set ns [new Simulator] 

  

 set tracefile [open out.tr w]  

 $ns trace-all $tracefile 

  

 set nf [open out.nam w]  

 $ns namtrace-all $nf 

  

 proc finish {} {  

  global ns tracefile nf  

  $ns flush-trace  

  close $nf  

  close $tracefile  

  exec nam out.nam &  

  exit 0  

 } 

  

  

 set n0 [$ns node]  

 set n1 [$ns node] 

  

 $ns duplex-link $n0 $n1 0.01Mb 1ms DropTail  

  

  

 set udp0 [new Agent/UDP]

 set udp1 [new Agent/Null]  

 $ns attach-agent $n0 $udp0

 $ns attach-agent $n1 $udp1


 $ns connect $udp0 $udp1 

  

 set cbr0 [new Application/Traffic/CBR]

 $cbr0 set packetSize_ 500

 $cbr0 set interval_ 0.005  

 $cbr0 attach-agent $udp0 

  

  

 $ns at 0.0 "$cbr0 start"  

 $ns at 5.0 "$cbr0 stop" 

 $ns at 6.0 "finish"  

  

 $ns run