csc305-lab1(1).pdf data communications and networks

7/27/2019 CSC305-Lab1(1).pdf Data Communications and Networks

1/24

CSC305 Communications and Networks (Fall 2013)

In this lab, you will be introduced to the network simulation tool OPNET. To familiarizeyourself with this tool run the software OPNET IT Guru Academic Edition and read the shorttutorial provided with this lab. The academic version of this tool is free and can be downloadedfrom the Internet by the visiting the following link:

http://www.opnet.com/university_program/itguru_academic_edition/Note that you should register first to be able to download the software.

Once familiar with OPNETs user interface, do the lab titled Small Internetworks included withthis document.

Create a third scenario containing 4 more networks (two in the third floor and 2 in the fourthfloor) and check the performance of the whole network. The new four networks are identical tothe first network except that the number of stations should be 25 for each. Use Subnets to

create the new networks.Prepare a report in which you should include the answers to the following two questions:- Will the server be able to handle the additional load of the added networks?- Will the total delay across the network be acceptable once the new networks are installed?You should include the graphs showing the comparison of the three scenarios: one floor,

two floors, and three floors, considering the two statistics Ethernet load and Ethernet delay.Discuss the results you obtained and compare them with your expectations. Mention anyanomalies or unexplained behaviors.

What you need to submit is:- Report with graphs, discussions, and answers to the two questions- All your project files generated by OPNET.

The work can be done individually or in teams of two students.This Lab1 counts for 5%.

Deadline: You should upload your work using Blackboard on time before October 6th, 23:59(STRICT DEADLINE). Any late submission will be penalized (-10%/ day).

CSC305: Data Communications and NetworksLab 1: Small InternetworksAn Introduction to OPNET Simulation tool


2/24

AboutIT

Guru

5

Abou

tITGuru

Beforeyoustart,yoush

ouldunderstandtheITGuru

workflow,theworkspace,andtheeditors.Become

familiarwiththeseessentialfeatures,thenbeginthe

tutoriallessons.

TheworkflowforITGuru(thatis,

thestepsyouusetobuilda

networkmodelandrun

simulations)centersaro

undthe

ProjectEditor.

Inthiseditor,youcancr

eatea

networkmodel,choose

statistics

tocollectfromeachnetwork

objectorfromthewhole

network,

executeasimulation,an

dview

results.

YourfirstlookatITGuru

in

Lesson1demonstrates

howto

usetheProjectEditorto

builda

smallinternetwork.

Choose

Statistics

RunSimulations

ViewandAnalyze

Results

Create

Network

Models

AboutITGuru

6

The

Pro

jec

tEditor

TheProjectEditoristhemainstagingareaforcreating

anetworksimulation.Fromthiseditor,youcanbuilda

networkmodelusingmodelsfromthe

standardlibrary,

chooses

tatisticsaboutthenetwork,runasimulation,

andview

theresults.

ANe

twork

Mo

de

linthe

Pro

jec

tEditor

The

Pro

jec

tEditor

Window

ThereareseveralareasintheProject

Editorwindow

thatareimportantforbuildingandexe

cutingamodel.

Theseareshownonthefollowingpag

es.


3/24

AboutIT

Guru

7

Whenyouopenanexistingproject,yourscreenshou

ld

looksimilartothefollow

ingfigure.

Pro

jec

tEditor

Window

ToolButtons

Message

Area

Menu

MessageBufferIcon

Workspace

AboutITGuru

8

TheMenu

Bar

Themenubarisatthetopoftheedito

rwindow.It

organizesallthenon-context-sensitive

editor

operation

sintoasetoftopicalmenus.

Thenumberofmenusandmenuoper

ationsavailable

changea

ccordingtotheproductmodulesthatare

enabled.

Context-sensitiveeditoroperationsareavailableby

right-clickingonanobjectorontheba

ckgroundofthe

workspace.


4/24

AboutIT

Guru

9

ToolButtons

Severalofthemorecom

monlyusedmenubar

selectionscanalsobea

ctivatedthroughtoolbuttons.

