22539544 Introduction to Information Technology Turban Rainer and Potter Chapter 6

8/11/2019 22539544 Introduction to Information Technology Turban Rainer and Potter Chapter 6

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Introduction to Information TechnologyTurban, Rainer and Potter

Chapter 6 Telecommunications and Networks

CHAPTER 6TELECOMMUNICATIONS

AND NETWORKS


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Learning b!ecti"es

Describe the components of a telecommunications system

Describe the five basic types of communication media, including

their advantages and disadvantages

Classify the major types of networks

Differentiate among the three types of distributed processing

Identify seven telecommunications applications and describe how

they help the organization attain competitive advantage


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Chapter "er"iewTelecommunicationsSystems#Signal#Communications

processors

#Communications media and channels#Communications carriers and services

etworks

#!ocal area networks#"ide area networks

etwork CommunicationSoftware#etwork operating system#etwork management software

##rotocols#Types of data transmission

etwork #rocessingStrategies

#$rganizationaldistributed processing

#$pen systems andenterprise networking

Telecommunications%pplications

#&lectronic mail#'ideo conferencing#&lectronic data interchange#&lectronic funds transfer#(acsimile

#Telecommuting#Distance learning


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Case $ Network %anagement

at &outhwest 'irlines The (usiness Problem

The &olution

etwork )ealth

to predict the possible ramifications of shifting network traffic

to virtually add and subtract applications and make theoretical changes in transmission capacity through*out the network

to help the network managers monitor network usage

it had to make the transition from its legacyapplications to client+severtechnology to maintain service levels and keep up with

network traffic volume

The Results

Save almost -..,... in staffing costs in the first year

%ble to smooth network traffic among reservations centersShorten customers/ waiting time


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)hat ha"e we learned from this case**

Case (continued)

+change of data - facilitated by telecommunications technologies -

brings a number of "ery significant changes

Take management of resources "ery seriously

(ring disastrous losses in re"enues and customer satisfaction by minor

disruption in telecommunications traffic

.nderstand technology in order to gain and maintain competiti"e

ad"antage

Rarely in modern companies do computers work in

isolation


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The Telecommunications &ystem )ardware * all types of computers and communication

processorsCommunications media * the physical media through which

electronic signals are transmitted ,including wireless media

Communications networks* the links among computers andcommunications devicesCommunications software* software that controls the

telecommunications system and the entire transmission processData communications providers* regulated utilities or

private firms that provide data communications servicesCommunications protocols* the rules for transmitting

information across networksCommunications applications* electronic data interchange,

teleconferencing, videoconferencing, electronic mail, facsimile,and electronic funds transfer, as well as others


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The Telecommunications &ystem

(continued )

ComputerCommunications

#rocessor

Communications

#rocessorComputer

etwork

Software

Communications

Channels and %edia

Transmitter

Recei"er


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Communication Processors

%odem

an analog network to carry "oice signals or sounds in ananalog wa"e format

%ultipleer

an electronic de"ice that allows a singlecommunications channel to carry data transmissionssimultaneously from many sources

/ront-end-Processor

a small secondary computer dedicated solely tocommunication in computer system


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Communication %edia and Channels

(continued ) )ireless %edia

%icrowa"e - transmission stations $ usually not spacedmore than 23 miles apart

&atellite - digital transmission

4eostationary earth orbit 04+1 - 55,233 miles

%edium earth orbit 0%+1 - 6,333 miles

Low earth obit 0L+1 - 33 to 7,333 miles

4lobal positioning system - 73,833 milesRadio

use when you do not ha"e to depend on microwa"e or satellitelinks, especially for short ranges


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Communication %edia and Channels

(continued )

Characteristics of Communications

%edia Transmission speed

(andwidth - range of fre9uencies a"ailable

(aud rate

%easured in bits per second 0bps1

Transmission mode

'synchronous or &ynchronous


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Telecommunications Carriers

Common Carriers

the long-distance telephone companies

:alue-added Carriers

ha"e de"eloped pri"ate telecommunications systems andpro"ide ser"ices for a fee

&witched Lines

a person can access from his or her computer to transmit datato another computer

;edicatedpro"ide a constant connection between two de"ices and

re9uire no switching or dialing


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Telecommunications &er"ices

)ide-area Telecommunications &er"ices 0)'T&1

method for billing customers who use "oice band media etensi"ely

Telephone and ;ialing &er"ices

'utomatic Number Identification 0'NI1

Integrated &er"ices ;igital Network 0I&;N1

transfer "oice, "ideo, image, and data simultaneously

;igital &ubscriber Line 0;&L1pro"ide high-speed, digital data transmission


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Networks

Local 'rea Network 0L'N1 -connect two ormore communicating de"ices within 5,333 feet

L'N Technology the network gateway connects the L'N to public

networks or other corporate networks so that the L'Ncan echange information with networks eternal to it

Pri"ate (ranch +changes 0a type of L'N1controls telephone switching at a company site

carry both "oice and data

perform call waiting, call forwarding, and "oice mail

I d i I f i T h l


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Network Typologies&tar network

Ring

network

(us network


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I t d ti t I f ti T h l


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Network Communications &oftware

