Hi Linus,
On tor, 2016-08-11 at 17:47 +0200, Linus Lüssing wrote:
Hi Ignacio,
Could you describe your setup a little more, just two devices? What hardware are you using, which wifi cards? Which operating system and version?
Which version of batman-adv are you using? What is your kernel version?
The test environment is 2 android phones with Android 5.1 running kernel 3.4 where I backported batman 2016.2, same wifi chip (same soc) BCM4339.
What is a typical bitrate your wifi cards are agreeing on (iw station dump)? What multicast rate have you configured for your wifi cards?
Sadly, the support of iw for these kind of chipsets is very limited and iw dev wlan0 station dump returns nothing. I don't know how to get you that information.
What software are you using for testing? What is the bitrate you have configured in there? Is the unicast test UDP as well? What bitrates are you able to achieve via TCP? Does a lower payload length make any difference?
The software used is a java program with 1 socket each where one sends and the other receives. The unicast is UDP as well, yes. I haven't tried with TCP but I can do it if it is necessary, my application only relies on UDP.
I just tried a lower payload (504 bytes) and the amount of packets per second becomes considerably higher but the amount of data is still almost the same.
Regards, Linus
On Thu, Aug 11, 2016 at 05:13:01PM +0200, Ignacio Quezada wrote:
Hello, I am trying to build an application using UDP multicast sockets based on a network mesh built with devices connected in IBSS mode.
The kernel documentation says that this was the place to ask questions or anything :).
Testing the application in the mentioned environment, it suffers some kind of throttling or buffering limiting the throughput. Testing with my application, without the batman interface, just 2 IBSS connected devices, the multicast rate goes around 100kb/s (not saying that the wifi link actually tops at that speed), but then just to add the batman-adv interface and use that instead, the multicast rate becomes unstable between 0-20kb/s.
Disabling multicast optimization, it changes a bit the behaviour but still the same speed.
If I change the multicast packet to a unicast packet, both setups achieve the same speed (~100kb/s), so the batman interface is working but the multicast packets are being handled in a different way. Is it supposed to be like that?
The packets are sent right away according to the iptables counter of packets as well as tcpdump, but the receiver only gets them in a very slow way (counting but not calculating, I think it is around 8 packets per second). The MTU is set as advised, 1532 and the payload for the UDP packets is as big as it can be so the packet does not get fragmented.
Any way to increase the rate or disabling the throttling? --
MVH Ignacio Quezada
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MVH Ignacio Quezada