Thebuttonsshowninthefollowingfigureappearinth

e

ProjectEditor:

Pro

jec

tEditor

Bu

ttons

Youwillusemanyofthe

actionbuttonsinthetutorial.

1

Openobjectpalette

6

Zoom

2

Checklinkconsistency

7

Restore

3

Failselectedobjects

8

Configurediscreteeventsimulation

4

Recoverselectedobjects

9

Viewsimulationresults

5

Returntoparentsubnet

10

Hideorshowallgraphs

10

8

9

7

6

5

4

3

2

1

AboutITGuru 1

0

TheWorkspace

Thecentral,scrollableregionoftheed

itorwindowis

theworkspace.Thenetworkmodelap

pearsinthe

workspace,whereyoucanselectand

dragnetwork

objects,a

ndchoosecontext-sensitive

menu

operation

sbyright-clickingonthebac

kground.

TheMess

ageArea

Themessageareaislocatedatthebottomofthe

editorwindow.Itprovidesinformationaboutthestatus

ofthetoo

l.

MessageA

rea

Youcanleft-clickontheiconnexttoth

e

message

areatoopenthemessageb

uffer

window.

Themessagebufferwindowshowsalistofmessages

thathave

appearedinthemessagearea.Youcan

openthe

messagebufferwindowifpa

rtofthe

message

lineistruncatedinthemess

ageareaorif

youthink

alatermessagehasreplace

danimportant

alertorn

otification.


5/24

AboutIT

Guru 1

1

Tooltips

Ifyourestthecursoroveratoolbuttonoranetwork

objectintheworkspace,ahelpballoonappears.The

tooltipdescribesoneof

thefollowing:

theactionthatocc

ursifthebuttonispressed

informationaboutthenetworkobject

Too

ltip


6/24

Introduction 1

SmallInternetworks

Introduction

Inthislesson,youwillle

arnhowITGurucanmodel

organizationalscalingbyusingthetooltomodela

real-worldwhatifprob

lem.

Youwilllearnhowtouse

ITGurufeaturestobuild

andanalyzenetworkmodels.

Inthislesson,youwill

Buildanetworkqu

ickly

Collectstatisticsaboutnetworkperformance

Analyzethesestatistics

Inthislesson,youusetheProjectEditortobuilda

topologyofasmallinter

network,choosestatisticsto

collect,runasimulation,andanalyzetheresults.

Inthislesson,youplanfortheexpansionofasmall

companysintranet.Currently,

thecompanyhasasta

r

topologynetworkonthe

firstfloorofitsofficebuilding

andplanstoaddanadd

itionalstartopologynetwork

onanotherfloor.Youwillbuildandtestthiswhat-if

scenariotoensurethattheloadaddedbythesecond

networkwillnotcausethenetworktofail.

Introduction 2

TheFinalN

etwork

Firstflo

or

Plannedexpansion


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GettingS

tarted 3

GettingStarted

Whencreatinganewne

tworkmodel,youmustfirst

createanewprojectan

dscenario.

Aprojectisa

groupofrelatedscenariosthateachexploreadifferent

aspectofthenetwork.P

rojectscancontainmultiple

scenarios.

Afteryoucreateanewproject,youusetheStartup

Wizardtosetupanewscenario.

Theoptionsinthe

Wizardletyou

Definetheinitialto

pologyofthenetwork

Definethescaleandsizeofthenetwork

Selectabackgroundmapforthenetwork.

Associateanobjectpalettewiththescenario

StartupWizardautoma

ticallyappearseachtimeyou

createanewproject.Th

eStartupWizardallowsyou

to

definecertainaspectso

fthenetworkenvironment.

GettingStarted 4

Touseth

eStartupWizardtosetupanewscenario,

do

thefollow

ing:

1

IfIT

Guruisnotalreadyrunning,startit.

2

SelectFile>New....

3

SelectProjectfromthepull-downmenuandclick

OK.

4

Nam

etheprojectandscenario,asfollows:

4.1

Nametheproject

_Sm_

Int

Includeyourinitialsintheprojectnameto

distinguishitfromotherversionsofthis

project.

4.2

Namethescenariofirst_flo

or.

4.3

ClickOK.

