NS-2 Tutorial - Part 2 -

University of Texas at Arlington

CSE 4346/5346 Networks II

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NS-2 TutorialNS-2 Tutorial- Part 2 -- Part 2 -

Choe, Hyun Jung (Stella)Choe, Hyun Jung (Stella) Spring 2008Spring 2008

Networks IINetworks IIDepartment of Computer Science and EngineeringDepartment of Computer Science and Engineering

The University of Texas at ArlingtonThe University of Texas at Arlington



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GTA Office HoursGTA Office Hours

Monday and Thursday 2:30 PM ~ 3:30 PM

NH 239

[email protected]



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OutlineOutline

• Simulation Examples

- Visualization: nam, xgraph

- Analysis example: awk

• Project

- Overview

- Submission Guideline

• Q & A


Simulation ExamplesSimulation Examples



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simple.tclsimple.tcl

#Create a simulator object

set ns [new Simulator]

#Open the NAM trace file

set nf [open out.nam w]

$ns namtrace-all $nf

# Open trace file

set tf [open out.tr w]

$ns trace-all $tf



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#Define a 'finish' procedure

proc finish {} {

global ns nf

$ns flush-trace

#Close the trace file

close $nf

exit 0

}



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#Create four nodesset n0 [$ns node]set n1 [$ns node]set n2 [$ns node]set n3 [$ns node]

#Create links between the nodes$ns duplex-link $n0 $n2 2Mb 10ms DropTail$ns duplex-link $n1 $n2 2Mb 10ms DropTail$ns duplex-link $n2 $n3 1.7Mb 20ms DropTail



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#Setup a TCP connectionset tcp [new Agent/TCP]$ns attach-agent $n0 $tcpset sink [new Agent/TCPSink]$ns attach-agent $n3 $sink$ns connect $tcp $sink$tcp set fid_ 1

#Setup a FTP over TCP connectionset ftp [new Application/FTP]$ftp attach-agent $tcp$ftp set type_ FTP



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#Setup a UDP connectionset udp [new Agent/UDP]$ns attach-agent $n1 $udpset null [new Agent/Null]$ns attach-agent $n3 $null$ns connect $udp $null$udp set fid_ 2

#Setup a CBR over UDP connectionset cbr [new Application/Traffic/CBR]$cbr attach-agent $udp$cbr set type_ CBR$cbr set packet_size_ 1000$cbr set rate_ 1mb



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#Schedule events for the CBR and FTP agents$ns at 0.1 "$cbr start"$ns at 1.0 "$ftp start"$ns at 4.0 "$ftp stop"$ns at 4.5 "$cbr stop"

#Detach tcp and sink agents (not really necessary)$ns at 4.5 "$ns detach-agent $n0 $tcp ; $ns detach-a

gent $n3 $sink"

#Call the finish procedure after 5 seconds of simulation time

$ns at 5.0 "finish"



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#Print CBR packet size and intervalputs "CBR packet size = [$cbr set packet_size_]"

puts "CBR interval = [$cbr set interval_]"

#Run the simulation$ns run



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TCP: Default ParametersTCP: Default Parameters

# max bound on window sizeAgent/TCP set window_ 100# congestion windows Agent/TCP set cwnd_ 10# initial/reset value of cwndAgent/TCP set windowInit_ 1# MSS sizeAgent/TCP set packetSize_ 1500



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NAMNAM#Define a 'finish' procedure

proc finish {} {

global ns nf

$ns flush-trace

#Close the trace file

close $nf

#Execute NAM on the trace file

exec nam out.nam &

exit 0

}



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awkawk

Set awkCodeTr { if ( NF == 12 ) {

event =$1time = $2

if (event = “d”) { dropCount += 1; print time, dropCount >> “drop.a”;}

}}



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XGRAPHXGRAPH

• exec xgraph -bb -tk -x time -y lossRatio -bg White -geometry 540x405 /tmp/team3/fs.xg &



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Using VariablesUsing Variables

set testTime 60.0………………

$ns at $testTime “$cbr0 stop”$ns at $testTime “$cbr1 stop”$ns at $testTime “tcp stop”$ns at [expr $testTime + 1.0] “finish”



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DiffServDiffServ

• To provide QoS by dividing traffic into different categories, scheduling packets accordingly

• Major components- Policy- Edge router- Core router

• Implementation- virtual queues, causing packets from one virtual

queue to be dropped more frequently than packets from another.