Network perating &ystems

Network %anagement &oftware

Protocols

set of rules and procedures go"erning transmission of dataacross a network

line access and collision a"oidance

identify each de"ice in the communication path

eample $ +thernet73 (aseT and Transmission ControlProtocol?Internet Protocol 0TCP?IP1

pen &ystem Interconnection 0&I1



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&e"en Layers of the &I %odel-0 #hysical

!ayer

Transmits raw bits over a communication channel1Its purpose is to provide a physical connection forthe transmission of data among network entitiesand the means by which to activate and deactivatea physical connection1

20 Data !ink

!ayer

#rovides a reliable means of transmitting dataacross a physical link3break up the input data intodata frames se4uentially and processes theacknowledgement frames sent back by data intodata frames se4uentially and processes the

acknowledgement frames sent back by the receiver50 etwork

!ayer

6outes information from one network computer toanother3 accepts messages from source host andsees to it that they are directed toward thedestination1 Computers may be physically located

within the same network or within another networkthat is interconnected in some fashion1



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&e"en Layers of the &I %odel

(continued )

70 Session

!ayer

#rovides user/s interface into network3 whereuser must negotiate to establish connection withprocess on another machine1 $nce the connectionis established, the session layer can manage the

dialogue in an orderly manner180 #resentation

!ayer

Translates message to and from the format usedin the network to a format used at the applicationlayer

90 %pplication

!ayer

Includes activities related to users, such assupporting file transfer, handling messages, andproviding security1

:0 Transport

!ayer

#rovides a network*independent transportservice to the session layer, accepts data fromsession layer, splits it up into smaller units asre4uired, passes these to the network layer, and

ensures all pieces arrive correctly at other end1



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Types of ;ata Transmission

Packet &witching breaks up blocks of tet into small, fied bundles of

data called packets

/iber ;istributed ;ata Interface 0/;;I1passes data around a ring, but with a bandwidth of

733 %bps

'synchronous Transfer %ode 0'T%1di"ides data into uniform cells

eliminates the need for protocol con"ersion

&witch


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Network Processing &trategies

Types of rgani=ational ;istributed Processing

Terminal-to-


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Client?&er"er ConfigurationT;#&S $( C!I&T+S&6'&6 C$

S&'&6S?Distributed#resentation

6emote#resentation

Distributed(unction

6emoteData


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Aenefits and !imitations of Client+Server

%rchitecture for etwork #rocessing

AenefitsAenefits

The network is not o"erloaded

with entire files being transferred

back and forth

/ile integrity is much easier to

maintain because only the ser"er

actually updates the files@ /ilesecurity easier to maintain with

ser"er in full control of file data

!imitations!imitations %icrocomputers with independent

processing power are moredifficult to coordinate andadminister on a network@

There is difficulty in writingsoftware that di"ides processingamong clients and ser"ers@

&pecific ser"ers can be slowedwhen too many clients needser"ice@

Introduction to Information Technology


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Types of rgani=ational

;istributed Processing

Client?&er"er 'rchitecture and Processing

Peer-to-peer processing

allows two or more computers to pool their resources

benefits

A there is no need for a network administrator

A the network is fast and inepensi"e to set up and maintain

A each computer can pro"ide backup copies of its files to other

computers for securityA it is the easiest network to build



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pen &ystems and +nterprise

Networking pen &ystems - allows any computing device to be

seamlessly connected to and interact with any other computingdevice, regardless of size, operating system, or application

Connecti"ity - ability of the various computer resources tocommunicate with each other through network devices

&nterprise*wide etwork


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Telecommunications 'pplications

+lectronic %ail 0e-mail1 - computer-based messagestransmitted through telephone wires or wireless networks

:ideoconferencing - allows people to ha"e Bface-to-face

communications with a group in another location+lectronic ;ata Interchange 0+;I1 - electronic

transmission of routine, repetiti"e business documents directlybetween the computer systems

+lectronic /unds Transfer 0+/T1 - electronically routingfunds, debits and credits, and charges and payments



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Telecommunications 'pplications

(continued ) /acsimiles 0/'D1 - con"ert modulated signals into white

and black areas for printing

Telecommuting - work at home, using personalcomputers and telecommunications technology to

communicate "ia electronic mail with other workers, and to

send and recei"e business work

;istance Learning - the students are able to see and hearthe professor, and the professor can hear the students off-

siteE students may be able to see each other



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/or 'ccounting

Corporate accountants perform cost?benefit

analyses on the telecommunications

infrastructure of the firm

/or /inance

/inancial managers use corporate networks

to transfer and recei"e funds, completetransactions, and use +/T

)hat>s in IT for %e*



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)hat>s in IT for %e* (continued )

/or %arketing %odern telecommunications technologies open

huge conduits of information to and from an

organi=ation, and pro"ide great strategicad"antage to the marketing function

/or Production?perations %anagement

Telecommunications can make the linkagebetween the customer and the production functionmuch more direct, making possible differentmanufacturing strategies



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)hat>s in IT for %e* (continued )

/or

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22539544 Introduction to Information Technology Turban Rainer and Potter Chapter 6