opensand team mailing list archive

[Julien BERNARD <jbernard@xxxxxxxxxxxxxxxxxxx>]

Hi,
> we have tried to changed the maximum value of RBDC and the 
> rt_fixed_bandwidth : when the RBDC value is higher than the throughput 
> we set up with iperf, the "Throughputs.gw_from_SAT" from the collector 
> is approximately the same in average than the throughput we set, as 
> expected.
>
> Iperf is showing different results though : lower throughputs received 
> by gw, datagrams loss. We have to change the value of 
> rt_fixed_bandwidth simultaneously, or to set the RBDC_max 
> significantly higher than the throughput we want to send (when we send 
> 4000kps with a 4500kps RBDC_max for 10s, 0% loss for 4s then 15% loss).
>
> How come ?

Please check your FIFO sizes statistics on terminal and verify if they 
increase.
I think your throughput is too high due to encapsulation overhead. In 
fact, the throughput in DVB layer is the throughput you send + overhead 
depending on your encapsulation scheme.
If you increase rt_fixed_bandwidth, you increase your static allocation 
that is added to the RBDC max.

Regards,

--
Julien BERNARD