radio station
  on the Internet
     – Extends blogging by adding audio messages



Fundamentals of Information Systems, Fourth Edition   46
                                Chat Rooms

• Chat room: facility that enables two or more
  people to engage in interactive “conversations”
  over the Internet




Fundamentals of Information Systems, Fourth Edition   47
Internet Phone and Videoconferencing
              Services
• Internet phone service enables you to
  communicate with others around the world
     – Relatively inexpensive
     – Useful for international calls
     – Ability to keep your phone number when you move
       to another location
• Internet videoconferencing
     – Supports both voice and visual communications



Fundamentals of Information Systems, Fourth Edition      48
                        Content Streaming

• Content streaming: a method for transferring
  multimedia files over the Internet so that the data
  stream of voice and pictures plays more or less
  continuously without a break, or with very few
  breaks
     – Enables users to browse large files in real time




Fundamentals of Information Systems, Fourth Edition       49
                     Shopping on the Web

• Shopping on the Web for books, clothes, cars,
  medications, and even medical advice can be
  convenient, easy, and cost effective
• Bot: software tool that searches the Web for
  information, products, or prices




Fundamentals of Information Systems, Fourth Edition   50
                              Web Auctions

• Web auction: Internet site that matches buyers
  and sellers
     – eBay is one of the most popular auction sites
• Traditional companies are starting their own
  auction sites




Fundamentals of Information Systems, Fourth Edition    51
    Music, Radio, Video, and TV on the
                 Internet
• Music, radio, and video are hot growth areas on the
  Internet
• Audio and video programs can be played on the
  Internet, or files can be downloaded for later use




Fundamentals of Information Systems, Fourth Edition   52
                         Office on the Web

• Many services and software products give you
  remote access to your files and programs over the
  Internet
     – Examples: Avvenu, EasyReach, BeInSync
• Companies that offer remote access include
  MyWebEx PC Pro, Citrix Online, and Laplink
• Works best with broadband Internet access




Fundamentals of Information Systems, Fourth Edition   53
              Other Internet Services and
                      Applications
• Internet services are constantly emerging
     – Libraries
     – Critical information during times of disaster or
       terrorism
     – Critical medical information
     – Translation
     – Distance learning




Fundamentals of Information Systems, Fourth Edition       54
                   Intranets and Extranets

• Intranet
     – Internal corporate network built using Internet and
       World Wide Web standards and products
     – Used by employees to gain access to corporate
       information
     – Reduces need for paper




Fundamentals of Information Systems, Fourth Edition          55
    Intranets and Extranets (continued)

• Extranet
     – A network based on Web technologies that links
       selected resources of a company’s intranet with its
       customers, suppliers, or other business partners
• Virtual private network (VPN): secure connection
  between two points across the Internet
• Tunneling: process by which VPNs transfer
  information by encapsulating traffic in IP packets
  over the Internet


Fundamentals of Information Systems, Fourth Edition          56
                                  Net Issues

  • Management issues
        – No centralized governing body controls the
          Internet
  • Service and speed issues
        – Web server computers can be overwhelmed by
          the amount of “hits” (requests for pages)
  • Privacy, fraud, security, and unauthorized
    Internet sites



Fundamentals of Information Systems, Fourth Edition    57
                                    Summary

• Telecommunications: electronic transmission of
  signals for communications
• Computer network: communications media,
  devices, and software needed to connect two or
  more computer systems or devices
• Network types: personal area network (PAN), local
  area network (LAN), metropolitan area network
  (MAN), wide area network (WAN), and international
  networks


Fundamentals of Information Systems, Fourth Edition   58
                     Summary (continued)

• Internet: collection of interconnected networks, all
  freely exchanging information
• Internet Protocol (IP): communication standard that
  enables traffic to be routed from one network to
  another as needed
• Uniform Resource Locator (URL): an assigned
  address on the Internet for each computer




Fundamentals of Information Systems, Fourth Edition   59
                     Summary (continued)

• Intranet: internal corporate network built using
  Internet and World Wide Web standards and
  protocols
• Extranet: network based on Web technologies that
  links selected resources of a company’s intranet
  with its customers, suppliers, or other business
  partners




Fundamentals of Information Systems, Fourth Edition   60

								
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