TheStartupWizardopens.

5

Enterthevaluesshowninthefollowingtablein

the

dialogboxesoftheStartupW

izard:


8/24

GettingS

tarted 5

ValuestoEnterintheS

tartupWizard

Aworkspaceof

thesizeyouspecifiedis

created.T

heobjectpaletteyouspecifiedopens

inaseparatewindow.

DialogBoxName

Value

1.InitialTopology

Selectthedefaultvalue:

CreateEmptyScenario.

2.ChooseNetworkScale

SelectOffice.

Checkthe

UseMetricUnitsbox.

3.SpecifySize

Selectthedefaultsize:

100mx100m

4.SelectTechnologie

s

IncludetheSm_

Int_Model_List

modelfamily.

5.Review

Checkvalues,thenclickOK.

CreatingtheNetwork

6

Creating

theNetwork

NetworkmodelsarecreatedintheProjectEditorusing

nodesandlinksfromtheobjectpale

tte.

Node-A

representationofareal-worldnetworkobject

thatcantransmitandreceiveinformation.

Nodes

Link-Acommunicationmediumthatconnectsnodes

toonean

other.Linkscanrepresentelectricalorfiber

opticcab

les.

ALink

Theseob

jectsarefoundintheobjectpalette,adialog

boxthatcontainsgraphicalrepresenta

tionsofnode

andlinkmodels.


9/24

CreatingtheNe

twork

7

Youcanuseanyofthreemethodstocreateanetwork

topology,oracombinationofallthree.

Onemethodis

toimportthetopology(discussedinalaterlesson).

Anotheristoplaceindiv

idualnodesfromtheobject

paletteintotheworkspa

ce.

Thethirdmethodistouse

RapidConfiguration.

RapidConfigurationcreatesanetworkinoneaction

afteryouselectanetwo

rkconfiguration,

thetypesof

nodeswithinthenetwor

k,andthetypesoflinksthat

connectthenodes.

Tocreatethefirst-floorn

etworkusingRapid

Configuration:

1

SelectTopology>

RapidConfiguration.

2

SelectStarfromth

edrop-downmenuofavailab

le

configurations,the

nclickOK....

AvailableConfigurationsPop-upMenu

CreatingtheNetwork

8

Specifythenodemodelsandlinkmod

elsinthe

network.

Modelsfollowthisnamingsc

heme:

_...___

where:

specifiesthespecificprotocol(s)

sup

portedbythemodel

isanabbreviationof

thegeneral

functionofthemodel

indicatesthelevelofderivationofthe

model

Forexam

ple:

ethernet2_

bridge_

int

specifies

theintermediate(int)derivationofa2-port

Ethernet

(ethernet2)bridge(bridge).

Vendorm

odelshaveanadditionalprefixthatspecifies

thevendorandthevendorproductnumberforthat

particularnetworkobject.


10/24

CreatingtheNe

twork

9

Forexample,

the3Com

switchusedinthislessonis

named:

3C_

SSII_

1100_

3300_4

s_ae52_e48_ge3

Thisnodeisastackoft

wo3ComSuperStackII1100

andtwoSuperstackII3300chassis

(3C_

SSII_

1100_

3300)withfourslots(4s),52

auto-sensingEthernetp

orts(ae52),48Ethernetports

(e48),and3GigabitEth

ernetports(ge3).

Tospecifythenodesan

dlinkstousetobuildthe

network:

1

SettheCenterNo

deModelto

3C_

SSII_

1100_33

00_

4s_ae52_e48_ge3.

This

is

a3Comswitch.

2

SetthePeriphery

NodeModelto

Sm_

Int_wkstn,andchangetheNumberof

peripherynodesto

30.

Thisprovides30Ethern

et

workstationsastheperipheralnodes.

3

SettheLinkMode

lto10BaseT.

CreatingtheNetwork 1

0

Specifyw

herethenewnetworkwillbe

placed:

1

Set

theXcenterandYcenterto25.

2

Set

theRadiusto20.

RapidConfigurationDialogBox

3

Clic

kOK.

