#Create a simulator object
  set ns [new Simulator]

  
  #Open a trace file
  set nf [open out.nam w]
  $ns namtrace-all $nf
  
  #Define a 'finish' procedure
  proc finish {} {
          global ns nf
          $ns flush-trace
          close $nf
          exec nam out.nam &
          exit 0
  }
  
  #Create three nodes
  set n2 [$ns node]
  set n1 [$ns node]
  
  ######################
  # Link definition
  ######################
  $ns duplex-link $n1 $n2 10Mb 2ms DropTail
  
  
  # Set up TCP connection
      #    set tcp1 [$ns_ create-connection TCP $n1 TCPSink $n2 0]
      #    $tcp1 set window_ 30
  set tcp1 [new Agent/TCP/FullTcp]
  set tcp2 [new Agent/TCP/FullTcp]
  
  $ns attach-agent $n1 $tcp1
  $ns attach-agent $n2 $tcp2
  $ns connect $tcp1 $tcp2
  
  $tcp2 listen
  
  #---------------------------------------------
  Application/TcpApp instproc app-recv {size} {
          global ns
          puts "[$ns now] app2 receives data $size from app1"
  }
  #---------------------------------------------
  
  set app1 [new Application/TcpApp $tcp1]
  set app2 [new Application/TcpApp $tcp2]

  $app1 connect $app2
  


  $ns at 1.2 "$app2 send 100 \"$app1 app-recv 100\""
  $ns at 1.1 "$app1 send 100 \"$app2 app-recv 100\""

  $ns at 6.5 "finish"
  
  #Run the simulation
  $ns run