Lab 1: Switch vs Hub Objective This lab teaches the differences between using a Hub or a switch in a LAN using Riverbed Modeler 17.5. In this lab the student will create a LAN with a hub and then re!lace the hub with the switch. The student will then e"a#ine the change in through!ut and dela$ in the LAN when u!grading fro# a hub to a switch.
Overview %thernet hubs wor& at the !h$sical la$er si#!l$ re!eating an$ fra#es the$ receive on one !ort onto all other !orts. 'or this reason the$ are also called #ulti!ort re!eaters. Hubs are la$er 1 devices. All the nodes connected to a hub are considered to be !art of the sa#e broadcast do#ain. In other words an$ fra#e trans#itted b$ one of the nodes will be received b$ all the rest. This configuration can li#it through!ut as all nodes #ust share the ca!acit$ of the LAN. (n the other hand switches are la$er ) devices and hence forward fra#es onl$ to the !ort that is connected to the ethernet fra#e*s destination. +ince switches switches forward fra#es onl$ on a single line the$ create #ulti!le broadcast do#ains leading to great gains in through!ut. The through!ut of a switch is restricted however b$ its !rocessing s!eed the s!eed at which it can forward fra#es onto the correct outgoing lin&. NOTE 1: Remember to save your models in you P Drive. You do not have access to save in the C drive. To load your saved models, you need to add your P drive in the models directory. NOTE : Do not !o and chan!e anythin! in the "rocess model. Your models #ill sto" com"ilin!
Lab Instructions Step 1: LAN using Hubs ,reate $our LAN using the hub and the ethernet wor&stations. 1.
,lic& ,lic& +tart - River Riverbed bed #odeler #odeler acade#ic acade#ic edition edition 17.5 - River Riverbed bed #odeler #odeler 17.5 a. NOTE: NOTE: it will will take some some time time to load. load. DO NOT NOT PRESS PRESS IT IT AGAIN AGAIN
). ou will will see see the the licens license e agree# agree#ent ent / Accept it 0. ou will will now now see see the the #ode #odell ller er.. . To create create a new new !ro2e !ro2ect ct cli clic& c& on File → New. New . ou ou will see the following dialog bo". 5. +ele +elect ct 3ro 3ro2e 2ect ct and and 3re 3ress ss ok. ok. 4. ou !ro2e !ro2ect ct editor editor wor&s! wor&s!ace ace will will o!en now. now. %nter %nter !ro2ect !ro2ect na#e na#e as LA1 and LA1 and change scenario na#e to onl! onl! hubs6 hubs6 7. 'ro# 'ro# the the ne"t ne"t dialog dialog bo" bo" selec selectt "reate "reate e#pt! scenario6 scenario6 and !ress Ne$t . 'ro# 'ro# the the ne"t ne"t dialog dialog bo" bo" selec selectt "a#pus "a#pus66 and !ress Ne$t 8. 9on*t 9on*t change change the si:e si:e 2ust 2ust !ress !ress Ne$t. Ne$t. 1;. 9on*t select select an$ technolog$ technolog$ 2ust 2ust !ress Ne$t. Ne$t. 11. 11. The setu! setu! is co#!lete co#!lete.. 3ress 3ress Finish 1). ou ou will now be able to see the ob2ect !alette !alette and the 3ro2ect wor&s!ace Now $ou will learn a
&api' "on(iguration. "on(iguration .
1. +et the the ,onfigur ,onfiguration ation to Star and clic& on Ne$t. Ne$t.
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15. +et the ,enter Node Model to ethernet)*+hub. 14. +et the 3eri!her$ Node Model to ethernet+wkstn. 17. +et the Lin& Model to 1,ase% and set the Nu#ber to 1*. 1. ,lic& O- to create the LAN.
18. ou shold now see the following LAN created.
);. Now add an .thernet server fro# the ob2ect !alette and connect it to the hub using a 1,ase% lin&. )1. Now add an application con(iguration and a pro(ile con(iguration ob2ects fro# the ob2ect !alette. a.
,onfigure the web a!!lication to heav$ browsing. ,hange the ob2ect si:e to 1,,,,b!tes and change the i#age to large i#age
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b.
