Re: [ns] SEGMENTATION FAULT

[Michael Bahr <bahr@ICSI.Berkeley.EDU>]

Hi Nitin,

you shouldn't use nam for your simulations. nam is the network
animator. For your simulations, use ns:

ns template.tcl

Bye,
Michael


On Tue, 31 Oct 2000, Nitin Nagar wrote:

> Hi
> We have installed the ns-2 pakage today and when i tried to simulate a
> topology file it gave the following script error:
>  
> 
> gum:8 ns-allinone-2.1b6> nam template.tcl
> Failed to start animator: 
> class Animator: constructor failed: unmatched open brace in list
> unmatched open brace in list
>     while executing
> "foreach item $traceevent {
> if { $next == 1 } {
> return $item
> }
> if { $item == $tag } {
> set next 1
> } 
> }"
>     (procedure "get_trace_item" line 3)
>     invoked from within
> "get_trace_item "-t" $line"
>     (procedure "_o3" line 9)
>     (Animator infer-network-model line 9)
>     invoked from within
> "$self infer-network-model $tracefile"
>     (procedure "_o3" line 80)
>     (Animator init line 80)
>     invoked from within
> "_o3 init template.tcl {}"
>     (Class create line 1)
>     invoked from within
> "Animator create _o3 template.tcl {}"
>     invoked from within
> "catch "$className create $o $args" msg"
>     (procedure "new" line 3)
>     invoked from within
> "new $ANIMATOR_CLASS_ $tracefile  [join $args]"
> 
> 
> The topology file is:
> 
> #Create a simulator object
> set ns [new Simulator]
> 
> $ns color 1 Blue
> $ns color 2 Red
> 
> 
> #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 $nf
>         #Execute nam on the trace file
>         exec nam out.nam &
>         exit 0
> }
> 
> 
> # Insert your own code for topology creation
> # and agent definitions, etc. here
> 
> set n0 [$ns node]
> set n1 [$ns node]
> set n2 [$ns node]
> set n3 [$ns node]
> 
> $ns duplex-link $n0 $n2 1Mb 10ms DropTail
> $ns duplex-link $n1 $n2 1Mb 10ms DropTail
> $ns duplex-link $n3 $n2 1Mb 10ms SFQ
> 
> #SQF = Stochastic Fair Queing mechanism
> 
> 
> #for more control over the layout
> 
> $ns duplex-link-op $n0 $n2 orient right-down
> $ns duplex-link-op $n1 $n2 orient right-up
> $ns duplex-link-op $n2 $n3 orient right
> 
> #Create two CBR agents
> 
> #--------------------------------------------------------
> set cbr0 [new Agent/CBR]
>   $ns attach-agent $n0 $cbr0
>   $cbr0 set packetSize_ 500
>   $cbr0 set interval_ 0.005
> 
>   set cbr1 [new Agent/CBR]
>   $ns attach-agent $n1 $cbr1
>   $cbr1 set packetSize_ 500
>   $cbr1 set interval_ 0.005
> 
>   set null0 [new Agent/Null]
>   $ns attach-agent $n3 $null0
> 
> $cbr0 set fid_ 1
> $cbr1 set fid_ 2
> #--------------------------------------------------------
> 
> $ns connect $cbr0 $null0
> $ns connect $cbr1 $null0
> 
> 
> $ns at 0.5 "$cbr0 start"
> $ns at 1.0 "$cbr1 start"
> $ns at 4.0 "$cbr0 stop"
> $ns at 4.5 "$cbr1 stop"
> 
> #Call the finish procedure after 5 seconds simulation time
> $ns at 5.0 "finish"
> 
> #Run the simulation
> 
> 
> 
> $ns run
> 
> 
> I will appreciate if any one could figure out what exacltly is the error
> and how to resolve it.
> thanks
> nitin
> 
> ------------------------------------------------------------------------------
> Nitin Nagar                            
> Graduate Teaching Assistant                                                           
> ------------------------------------------------------------------------------ 
> 
>