Dear ns2 users,
I am trying to simulation a lossy link in a wireless environment using
 the ErrorModel. However the code I inserted to simulate a uniform
packet  loss has no effect on my results (see below). Can anybody tell me,
what's  wrong with me. I am using version 2.29.

# simple-wireless.tcl
# A simple example for wireless simulation
# ======================================================================
# Define options
# ======================================================================
set val(chan)           Channel/WirelessChannel    ;# channel type
set val(prop)           Propagation/TwoRayGround   ;# radio-propagation
model
set val(netif)          Phy/WirelessPhy            ;# network interface type
set opt(err)            UniformErrorProc
set val(mac)            Mac/802_11                 ;# MAC type
set val(ifq)            Queue/DropTail/PriQueue    ;# interface queue type
set val(ll)             LL                         ;# link layer type
set val(ant)            Antenna/OmniAntenna        ;# antenna model
set val(ifqlen)         50                         ;# max packet in ifq
set val(nn)             2                          ;# number of mobilenodes
set val(rp)             DSDV                       ;# routing protocol
LL set delay_ 20ms
# ======================================================================
# Main Program
# ======================================================================
#
# Initialize Global Variables
#
set ns_         [new Simulator]
set tracefd     [open simplewireless1.tr w]
$ns_ trace-all $tracefd
# set up topography object
set topo       [new Topography]
$topo load_flatgrid 500 500
# Create God
#
create-god $val(nn)
#
#  Create the specified number of mobilenodes [$val(nn)] and "attach" them
#  to the channel.
#  Here two nodes are created : node(0) and node(1)
# configure node
       $ns_ node-config -adhocRouting $val(rp) \
                        -llType $val(ll) \
                        -macType $val(mac) \
                        -ifqType $val(ifq) \
                        -ifqLen $val(ifqlen) \
                        -antType $val(ant) \
                        -propType $val(prop) \
                        -phyType $val(netif) \
                        -channelType $val(chan) \
                        -topoInstance $topo \
                        -agentTrace ON \
                        -routerTrace ON \
                        -macTrace OFF \
                        -movementTrace OFF \
                        -IncomingErrProc UniformErr -OutgoingErrProc
UniformErr

       for {set i 0} {$i < $val(nn) } {incr i} {
               set node_($i) [$ns_ node]
               $node_($i) random-motion 0              ;# disable random
motion
       }
#
# Provide initial (X,Y, for now Z=0) co-ordinates for mobilenodes
#
$node_(0) set X_ 5.0
$node_(0) set Y_ 2.0
$node_(0) set Z_ 0.0

$node_(1) set X_ 390.0
$node_(1) set Y_ 385.0
$node_(1) set Z_ 0.0

# Now produce some simple node movements
# Node_(1) starts to move towards node_(0)
#
$ns_ at 50.0 "$node_(1) setdest 25.0 20.0 15.0"
$ns_ at 10.0 "$node_(0) setdest 20.0 18.0 1.0"
# Node_(1) then starts to move away from node_(0)
$ns_ at 100.0 "$node_(1) setdest 490.0 480.0 15.0"
# Setup traffic flow between nodes
# TCP connections between node_(0) and node_(1)

set tcp [new Agent/TCP]
$tcp set class_ 2
set sink [new Agent/TCPSink]
$ns_ attach-agent $node_(0) $tcp
$ns_ attach-agent $node_(1) $sink
$ns_ connect $tcp $sink
set ftp [new Application/FTP]
$ftp attach-agent $tcp
$ns_ at 10.0 "$ftp start"

#$ns_ node-config -IncomingErrProc UniformErr -OutgoingErrProc UniformErr

ErrorModel set rate_ 10
proc UniformError {} {
   global opt
   set errObj [new ErrorModel]
   $errObj unit packet
   $errobj drop-target [new Agent/null]
   return $errObj
}
#$ns_ lossmodel errObj $node_(0) $node_(1)
#$ns_ lossmodel $loss_module $node_(0) $node_(1)
#
# Tell nodes when the simulation ends
#
for {set i 0} {$i < $val(nn) } {incr i} {
   $ns_ at 150.0 "$node_($i) reset";
}
$ns_ at 150.0 "stop"
$ns_ at 150.01 "puts \"NS EXITING...\" ; $ns_ halt"
proc stop {} {
   global ns_ tracefd
   $ns_ flush-trace
   close $tracefd
}


puts "Starting Simulation..."

$ns_ run



Waiting for your reply,
Thanking you
 Mandar

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