T

henetworkisdrawnintheP

rojectEditor:


11/24

CreatingtheNe

twork 1

1

TheFirstFloorNetwork

Nowthatthegeneralne

tworktopologyhasbeenbuilt,

youneedtoaddaserve

r.Youwillusethesecond

methodofcreatingnetw

orkobjects:draggingthem

fromtheobjectpaletteintotheworkspace.

1

Ifitisnotalreadyopen,openthe

objectpalettebyclickingonthe

ObjectPaletteactionbutton.

2

FindtheSm_

Int_s

erverobjectinthepaletteand

dragitintotheworkspace.

Youwillnotfindthisexactservermodelonothe

r

objectpalettesbecausewecreateditwiththe

correctconfigurationforthistutorial.


2

Bydefault,youcancreateadditionalinstancesof

the

sameobjectbyleft-clickinga

ftertheinitial

dra

g-and-dropfromthepalette.

3

Bec

auseyoudonotneedadditio

nalcopiesofthis

model,right-clicktoturnoffnode

creation.


12/24

CreatingtheNe

twork 1

3

Youalsoneedtoconnecttheservertothestar

network.

1

Findthe10BaseT

linkobjectinthepaletteand

clickonit.

2

Clickontheserverobject,

thenclickontheswitch

objectinthecente

rofthestar.

Alinkisdrawn,connectingthetwoobjects.

3

Right-clicktoturnofflinkcreation.

Finally,youneedtoadd

configurationobjectsto

specifytheapplicationtrafficthatwillexistonthe

network.

Configuringtheapplicationdefinitionand

profiledefinitionobjects

canbecomplicated,soyoud

o

nothavetodothesetas

ksrightnow.

Forthistutorial,

weincluded,ontheobje

ctpalette:

anapplicationdefinitionobjectwiththedefault

configurationsofthestandardapplications,and

aprofiledefinitionobjectwithaprofilethatmode

ls

lightdatabaseaccess


4

Youneed

onlydragtheobjectsintoyo

urnetwork.

Doingso

meansthatthetrafficcaused

byworkstations

accessingadatabaseatalowratewillbemodeled.

1

FindtheSm_

Application_

Configobjectinthe

paletteanddragitintotheworks

pace

2

Right-clicktoturnoffobjectcreation.

3

FindtheSm_

Profile_

Configobjectinthepalette,

dragitintotheworkspace,andright-click.

4

Closetheobjectpalette.


13/24

CreatingtheNe

twork 1

5

Thenetworkisnowbuiltandshouldlooksimilartoth

e

followingfigure.

TheFinishedFirstFloorNetw

ork

Youarenowreadytobe

gincollectingstatistics.

CollectingStatistics 1

6

Collectin

gStatistics

Youcancollectstatisticsfromindividualnodesinyour

network(objectstatistics)orfromtheentirenetwork

(globals

tatistics).

Nowthat

youhavecreatedthenetwor

k,youshould

decidewhichstatisticsyouneedtoco

llecttoanswer

thequestionspresentedearlierinthis

lesson:

Willtheserverbeabletohandle

theadditional

loadofthesecondnetwork?

Willthetotaldelayacrossthene

tworkbe

acceptableoncethesecondnetworkisinstalled?

Toanswe

rthesequestions,youneedasnapshotof

currentperformanceforcomparison.T

ogetthis

baseline,youwillcollectoneobjectstatistic,Server

Load,an

doneglobalstatistic,Ethern

etDelay.


14/24


7

Serverloadisakeystatisticthatreflectsthe

performanceoftheentirenetwork.

Tocollectstatistic

s

relatedtotheserverslo

ad,

dothefollowingsteps:

1

Right-clickontheservernode(node_

31)and

selectChooseInd

ividualStatisticsfromthe

serversObjectpop-upmenu.

TheChooseRe

sultsdialogboxfornode_

31

appears.

TheChooseResultsdialogboxhierarchically

organizesthestatisticsyoumaycollect.

Tocolle

ct

theEthernetloadontheserver:

2

Clicktheplussign

nexttoEthernetintheChoose

Resultsdialogbox

toexpandtheEthernetstatistic

hierarchy.


