Fundamentals of Information Systems Fourth Edition

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Fundamentals of Information SystemsFourth Edition

• Chapter 4
• Telecommunications, the Internet, Intranets, and
  Extranets

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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

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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

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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

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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

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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

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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

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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)

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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
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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

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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

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Network Types

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

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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

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Client/Server Systems

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

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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

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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

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Wireless Communications Protocols (continued)
Table 4.5 Wireless Networks Based on IEEE 802.xx
Standards
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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

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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

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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

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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

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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

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How the Internet Works (continued)
Figure 4.11 Routing Messages over the Internet
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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

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Internet Service Providers (continued)
Table 4.7 A Representative List of Internet
Service Providers
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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

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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

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The World Wide Web (continued)
Figure 4.13 Sample Hypertext Markup Language
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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 Computers Safari

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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

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Search Engines and Web Research (continued)
Table 4.10 Popular Search Engines
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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

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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

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Web Services

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

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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

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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

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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

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Chat Rooms

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

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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

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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

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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

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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

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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

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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

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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

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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

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Intranets and Extranets (continued)

• Extranet
• A network based on Web technologies that links
  selected resources of a companys 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

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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

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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

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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

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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 companys intranet
  with its customers, suppliers, or other business
  partners