CN 3 - ETHERNET LAN USING N NODES

3. Implement an Ethernet LAN using n nodes and set multiple traffic nodes and plot congestion window for different source / destination.

cn3.tcl - PROGRAM

# Simulation parameters setup

set val(stop) 10.0 ;# time of simulation end

# Initialization

#Create a ns simulator

set ns [new Simulator]

#Open the NS trace file

set tracefile [open 5.tr w]

$ns trace-all $tracefile

#Open the NAM trace file

set namfile [open 5.nam w]

$ns namtrace-all $namfile

$ns color 1 Blue

$ns color 2 Red

# Nodes Definition

#Create 9 nodes

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

set n4 [$ns node]

set n5 [$ns node]

set n6 [$ns node]

set n7 [$ns node]

set n8 [$ns node]

# Create LAN

$ns make-lan "$n3 $n4 $n5 $n6 $n7 $n8" 512Kb 50ms LL Queue/DropTail

# Links Definition

#Createlinks between nodes

$ns duplex-link $n1 $n0 2.0Mb 50ms DropTail

$ns queue-limit $n1 $n0 50

$ns duplex-link $n2 $n0 2.0Mb 50ms DropTail

$ns queue-limit $n2 $n0 50

$ns duplex-link $n0 $n3 1.0Mb 50ms DropTail

$ns queue-limit $n0 $n3 7

#Give node position (for NAM)

$ns duplex-link-op $n1 $n0 orient right-down

$ns duplex-link-op $n2 $n0 orient right-up

$ns duplex-link-op $n0 $n3 orient right

# Agents Definition

#Setup a TCP/Reno connection

set tcp0 [new Agent/TCP/Reno]

$ns attach-agent $n1 $tcp0

set sink1 [new Agent/TCPSink]

$ns attach-agent $n7 $sink1

$ns connect $tcp0 $sink1

$tcp0 set packetSize_ 1500

$tcp0 set class_ 1

set tfile1 [open cwnd1.tr w]

$tcp0 attach $tfile1

$tcp0 trace cwnd_

#Setup a TCP/Vegas connection

set tcp5 [new Agent/TCP/Vegas]

$ns attach-agent $n2 $tcp5

set sink6 [new Agent/TCPSink]

$ns attach-agent $n8 $sink6

$ns connect $tcp5 $sink6

$tcp5 set packetSize_ 1500

$tcp5 set class_ 2

set tfile2 [open cwnd2.tr w]

$tcp5 attach $tfile2

$tcp5 trace cwnd_

# Applications Definition

#Setup a FTP Application over TCP/Reno connection

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

$ns at 0.3 "$ftp0 start"

$ns at 8.0 "$ftp0 stop"

#Setup a FTP Application over TCP/Vegas connection

set ftp4 [new Application/FTP]

$ftp4 attach-agent $tcp5

$ns at 0.3 "$ftp4 start"

$ns at 8.0 "$ftp4 stop"

# Termination

#Define a 'finish' procedure

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam 5.nam &

exit 0

}

$ns at $val(stop) "$ns nam-end-wireless $val(stop)"

$ns at $val(stop) "finish"

$ns at $val(stop) "puts \"done\" ; $ns halt"

$ns run

cn3.awk - PROGRAM

BEGIN{}

{

if($6=="cwnd_")

{ printf("%f\t%f\n",$1,$7); }

}

END{}

STEPS :

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OUTPUT :

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X_GRAPH -1 :

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X_GRAPH -2 :

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X_GRAPH -3 :

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