8

ChooseResultsDialogBox

3

Clic

kthecheckboxnexttoLoad

(bits/sec)to

ena

blecollectionforthatstatistic

.

4

Clic

kOKtoclosethedialogbox.


15/24


9

Globalstatisticscanbeusedtogatherinformation

aboutthenetworkasawhole.

Forexample,youcan

findoutthedelayforthe

entirenetworkbycollecting

theglobalDelaystatistic:

1

Right-clickinthew

orkspace(butnotonanobject)

andselectChoose

IndividualStatisticsfromthe

Workspacepop-up

menu.

GlobalStatisticChosen

2

ExpandtheGlobalStatisticshierarchy.

3

ExpandtheEthern

ethierarchy.


0

4

Clic

kthecheckboxnexttoDelay

(sec)toenable

datacollection.

5

Clic

kOKtoclosetheChooseRe

sultsdialogbox.

Itisgood

togetintothehabitofsavingyourproject

everyso

often.

Tosavetheproject:

1

Cho

oseFile>Save,

thenclickO

K(theproject

alre

adyhasaname,soyoudontneedtorename

it).

Nowthat

youhavespecifiedwhichsta

tisticstocollect

andsave

dtheproject,youarealmost

readytorun

yoursimulation.

First,

though,verifythatyourreposito

riespreference

isset.Re

positoriescontainuser-definedcomponents

suchasprocessmodelsandpipelinestagesthatare

savedso

thatsimulationswilltakelesstimetobegin

execution

.

1

Cho

oseEdit>Preferences.

2

TyperepositoriesintheFindfie

ldandclickon

the

Findbutton.


16/24


1

3

Ifthevalueforrep

ositoriesisnotstdmod,click

onthefieldanden

terstdmodinthedialogbox.

4

ClickOKtoclosetherepositoriesand

Preferencesdialo

gboxes

Torunasimulation:

1

SelectSimulation

>ConfigureDiscreteEven

t

Simulation.

Youcanalsoopen

theConfigureDiscrete

EventSimulationd

ialogboxbyclicking

ontheconfigure/runsimulationaction

button.

2

Type0.5

intheDu

ration:fieldtosimulate

one-halfhourofnetworkactivity.

ConfigureDiscreteEventSimulationDialogBox

3

ClicktheRunbuttontobeginthesimulation.


2

Whilethesimulationruns,adialogboxappears

sho

wingthesimulationsprogres

s.

SimulationSequenceDialogBox

The

dialogboxaboveshowsthat,in5secondsof

elapsed(actual)time,

ITGuruhassimulated15

min

utesand19secondsofnetw

orktime.

The

entiresimulationshouldtakeless

thanoneminute

toc

ompletetheelapsedtimevariesaccording

tothespeedofyourcomputer.

4

Whenthesimulationfinishes,thecontentsofthe

Messagestabappears.

Clickthe

Closebuttonin

the

SimulationSequencedialog

box.

E

lapsedTime:Numberofsecondsthesimulationhasrun

SimulatedTime:Minutesofnetworktime


17/24


3

5

Ifyoursimulationd

oesnotcomplete,

ifnoresults

werecollected,or

iftheresultsvarysignificantly

fromthoseshown,youwillhavetotroubleshoot

yoursimulation.See"TroubleshootingTutorial

Simulations".

ViewingResults 2

4

ViewingResults

Youcanviewresultsgraphicallyinthe

ProjectEditorby

selecting

ViewResultsfromtheWork

spacepop-up

menu.

Afteryou

rsimulationhasexecuted,yo

uwillwantto

seetheinformationcollectedforeach

statistic.

There

areseveralwaystoviewresults;inthislessonyouwill

usetheV

iewResultsoptionintheWo

rkspacepop-up

menu.

Youwilllearndifferentwaystoviewre

sultsinlater

lessons.

ToviewtheserverEthernetloadforth

esimulation:

1

Right-clickontheservernode(n

ode_

31)choose

ViewResultsfromtheserversObjectpop-up

menu.

T

henodesViewResultsdialo

gboxopens.

2

Exp

andtheOfficenetwork.nod

e_

31>Ethernet

hierarchy.