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DiffServ ConfigurationDiffServ Configuration

• $dsredq set numQueues_ 1• $dsredq setNumPrec 2

• $dsredq configQ 0 1 10 20 0.10• $dsredq setSchedularMode WRR

•$ns simplex-link $edge $core 10Mb 5ms dsRED/edge

•$ns simplex-link $core $edge 10Mb 5ms dsRED/core



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# Set DS RED parameters from Edge to Core:

set qEC [[$ns link $edge $core] queue]

$qEC meanPktSize $packetSize

$qEC set numQueues_ 1

$qEC setNumPrec 2

$qEC addPolicyEntry [$s1 id] [$dest id] TokenBucket 10 $cir0 $cbs0

$qEC addPolicyEntry [$s2 id] [$dest id] TokenBucket 10 $cir1 $cbs1

$qEC addPolicerEntry TokenBucket 10 11

$qEC addPHBEntry 10 0 0

$qEC addPHBEntry 11 0 1

$qEC configQ 0 0 20 40 0.02

$qEC configQ 0 1 10 20 0.10



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# Set DS RED parameters from Core to Edge:

set qCE [[$ns link $core $e1] queue]

$qCE meanPktSize $packetSize$qCE set numQueues_ 1$qCE setNumPrec 2$qCE addPHBEntry 10 0 0$qCE addPHBEntry 11 0 1$qCE configQ 0 0 20 40 0.0293$qCE configQ 0 1 10 20 0.10


ProjectProject



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Phase 1Phase 1

• Purpose- To be familiar with NS2- To master how to configure network topology

• Stepsi. Setup system environmentii. Run specified two example filesiii. Establish specified network topologyiv. Establish traffic flowsv. Submit your file

You are free to experiment various parameters if your simulation satisfies requirements, specified topology and traffic flows!



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Phase 2Phase 2

• Purpose- To know how to trace/monitor/analyze simulation

results - To understand different characteristics of TCP and

UDP congestion control

• Requirements- Simulate your program with specified parameter

values- Generate result graphs to verify the performance- Compare and analyze the results- Make a comprehensive analysis report



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TopologyTopology

2 Mbps, 10ms5 Mbps, 5/10ms 1 Mbps, 10ms

R1 R4

R2

R3

R5 R6

Host 1

Host 2

Host 3

Host 4

Host 5

Host 6



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Phase 3Phase 3

• Purpose- To help the student master the concepts and

practices quality of service (QoS) and traffic management

• Requirement- Use Differentiated Service modules- Try to satisfy specified QoS requirements



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Phase 4Phase 4

• Purpose- To help the student master the concepts and

practices of traffic engineering - To compare and analyze the relationship of

measured performance metrics

• Requirement- Measure additional QoS metrics- Compare the results



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Submission FormatSubmission Format

• Analysis Report- *.ps or *.pdf

• Readme - *.txt

• phase#_last name.* - phase4_choe.tcl, phase4_choe.ps,

phase4_choe.tar.gz



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CompressionCompression

• mkdir phase1• cp files phae1• tar –cvf project.tar ./phase1• gzip phase1.tar

phase1.tar.gz [email protected]

Please DO NOT include trace files!



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Hard Deadline Hard Deadline

• Hard copy- to Gergely Záruba prior to the beginning of class on the due date

• Soft copy- to [email protected] prior to the beginning of class on the due date

• Late submissions will receive 10% (of the total possible grade) deduction. They will also be amortized 20% (of the total possible grade) each day after the assignment was due.

Documents

NS-2 Tutorial - Part 2 -