# Star Topology
set ns [new Simulator]

set nf [open st.nam w]
$ns namtrace-all $nf

proc finish {} {
global ns nf
$ns flush-trace
close $nf
exec nam st.nam &
exit 0
 }

set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]

$ns duplex-link $n0 $n2 10Mb 10ms DropTail
$ns duplex-link $n1 $n2 10Mb 10ms DropTail
$ns duplex-link $n2 $n3 10Mb 10ms DropTail

$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 at 5.0 "finish"

$ns run

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#Throuhput Latency

set ns [new Simulator]

$ns color 1 red
$ns color 2 green

set nf [open tl.nam w]
$ns namtrace-all $nf

set nt [open tl.tr w]
$ns trace-all $nt

proc finish {} {
global ns nf nt
$ns flush-trace
close $nf
close $nt
exec nam tl.nam &
exec awk -f throughput.awk tl.tr &
exit 0
}

set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]

$ns duplex-link $n0 $n2 10Mb 10ms DropTail
$ns duplex-link $n1 $n2 10Mb 10ms DropTail
$ns duplex-link $n2 $n3 10Mb 10ms DropTail

$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

set tcp [new Agent/TCP]
$tcp set class_ 2
$ns attach-agent $n0 $tcp
set sink [new Agent/TCPSink]
$ns attach-agent $n3 $sink
$ns connect $tcp $sink
$tcp set fid_ 1

set ftp [new Application/FTP]
$ftp attach-agent $tcp
$ftp set type_ FTP
$ftp set packet_size_ 1000
$ftp set rate_ 1mb

set udp [new Agent/UDP]
$ns attach-agent $n1 $udp
set null [new Agent/Null]
$ns attach-agent $n3 $null
$ns connect $udp $null
$udp set fid_ 2

set cbr [new Application/Traffic/CBR]
$cbr attach-agent $udp
$cbr set type_ UDP
$cbr set packet_size_ 1000
$cbr set rate_ 1mb

$ns at 1.0 "$ftp start"
$ns at 2.0 "$ftp stop"

$ns at 1.2 "$cbr start"
$ns at 2.2 "$cbr stop"

$ns at 5.0 "finish"

$ns run



# throughput.awk

BEGIN {
stime=0
ftime=0
flag=0
fsize=0
throughput=0
latecy=0
}

{
if($1=="r" && $4==3)
 {
  fsize+=$6
  if(flag==0)
   {
    stime=$2
    flag=1
   }
  ftime=$2
 }
}

END {
latency=ftime-stime
throughput=(fsize*8)/latency
printf("\nLatency: %f",latency)
printf("\nThroughput: %f",throughput)
}

----------------------------------------------------------------------------------------

#ping

set ns [new Simulator]

set tracefile [open out.tr w]
$ns trace-all $tracefile

set namfile [open out.nam w]
$ns namtrace-all $namfile

proc finish {} {
    global ns tracefile namfile
    $ns flush-trace
    close $tracefile
    close $namfile
    exec nam out.nam &
    exec awk -f pingtp.awk out.tr &
    exit 0
}

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 "ping0"
$n1 label "ping1"
$n2 label "R1"
$n3 label "R2"
$n4 label "ping4"
$n5 label "ping5"
$ns color 1 red
$ns color 2 blue
$ns color 3 green
$ns color 4 orange

$ns duplex-link $n0 $n2 1Mb 10ms DropTail
$ns duplex-link $n1 $n2 0.4Mb 10ms DropTail
$ns duplex-link $n2 $n3 4Kb 10ms DropTail
$ns duplex-link $n3 $n4 1Mb 10ms DropTail
$ns duplex-link $n3 $n5 1Mb 10ms DropTail

$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 $n3 $n4 orient right-up
$ns duplex-link-op $n3 $n5 orient right-down

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

$ping0 set class_ 1
$ping1 set class_ 2
$ping4 set class_ 3
$ping5 set class_ 4

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



# Pingtp.awk

BEGIN {
 count=0
}

{
 event=$1
 if(event=="d") {
   count++
 }
}

END {
 printf("No. of Packets dropped: %d\n",count);
}

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