[ns] Using integrator with flow monitoring

["TG Uko" <ukoid@hotmail.com>]

Hi NS-USERS,

I am trying to use an integrator to obtain the value "sum_" in my 
simulation.  The problem is I am not certain if my syntax is correct or not, 
because the value I get for sum_  is zero, which should not be the case.  I 
have included the script below, but I'll briefly introduce the simulation 
first.

I am simulating a lan with poisson agents attached to 3 of the 5 nodes, and 
a sink node connected to the 5th lannode using a duplex link.  I am 
attempting to calculate the delay using the sum_ obtained from 
[get-pkts-integrator], but the value I get is incorrect.

Is there something I am missing?

Please provide any advice you can as I am approaching a deadline and I need 
to get this fixed.
Thanks
ID

Script---------

#Create a simulator object
set ns [new Simulator]

#Open the nam trace file
set nf [open out.nam w]
$ns namtrace-all $nf

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

# Color Packets for Nam
$ns color 1 Blue
$ns color 2 Red
#$ns color 3 Yellow
#$ns color 4 Green
#$ns color 5 Black

# Set random number generator seed
set seed 1234567
ns-random $seed

# Simulation end time
set startDump 0.0
set intDump 0.2
set endTime 10.0

# Set some physical parameters
set NumNodes 5;
set LinkRate 10e6; #Bps
set LinkDelay 1e-6;
set PacketSize 1000; #bits
set normalizedArrivalrate 0.9
set BitsPerByte 8

#Create the nodes
for {set i 0} {$i < $NumNodes} {incr i} {
    set node($i) [$ns node]
    lappend nodelist $node($i)
}

#Create srcnode and sinknode
set sinknode [$ns node]

#Create LAN
set lan_ [$ns make-lan $nodelist $LinkRate $LinkDelay LL Queue/DropTail 
Mac/802_3 Channel]


#Create a duplex link between sinknode and lannode node(4)
$ns duplex-link $sinknode $node(4) $LinkRate $LinkDelay DropTail
$ns duplex-link-op $sinknode $node(4) orient left
$ns duplex-link-op $sinknode $node(4) queuePos 0.5


# Create agents for all the nodes
for {set i 0} {$i < $NumNodes} {incr i} {
    set src($i) [new Agent/UDP]
    set sink($i) [new Agent/Null]

    #$src($i) set class_ [expr $i + 1] ;#Marks Flow id

    $ns attach-agent $node($i) $src($i)
    $ns attach-agent $sinknode $sink($i)
    $ns connect $src($i) $sink($i)
}

$src(0) set class_ 1
$src(1) set class_ 2

set pps [expr $normalizedArrivalrate /$NumNodes * $LinkRate / $PacketSize]

puts [expr ${PacketSize} / $BitsPerByte]
puts [expr $normalizedArrivalrate /$NumNodes * $LinkRate / $PacketSize]

# Create Poisson arrivals at source nodes
for {set i 0} {$i < $NumNodes} {incr i} {
    set e($i) [new Application/Traffic/Poisson]
    $e($i) attach-agent $src($i)

    $e($i) set packetSize_ [expr ${PacketSize} / $BitsPerByte]
    $e($i) set meanArrivalrate_ [expr $normalizedArrivalrate /$NumNodes * 
$LinkRate / $PacketSize]
}


#-----------------Flow Monitoring-----
set flow_file [open cs_flow.out w];		# create file for monitoring flows
set fmon [$ns makeflowmon Fid]
$fmon attach $flow_file

set llink1 [$ns link $node(4) $sinknode]

$ns attach-fmon $llink1 $fmon 0;	# from Source to lanNode 1

#$fmon dump ;#dumps all traces to flow file

set pktsInt_ [new Integrator]
$fmon set-pkts-integrator $pktsInt_
set finteg [$fmon get-pkts-integrator]


proc flowdump { link flwmon ffile interval } {
        global ns pps finteg
        $ns at [expr [$ns now] + $interval] "flowdump $link $flwmon $ffile 
$interval"

	$flwmon dump
	puts "[$finteg set sum_]"

	set delay [expr [$finteg set sum_] / $interval / $pps]

        #set delay [expr [$integ set sum_] / [[$link link] set bandwidth_]]

	#puts $ffile [format "FID= %d PKTarrv= %d" [$fm set flowid_] [$fm set 
parrivals_]]
        puts "[$ns now] delay = $delay"
}

#Define a 'finish' procedure
proc finish {} {
        global ns nf f flow_file
        $ns flush-trace
	#Close the trace file
        close $nf
	close $f
	close $flow_file
	#Execute nam on the trace file
        exec nam out.nam &
        exit 0
}

$ns at $startDump "flowdump $llink1 $fmon $flow_file $intDump"

# Schedule the start of traffic flow
for {set i 0} {$i < [expr $NumNodes-2]} {incr i} {
    $ns at 0.0 "$e($i) start"
    $ns at $endTime "$e($i) stop"
}
#$ns at 0.0 "$e start"
#$ns at $endTime "$e stop"

#Call the finish procedure after 10 seconds of simulation time
$ns at $endTime "finish"

#Run the simulation
$ns run


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