Re: Wanted : A script using Error model

[Hari Balakrishnan <hari@desolation.CS.Berkeley.EDU>]

We're working on a test suite for the several flavors of error models (both 
probabilistic and empirically-derived) and how they work in 2 contexts -- 
wireless and wired (packet drops).  But owing to other constraints and 
deadlines, this won't be part of the standard release any time soon, 
unfortunately.

In the meantime, you may find the following simple test script, that Ramon 
Caceres originally wrote, a good place to start:


#
# Test the error model
#
set ns [new Simulator]

set f [open out.tr w]
$ns trace-all $f

set n0 [$ns node]
set n1 [$ns node]
$ns duplex-link $n0 $n1 1.5Mb 10ms DropTail

set cbr [new Agent/CBR]
$ns attach-agent $n0 $cbr

set rcvr [new Agent/LossMonitor]
$ns attach-agent $n1 $rcvr

$ns connect $cbr $rcvr

set em [new ErrorModel]
$em set rate_ 3.0

set tr [$ns create-trace Loss $f $n0 $n1]
$em drop-target $tr
$ns lossmodel $em $n0 $n1

$ns at 0.0 "$cbr start"
$ns at 1.0 "finish"

proc finish {} {
        global ns
        $ns flush-trace
        exit 0
}

$ns run

If you're interested in wireless error models and how they need to be set 
up, look at tcl/ex/mac-test.tcl.  It has a call to create-error, defined in 
tcl/lan/ns-lan.tcl (and you can follow the chain from there!).

-- Hari.


>>> Biaz Saad said:
 > Hi everybody!
 > 
 > 	Does anybody have a script using the ErrorModel ?
 > 
 > 	I try to use the error model. The chapter on the error model is, I
 > believe, on progress because it has only two pages and there is no clue 
on
 > how to associate the error model with a link. The samples in ns/tcl/ex
 > deal only with the SRMErrorModel.
 > 
 > 	Does anybody have a script using the ErrorModel ?
 > 
 > 						Thanks. Saad
 > 
 > ___________________________________________________________________
 > Saad Biaz				Abou Youssef
 > Graduate Research Assistant		Office : (409) 845 50 07
 > Department of Computer Science		Home   : (409) 862 91 35
 > College Station, TX, 77843-3112
 > ___________________________________________________________________
 >