From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <1470931774.10121.10.camel@gmail.com> From: Ignacio Quezada Date: Thu, 11 Aug 2016 18:09:34 +0200 In-Reply-To: <20160811154723.GJ4483@otheros> References: <1470928381.10121.0.camel@gmail.com> <20160811154723.GJ4483@otheros> Content-Type: text/plain; charset="utf-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [B.A.T.M.A.N.] is the multicast performance throttled? List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: b.a.t.m.a.n@lists.open-mesh.org 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 -- MVH Ignacio Quezada