Re: [B.A.T.M.A.N.] problem with mesh network

[gtolon@inti.gob.ar]

Hi Marek, thanks for the reply.


El 10/01/2012 08:00 a.m., b.a.t.m.a.n-request@lists.open-mesh.org escribió:
> Date: Mon, 9 Jan 2012 20:22:37 +0800
> From: Marek Lindner<lindner_marek@yahoo.de>
> To: "The list for a Better Approach To Mobile Ad-hoc Networking"
> 	<b.a.t.m.a.n@lists.open-mesh.org>
> Subject: Re: [B.A.T.M.A.N.] problem with mesh network
> Message-ID:<201201092022.37637.lindner_marek@yahoo.de>
> Content-Type: Text/Plain;  charset="iso-8859-1"
>
>
> Hi,
>
>> >  We are using batman-adv 2011.2.0 with Openwrt Backfire-rc6 on D-Link
>> >  Dir-615 routers (2 Antennas, 1 single radio), each router with an adhoc
>> >  interface managed by batman-adv for the mesh network and an Acces Point
>> >  interface bridged with bat0 and ethernet to allow non batman-adv clients
>> >  to connect. The problem is that sometimes all works fine, but sometimes
>> >  we get very poor bitrates between routers, even using just two routers,
>> >  testing with iperf. We don't know where the problem is, specially
>> >  because it's a very erratic behavior. If any of you have used this
>> >  configuration with openwrt and ath9k driver we'd really appreciate some
>> >  help.
> this does not sound like a batman issue. Did you try contacting the
> ath9k/linux-wireless/openwrt developers ?

Yes, we suspected it could be a TX dma problem, because occasionally we 
found that error in the logs, so we followed some openwrt tickets 
related with that, but we're not sure that's the problem, and anyway it 
has not been solved yet. We've also asked on ath9k list about the driver 
debug files in case we could find something there, but they did't 
answered, I guess it's hard to explain in a mail list. We haven't asked 
to linux-wireless, maybe it would be better, since it could be something 
on top of the driver.

>
>> >  By the way, the D-Link Dir-615 is an n router, but for some reason
>> >  related with hostapd the ap vif gets configured in g mode, and the adhoc
>> >  in n mode, no matter what we set in the uci files. So in case the
>> >  problem were related with the adhoc and ap virtual interface, we were
>> >  thinking about the possibility of setting the mesh network without using
>> >  adhoc mode. In that case each router should have one ap for non
>> >  batman-adv clients, and two additional interfaces, one in ap and the
>> >  other managed, these two used to connect with other routers via
>> >  batman-adv, would that be correct? In that case, you think this
>> >  configuration could be more or less stable than the other using adhoc
>> >  mode?
> batman-adv does not care how you configure your interfaces. Using managed/AP
> with batman-adv on top works as well. However, you will need to configure each
> managed/AP setup manually which will be cumbersome in a larger network and has
> no failover. A single failure in your managed/AP chain will bring down all
> nodes depending on it.
We were thinking in a script that managed the stations to connect to the 
different APs to avoid configuring each router manually. However we 
realized that with just one managed interface, each router could connect 
to only one AP, so if we wanted that every router could connect 
bidirectionally to others we should use a number of managed interfaces 
enough to connect to all neigbours,  shouldn't we?
In any case it would be just another test to see if the results are 
different.

Gabriel