,reate a !rofile for this a!!lication and a!!l$ it to each wor&station. Right=clic& on an$ of the station and choose +elect +i#ilar Nodes. Ne"t right clic& on one of the stations and choose %dit Attributes. 3ut a chec& in the chec&bo" ne"t to A!!l$ ,hanges to +elected (b2ects. And now add the !rofile.
)). ou networ& should loo& li&e this.
)0. Now select the statistics $ou want to collect. a. +elect the +i#ulation tab
,hoose
Individual +tatistics>
b.
%"!and the Node +tatistics ite# and select? ,lient htt! +erver htt! and %thernet
c.
%"!and the @lobal +tatistics ite# and the %thernet ite# and select the 9ela$
d. ,lic& on ( to close the window. ). Now run the si#ulation for 1; #inutes. )5. ,hec& $our results.
Step *: LAN using a Switch 1. 9u!licate the +cenario a. ,hoose Scenarios /uplicate Scenario and na#e the new scenario Onl! Switch. b. ,lic& on O- to create the scenario. ).
&ight0click on the hub and choose .'it Attributes. Left clic& on the #odel attribute and choose enthernet1+switch+a'v fro# the !ull=down #enu.
0. Also change the na#e to be Switch. .
,lic& on O- to #a&e the change.
5.
Now $ou should get the scenario li&e the following?
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4. Run +i#ulation and ,o#!are Results a. +elect the Scenarios tab 2anage Scenarios b.
%dit the Results field in both rows and set the values to BcollectC or BrecollectC
c.
,lic& on O- to run both scenarios. Dhen the si#ulation is co#!leted clic& on "lose to close the window.
7. To co#!are the result select the &esult tab "o#pare &esults .
%"!and the %ra((ic Sink and select the %ra((ic &eceive' statistics. Eiew the statistics in As Is #ode. ,lic& on +how for a #ore detailed gra!h. This statistics shows the total of traffic received b$ all stations in the LAN. 'ro# the result we can see that the switch can al#ost handle twice traffic as #uch as the hub.
Lab 3uestions: 3uestion Lab141: ,o#!are the average HTT3 (b2ect Res!onse Ti#e and HTT3 3age Res!onse Ti#e for an$ wor&station for the two scenarios. %"!lain $our results. 3uestion Lab14*: ,o#!are the average ,ollision ,ount and the average Trans#ission Atte#!ts for an$ wor&station for the two scenarios. %"!lain $our results. 3uestion Lab14): ,o#!are the average traffic !rocessing ti#e and the average load on the web server for the two scenarios. %"!lain $our results. 3uestion Lab145: ,o#!are the @lobal %thernet dela$ for the two scenarios. %"!lain $our results.
The results graphs and eplanations !or these "uestions need to #e su#mitted in the la# report.
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Step ): switch an' hubs in the LAN Now create a new scenario for the following networ&
Run the si#ulation and co#!are the results with the !revious scenarios.
Lab 3uestions: 3uestion Lab146: ,o#!are the average HTT3 (b2ect res!onse ti#e and the average HTT3 !age res!onse for nodeF1 for the three scenarios. %"!lain $our results. 3uestion Lab14: ,o#!are the average ,ollision count and the average trans#ission atte#!ts for nodeF7 for the three scenarios. %"!lain $our results. 3uestion Lab147: ,o#!are the average %thernet dela$ and for nodeF4 for the three scenarios. %"!lain $our results. 3uestion Lab148: ,o#!are the average load and the average traffic !rocessing ti#e for the web server for the three scenarios. %"!lain $our results.
The results graphs and eplanations !or these "uestions need to #e su#mitted in the la# report.
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Step 5: Heav! application 1.
'or the three scearnios defined before u!date the a!!lication a.
).
,onfigure the web a!!lication to heav$ browsing. ,hange the ob2ect si:e to 16,,,, b!tes and change the i#age to large i#age 9with #ini#u# outco#e set to *,,,, an' #a$i#u# outco#e to 1,,,,,
Run the si#ulation and co#!are the results with the !revious scenarios.
Lab 3uestions: 3uestion Lab14;: ,o#!are the @lobal HTT3 (b2ect res!onse ti#e and the HTT3 !age res!onse for the three scenarios. %"!lain $our results. 3uestion Lab141,: ,o#!are the @lobal %thernet dela$ f or the three scenarios. %"!lain $our results.
The results graphs and eplanations !or these "uestions need to #e su#mitted in the la# report.
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