#Create a simulator objectset ns [new Simulator]#set ch [new Channel]#$ch set delay_ 1us#set mcl [new Classifier/Mac]#$ch target $mcl#Open a trace fileset nf [open out.nam w]$ns namtrace-all $nf#Define a 'finish' procedureproc finish {} {        global ns nf        $ns flush-trace        close $nf#        exec ../../../nam-1.0a10/nam out.nam &        exit 0}#Create three nodesset n0 [$ns node]set n1 [$ns node]set n2 [$ns node]set n3 [$ns node]set n4 [$ns node]#Create a IEEE1394 'LAN'#set lan0 [$ns make-lan "$n0 $n1 $n2" 1Mb 10us LL/ieee1394 Queue/DropTail Mac/ieee1394]#set lan0 [$ns make-lan "$n0 $n1 $n2 $n3 $n4" 1Mb 10us LL Queue/DropTail Mac/802_3]#set lan0 [$ns make-lan "$n0 $n1 $n2" 1Mb 10us LL Queue/DropTail Mac/ieee1394]#set lan0 [$ns make-lan "$n0 $n1 $n2 $n3 $n4" 1Mb 10us LL/ieee1394 Queue/DropTail Mac/ieee1394 Classifier/Mac/ieee1394]#set lan0 [$ns make-lan "$n0 $n1 $n2 $n3 $n4" 1Mb 10us LL Queue/DropTail Mac Classifier/Mac/ieee1394]#set lan0 [$ns make-lan "$n0 $n1 $n2 $n3 $n4" 1Mb 1us LL Queue/DropTail Mac]#set lan0 [$ns make-lan "$n0 $n1 $n2 $n3 $n4" 1Mb 10us LL Queue/DropTail Mac/ieee1394]    puts "$n0 $n1 $n2 $n3 $n4"    set lan0 [$ns newLan "$n0 $n1 $n2 $n3 $n4" 10Mb 5us \                -llType LL -ifqType Queue/DropTail -macType Mac/802_3 \                -chanType Channel -phyType Phy/WiredPhy -mactrace false]#Connect the nodes with two links#$ns duplex-link $n0 $n1 1Mb 10ms DropTail#$ns duplex-link $n1 $n2 1Mb 10ms DropTail#Define a 'recv' function for the class 'Agent/ieee1394'Agent/ieee1394 instproc recv {from} {	$self instvar node_	puts "node [$node_ id] received answer."}proc create-slan {num_nodes start_time end_time interval pkt_size} {    global ns sink0    create-trace-files $num_nodes $start_time $end_time $interval $pkt_size     for {set i 0} {$i < 5} {incr i} {	set node($i) [$ns node]	lappend nodelist $node($i)    }   #    set n0 [$ns node]#    set n1 [$ns node]#    set n2 [$ns node]#    set n3 [$ns node]#    set n4 [$ns node]    puts "$nodelist"    set lan0 [$ns newLan "$nodelist" 10Mb 5us \                -llType LL -ifqType Queue/DropTail -macType Mac/802_3 \                -chanType Channel -phyType Phy/WiredPhy -mactrace false]    #Create two ieee1394 agents and attach them to the nodes n0 and n2#    set p0 [new Agent/ieee1394]    set p0 [new Agent/LossMonitor]    $ns attach-agent $node(0) $p0#    set p1 [new Agent/ieee1394]    set p1 [new Agent/UDP]    $ns attach-agent $node(4) $p1    #Connect the two agents    $ns connect $p0 $p1    #Schedule events    $ns at 0.2 "$p1 send 500"    $ns at 0.4 "$p1 send 400"    $ns at 0.6 "$p1 send 500"    $ns at 0.6 "$p1 send 400"            return $lan0}#Create two ieee1394 agents and attach them to the nodes n0 and n2set p0 [new Agent/ieee1394]$ns attach-agent $n0 $p0set p1 [new Agent/ieee1394]$ns attach-agent $n4 $p1#Connect the two agents$ns connect $p0 $p1#Schedule events$ns at 0.2 "$p0 send"$ns at 0.4 "$p1 send"$ns at 0.6 "$p0 send"$ns at 0.6 "$p1 send"$ns at 1.0 "finish"#Run the simulation$ns run