[ns] end to end delay

["Bilgin Metin" <bilginx@boun.edu.tr>]

Dear Lloyd Wood,

To compute end-to-end delay you gave an awk code. It is a stupid stuation
but I do not  know how to use this code.

Could you please show how to use your awk code with simple tcl example
below:

^#######example ################

#Create a simulator object
set ns [new Simulator]

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

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

#Create two nodes
set n0 [$ns node]
set n1 [$ns node]

#Create a duplex link between the nodes
$ns duplex-link $n0 $n1 1Mb 10ms DropTail

#Create a CBR agent and attach it to node n0
set cbr0 [new Agent/CBR]
$ns attach-agent $n0 $cbr0
$cbr0 set packetSize_ 500
$cbr0 set interval_ 0.005

#Create a Null agent (a traffic sink) and attach it to node n1
set null0 [new Agent/Null]
$ns attach-agent $n1 $null0

#Connect the traffic source with the traffic sink
$ns connect $cbr0 $null0

#Schedule events for the CBR agent
$ns at 0.5 "$cbr0 start"
$ns at 4.5 "$cbr0 stop"
#Call the finish procedure after 5 seconds of simulation time
$ns at 5.0 "finish"

#Run the simulation
$ns run

^##########AWK SCRIPT###############

BEGIN {
# simple awk script to generate end-to-end packet lifetime statistics
# in a form suitable for plotting with xgraph.
# Lloyd Wood, July 1999.
# http://www.ee.surrey.ac.uk/Personal/L.Wood/ns/

highest_packet_id = 0;
}

{
action = $1;
time = $2;
node_1 = $3;
node_2 = $4;
src = $5;
flow_id = $8;
node_1_address = $9;
node_2_address = $10;
seq_no = $11;
packet_id = $12;

if ( packet_id > highest_packet_id ) highest_packet_id = packet_id;

# getting start time is not a problem, provided you're not starting
# traffic at 0.0.
# could test for sending node_1_address or flow_id here.
if ( start_time[packet_id] == 0 ) start_time[packet_id] = time;

# only useful for small unicast where packet_id doesn't wrap.
# checking receive means avoiding recording drops
if ( action != "d" ) {
if ( action == "r" ) {
# could test for receiving node_2_address or flow_id here.
end_time[packet_id] = time;
}
} else {
end_time[packet_id] = -1;
}
}
END {
for ( packet_id = 0; packet_id <= highest_packet_id; packet_id++ ) {
start = start_time[packet_id];
end = end_time[packet_id];
packet_duration = end - start;

if ( start < end ) printf("%d %f\n", start, packet_duration);
}
}