3

Clic

konthecheckboxnexttoLo

ad(bits/sec)to

indicatethatyouwanttoviewthatresult.


18/24

ViewingResults 2

5

4

ClicktheShowbu

ttonintheViewResultsdialo

g

box.

Thegraphoftheserverloadappearsinthe

ProjectEditor,a

sshowninthefollowingfigure.

Thegraphoftheserver

loadshouldresemblethe

followinggraph.

Yourresultsmaydifferslightlydueto

differencesinnodeplac

ementandlinklength,

butthe

generaltrendsshouldbeconsistent.

ServerLoadGraph

Simulationtime,inminutes

bits/second.The

unitofmeasure

onthisaxisis

showninthe

statisticinthe

ChooseResults

dialogbox

ViewingResults 2

6

Notethatatitspeak,theloadonthes

erveriswell

below6,000bits/second.

Youwillneedthisbaseline

forcomparisonafteryouaddtheseco

ndnetwork.

Whenyoufinishviewingtheserverloadgraph,close

thisdialogboxandtheViewResultsd

ialogbox.(Ifthe

systemp

romptsyou,choosetodelete

thegraph

panel.)

Youalso

shouldlookattheGlobalEth

ernetDelayon

thenetwork.

Toviewthisstatistic:

1

Right-clickintheworkspace,

the

nselectView

Res

ultsfromthepop-upmenu.

2

Che

cktheboxnexttoGlobalStatistics>

Eth

ernet>Delay,thenclickthe

Showbuttonto

view

theEthernetdelayforthew

holenetwork.


19/24

ViewingResults 2

7

ViewingEthernetDelayfortheWholeNetwork

TheEthernetdelaygraphappearsinthe

ProjectEditor.Thegraphshouldresemblethe

followingfigure.

ViewingResults 2

8

EthernetDelayGraph

Notethatafterthenetworkreachessteadystatethe

maximum

delayisaround0.4milliseconds.

Whenyouarefinishedviewingthegra

ph,closeitand

theView

Resultsdialogbox.


Seconds


20/24

ExpandingtheNe

twork 2

9

ExpandingtheNetwo

rk

Youhavecreatedabaselinenetworkandgathered

statisticsaboutit.Nowy

ouarereadytoexpandthe

networkandverifythatitstilloperatessufficientlywell

withtheadditionalload.

Whenperformingawhat-ifcomparison,

itis

convenienttostorethebaselinenetworkasone

scenarioandcreatethe

experimentalnetworkasa

differentscenario.

Youw

illduplicatetheexisting

scenarioandmakechangestoitinsteadofbuilding

thenewtopologyfromthebeginning.

Toduplicateascenario:

1

ChooseScenarios>DuplicateScenario...

2

Enterexpansionasthenameforthenew

scenario.

3

ClickOK.

Thescenario,w

ithallthenodes,links,

statistics,andth

esimulationconfiguration,is

duplicatedandnamedexpansion.

E

xpandingtheNetwork 3

0

Theseco

nd-floorsegmentwillresemb

lethefirst-floor

segment,

butwillnothaveaserverof

itsown.

Tobuild

thenewsegment:

1

SelectTopology>RapidConfiguration.

2

Cho

oseStarforthetopologyandclickOK...

3

Com

pletetheRapidConfiguratio

ndialogboxwith

thesevalues:

CenterNodeModel:

3C_

SSII_

1100_

3300_

4s_ae

52_e48_ge3

PeripheryNodeModel:Sm_

Int_wkstn

Number:15

Linkmodel:10BaseT

X:75,

Y:62.5,

Radius:20

RapidConfigurationDialogBox


21/24

ExpandingtheNe

twork 3

1

4

ClickOKtocreate

thenetwork.

Jointhetwonetworks:

1

Ifitisnotalreadyo

pen,clicktheaction

buttontoopenthe

objectpalette.

2

DragtheCisco2514routericonintothe

workspacebetwee

nthetwonetworks.Right-click

toturnoffnodecreation.

3

Clickonthe10BaseTlinkiconintheobject

palette.

