#Start NS and DV Agent
    set ns [new Simulator]
    $ns rtproto DV

    #Trace File Creation
    set nf [open tcp_Tahoe_out_drop7.nam w]
    $ns namtrace-all $nf
    set f [open tcp_Tahoe_out_drop7.tr w]
    $ns trace-all $f

    #Node Creation
    set S1 [$ns node]
    set R1 [$ns node]
    $ns duplex-link $S1 $R1 1Mb 10ms DropTail

    #Transport Connection Creation set to Tahoe
    set tcptahoe [new Agent/TCP]
    $ns attach-agent $S1 $tcptahoe
    set tcpsink [new Agent/TCPSink]
    $ns attach-agent $R1 $tcpsink
    $ns connect $tcptahoe $tcpsink

    #CWND Trace File Creation
    set cwndf [open tcp_Tahoe_cwnd_drop7.tr w]
    $tcptahoe attach $cwndf
    $tcptahoe trace cwnd_

    #FTP Application Creation
    set ftp [new Application/FTP]
    $ftp attach-agent $tcptahoe

    #Error Generation Drop 7 13 14
    set loss_module [new ErrorModel/List]
    $loss_module droplist 7
    $ns lossmodel $loss_module $S1 $R1

    #Run Simulation and End Trace File
    $ns at 0.5 "$ftp start"
    $ns at 3.0 "finish"
    proc finish {} {
    global ns  nf
    $ns flush-trace
    close $nf
    puts "running nam..."
    exit 0
    }
    $ns run