Re: [B.A.T.M.A.N.] Unterstanding gateway-mode - why do nodes have a "sticky" gateway

[Marek Lindner <lindner_marek@yahoo.de>]

On Friday, January 04, 2013 08:06:17 NicoEchániz wrote:
> > You did mention you were using selection class 1. I was referring to your
> > test in which you turn on/off your best gateway. As I explained in my
> > previous mail: batman-adv does not switch the gateway once it has chosen
> > a gateway unless you select fast or late switching as selection class.
> > Selection class 1 does not fall into this category which means a gateway
> > reselection only happens if the currently selected gateway disappears.
> 
> Marek, could you please clarify this?
> 
> From the man page I don't see an option that would behave as Jan (and I)
> seem to be expecting it to work. That is: switch to a better gateway -
> with more bandwidth and comparable link quality - when it's available.
> 
> [..]
> 
> Would mode 3 accomplish this fast switching? It doesn't mention if this
> mode will consider advertised throughput or not; only selection class 1
> mentions throughput.

Selection class 3 and beyond do change the gateway when a better one becomes 
available. But as you correctly pointed out these selection classes don't 
consider the announced bandwidth for the simple reason that nobody cared. In 
most wireless scenarios (the main playground for batman-adv) the path towards 
the gateway turned out to be more critical than the gateway's pipe to the 
internet.

Feel free to propose something if you care about having this option. The 
necessary code shouldn't be too hard to add. Backward compatibility will be 
more difficult to achieve.

By the way, I posted a patch to improve the man page explanation a couple of 
hours ago.

Cheers,
Marek