Re: [B.A.T.M.A.N.] Route selection over VPN links

[Marek Lindner <lindner_marek@yahoo.de>]

Hi,

> As we are nearing to our transition to Batman, we are playing some
> scenarios with it and our current setups and layouts. Currently we
> have many nodes connected to more and more VPN servers we have. And we
> would like to use Batman on top of that. What happens is that we would
> like to use the Batman also for routing over those VPN links. So that
> we can connect our nodes to all VPN servers at the same time and
> Batman then chooses over which tunnel the data should be routed. And
> of course this is a bit different situation then wireless routing. For
> example, different VPN servers might have different free capacities at
> the moment available, or at least different overall capacity provided
> (somebody can donate 100 Mbit/s on the server, somebody else 50
> Mbit/s), and then there are also different latencies. Is there some
> way for Batman to prefer routes based on this information? So latency
> over one link and capacity? I know that capacity is problematic to
> measure for wireless links, but here we could configure them manually.
> Latency could be measured. And maybe it would even be enough to
> measure latency, assuming that congested link would have higher
> latency. So the logic could be:
>  * if packet loss is different, choose the one with lower packet loss
>  * if packet loss is the same, choose the one with lower latency
> 
> Such logic could probably be even user also on wireless links, no?
> 
> Anyway, is this doable? If I understand correctly, Batman does not
> support some plugin system where we could inject this in? Would be
> this some addition which could go into the core implementation?
> 
> I think I asked a bit of this questions before, but now we have a bit
> more concrete picture what would be nice to have for our setup to play
> really nicely.

the later versions of batman support a routing protocol plugin structure 
(check bat_iv_ogm.c to get an idea). Using bandwidth information for the 
routing decision is a nice idea but how does your concept look like ? How 
should the routing logic look like ?

Cheers,
Marek