fundamentals of information systems, fifth edition chapter 4 telecommunications, the internet,...

Fundamentals of Information Systems, Fifth Edition

Chapter 4 Telecommunications, the Internet,

Intranets, and Extranets

Principles and Learning Objectives

• A telecommunications system has many fundamental components that must be carefully selected and work together effectively to enable people to meet personal and organization objectives– Identify and describe the fundamental components of a

telecommunications system including media and hardware devices

– Identify several network types and describe the uses and limitations of each

– Name three basic processing alternatives for organizations that require two or more computer systems and discuss their fundamental features

Fundamentals of Information Systems, Fifth 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 are still evolving, and still others 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 and briefly describe several applications associated with the Internet and the Web


Principles and Learning Objectives (continued)

• Because use of the Internet and World Wide Web is becoming universal in the business environment, management, service and speed, privacy, and security issues must continually be addressed and resolved– Outline a process and identify tools used to create

Web content– Define the terms intranet and extranet and discuss

how organizations are using them– Identify several issues associated with the use of

networks


An Overview of Telecommunications

• Telecommunications– The electronic transmission of signals for

communications

• Telecommunications medium– Any material substance that carries an electronic

signal to support communications between a sending and receiving device



An Overview of Telecommunications (continued)


Channel Bandwidth

• The rate at which data is exchanged

• Broadband communications– A telecommunications system that can exchange

data very quickly


Communications Media

• Guided transmission media types– Many utilities, cities, and organizations are

experimenting with broadband over power lines (BPL)

• Wireless technologies– Broadcast of communications in one of three

frequency ranges: microwave, radio, and infrared– Near Field Communication (NFC)– Bluetooth– Ultra wideband (UWB)– Wi-Fi


Communications Media (continued)


Telecommunications Hardware

• Devices include: – Modems, multiplexers, PBXs and front-end

processors that enable electronic communications to occur or occur more efficiently

• Switches, bridges, routers and gateways – Devices for sending packets of data through one or

more networks


Telecommunications Hardware (continued)


Services

• Digital subscriber line (DSL)– Telecommunications service that delivers high-

speed Internet access to homes and small businesses over the existing phone lines

• Asymmetric DSL (ADSL) line – Does not require an additional phone line and yet

provides “always-on” Internet access

• Voice over Internet Protocol (VoIP)– Enables voice conversations to be converted into

packets of data that can be sent over a data network


Services (continued)

Networks and Distributed Processing

• Computer network– Communications media, devices, and software

needed to connect two or more computer systems and/or devices

• Network nodes– Computers and devices on the networks


Network Types

• Personal area network (PAN)– Wireless network that connects information

technology devices within a range of 33 feet or so

• Local area network (LAN)– Connects computer systems and devices within a

small area, such as an office

• Metropolitan area network (MAN)– Connects users and their computers in a geographical

area

• Wide area network (WAN)– Connects large geographic regions



Network Types (continued)


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


Client/Server Systems

• Multiple computer platforms are dedicated to special functions, such as:– Database management, printing, communications,

and program execution


Communications Protocols

• Set of rules that govern the exchange of information over a communications channel

• Protocols – Govern several levels of a telecommunications

network


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– Simplifies the process of updating files and programs

on computers on the network


Use and Functioning of the Internet

• Internet– Collection of interconnected networks, all freely

exchanging information

• ARPANET– Ancestor of the Internet– A project started by the U.S. Department of Defense

(DoD) in 1969

• Internet Protocol (IP)– Enables traffic to be routed from one network to

another as needed


How the Internet Works

• Packets– Carry the addresses of its sender and its receiver

• Transmission Control Protocol (TCP)– Widely used transport-layer protocol used in

combination with IP

• Backbone– One of the Internet’s high-speed, long-distance

communications links

• Uniform Resource Locator (URL)– Assigned address


How the Internet Works (continued)



• Accessing the Internet– Internet access is not distributed evenly

• Connect via LAN server– Used by businesses that manage a LAN

• Connect via dial-up– Requires a modem that allows the computer to use

standard phone lines



• Connect via an online service– High-speed services provide data transfer rates

between 1 and 7 Mbp

• Connect wirelessly– Thousands of public Wi-Fi services are available in

coffee shops, airports, hotels, and elsewhere


Internet Service Providers

• 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


Internet Service Providers (continued)


The World Wide Web

• A hyperlink-based system that uses the client/server model

• Organizes Internet resources throughout the world into a series of linked file

• Tools: Web browser, Web portal, Web plug-ins

• Hypertext Markup Language (HTML)– Standard page description language for Web pages

