21CS52 Program 3

#Create Simulator 
set ns [new Simulator] 
#Use colors to differentiate the traffic 
$ns color 1 Blue 
$ns color 2 Red 
#Open trace and NAM trace file 
set ntrace [open prog3.tr w] 
$ns trace-all $ntrace 
set namfile [open prog3.nam w] 
$ns namtrace-all $namfile 
#Finish Procedure 
proc Finish {} {
global ns ntrace namfile
#Dump all trace data and close the file 
$ns flush-trace 
close $ntrace 
close $namfile 
#Execute the nam animation file 
exec nam prog3.nam & 
#Find the number of ping packets dropped 
puts "The number of ping packets dropped are " 
exec grep "^d" prog3.tr | cut -d " " -f 5 | grep -c "ping" &
 exit 0 
} 
#Create six nodes 
for {set i 0} {$i < 6} {incr i} { 
set n($i) [$ns node] 
} 
#Connect the nodes
for {set j 0} {$j < 5} {incr j} {
 $ns duplex-link $n($j) $n([expr ($j+1)]) 0.1Mb 10ms DropTail 
} 
#Define the recv function for the class 'Agent/Ping' 
Agent/Ping instproc recv {from rtt} {
 $self instvar node_ puts "node [$node_ id] received ping answer from $from with round trip time $rtt ms" 
} 
#Create two ping agents and attach them to n(0) and n(5) 
set p0 [new Agent/Ping] 
$p0 set class_ 1 
$ns attach-agent $n(0) $p0 
set p1 [new Agent/Ping] 
$p1 set class_ 1 
$ns attach-agent $n(5) $p1 
$ns connect $p0 $p1
#Set queue size and monitor the queue 
#Queue size is set to 2 to observe the drop in ping packets 
$ns queue-limit $n(2) $n(3) 2 
$ns duplex-link-op $n(2) $n(3) queuePos 0.5 
#Create Congestion 
#Generate a Huge CBR traffic between n(2) and n(4) 
set tcp0 [new Agent/TCP] 
$tcp0 set class_ 2 
$ns attach-agent $n(2) $tcp0 
set sink0 [new Agent/TCPSink] 
$ns attach-agent $n(4) $sink0 
$ns connect $tcp0 $sink0
#Apply CBR traffic over TCP 
set cbr0 [new Application/Traffic/CBR] 
$cbr0 set packetSize_ 500 
$cbr0 set rate_ 1Mb 
$cbr0 attach-agent $tcp0 
#Schedule events 
$ns at 0.2 "$p0 send" 
$ns at 0.4 "$p1 send" 
$ns at 0.4 "$cbr0 start" 
$ns at 0.8 "$p0 send" 
$ns at 1.0 "$p1 send" 
$ns at 1.2 "$cbr0 stop" 
$ns at 1.4 "$p0 send" 
$ns at 1.6 "$p1 send" 
$ns at 1.8 "Finish" 
#Run the Simulation 
$ns run