mcps_data_request and losses

[Réjane Dalcé]

Hello everyone,
I'm simulating 802.15.4 with ns2.33. As using CBR Traffic sources was
generating unwanted traffic, I switched to calling mcps_data_request from my
Tcl file. This works but there is an issue: when I look at the trace, there
are almost no lost packets. The ratio
(received packets*100)/(transmited packets)
is always close to 100%!!!
When I ran the same scenario using CBR traffic, my hit ratio was 75.08%
So I need to know what is causing this difference: Can someone point to me
what is missing?
Thanks and regards,
R

--
Life is too short to be pissed off all the time.

[Réjane Dalcé]

Hello,
please disregard my last mail. I had overlooked another cause and thought
that the issue's origins were related to the processing of the packet after
the call to mcps_data_request. In fact, the problem was elsewhere: in
taskFailed, it seems the handle does not exist therefore the rest of my code
gets ignored.
BR,

RD

2009/7/3 Réjane Dalcé <rejane86@...>

> Hello everyone,
> I'm simulating 802.15.4 with ns2.33. As using CBR Traffic sources was
> generating unwanted traffic, I switched to calling mcps_data_request from my
> Tcl file. This works but there is an issue: when I look at the trace, there
> are almost no lost packets. The ratio
> (received packets*100)/(transmited packets)
> is always close to 100%!!!
> When I ran the same scenario using CBR traffic, my hit ratio was 75.08%
> So I need to know what is causing this difference: Can someone point to me
> what is missing?
> Thanks and regards,
> R
>
> --
> Life is too short to be pissed off all the time.
>

--
Life is too short to be pissed off all the time.

[Réjane Dalcé]

Hello,
Thanks for your proposition. I'm not near the computer I use for work but
I'll explain.
In my Tcl script, I call mcpsDataRequest to send frames. In the command
function of SSCS, I defined the mapping and made the call to
MCPS_DATA_request which in turn calls mcps_data_request. The issue I was
facing was that with 3 nodes, I had 99% packets successfully sent which was
just impossible. I checked the call to MCPS_DATA_request and noticed that I
had set the handle to 0. Since the handle was used later on to direct to
MCPS_DATA_confirm, I never got to that point as soon as there was one lost
frame. So the first two nodes to fail in sending a frame will never recover
from it and the last one will continue sending, leading to a near zero loss
ratio.
I don't really know awk. I use databases to process my files.
BR

RD

2009/7/6 hakim anouar <hakim.anouar@...>

> *Hi,
> Related to your pb,i'm also working on zigbee technologie (802.15.4), and
> with pleasure to collaborate with you on this topic.
> if you can send me your script file and also the script used to calculate
> the ratio of packets losed and  received in order to analyse it and giving
> if possible my helps.Me i use a simple CBR traffic, i can calculate  those
> statistics  by using a awk script.
> *
>
>
> --
> ANOUAR Abdelhakim
> Systèmes Informatiques et Réseaux
> Département de Génie Informatiques
>
>
>

--
Life is too short to be pissed off all the time.