From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <1470988256.16102.4.camel@gmail.com> From: Ignacio Quezada Date: Fri, 12 Aug 2016 09:50:56 +0200 In-Reply-To: <20160811163153.GK4483@otheros> References: <1470928381.10121.0.camel@gmail.com> <20160811154723.GJ4483@otheros> <1470931774.10121.10.camel@gmail.com> <20160811163153.GK4483@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 -- MVH Ignacio Quezada On tor, 2016-08-11 at 18:31 +0200, Linus Lüssing wrote: > On Thu, Aug 11, 2016 at 06:09:34PM +0200, Ignacio Quezada wrote: > > > > 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. > > Note sure how usable IBSS on Android is. Last time I heard someone > talking about it, it was supposedly unusable. But maybe someone > else has some more current information :-). > After some tweaking, it works good enough. > > > > > > > > > > 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. > > And the multicast rate is still left at the 1MBit/s default? > Unfortunately, usually multicast packets are sent at the lowest > rate available as there are no wifi ACKs. To maximize the probability > of > reception. There are some tweaks in OpenWRT though. > > Also, often people change the bitrate from 1MBit/s to more like > 12MBit/s or even above. That gives more free airtime and enhances the > batman-adv estimations (BATMAN IV). > Do you mean that with 1MBit/s for multicast, batman protocol needs 80kb/s to set up the connections? 1MBit/s for my application is more than enough.  > > > > > > > > > > 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. > > UDP has no flow control. That's why I was asking about the bitrate > you have configured in the application. Sending with "as fast as > possible" will basically jam your (and your neighbors) wifi. And > will create trouble for batman-adv to find usable routes too > without any airtime available. > > Regards, Linus What I don't understand is that you are explaining standard behavior of WiFi networks, but using plain WiFi without batman works ok and the multicast goes up to 100kb/s (I think I wrote that in my first email).  The tests have been like this so far: - wlan0 (no batman),  multicast: 100kb/s - wlan0 (no batman),  unicast: 100kb/s - bat0,  unicast: 100kb/s - bat0,  multicast: 20kb/s PS: Emails from the Gmail Android App get rejected by the mailinglist, I guess it is because of the HTML format? I wasn't able to disable it, back at the desktop. MVH  Ignacio Quezada