• Extensible Markup Language (XML)– Markup language for Web documents containing

structured information containing various elements

Web 2.0 and the Social Web

• The Web as a computing platform that supports software applications and the sharing of information between users

• Rich Internet application– Software that has the functionality and complexity of

traditional application software, but does not require local installation and runs in a Web browser


Web Programming Languages

• Java– Object-oriented programming language from Sun

Microsystems based on C++– Allows small programs (applets) to be embedded

within an HTML document


Developing Web Content

• Products that simplify the creation of a Web page– .NET platform– Bubbler– Homestead QuickSites– JobSpot

• Mash-up: Programs and procedures combining two or more Web applications into a new service



Web Services

• Standards and tools that streamline and simplify communication among Web sites

• XML is key to Web services


Internet and Web Applications

• Search engines and Web research– Search engine

• Enables you to find information on the Web

• Scours the Web with bots that follow all Web links in an attempt to catalog every Web page by topic

• Important businesses tool used to drive visitors to Web sites

E-Mail, Instant Messaging, and Video Chat

• E-mail – No longer limited to simple text messages

• Instant messaging– Online, real-time communication between two or

more people who are connected to the Internet



Career Information and Job Searching

• Search engines – Can be a good starting point for searching for

specific companies or industries

• Some sites – Can help you develop a résumé and find a good job


Telnet, SSH, and FTP

• Telnet – Network protocol that enables users to log on to

networks remotely over the Internet

• File Transfer Protocol (FTP) – Protocol that supports file transfers between a host

and a remote computer


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

• Video log (vlog)– Video content placed on the Internet using the same

overall approach as a blog

• Podcast– Audio broadcast over the Internet


Chat Rooms

• Facility that enables two or more people to engage in interactive “conversations” over the Internet

• Internet Relay Chat (IRC)– Requires participants to type their conversation

rather than speak


Internet Phone and Videoconferencing Services

• Internet phone service – Enables you to communicate with others around the

world

• Internet videoconferencing– Supports both voice and visual communications


Social Networks

• Provide Web-based tools for users to:– Share information about themselves with people on

the Web

• MySpace and Facebook– Popular social networking sites

• LinkedIn – Social network that allows professionals to find

others who work in the same field


Media Sharing

• Provide methods for members to store and share digital media files on the Web– YouTube– Flickr


Content Streaming

• Method for transferring multimedia files, radio broadcasts, and other content over the Internet so that the data stream plays continuously


Shopping on the Web

• Bot (intelligent agent)– Software tool that searches the Web for information,

products, or prices– Can find the best prices or features from multiple

Web sites


Web Auctions

• A way to connect buyers and seller

• Web auction sites – Place where businesses are growing their markets

or reaching customers for a low cost per transaction


Music, Radio, Video, and TV on the Internet

• Hot growth areas on the Internet– Music, radio, and video

• Radio broadcasts are now available on the Internet

• Video and TV are also becoming available on the Internet


Office on the Web

• Internet office – Web site that contains files, phone numbers, e-mail

addresses, an appointment calendar, and more– Allows your desktop computer, phone books,

appointment schedulers, and other important information to be with you wherever you are


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

Intranets and Extranets• Intranet

– Internal corporate network built using Internet and World Wide Web standards and products

• Extranet– Network that links selected resources of the intranet

with customers, suppliers, or other business partners

• Virtual private network (VPN) – Secure connection between two points on the Internet

• Tunneling– VPNs transfer information by encapsulating traffic in IP

packets and sending the packets over the Internet


Net Issues

• Management issues– No centralized governing body controls the Internet

• Service and speed issues– Traffic volume on company intranets is growing even

faster than the Internet

• Privacy, fraud, security, and unauthorized Internet sites– Unauthorized and unwanted Internet sites are also

problems some companies face


Summary

• Telecommunications – Electronic transmission of signals for communications,

including telephone, radio, and television

• Telecommunications media – Guided transmission media and wireless media

• Network types– Personal area network (PAN)– Local area network (LAN)– Metropolitan area network (MAN)– Wide area network (WAN)


Summary (continued)

• The Internet started with ARPANET

• Internet service provider – Any company that provides access to the Internet

• The Web – A collection of independently owned computers that

work together as one

• Web programming languages – Java, JavaScript, VBScript, ActiveX, and Hypertext

Preprocessor


Summary (continued)

• Intranet – Internal corporate network built using Internet and

World Wide Web standards and products

• Extranet – Network that links selected resources of the intranet

of a company with its customers, suppliers, or other business partners


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