NS2 - Program 4

 #  TCP Variant Tahoe

# ========================

#

#     (0)tcp0,ftp0     (5)tcpSink0

# \   /

#   \2Mb /2Mb

# 2Mb    \   3Mbps /   2Mb

# (1)---------(3)---------------(4)------------(6)tcpSink1

#   tcp1,ftp1  / \

#   /2Mb \2Mb

# /   \

#    (2)tcp2,ftp2     (7)tcpSink2

#   

#

# [.001s]

#  tcp0 [1000b]----------> tcpsink0

# [.001s]

#  tcp1 [1000b]----------> tcpsink1

# [.001s]

#  tcp2 [1000b]----------> tcpsink2

#

#  All 10ms DropTail

# 

set ns [new Simulator]

set f0 [open tahoe0.tr w]

set f1 [open tahoe1.tr w]

set f2 [open tahoe2.tr w]

set nr [open taho.tr w]

$ns trace-all $nr

set nf [open taho.nam w]

$ns namtrace-all $nf

#Define a 'finish' procedure

proc finish {} {

global ns nr nf f0 f1 f2

$ns flush-trace

   #Close the NAM trace file

   close $nf

close $nr

close $f0

close $f1

close $f2

exec nam taho.nam &

exec xgraph tahoe0.tr tahoe1.tr tahoe2.tr -bg white -t ConjestionWindowAnalysis_Tahoe -x Seconds -y ConjestionWindowSize

   exit 0

}

#for{set i 0} {$i<12} {incr i}{

#set n($i) [$ns node]

#}

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]

#creating links

#for {set i 0} {$i<9}{incr i}{

#$ns duplex-link $n($i) $n([expr$i+1]) 1Mb 10ms DropTail

#} 

$ns duplex-link $n0 $n3 2Mb 10ms DropTail

$ns duplex-link $n1 $n3 2Mb 10ms DropTail

$ns duplex-link $n2 $n3 2Mb 10ms DropTail

$ns duplex-link $n3 $n4 3Mb 10ms DropTail

$ns duplex-link $n4 $n5 2Mb 10ms DropTail

$ns duplex-link $n4 $n6 2Mb 10ms DropTail

$ns duplex-link $n4 $n7 2Mb 10ms DropTail

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

$ns duplex-link-op $n1 $n3 orient middle

$ns duplex-link-op $n2 $n3 orient right-down

$ns duplex-link-op $n3 $n4 orient middle

$ns duplex-link-op $n4 $n5 orient right-up

$ns duplex-link-op $n4 $n6 orient middle

$ns duplex-link-op $n4 $n7 orient right-down

#create a tcp agent and attach it to nodes

set tcp0 [new Agent/TCP]

$ns attach-agent $n0 $tcp0

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

$ftp0 set packetSize_ 1000

$ftp0 set interval_ 0.001

set tcpsink0 [new Agent/TCPSink]

$ns attach-agent $n5 $tcpsink0

$ns connect $tcp0 $tcpsink0

set tcp1 [new Agent/TCP]

$ns attach-agent $n1 $tcp1

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

$ftp1 set packetSize_ 1000

$ftp1 set interval_ 0.001

set tcpsink1 [new Agent/TCPSink]

$ns attach-agent $n6 $tcpsink1

$ns connect $tcp1 $tcpsink1

set tcp2 [new Agent/TCP]

$ns attach-agent $n2 $tcp2

set ftp2 [new Application/FTP]

$ftp2 attach-agent $tcp2

$ftp2 set packetSize_ 1000

$ftp2 set interval_ 0.001

set tcpsink2 [new Agent/TCPSink]

$ns attach-agent $n7 $tcpsink2

$ns connect $tcp2 $tcpsink2

#setting colour

$tcp0 set fid_ 1 #to set flow ID

$tcp1 set fid_ 2

$tcp2 set fid_ 3

#flow ID 1 --->RED

$ns color 1 Red

$ns color 2 Green

$ns color 3 Blue

proc record {} {

global ns tcp0 tcp1 tcp2 f0 f1 f2

set time 0.01

set wnd0 [$tcp0 set cwnd_]

set wnd1 [$tcp1 set cwnd_]

set wnd2 [$tcp2 set cwnd_]

set timenow [$ns now]

puts $f0 "$timenow $wnd0"

puts $f1 "$timenow $wnd1"

puts $f2 "$timenow $wnd2"

$ns at [expr $timenow + $time] "record"

}

$ns at 0.1 "record"

$ns at 0.5 "$ftp0 start"

$ns at 1.0 "$ftp1 start"

$ns at 1.5 "$ftp2 start"

$ns at 25.0 "$ftp0 stop"

$ns at 25.5 "$ftp1 stop"

$ns at 26.0 "$ftp2 stop"

$ns at 27.0 "finish"

$ns run