lab1a.tcl

set ns [new Simulator]

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

set f [open lab1a.tr w]
$ns trace-all $f

set nf [open lab1a.nam w]
$ns namtrace-all $nf

$ns duplex-link $n0 $n2 5Mb 2ms DropTail
$ns duplex-link $n1 $n2 5Mb 2ms DropTail
$ns duplex-link $n0 $n1 1.5Mb 10ms DropTail

$ns queue-limit $n0 $n2 10
$ns queue-limit $n1 $n2 10
$ns queue-limit $n0 $n1 10

set udp0 [new Agent/UDP]
$ns attach-agent $n0 $udp0 

set cbr0 [new Application/Traffic/CBR]
$cbr0 attach-agent $udp0 

set udp1 [new Agent/UDP]
$ns attach-agent $n2 $udp1 

set cbr1 [new Application/Traffic/CBR]
$cbr0 attach-agent $udp1

set null0 [new Agent/Null]
$ns attach-agent $n1 $null0

set null1 [new Agent/Null]
$ns attach-agent $n1 $null1


$ns connect $udp0 $null0
$ns connect $udp1 $null1

$ns at 1.0 "$cbr0 start"
$ns at 1.1 "$cbr1 start"

set tcp [new Agent/TCP]
set sink [new Agent/TCPSink]
$ns attach-agent $n0 $tcp
$ns attach-agent $n2 $sink

$ns connect $tcp $sink
set ftp [new Application/FTP]
$ftp attach-agent $tcp

$ns at 1.2 "$ftp start"
$ns at 3.0 "finish"

proc finish { } {

	global ns f nf
	$ns flush-trace
	close $f
	close $nf
	puts "Running Name Command: "
	exec name lab1.nam &
	exit 0
}

$ns run