Hi,
According to NS manual ( http://www.isi.edu/nsnam/ns/doc/node251.html )
add-rule command of DelayBox class sets a delay for packets flowing from src
to dst but when I run the following script, d0 (DelayBox object) causes a
delay for all packets in both directions. from src to dst and dst to src.
does anyone know why this happens?
Thanks,
Mobin
set ns [new Simulator]
# NAM file
set nf [open outtcp2.nam w]
$ns namtrace-all $nf
# finish procedure
proc finish {} {
global ns nf
$ns flush-trace
close $nf
exec nam outtcp2.nam &
exit 0
}
# create nodes
set n0 [$ns node]
set n1 [$ns node]
set db0 [$ns DelayBox]
$ns duplex-link $n0 $db0 1Mb 100ms DropTail
$ns duplex-link $n1 $db0 1Mb 100ms DropTail
# create TCP agents
set src [new Agent/TCP/FullTcp]
set sink [new Agent/TCP/FullTcp]
$ns attach-agent $n0 $src
$ns attach-agent $n1 $sink
$src set fid_ 0
$src set fid_ 0
$ns connect $src $sink
# set up TCP-level connections
$sink listen
$src set window_ 100
# create traffic generator
set ftp0 [new Application/FTP]
$ftp0 attach-agent $src
# setup DelayBox
set delay_ms [new RandomVariable/Uniform];
$delay_ms set min_ 2000
$delay_ms set max_ 2000
$db0 add-rule [$n0 id] [$n1 id] $delay_ms
# run NS
$ns at 0.5 "$ftp0 start"
$ns at 10.0 "finish"
$ns run
