[Battlemesh] WBMv8 -- a personal perspective

Juliusz Chroboczek jch at pps.univ-paris-diderot.fr
Sun Aug 9 22:01:33 CEST 2015


First of all, many, many thanks to Musti and the other organisers of WBMv8
in Maribor, Slovenia.  This was very well done.

For those who couldn't come, here is a quick summary of what I saw.  As
usual, this mail does not reflect the views of any organisation,
community, or individual.  I have removed all of the offensive jokes
before sending out this mail, I am told there are Americans on this list ;-)

The venue and organisation

Wlan-SI has a large production network (over 400 nodes, if memory serves),
and covers much of Slovenia and some of the bordering areas (if you
haven't seen their website yet, do so now -- they make a serious effort at
translating everything into English).  Because of that, they have a large
number of technically competent people, and discussions here are
particularly interesting.  (There are too many competent people to list
here, so I'll only mention my good friends Mitar and Jernej, who gave me
a really hard time.)

Maribor is the second largest city in Slovenia, in a large valley between
the mountains.  One side is covered in vineyards, the other side has ski
slopes.  WBMv8 was held in a large, convenient building at the foot of the
ski slopes, some 7km away from the city center.  We were lodged in two
hotels and one camping a kilometre or so downhill from the vanue.  (That
means we needed to go uphill in the heat -- a strong incentive to get up

Hacking and discussions happened in a large hall with good lighting (which
unfortunately made it uncomfortably hot at times, you cannot have
everything).  The talks were in a luxurious, large lecture hall, and there
was a small classroom with a blackboard for more private discussions.
Toilets, kitchen, fridge, large lawn for naps and informal discussions,
what more could you wish for?

(A shower?)

I was impressed by the food -- a late lunch was served daily, solid and
good countryside food.  I was particularly impressed by the mushroom soup
(juha), made with a variety of real mushrooms.  The most exotic thing we
had was something made of cooked flour that had the consistence of
a potato gratin but completely different taste.  (What's it called?  Ras
told me, but I forgot.)  We weren't served burek, surprisingly, I guess
it's difficult to organise for that number of people.

I had never been to Slovenia before, and I was pleasantly surprised.  The
Slovenians are friendly and helpful, everything works (trains, busses,
hotels, etc.), and the cities are suspiciously clean (although you can see
the effect of the economic crisis when you go away from the main streets).
If you come here for holidays, I would tend to recommend it, but be aware
that it is not exactly cheap -- cheaper than France, certainly, but way
more expensive than Poland, let alone the Czech republic.

Musti remained reasonably calm and managed to keep smiling throughout the

The technical achievements and otherwise

We quickly split into two teams, one that was preparing configuration
files for the various protocols (Batman-Advanced, grr) and one that was
setting up the mysterious WiBed firmware.  The configuration team was
flashing routers, obviously, since you cannot verify a config file without
working routers.

After a couple of days, the configuration team was ready, so we decided to
flash 10 routers.  Amadeus, Federico, Goran and Tomislava were busily
flashing, getting it wrong, reflashing, tweaking something, reflashing
(have you recovered yet, Fede?), while Henning and Thijs were scripting
the tests and Matthieu was scripting the data analysis, and Toke was
preparing his favourite analysis tool (flent), while Amadeus was trying to
bring order to this chaos.  (Yes, Amadeus appears twice in this list,
that's deliberate.)  It was a lot of fun.

We were planning two topologies (full mesh and ring) and two mobility
tests (router crash and mobile node).  The good news is that we managed to
run both analysis scripts.  The bad news is that we only did one topology
(full mesh), and none of the mobility tests.

The horrible news is that the official firmware team never finished.  This
is not the first time that this happens, and we must understand why this
is and ensure it never happens again.  Should WiBed be abandoned in favour
of the scripts written by Henning and Thijs?


As pointed out above, we only have results for the full mesh case.  I've
looked carefully at the results, and the only conclusion I can draw is
that OLSRv2 works very well in this particular topology.  This is great
news, since we've been waiting for OLSRv2 for a long time, and Henning has
beein doing some great work both in the standardisation forums and on the
implementation front.

I'll be back home on Wednesday, we'll look at the results real hard
together with Matthieu, Toke and Dave (anyone else?), and try to put
something comprehensible on the web.

Suggested improvements

No event is so perfect that it cannot be improved upon, and WBMv8 is no

I thought many talks were too long -- everyone got a one hour slot, while
many of the talks could have been done just as well in 30 minutes or so.
(I originally asked for 40 minutes for my Babel talk, but got one hour
anyway.)  I also thought there were many talks that were not clearly mesh
related -- I think we should have a rule that says "if it's not mesh
related, you get 15 minutes, and we'll interrupt you rudely if you go over
your allotted time".  (And if you intend to sit down and scroll a text
file rather than preparing a proper set of overhead slides and speaking to
the audience, you get 0 minutes.  Sorry.)

There were a small number of talks from commercial entities advertising
their wares, which I think is great, but we should respect the right of
other folks to avoid such talks.  Hence, they should be clearly described
as marketing talks.  For example, one talk was described as "Talk about
products from $COMPANY", where it should have said "This is a talk given
by the marketing people from $COMPANY.  Full disclosure: $COMPANY has
donated $NUMBER antennas and a small goat to WLAN-SI."

Somebody bullied Federico into adding Gnunet to the firmwares at the last
moment.  Folks, that's not how it is done -- last minute additions are not
acceptable, no matter how good your sales pitch.  Thanks to the cjdns and
MaidSafe people for their restraint.

-- Juliusz

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