Re: [B.A.T.M.A.N.] Batman-Adv : Hops and Throughput with Collocated dual-radio

["Linus Lüssing" <linus.luessing@web.de>]

Hi Jack,

One more test could be interesting: What throughput do you get
with static routes over the wifi interfaces directly, without
batman-adv?

Just to check whether it's batman-adv's fault or something else
(e.g. cheap, unshielded wifi chips, a bug in the test setup /
configuration).

Cheers, Linus


On Thu, Oct 17, 2013 at 11:21:57AM +0800, Zaki wrote:
> Hi Linus,
> 
> From A to B(radio 1) it is 5.24GHz. Throughput is 40Mbps.
> 
> From B(radio 2) to C it is 2.412GHz.
> Throughput is 38Mbps.
> 
> From A to C the throughput is just 20Mbps.
> 
> Thanks.
> Jack.
> 
> On Mon, Oct 14, 2013 at 11:37 PM, Linus Lüssing <linus.luessing@web.de> wrote:
> > Hi Jack,
> >
> > what is the throughput you get from B to C? What was the
> > throughput you got on the 2.4GHz link alone? Did you change to
> > 2.4GHz on A-B or B-C?
> >
> > Cheers, Linus
> >
> >
> > On Mon, Oct 14, 2013 at 09:26:41AM +0800, Zaki wrote:
> >> Hi Simon,
> >>
> >> Thanks for your reply.  I am using omni antenna right now and what i
> >> got when i did an iPerf from A to C is only 20Mbps.  It looks like the
> >> throughput is cut to half (just like a single radio mesh).  Tried 2.4G
> >> frequency in one of the pair, had the same result too.  Anything in
> >> terms of setting of batman-adv i can look for?.
> >>
> >> Rgds,
> >> Jack
> >>
> >> On Sun, Oct 13, 2013 at 10:36 PM, Simon Wunderlich
> >> <simon.wunderlich@s2003.tu-chemnitz.de> wrote:
> >> > Hi Zaki/Jack,
> >> >
> >> > On Fri, Oct 11, 2013 at 11:11:04AM +0800, Zaki wrote:
> >> >> Hi,
> >> >>
> >> >> I am a newbie in batman-adv.  I got a question regarding Hops and
> >> >> Throughput, especially in regards with a collocated dual-radio device.
> >> >>  Hopefully somebody could offer some help here for me to fully
> >> >> understand batman-adv operation.  I have 3 devices, namely A, B and C.
> >> >>
> >> >> A is only having single radio (operating at Freq 5.20G in AdHoc mode).
> >> >>  Put this under bat0.  Bridge bat0 with eth0.
> >> >> B is having dual-radio (radio1 operates at 5.20G in AdHoc mode, radio2
> >> >> is at 5.24G in AdHoc mode). Put these under bat0. Bridge bat0 with
> >> >> eth0
> >> >> C is like A (single radio, operating at 5.24G in AdHoc mode). Put this
> >> >> under bat0.  Bridge bat0 with eth0.
> >> >>
> >> >> So, the wireless link will be like this :
> >> >>
> >> >> [A]::::::::::::::: [B(radio1)---B(radio2)]::::::::::::::::[C]
> >> >>
> >> >> 1) If i were to ping from A to C, how many hops is it considered?.  Is
> >> >> it 2 hops or 3 hops?.
> >> >
> >> > that would be two hops. One hop is considered traversing one link, and
> >> > you have two links here.
> >> >
> >> >> 2) If my Iperf TCP throughput from A to B is 40Mbps, what is the
> >> >> expected throughput of Iperf from A to C ?.
> >> >
> >> > That depends. If the links are not interferring, you should get approx.
> >> > the maximum of both link throughputs. So if one link is 30 mbit/s, the second
> >> > is 25 mbit/s, that whole path would yield 25 mbit/s - there might be tcp
> >> > effects further decreasing throughput (latency etc).
> >> >
> >> > However you use two frequencies adjacent to each other. If you use omni
> >> > antennas, expect a lot of interferences (even if the channels are not
> >> > overlapping). If you use directional antennas you should be fine.
> >> >
> >> > Cheers,
> >> >         Simon
> >> >
> >> >
> >> >>
> >> >> Thanks a lot.
> >> >>
> >> >> Jack.