[Olsr-dev] olsrd etx + plugin

[Henning Rogge]

Am Tuesday 21 April 2009 14:11:54 schrieb Erik Tromp:
> Hi Henning,
>
> I am looking into your lq-plugin system. It looks very nice!
>
> Could you point me to some background reading or documentation? I'm pretty
> handy in reading the code but I could miss some things that you may have
> documented.
Each lq_plugin defines a large struct which contains all necessary pointers
for the olsr-core to use your lq-metric without knowing what you are doing
(see struct lq_handler in src/lq_plugin.h). The structure changed a little
bit from 0.5.6 to the development top so we could get rid of the void*
pointers. Both versions allow you to add additional parts to several internal
databases of the OLSR and allow you do handle (de-)serialization of the LQ
part of TCs/Hellos yourself. All you have to give back is a "link cost" value
which is just a unsigned integer (maximum allowed value is ~2^24 to prevent
an integer overflow during dijkstra).

the layer2metric development tree adds a "layer 2" metric database which is
filled by a plugin (/lib/ll_linux_nl80211) directly from a recent mac80211
link wlan stack (2.6.29 or better, 2.6.28 + compat-wireless will work too).
Unfortunately noone had enough time to test the prototype to get some
experience on layer 2 metric, we had/have too much todo with the normal
OLSR core at the moment and creating a firmware with 2.6.29 so we get an
user base which is able to run the linklayer metric code.

My plans for the future of this tree is to test what happens if I switch
the OLSR to raw sockets for package handling, so I get the mac address
of each neighbor for free (see arprefresh plugin). Then we would have to
create a good and flexible linklayer database and some lq-plugins which
use it to calculate ETT and similar stuff.

If you are interested, just tell me. I think the olsr.org implementation
is much closer to a linklayer based metric system (maybe ETT for example)
than you 0.5.5 fork, but we need more manpower to test/experiment with it
so it can be included into 0.5.7 (or maybe 0.5.8).

Henning

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Diplom Informatiker Henning Rogge
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