set ns [new Simulator]
set Bandwidth "1Mb"
set packetsize 5000
set wind 1
set cwnd 1 

$ns color 1 purple
$ns color 2 seagreen
$ns color 3 orange

foreach i " 0 1 2 3 4 5 6 " {
     set n$i [$ns node] 
   }

$n0 color "blue"
$n1 color "purple"
$n2 color "seagreen"
$n3 color "orange"
$n4 color "skyblue"
$n5 color "red"
$n6 color "black"

$ns at 0.0 "$n0 label Sender"
$ns at 0.0 "$n1 label Receiver1"
$ns at 0.0 "$n2 label Receiver2"
$ns at 0.0 "$n3 label Receiver3"

set nf [open bus.nam w]
$ns namtrace-all $nf
set f [open bus.tr w]
$ns trace-all $f

$ns duplex-link $n0 $n5 $Bandwidth 30ms DropTail
$ns duplex-link $n5 $n2 $Bandwidth 30ms DropTail
$ns duplex-link $n4 $n1 $Bandwidth 30ms DropTail
$ns duplex-link $n4 $n5 $Bandwidth 30ms DropTail
$ns duplex-link $n5 $n6 $Bandwidth 30ms DropTail
$ns duplex-link $n6 $n3 $Bandwidth 30ms DropTail

$ns duplex-link-op $n0 $n5 orient down
$ns duplex-link-op $n5 $n2 orient down
$ns duplex-link-op $n4 $n1 orient down
$ns duplex-link-op $n4 $n5 orient right
$ns duplex-link-op $n5 $n6 orient right
$ns duplex-link-op $n6 $n3 orient down

$ns queue-limit $n4 $n5 10

Agent/TCP set nam_tracevar_ true
Agent/TCP set window_ $wind
Agent/TCP set cwnd_ $cwnd

set tcp1 [new Agent/TCP]
$ns attach-agent $n0 $tcp1
$tcp1 set fid_ 1 ; 

set sink1 [new Agent/TCPSink]
$ns attach-agent $n1 $sink1

$ns connect $tcp1 $sink1 

set ftp1 [new Application/FTP]
$ftp1 attach-agent $tcp1

set tcp2 [new Agent/TCP]
$ns attach-agent $n0 $tcp2
$tcp2 set fid_ 1 ; 

set sink2 [new Agent/TCPSink]
$ns attach-agent $n2 $sink2

$ns connect $tcp2 $sink2

set ftp2 [new Application/FTP]
$ftp2 attach-agent $tcp2

$ns at 0.05 "$ftp1 start"
$ns at 0.35 "$ns detach-agent $n0 $tcp1 ; $ns detach-agent $n1 $sink1" 
$ns at 0.45 "$ftp2 start"
$ns at 0.90 "$ns detach-agent $n0 $tcp2 ; $ns detach-agent $n2 $sink2" 

$ns at 0.90 "finish"

proc finish {} {
        global ns nf
        $ns flush-trace
        close $nf
        exec awk {
               {
                 if ($1=="-" && $5=="tcp")  {
                     print $2  "\t" $11  
                 }
}
} bus.tr > throughput.data


        puts "filtering..."
        # exec tclsh ../bin/namfilter.tcl multicast.nam
        # puts "running nam..."
        exec nam bus.nam &
        exec xgraph throughput.data &
        exit 0
}

$ns run