Re: Question about the trace file format

[Haobo Yu <haoboy@isi.edu>]

'r' means that a packet is received. It's previously used for nam
traces. Please look at the nam man page for details.

If you want to do is calculating the number of packets on transit,
you'll need to add a callback to it. It can be done by including the
following in your script:

SimpleLink instproc trace-callback {ns cmd} {
	$self trace $ns {}
	foreach part {enqT_ deqT_ drpT_ rcvT_} {
		$self instvar $part
		set to [$self set $part]
		$to set callback_ 1
		$to proc handle a "$cmd \$a"
	}
}

(This function is previously defined in tcl/lib/ns-link.tcl)

- Haobo

> I happened to assume that 'r' is the event when a packet already sent 
> through a link. So, now I am trying to use the trace-back command to 
> collect the statistics such as average number of packets in the system and 
> end-to-end packet delay time. The problem is trace-back doesn't capture 
> 'r' status trace (even it shown in trace-all file). 
> Does anyone know if this is a limitation of ns tracing mechanism ? 
> The network in my simulation is quite large. So, if you have any easier 
> way to collect these statistics (avg. number in system and 
> end-to-end pkt. delay) , please help me out. 
> Thank you in advance for your corresponding.
> 
> --Anotai
>   
>