下载后可任意编辑第 4 章例 1#建立一个模拟set ns [new Simulator]#定义不同数据流的颜色（NAM显示时用到）$ns color 1 Blue$ns color 2 Red#开启Trace跟踪和NAM跟踪set tracefd [open wired.tr w]$ns trace-all $tracefdset nf [open wired.nam w]$ns namtrace-all $nf#定义结束进程proc finish {} {global ns tracefd nf$ns flush-traceclose $tracefdclose $nfexit 0}#定义节点set n0 [$ns node]set n1 [$ns node]set n2 [$ns node]set n3 [$ns node]set n4 [$ns node]set n5 [$ns node]#$n5 color black$n5 color red#定义节点间的链路下载后可任意编辑$ns duplex-link $n0 $n1 2Mb 10ms DropTail$ns duplex-link $n1 $n2 2Mb 10ms DropTail$ns duplex-link $n1 $n4 2Mb 20ms DropTail$ns duplex-link $n3 $n4 2Mb 10ms DropTail$ns duplex-link $n4 $n5 2Mb 10ms DropTail#定义链路的队列长度$ns queue-limit $n1 $n4 10#指定节点间的相互位置（NAM显示用到）$ns duplex-link-op $n0 $n1 orient right-down$ns duplex-link-op $n2 $n1 orient right-up$ns duplex-link-op $n1 $n4 orient right$ns duplex-link-op $n3 $n4 orient left-down$ns duplex-link-op $n5 $n4 orient left-up#监视链路的队列$ns duplex-link-op $n1 $n4 queuePos 0.5#建立一个TCP连接set tcp [new Agent/TCP] $tcp set class_ 2$ns attach-agent $n0 $tcpset sink [new Agent/TCPSink]$ns attach-agent $n5 $sink$ns connect $tcp $sink$tcp set fid_ 1#在TCP连接上建立FTP流set ftp [new Application/FTP]$ftp attach-agent $tcp$ftp set type_ FTP#建立一个UDP代理set udp [new Agent/UDP] ;#建立一个数据发送代理$ns attach-agent $n2 $udp ;#将数据发送代理绑定到发送节点set null [new Agent/Null] ;#建立一个数据接收代理$ns attach-agent $n3 $null ;#将数据接收代理绑定到接收节点$ns connect $udp $null ;#连接两个代理（也就决定了数据包的发送和接收节点）$udp set fid_ 2#在UDP代理上建立CBR流set cbr [new Application/Traffic/CBR]下载后可任意编辑$cbr attach-agent $udp$cbr set type_ CBR$cbr set packet_size_ 1000$cbr set rate_ 1mb$cbr set r...
