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Re: [ns] problem with pareto sources



 hmmm...that's strange....i am running this on red hat (linux
-2.2.18pre16)....

its not the disk issue as the program dies before starting the simulation
(the trace file is 0 size)....

anyways, i will check it out..thanks...

-Vikram


> 
> 
> Vikram hi,
> 
> I am running pareto examples with many flows without any problems. I am
> having 2.1b7 on a Solaris OS version: 5.7. 
>  
> I 've also checked your example (with up to 200 flows) again without any
> problem. So there must be something particular to your case. Possible
> actions: (a) if on unix check you quota :-) (creates a ruther big out.tr
> file), else (b) re-install.
> 
> regards
> 
> PanOS
> 
> On Mon, 26 Mar 2001, Vikram Kanodia wrote:
> 
> -Hi,
> -
> -I have been experiencing this weird problem with pareto sources. Whenever
> -i have more than certain number of flow active it gives me a segmentation
> -fault. The threshold of number of flows is variable. On
> -tracing this error using gdb i traced it to rng.cc:
> - 
> -" Program received signal SIGSEGV, Segmentation fault.
> - RNGImplementation::next (this=0x30) at rng.cc:136 "
> -
> -I searched the mailing list and someone else had the same problem but with
> -10 to 11 sources (11th one gave him a segmentation fault). Someone replied
> -to him saying that that was a nam problem not a ns fault.
> -
> -I am not using any nam stuff.....and am using ns-2.1b7.....plus it really
> -confuses me as some of my friends running ns-2.1b6 can run simulations
> -with hundreds of pareto on/off flows with no problems whatsoever. Do i
> -need to downgrade/upgrade (to current snapshot)....
> -
> -Any feedback would be appreciated. I have attached my script below:
> -
> -Thanks,
> --Vikram
> -
> ----------------------------------------------------------------------------
> -
> -# Define Values
> -#
> -set val(flows)                      20;
> -set val(stop)                  30.00;# simulation time (sec)
> -set val(bandwidth)                 10;# link bandwidth (Mb)
> -set val(queue-length)               5;# Queue Length (pkts)            
> -set val(trace)                 out.tr;# trace file    
> -
> -# Source detail for an ON/OFF source
> -set val(pktsize)                 250;# Packet size (bytes)
> -set val(burst)                    .5;# Burst time (sec)
> -set val(idle)                     .5;# Idle time (sec)
> -set val(peak)                     100;# Peak rate (Kbps)
> -
> -# =======================================================================
> -# Main stuff
> -# ======================================================================
> -
> -#Create a simulator object
> -set ns [new Simulator]
> -
> -#Open the trace file
> -set tracefile [open $val(trace) w]
> -$ns trace-all $tracefile
> -
> -#Queue limit
> -Queue set limit_ $val(queue-length)
> -
> -#Create two nodes
> -set n0 [$ns node]
> -set n1 [$ns node]
> -
> -#Create a simplex link between the nodes
> -$ns simplex-link $n0 $n1 ${val(bandwidth)}Mb 5ms DropTail
> -
> -# Setting up flows from n1 to n0
> -for {set i 0} {$i < $val(flows) } {incr i} {
> -
> -    #Create a Null agent (a traffic sink) and attach it to node n1
> -    set null_($i) [new Agent/Null]
> -    $ns attach-agent $n1 $null_($i)
> -
> -    #Create a UDP agent and attach it to node n0
> -    set udp_($i) [new Agent/UDP]
> -    $ns attach-agent $n0 $udp_($i)
> -    
> -    # Create a pareto on/off traffic traffic source and attach it to udp_i
> -    set pareto_($i) [new Application/Traffic/Pareto]
> -    $pareto_($i) set packetSize_ $val(pktsize)
> -    $pareto_($i) set burst-time_ $val(burst)
> -    $pareto_($i) set idle-time_ $val(idle)
> -    $pareto_($i) set rate_ ${val(peak)}k
> -    $pareto_($i) set shape_ 1.5
> -    $pareto_($i) attach-agent $udp_($i)
> - 
> -    #Connect the traffic source with the traffic sink null0
> -    $ns connect $udp_($i) $null_($i)
> -
> -    #Schedule events 
> -    $ns at 10.0 "$pareto_($i) start"
> -    $ns at $val(stop) "$pareto_($i) stop"
> -}
> -
> -#Call the finish procedure at end of simulation time
> -$ns at $val(stop) "finish"
> -
> -
> -#Define a 'finish' procedure
> -proc finish {} {
> -
> -    global ns tracefile qmon bandwidth stop buffer
> -    $ns flush-trace
> -    exit 0
> -}
> -
> -#Run the simulation
> -$ns run
> -
> -
> -
> --- 
> -
> -Department of ECE, Rice University | 713 348 3786 (O)| 713 664 5650(H)
> -WWW: http://www.ece.rice.edu/~kanodia 
> -
> -
> 
> =======================================================
>  Panos Trimintzios                                                          
>  Research Fellow, Networks Research Group
>  Centre for Communication Systems Research (CCSR)
>  Univ. of Surrey, Guildford, Surrey GU2 7XH, U.K.
>  Office: U37 / BA Building                                                    
>  Tel: +44 (0)1483 876005  Fax: +44 (0)1483 876011                             
>  Email: <p.trimintzios@eim.surrey.ac.uk>                                    
>  WWW:   <http://www.ee.surrey.ac.uk/CCSR/Networks>      
> =======================================================
> 
> 

-- 

Department of ECE, Rice University | 713 348 3786 (O)| 713 664 5650(H)
WWW: http://www.ece.rice.edu/~kanodia