Hello, All,
I want to introduce error in LAN, tried like in following code but its
giving error.
set ns [new Simulator]
#Define different colors for data flows (for NAM)
$ns color 1 Blue
$ns color 2 Red
#Open the Trace files
set file1 [open out.tr w]
set winfile [open WinFile w]
$ns trace-all $file1
#Define a 'finish' procedure
proc finish {} {
global ns file1
$ns flush-trace
close $file1
exec nam out.nam &
exit 0
}
set n1 [$ns node]
set n2 [$ns node]
set lan [$ns newLan "$n1 $n2" 1Mb 40ms LL Queue/DropTail MAC/Csma/CdChannel]
set tcp [new Agent/TCP/Newreno]
$ns attach-agent $n1 $tcp
set sink [new Agent/TCPSink/DelAck]
$ns attach-agent $n2 $sink
$ns connect $tcp $sink
$tcp set fid_ 1
$tcp set window_ 65536
$tcp set packetSize_ 1024
#Setup a FTP over TCP connection
set ftp [new Application/FTP]
$ftp attach-agent $tcp
$ftp set type_ FTP
set LossyLink [$ns link $n1 $n2]
insert_error $LossyLink
proc get_throughput { tcp } {
#now calculate the average throughtput (in Mb/s)
puts "[expr [$tcp set ndatapack_]*8.0/1000/2]Mb/s"
}
# Creating Error Module
proc insert_error {LossyLink} {
set loss_module [new ErrorModel]
$loss_module unit pkt
$loss_module set rate_ 0.1
$loss_module ranvar [new RandomVariable/Uniform]
$loss_module drop-target [new Agent/Null]
#$ns link-lossmodel $loss_module $n1 $n2
$LossyLink errormodule $loss_module
}
$ns at 0 "$ftp start"
$ns at 2.0 "$ftp stop"
$ns at 2.0 "get_throughput $tcp"
$ns at 2.0 "finish"
$ns run
Please suggest a simple method by which I can introduce error in LAN.
Thanks in advance.
Regards,
Anup
