Hi all,
As I said, it depends on what you want to extract from the trace graph. In my
case, for example, one parameter that I want to calculate is the average
normalized throughput. I defined it as the ratio between the useful throughput
or goodput (received data packets without duplication divided by simulation
time) to the offered data rate (amount of useful data sent without
retransmission devided by simulation time). To calculate the normalized
throughput I need to find number of received data packets without duplications
at AGT level. To do so (assuming that the trace file is output.tr in new
wireless format):
grep -e "r -t " output.tr > temp1.tr
grep -e "tcp -Il $rpktsize" temp1.tr > temp2.tr
grep -e "-Nl AGT " temp2.tr > datarecv.tr
(now datarecv.tr contains all trace lines concerning the received data only on
AGT level but "with duplications". $rpktsize depends on your simulation.
output.tr, temp1.tr, and temp2.tr can be deleted if you do not need them
anymore)
to calculate number of received data without duplications I used matlab making
use of the source address.source port port number (-Is), dest address.dest port
port number (-Id), and packet uniqe id (-Ii). Tracegraph does not deal with -Is
and -Id, so with Tracegraph one cannot calculate number of received data
packets without duplications at AGT level (throghput calculated in Tracegraph
is not the useful throughput, so be careful !!!). ***THIS IS ONLY ONE
EXAMPLE****.
All these steps are done automatically by a certain software written in tcl and
matlab that I did it for my own simulations, I do not extend them to support
other simulations.
Anyway, as a final conclusion: with ns-2, one should write his own scripts to
ensure that he obtains the right results from trace files. I spent 3 months
trying understanding how Tracegrapgh works, whereas it tooks only 2 weeks to
write my own script.
Cheers,
Samer
----- Original Message -----
From: Old Maven
To: Samer Bali
Cc: ns-users@isi.edu
Sent: Sunday, February 25, 2007 3:37 PM
Subject: Re: [ns] ns2 post-analysis of the trace files
Hi Samer,
I agree that Tracegraph could not provide us with the output we desire. But
anyways, how can i base that my scripts were correct. As for that matter, could
you share how you perform your post-analysis for new wireless format.
Your help will be much appreciated.
Thanks
On 2/24/07, Samer Bali <[EMAIL PROTECTED] > wrote:
hi all,
I used Tracegraph to analyse trace file of ns-2. I found that it works good
when there is no frequent packet drops and retransmission. In a simulation
where a large packet drops and retransmission exist (for example in my case
I used the shadowing model in the PHY layer and used a multihop scenario
with up to 4 hops) Tracegraph fails to give a correct analysis results. I
think that Tracegraph CANNOT BE TRUSTED in all simulation scenarios. One
should check his results using another tool (do some sample checks with awk
or perl or grep command).
Yours,
Samer
----- Original Message -----
From: "Old Maven" <[EMAIL PROTECTED]>
To: < ns-users@ISI.EDU>
Sent: Saturday, February 24, 2007 7:29 PM
Subject: Re: [ns] ns2 post-analysis of the trace files
>
> I used ns2 simulator to create trace files in two formats from tdma
> simulation.
>
> 1) old wireless format
> 2) new wireless format
>
> I usually feed this to "tracegraph" to get my results and plot them. I
> have
> been looking for custom AWK/PERL scripts to write those analysis myself.
>
> In the old wireless format , with some simple counts and pattern matching,
> i
> can find the generated packets, dropped packets and bytes, forwarded
> packets
> and bytes. But sent packets: i couldnt find anyway that matches with the
> output from the tracegraph file.
>
> And when i run the same scripts for the new wireless format .. [ i mean
> the
> idea same with counts ] , most of the parameters differ. Basically, i
have
> to come up with scripts to calculate average delay, variation in delays
> (or
> jitter), throughput in bits per seconds, packets
> generated/sent/forwarded/dropped.
>
>
> Is there any available scripts already, or any documentation that can
lead
> me to find the exact definition of how to calculate these.[ in the new
> wireless format ].
>
> I tried this link
> http://mailman.isi.edu/pipermail/ns-users/2004-September/044669.html from
> the archives, but no luck.
>
> Thanks
