Re: flow monitor

[kpoduri@BayNetworks.COM (Kedarnath Poduri)]

> Hi,
> 
> Thanks for the reply.
> 
> Could you roughly explain what these lines meant,
> 
> set flow_stat10 [open flow.stat10 w]

opening a file that the tcl_channel later on uses to dump the data.

> set flowmon_10[$ns makeflowmon Fid]

setting a flowmonitor. makeflowmon is a procedure that does this. It has the  
argument Fid indicating that it distinguishes the flows usign Fid.

> $ns attach-fmon [$ns duplex-link $n1 $n2 1.5Mb 10ms DropTail] $flowmon_10 0

Ataaching the flow_monitor to the link I'm interested in.

> set_flowMonitor $flowmon_10 $flow_stat10

Attaching the flowmonitor to the appropriate file handle.

> $ns at 5.0 "$flowmon_10 dump"

Time at which the statistics of the flow_monitor are written to the output file. 
So you could repeat it at regular intervals or times when you are interested.


------
so, the procedure is very striaght forward.

1) You instantiate a flow monitor
2) Set it up on the required link.
3) Create a output file.
4) attach the file-handle the flow monitor
5) specify the interval at which you want to obtain your statistics.


> 
> why is flow_stat10?

It could be anything really. This is the syntax we use that tells us the 
statistics belong to flow_monitor set up on the link connecting node 1 and node 
0. 


 
> I run my script with these lines, it give error mesgs as the following,
> 
> can't read "flow_stat10file5": no such variable

should be a very basic syntax error. Take a careful look at the routines in 
ns-test scripts and I'm sure you would be able to spot it.

good luck
kedar
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