4

Create10BaseTlinksbetweentheCiscorouter

(node_

50)andthe

3Comswitchesatthecente

r

ofeachstar.

5

Right-clicktoturnofflinkcreation.

6

Closetheobjectpalette.

7

SelectFile>Save

.

E

xpandingtheNetwork 3

2

Thefinal

networkshouldlooklikethis:

TheFinalN

etwork

Toruntheexpansionscenario:

1

SelectSimulation>ConfigureDiscreteEvent

Sim

ulation.

2

VerifythattheDurationissetto

0.5

hours.


22/24

ExpandingtheNe

twork 3

3

3

ClicktheRunbuttontobeginthesimulation.

SimulationSequenceD

ialogBox,SimulationSpeedTabSe

lected

Asbefore,awin

dowappearsshowingthe

simulationspro

gress.

WhentheSimulation

Speedtabisse

lected,ananimatedgraph

showsboththe

currentandaveragespeedin

eventsperseco

nd.

4

Whenthesimulationisdone,closetheSimulation

Sequencedialogb

ox.Ifyouhadproblems,see

"TroubleshootingT

utorialSimulations".

ComparingResults 3

4

ComparingResults

Toanswe

rthequestionsposedabout

theadditionofa

secondn

etworktotheexistingLAN,youneedto

compare

theresultsfrombothofthes

imulationsyou

ran.

Youwillu

setheCompareResultsmenuiteminthe

ObjectandWorkspacepop-upmenus

tocombine

statistics

fromdifferentscenariosinth

esamegraph.

Tolooka

ttheserverloadfrombothsc

enariosatonce:

1

Right-clickontheservernode(n

ode_

31)tobring

upitsObjectpop-upmenu.

2

Cho

oseCompareResults(you

candothisfrom

eith

erscenariointheproject).

A

ViewResultsdialogboxappearscontaining

a

hierarchicalrepresentationofstatistics

c

ollectedfortheservernode.

Ifyourresultsdifferradicallyfromthos

eshowninthe

following

figures,youwillhavetotroub

leshootyour

simulation.

See"TroubleshootingTutorialSimulations".


23/24

ComparingResults 3

5

Whencomparingresults,choosingastatisticinone

scenarioproducesagra

phshowingthevalueofthat

statisticinallscenarios.

Toviewtheresults:

1

SelecttheOfficeN

etwork.node_

31>Etherne

t

>Load(bits/sec)

statisticandclicktheShow

button.

Yourresultsshouldresemblethoseinth

e

followingfigure(bu

tmaynotbeidentical):

ServerLoadCompared


bits/second

ComparingResults 3

6

ThefollowinggraphisthetimeaverageoftheEthernet

loadbetw

eenthebaseline(first_

floor)

scenarioand

theexpansionscenario.

Youwilllearn

howtocreatea

graphofthetimeaverageinthenextlesson.

Time-avera

gedServerLoadCompared

Notethatwhiletheaverageloadforth

eexpansion

scenario

ishigher(asexpected),theloadasawhole

appearstobelevelingoff(thatis,notmonotonically

increasin

g),indicatingastablenetwor

k.


24/24

ComparingResults 3

7

Thelaststepistoseehowmuchthenetworksdelayis

affectedbyaddingasecondfloor.Tocompare

Ethernetdelayforthetw

oscenarios:

1

ClosethegraphandtheCompareResultsdialo

g

boxfortheserver.

2

Right-clickinthew

orkspace,

thenselect

CompareResults

fromtheWorkspacepop-up

menu.

3

SelecttheGlobal

Statistics>Ethernet>Dela

y

(sec)statistic.

4

ClickShowtodisp

laythegraph.

ThegraphoftheGlobalEthernetDelay

appears.

ComparingResults 3

8

Yourgrap

hofEthernetDelayshouldresemblethe

following:

EthernetDelayCompared

Thisgrap

hshowsthatthereisnosignificantchangein

Ethernet

delayonthenetwork.

Althoughserverload

hasincre

ased,

delayhasnot.

SelectFile>Closeandsavechangesbeforeclosing.

Simulationtime,inm

inutes

Seconds

csc305-lab1(1).pdf data communications and networks

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