Dear viewer, these subtitles were generated by a machine via the service YouTube and therefore are (very) buggy. If you are capable, please help us to create good quality subtitles: https://c3subtitles.de/talk/618 Thanks!
[Music]
you're going to get a
small glimpse of what infrastructure is
being built up here every year
so please give it up for all of the
people of our
various infrastructure crews
and we'll start with leon and the
32c3 knock review
all right good morning everyone this is
the knock talk
so i'll start with the bad news we had
no sauna this year the issues um were
quite interesting this year because we
had some problems acquiring
backbone hardware which was quite
serious
usually we had a sponsor who
who lend us a ton of equipment that we
can that we could use and that we had
everything from one source and that was
really easy we just sent a wish list
and we got everything we wanted and we
could build
the nice network with many features that
we didn't really need but just made it
fun to have
this year however the sponsor had
already agreed to
do the same thing again but then they
had some internal difficulties so they
couldn't do that
and we learned that basically one week
prior to build up
so i got a phone call and we basically
were left without any backbone equipment
so it was back to the roots what have we
done the years before
we called many people and we got many
offers
uh from amazing folks who helped us out
um uh we decided that
basically everyone in the north would
bring his fritz box and it'll be fine
um so the temperatures were fine in all
rooms the first boxes don't have
that much energy to dissipate
um so this happened
um now what we seriously did was um
some emergency planning we got help from
many amazing companies especially
we have to thank team x who are in
nuremberg
a company um they've been incredibly
helpful um
arranging stuff from their storage i'm
talking to people if we can use their
stuff and
we spent many hours on the phone late in
the evening with a man from tmx so that
was really helpful thanks for that
um other companies helped as well um
especially
huawei uh via the company called 10 ict
who lend us some routers um secure link
which is another netherlands company um
helped us with equipment and e-cigs
learned some they've learned a
big router and switch which we use in
the data center
so what we ended up with in the end uh
was this equipment it's uh basically
basically it's a mixture of many vendors
which made the
network very interesting to build but it
worked out
pretty nicely in the end we we even got
the
force 10 router the e600 which we had
first used
at 20 23 c3
um which we got from a friend of mine uh
a friend of us
um the good thing about that is we don't
have to give it back
um so that was really useful
uh yeah you want to continue in the
backbone yeah sure
hello is this thing okay i think that's
working now thank you
um yeah with all the equipment we got in
we went in
and did basically within one week a
complete redesign of the backbone
we had we knew of course in which patch
rooms we needed to go
and how many ports we needed each patch
room but
the whole vpls routed setup we had in
before
was oh yeah this is maybe you can see it
in the first two rows or if you have
really sharp eyes although in the back
rows but uh yeah it's also
later on the slides so yeah we went in
and redesigned the whole
uh the whole backbone basically this
year we just did a
simple layer two backbone no vpls
nothing fancy
we just needed to get it running the
routing was done
mostly usually on the huawei's in the
larger patch rooms
and where we were as in the since we've
been here in the ip and the cch actually
we've been in the
data center of iphh where we were
connected to upstream isps
and had four times 10 gig wdm back
back link to the cch here
and then we had a couple of um upstream
isps too
uh for the really for the first time we
had 10 gig from dodger telecom here in
cch
so for the first time since we've been
here we had actually redundancy on the
uplink
if the uplink to the iph would fail
we would have still 10 gig to dodge a
telecom for internet traffic here
in the cch which was pretty cool to have
and then at iph we were connecting to
e-cigs
internet exchange point to kaya global
kpn and
lw lcom our three
other upstreams and
at ecx we were mostly doing peering with
the route server later on they came
appearing sessions to kabul deutschland
and we had two peering requests from one
isp
which didn't set up the iptd bgp session
actually
so we're still waiting for it they have
still a couple of hours before we shut
down our equipment so maybe we'll get it
in the end
[Applause]
yeah and with all the well all the
actually quite big isps we had as an
upstream we had the
some problems or not some challenges
difficulties
balancing between those uplinks we were
moving around traffic a bit
from one from romi some asses from one
uplink to the other
and stuff like that uh to to balance it
out and to find a good uh
find good connectivity basically for all
of you and in the end i think
we managed to do this and uh we had
quite a few complaints
and uh the ddos's were coming in pretty
fast too so i guess we were a pretty
successful
successful with that
[Applause]
so after all those years we used the
e600 basically
many years in berlin then we didn't use
it in the cch
and we used it at camp again this year
we finally found its limits um because
this this
was always like that one box that always
stood up to the challenges of the
congress
but this year i think we filled its
tcamp table
which couldn't hold more than 16 000
ipv6 neighbor entries
well it's basically you you have three
entries per device so
there's not this many entries basically
so
that device was just too small to hold
all the v6 traffic
um but yeah we could um mitigate that by
moving v6 routing to another device we
still had lying around
so that worked um another issue was that
for the first time uh we actually had a
ddos
so someone tried to attack our network
