Notes

set ns [new Simulator]
set f [open 3.tr w]

set nf [open 3.nam w]
$ns trace-all $f
$ns namtrace-all $nf
#===================================
# Nodes Definition
#===================================
#Create 6 nodes
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
set n4 [$ns node]
set n5 [$ns node]

$n0 label "Ping 0"
$n1 label "Ping 1"
$n2 label "R1"
$n3 label "R2"
$n4 label "Ping 4"
$n5 label "Ping 5"

$ns color 1 "red"
$ns color 2 "blue"
$ns color 3 "green"
$ns color 4 "orange"

set Ping0 [new Agent/Ping]
$ns attach-agent $n0 $Ping0

set Ping1 [new Agent/Ping]
$ns attach-agent $n1 $Ping1

set Ping4 [new Agent/Ping]
$ns attach-agent $n4 $Ping4

set Ping5 [new Agent/Ping]
$ns attach-agent $n5 $Ping5

$ns connect $Ping0 $Ping4
$ns connect $Ping1 $Ping5

$ns duplex-link $n0 $n2 2.0Mb 10ms DropTail
$ns duplex-link $n1 $n2 2.0Mb 10ms DropTail
$ns duplex-link $n2 $n3 1.0Mb 10ms DropTail
$ns duplex-link $n4 $n3 10.0Mb 10ms DropTail
$ns duplex-link $n3 $n5 10.0Mb 10ms DropTail

#Give node position (for NAM)
$ns duplex-link-op $n0 $n2 orient right-down
$ns duplex-link-op $n1 $n2 orient right-up
$ns duplex-link-op $n2 $n3 orient right
$ns duplex-link-op $n4 $n3 orient left-down
$ns duplex-link-op $n3 $n5 orient right-down

#===================================
# Agents Definition
#===================================

#===================================
# Applications Definition
#===================================

#===================================
# Termination
#===================================
#Define a 'finish' procedure
proc finish {} {
global ns f nf
$ns flush-trace
close $f
close $nf
exec nam 3.nam &
exit 0
}
proc sendPingPacket {} {
global ns Ping0 Ping1
set intervalTime 0.001
set now [$ns now]
$ns at [expr $now + $intervalTime] "$Ping0 send"
$ns at [expr $now + $intervalTime] "$Ping1 send"
$ns at [expr $now + $intervalTime] "sendPingPacket"
}

Agent/Ping instproc recv {from rtt} {
global seq
$self instvar node_
puts "the node [$node_ id] received an ACK from the node $from with RTT $rtt ms"
}


$ns at 0.01 "sendPingPacket"
$ns at 10.0 "finish"
$ns run