[B.A.T.M.A.N.] VIS labels

[B.A.T.M.A.N.] VIS labels

[Gustavo Lindberg]

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Hi

I would like to know where I can find information about the data that
the VIS Server gives. More precisely the label on each link and its
relation with the link quality that B.A.T.M.A.N. gives.

Also, which is the general criteria to know from which number, that
the output shows, is considered a good, regular, bad or "imposible to
use" link?

An example:
digraph topology
{
"5.174.37.225" -> "5.224.160.202"[label="2.13"]
"5.174.117.226" -> "5.174.37.225"[label="5.00"]
"5.174.117.226" -> "0.0.0.0/0.0.0.0"[label="HNA"]
"5.224.160.202" -> "5.174.37.225"[label="1.28"]
"5.224.160.202" -> "0.0.0.0/0.0.0.0"[label="HNA"]
}


Thanks in advance.

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Re: [B.A.T.M.A.N.] VIS labels

[Marek Lindner]

Hi,

> Also, which is the general criteria to know from which number, that
> the output shows, is considered a good, regular, bad or "imposible to
> use" link?

the number gives information about the link quality as batman measures it. 
1.00 means 100% link quality, 2.00 means 50%, etc. Basically the idea is that 
the number tells you how many packets you need to send in order to get a 
single successful transmission. HNA are announced networks which do not run 
batman.

The criteria for a good / bad / regular / etc link is rather subjective and 
depends on your demands. Do you need high throughput or just a few bytes per 
week ?  A live video stream over a link which looses more than 50% of the 
packets requires quite some patience.  ;-)

Regards,
Marek

Re: [B.A.T.M.A.N.] VIS labels

["Sebastián D. Criado"]

El 17/07/09 10:54, Marek Lindner escribió:
> Hi,
> 
>> Also, which is the general criteria to know from which number, that
>> the output shows, is considered a good, regular, bad or "imposible to
>> use" link?
> 
> the number gives information about the link quality as batman measures it. 
> 1.00 means 100% link quality, 2.00 means 50%, etc. 

Hi.

Is 3 = 25% or 3 = 33,3 %?

What function is in use?

Regards

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Re: [B.A.T.M.A.N.] VIS labels

[Marek Lindner]

On Friday 17 July 2009 23:12:09 Sebastián D. Criado wrote:
> Is 3 = 25% or 3 = 33,3 %?

3 is 33.3% and 4 is 25%.


> What function is in use?

Not sure that I get your question. Do you mean that:
link quality = 100 / $number

Regards,
Marek

Re: [B.A.T.M.A.N.] VIS labels

["Sebastián D. Criado"]

El 17/07/09 15:52, Marek Lindner escribió:
> On Friday 17 July 2009 23:12:09 Sebastián D. Criado wrote:
>> Is 3 = 25% or 3 = 33,3 %?
> 
> 3 is 33.3% and 4 is 25%.

Ok.
> 
> 
>> What function is in use?
> 
> Not sure that I get your question. Do you mean that:
> link quality = 100 / $number

In http://www.open-mesh.net/browser/trunk/vis/vis.c
i saw the following calculation.

orig_node->tq_max/(float)neigh->tq_avg

for link quality (VIS label).

If this is correct, would not be so linear.
Am I wrong?

Saludos.-


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Re: [B.A.T.M.A.N.] VIS labels

[Marek Lindner]

On Saturday 18 July 2009 06:43:38 Sebastián D. Criado wrote:
> In http://www.open-mesh.net/browser/trunk/vis/vis.c
> i saw the following calculation.
>
> orig_node->tq_max/(float)neigh->tq_avg
>
> for link quality (VIS label).
>
> If this is correct, would not be so linear.
> Am I wrong?

The given code converts batman's own format into the format I mentioned 
earlier. Currently, batman uses a so called TQ value which expresses link 
quality as well and has its max value at 255. Performance considerations led 
to this kind of representation (you want to avoid float operations on embedded 
devices). Imagine a link quality of 66.6%:

255 (TQ max) * 66.6% = 170

255 / 170 [orig_node->tq_max/(float)neigh->tq_avg] = 1.5 (vis label)

100 / 1.5 [100 / $number] = 66.6% (link quality)


May be I should put that in the wiki somewhere ... :-)

Regards,
Marek

Re: [B.A.T.M.A.N.] VIS labels

["Sebastián D. Criado"]

El 18/07/09 02:38, Marek Lindner escribió:
> On Saturday 18 July 2009 06:43:38 Sebastián D. Criado wrote:
[...]
>> Am I wrong?
> 
> The given code converts batman's own format into the format I mentioned 
> earlier. Currently, batman uses a so called TQ value which expresses link 
> quality as well and has its max value at 255. Performance considerations led 
> to this kind of representation (you want to avoid float operations on embedded 
> devices). Imagine a link quality of 66.6%:
> 
> 255 (TQ max) * 66.6% = 170
> 
> 255 / 170 [orig_node->tq_max/(float)neigh->tq_avg] = 1.5 (vis label)
> 
> 100 / 1.5 [100 / $number] = 66.6% (link quality)

Thank you very much Marek.
I now understand it better

> 
> May be I should put that in the wiki somewhere ... :-)

Yes. Sure that will be helpful for more people

Saludos.-

-- 
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"Si  el Universo fuera un programa estaría hecho
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