set ns [new Simulator]
set nf [open ass1.nam w]
$ns namtrace-all $nf
$ns rtproto Session
proc finish {} {

global ns nf
$ns flush-trace
close $nf

exec nam ass1.nam &
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]
set n6 [$ns node]
set n7 [$ns node]
set n8 [$ns node]
set n9 [$ns node]

$n1 color red
$n2 color cyan
$n3 color green
$n6 color green
$n0 color red
$n7 color cyan

$ns color 1 red
$ns color 2 blue
$ns color 3 green

$ns duplex-link $n1 $n2 20Mb 10ms DropTail
$ns duplex-link-op $n1 $n2 orient right
$ns duplex-link $n3 $n4 20Mb 10ms DropTail
$ns duplex-link-op $n3 $n4 orient right
$ns duplex-link $n4 $n5 20Mb 10ms DropTail
$ns duplex-link-op $n4 $n5 orient right
$ns duplex-link $n5 $n6 20Mb 10ms DropTail
$ns duplex-link-op $n5 $n6 orient right
$ns duplex-link $n1 $n4 20Mb 10ms DropTail
$ns duplex-link-op $n1 $n4 orient down
$ns duplex-link $n2 $n5 20Mb 10ms DropTail
$ns duplex-link-op $n2 $n5 orient down
$ns duplex-link $n8 $n9 20Mb 10ms DropTail
$ns duplex-link-op $n8 $n9 orient right

$ns simplex-link $n3 $n7 10Mb 5ms SFQ
$ns simplex-link-op $n3 $n7 orient down
$ns simplex-link $n4 $n8 10Mb 5ms SFQ
$ns simplex-link-op $n4 $n8 orient down
$ns simplex-link $n9 $n5 10Mb 5ms SFQ
$ns simplex-link-op $n9 $n5 orient up
$ns simplex-link $n6 $n0 10Mb 5ms SFQ
$ns simplex-link-op $n6 $n0 orient down
$ns simplex-link $n7 $n8 10Mb 5ms SFQ
$ns simplex-link-op $n7 $n8 orient right
$ns simplex-link $n0 $n9 10Mb 5ms SFQ
$ns simplex-link-op $n0 $n9 orient left


set tcp [new Agent/TCP]
$ns attach-agent $n1 $tcp
set sink [new Agent/TCPSink]
$ns attach-agent $n0 $sink
$ns connect $tcp $sink
$tcp set packetSize_ 1024

set ftp [new Application/FTP]
$ftp attach-agent $tcp
$ftp set type_ FTP
$ftp set random_ false
$ftp set rate_ 0.02
$ftp set fid_ 1
$ns at 0.0 "$ftp start"

set udp0 [new Agent/UDP]
$ns attach-agent $n2 $udp0

set cbr0 [new Application/Traffic/CBR]
$cbr0 set packetSize_ 512
$cbr0 set random_ false
$cbr0 set rate_ 0.01
$cbr0 set fid_ 2
$cbr0 attach-agent $udp0

set null0 [new Agent/Null]
$ns attach-agent $n7 $null0
$ns connect $udp0 $null0

set udp1 [new Agent/UDP]
$ns attach-agent $n3 $udp1

set cbr1 [new Application/Traffic/CBR]
$cbr1 set packetSize_ 512
$cbr1 set random_ true
$cbr1 set rate_ 0.01
$cbr1 set fid_ 3
$cbr1 attach-agent $udp1

set null1 [new Agent/Null]
$ns attach-agent $n6 $null1
$ns connect $udp1 $null1

$ns at 0.0 "$cbr0 start"
$ns at 0.0 "$cbr1 start"
$ns rtmodel-at 5.0 down $n4 $n5
$ns rtmodel-at 55.0 up $n4 $n5

$ns rtmodel-at 20.0 down $n8 $n9
$ns rtmodel-at 40.0 up $n8 $n9





$ns at 100.0 "finish"
$ns run