[ns] Help: Strange behavior..

[Ind m <irmadapati@yahoo.com>]

Dear NS-gurus,

I don't know why this happens, but for some reason
my on-off sources _with same parameters_ give me 
different traffic in two systems. 

In system X, the pkt generation times are as follows:

0.0497345,0.0531345,0.0565345 0.0599345 0.0633345
0.0667345 0.0701345 0.0735345 0.0769345 0.0803345
0.0837345 0.0871345 0.0905345 0.0939345 0.0973345
0.100735 0.104135 0.107535 0.110935 0.114335
0.117735 0.121135 0.124535 0.127935 0.131335
0.134735 0.138135 0.141535 0.144935 0.148335
0.151735 0.155135 0.158535 0.161935 0.165335
0.168735 0.172135 <deleted some sq nos> 
0.325594 0.328994 0.332394 0.335794 0.339194
0.399209 0.402609 0.406009 0.409409 0.412809
and so on...

In system Y, the pkt generation times are same upto 
0.399209 sec, but from then on it generates different
set of times!
0.512243 0.515643 0.519043 0.522443 0.525843 0.529243
0.532643 0.536043 0.539443 0.542843 0.546243 0.549643
0.553043 0.556443 <and so on>


The tcl script for on-off source is as follows (same
is used in X and Y systems):

set i 1
set src($i) [new Agent/UDP]
$ns attach-agent $ing2 $src($i)
set udpsrc($i) [new Application/Traffic/Pareto]
$udpsrc($i) attach-agent $src($i)
$udpsrc($i) set packet_size_ 510
$udpsrc($i) set burst_time_ 250ms
$udpsrc($i) set idle_time_ 70ms
$src($i) set shape_  1.3
$udpsrc($i) set rate_ 1.2Mb
$src($i) set fid_ 2



For both systems, 
ns-random 45789
$defaultRNG seed 1973272912

even if I delete the above or change the values, 
I still get different traffic generated. 
I use ns-2.1b4

Is this normal? or shouldn't the traffic sources be
independent of the simulation setup (topology, etc)

When I iterate each system individually, I get the
above numbers consistently (w.r.t each system)


any pointers to this dilemma would be highly
appreciated..

Thanks a lot in advance,

with best regards
CG

PS: my apologies in advance, if you recvd this message
twice

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