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Re: questions about errormodel
hi,
thanks for the answer that's very helpfull.
>
> The Periodic error model is parameterized like a periodic
> function. So, the offset is sort of like the phase offset,
> indicating the first item to drop. It will then drop every
> period_ items. I say "item" because what is dropped is
> sensitive to the "unit" parameter. The (current) choices
> are "time", "byte", or "pkt". If you choose time, the period
> and offset are in units of seconds [new: not yet tested for Periodic],
> if you choose "byte", the packet containing the specified bytes
> are dropped, and if you choose "pkt", its in packet units.
>
> Another item that may interest you. There is a new error model
> called "List".. For this one, you say:
>
> $errmodel droplist "1 3 2 15 89"
>
> which will arrange to drop the specified [pkt containing byte #s
> or pkts, time is not implemented].
>
> - K
I have another question.
I want to issue a nam trace with annotations about the sequence number
of the lost tcp packets.
I have the following code :
...
set puit [new Agent/LossMonitor]
$puit proc log-loss {} {
global ns
$ns trace-annotate "loss"
}
set lossylink [$ns link $n(2) $n(3)]
set em [new ErrorModule Fid]
set errmodel [new ErrorModel/Periodic]
$errmodel unit pkt
$errmodel set offset_ 2
$errmodel set period_ 10.0
$em insert $errmodel
$lossylink errormodule $em
$errmodel drop-target $puit
$em bind $errmodel 1
...
The creation of the LossMonitor agent is only a trick to show me when
there is losses by the annotation "loss" (is there an easier why to do
that).
I want to obtain an annotation with the sequence number of the lost
packet but
I don't know how to do that.
thanks for any help
Arnaud.
--
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Arnaud Legout
Institut Eurecom Phone : 00.33.4.93.00.26.61
2229, route des Cretes Fax : 00.33.4.93.00.26.27
BP 193 E-mail: [email protected]
06904 Sophia Antipolis cedex Web : http://www.eurecom.fr/~legout
FRANCE
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