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Re: [ns] ACK not coming on ErrorModel
On Mon, 28 Aug 2000, Arnold P. Siboro wrote:
> I've succesfully used ErrorModel for simulation using one-way error
> links. But when I used the model in the opposite direction, where ACKs
> travel back to sender, the simulation ended with almost no ACKs arrived
> at the sender.
>
> Any idea what the problem is?
ErrorModel defaults to an error rate *per packet*. rather than across
a whole bitstream as an engineer might expect. As a result, the
shorter ACKs will be experiencing a much much much higher actual error
rate than the forward packets unless you step in to alter this.
set em [new ErrorModel]
# You have the choice of
$em unit pkt ;# default
# or
$em unit byte
# or
$em unit time
Either of the other two options is more useful and meaningful than the
default pkt; it would be nice if the docs pointed this out.
L.
<[email protected]>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>