Notes

# 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 p3.tr w]
$ns trace-all $tracefile
#Open the NAM trace file
set namfile [open p3.nam w]
$ns namtrace-all $namfile
# Nodes Definition
#Create 7 nodes
set n0 [$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]
# Links Definition
#Createlinks between nodes
#Add following line to create LAN
$ns make-lan "$n0 $n1 $n2 $n3 $n4 $n5" 100Mb 100ms LL Queue/DropTail
Mac/802_3

$ns duplex-link $n5 $n6 100.0Mb 10ms DropTail
$ns queue-limit $n5 $n6 50

#Give node position (for NAM)
$ns duplex-link-op $n5 $n6 orient right
# Agents Definition
#Setup a TCP connection
set tcp0 [new Agent/TCP]
$ns attach-agent $n0 $tcp0
set sink1 [new Agent/TCPSink]
$ns attach-agent $n6 $sink1
$ns connect $tcp0 $sink1
$tcp0 set packetSize_ 1500

#Setup a TCP connection
set tcp2 [new Agent/TCP]
$ns attach-agent $n3 $tcp2
set sink3 [new Agent/TCPSink]
$ns attach-agent $n4 $sink3
$ns connect $tcp2 $sink3
$tcp2 set packetSize_ 1500

# Applications Definition

#Setup a FTP Application over TCP connection
set ftp0 [new Application/FTP]
$ftp0 attach-agent $tcp0
$ns at 1.0 "$ftp0 start"
$ns at 2.0 "$ftp0 stop"

#Setup a FTP Application over TCP connection
set ftp1 [new Application/FTP]
$ftp1 attach-agent $tcp2
$ns at 1.0 "$ftp1 start"
$ns at 2.0 "$ftp1 stop"

#Add below code
set file1 [open file1.tr w]
$tcp0 attach $file1
set file2 [open file2.tr w]
$tcp2 attach $file2

$tcp0 trace cwnd_
$tcp2 trace cwnd_
#till here

#===================================
# Termination
#===================================
#Define a 'finish' procedure
proc finish {} {
global ns tracefile namfile
$ns flush-trace
close $tracefile
close $namfile
exec nam p3.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


#execute following commands one by one in command line to generate graph

#awk -f p3.awk file1.tr >a1
#awk -f p3.awk file2.tr >a2
#xgraph a1 a2