Re: QueueMonitor object

[Christof Brandauer <cbrand@wapiti.cosy.sbg.ac.at>]

On Mon, 23 Nov 1998, hongyi chen wrote:

: Hi;
: 
: I try to monitor a queue statistics, so I try to set up a queuemonitor 
: object.
: I try to use 
: " $ns queue-monitor $n0 $n1" 
: statement to get a QueueMonitor object for the queue on link between n0 
: and n1, but get a error message saying 
: " no value given to parameter "qtrace" to "_o3"".
: On the manual, it says that this part is not verified to up to date. 
: Do you know is that I did something wrong or something else?


to attach a queue-monitor object for a given link you can do the
following:

# open a trace file
set tFile [open queue.tr w]
# set up the queue-monitor
$ns monitor-queue $n0 $n1 $tFile {sampleInterval}
# sampleInterval is optional and defaults to 0.1 seconds

# start tracing using either
[$ns link $n0 $n1] start-tracing
# or
# [$ns link $n0 $n1] queue-sample-timeout
# which averages over the last sampleInterval

BTW: remember to close your trace file at the end of your simulation
(otherwise you are very likely to get falsified results (just like i
did))


chris

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  Christof Brandauer                        cbrand@cosy.sbg.ac.at
  Student of Applied Informatics                 
  Department of Computer Science, University of Salzburg, Austria
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