[ns] set: Variable name must begin with a letter.

[Arvind Swaminathan]

Hi Atiur,

It was my mistake.  I made some mistake while copying it to linux.

Arvind

On Dec 17, 2007 9:47 PM, Md. Atiur Rahman Siddique <atiurrs at yahoo.com> wrote:
>
> I ran your tcl file without any problem. Which line is it complaining about?
>
>
> --- Arvind Swaminathan <arvind.phd at gmail.com> wrote:
>
> >
> > Hi,
> >
> > When I run the first example in the NS by example (hosted by Worcester
> > Polytechnic Inst.), I get the following error message
> >
> > set: Variable name must begin with a letter.
> >
> > How do I make tcl give me a more detailed error message (line number etc.)?
> >
> > The tcl script is below. I would really appreciate it if someone could
> > tell me what the problem is.
> >
> >
> > #Create a simulator object
> > set ns [new Simulator]
> >
> > #Define different colors for data flows (for NAM)
> > $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 NAM trace file
> >         close $nf
> >         #Execute NAM on the trace file
> >         exec nam out.nam &
> >         exit 0
> > }
> >
> > #Create four nodes
> > set n0 [$ns node]
> > set n1 [$ns node]
> > set n2 [$ns node]
> > set n3 [$ns node]
> >
> > #Create links between the nodes
> > $ns duplex-link $n0 $n2 2Mb 10ms DropTail
> > $ns duplex-link $n1 $n2 2Mb 10ms DropTail
> > $ns duplex-link $n2 $n3 1.7Mb 20ms DropTail
> >
> > #Set Queue Size of link (n2-n3) to 10
> > $ns queue-limit $n2 $n3 10
> >
> > #Give node position (for NAM)
> > $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
> >
> > #Monitor the queue for link (n2-n3). (for NAM)
> > $ns duplex-link-op $n2 $n3 queuePos 0.5
> >
> >
> > #Setup a TCP connection
> > set tcp [new Agent/TCP]
> > $tcp set class_ 2
> > $ns attach-agent $n0 $tcp
> > set sink [new Agent/TCPSink]
> > $ns attach-agent $n3 $sink
> > $ns connect $tcp $sink
> > $tcp set fid_ 1
> >
> > #Setup a FTP over TCP connection
> > set ftp [new Application/FTP]
> > $ftp attach-agent $tcp
> > $ftp set type_ FTP
> >
> >
> > #Setup a UDP connection
> > set udp [new Agent/UDP]
> > $ns attach-agent $n1 $udp
> > set null [new Agent/Null]
> > $ns attach-agent $n3 $null
> > $ns connect $udp $null
> > $udp set fid_ 2
> >
> > #Setup a CBR over UDP connection
> > set cbr [new Application/Traffic/CBR]
> > $cbr attach-agent $udp
> > $cbr set type_ CBR
> > $cbr set packet_size_ 1000
> > $cbr set rate_ 1mb
> > $cbr set random_ false
> >
> >
> > #Schedule events for the CBR and FTP agents
> > $ns at 0.1 "$cbr start"
> > $ns at 1.0 "$ftp start"
> > $ns at 4.0 "$ftp stop"
> > $ns at 4.5 "$cbr stop"
> >
> > #Detach tcp and sink agents (not really necessary)
> > $ns at 4.5 "$ns detach-agent $n0 $tcp ; $ns detach-agent $n3 $sink"
> >
> > #Call the finish procedure after 5 seconds of simulation time
> > $ns at 5.0 "finish"
> >
> > #Print CBR packet size and interval
> > puts "CBR packet size = [$cbr set packet_size_]"
> > puts "CBR interval = [$cbr set interval_]"
> >
> > #Run the simulation
> > $ns run
> >
> >
> > Thanks,
> > Arvind
> >
> >
>
>
>
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