from the outside um
basically they've filled two of our 10
gig uplinks with
dns amplification traffic so
that was one evening of some issues for
us it was
it was going against one of the colo
servers
so we don't really know if they were
trying to attack the event
or some specific server they didn't like
but we could mitigate that with the help
of our upstream knocks so
that worked
[Music]
what we tried to do with kbn this time
which is one of our uplinks
is to run a 100 gigabit connection to
them
um they
they arranged hardware especially to do
that test with us um
and we arranged hardware to to do that
but in the end it didn't work well
we tried some we suspected a broken
optic
so flex optics sent us another one which
didn't work
either so we are suspecting currently a
broken line card in their router or
something
um but yeah in the end we were stuck
with uh with your grandmother's 10
gigabit ethernet again
um but that's fine we don't need all the
bandwidth it just would have been nice
to
test the technology
uh marcus um yeah
and then we had some problems uh
problems with physics routing
on the huawei's basically they were
working quite fine in most locations but
in one of the patch rooms where we had a
lot of vlans terminated
they were it seems like they were
running out of cam
basically which is the memory where the
addresses are stored in
and we noticed that it was mostly for
ipv6 only we had package
strange packet loss on some vlans not on
others so
it was quite a hard problem to debug and
to find out
eventually and when we when we figure
out that it's
it it has to be cam related we were
moving
most of the routing of the one patch
room back to the e600
which made sure that it was still below
sixteen thousand
neighbors of course and then suddenly
the latency went back to normal on the
ipv6 networks and everything was working
quite fine
we didn't really find out what happened
there but
it had to be something like that and we
had the same problem basically with a
wi-fi network
where uh we had uh almost like well
we have the numbers like 8 000 something
users in there
um so we were routing that at the
beginning on the
on the e600 basically right yeah yeah
another on the e600
and uh there we have we're running in
the cam issues too
then we were moving this actually to an
mx mx80 so moving about
around a little bit of locally without a
traffic but then it was fine
and then in between there were
some people trying to be funny and
sending some stuff to our monitoring
servers
which took down some of the monitoring
for some time but
eventually we found out that too and
we're
blocking the drp addresses and then we
could see that all the network was
working
anyways so that was fine too
yeah and then we have some some random
notes so to speak
we were not we were noticing that the
facebook traffic was really really low
it didn't it didn't get into the top 20
top 200 of the ass
yeah we were talking that the most
facebook traffic we've seen was that one
visitor
walking around in a facebook shirt
and actually on a quite interesting note
there was more v6 traffic from facebook
than v4 traffic so
that's good to come somehow
um for the colo we saw this year some
requirements
oh yeah we need this like uh 10 times 10
10
10 gig no it wasn't 10 times but some
people wanted to actually
have multiple 10 gig channels for the
for the servers
i mean we are quite happy to write
connectivity and color we were quite
happy to provide the caller
and do anything we can to to provide
bandwidth there but
there are there are some limits so we
think at least at this for this congress
10 gig was quite enough
for one server in the cola so
especially i mean the people couldn't
know that we had this problem with the
backbone and everything else but still
i mean please keep your requirements
aligned with reality
that's all what we're saying
uh we learned some interesting new facts
that well
people couldn't tell us when we asked
them uh
we have om2 multi-mode fiber in this
building and
with the hectic arrangement of hardware
before the build
up we had a situation when where we had
to run
40 gigabit ethernet links between some
sites
well we would have only needed 10 but we
had the equipment only for 40 gigabits
so we had to figure out whether those
links would work over
this fiber that's not designed for this
kind of use
the the stuff is specified to run uh for
100 meters over om3 fiber which is
better fiber than we have
um and we were able to get it working
for 190 meters
uh on the bad fiber we had so that was
nice to learn
uh yeah another interesting fact that's
barely visible in the slides due to a
formatting [ __ ] up
um the maximum outgoing traffic was
21.4 gigabits per second people always
ask for that number
which is about four gigabits more than
last year so it's steadily increasing
here's a pretty graph that's
just it just shows um the load and our
backbone links uh
we just noticed that an hour ago it
would be fun to show
um this is where we announced the end of
the
color or the shutdown of the color so
basically all of you walked to the color
and probably
got their servers out so most of our
traffic is gone now
wi-fi wi-fi we have wifi
no but but really we have wi-fi
what we were using this time the same as
last year
aruba controllers to
high value in a high value with a high
availability setup
with 10 gig links towards the
the core we had deployed 145 access
points throughout the building
in uh all over the building we saw um 20
000 unique clients and had a peak of 1 8
150 clients so it's not over 9 000
yeah our wi-fi wi-fi team didn't deliver
on that apparently
yeah and so
sorry um
on a really serious note we saw 40
percent of clients on and
on the unencrypted network which we
really couldn't explain because
we were actually trying to push the
people on the encrypted wi-fi we had the
32 c3 ssid and the
32 c3 open ssid and
somehow 40 were ending up on the
unencrypted open network
although we provided an android app to
configure the encrypted network
we had profiles for apple and windows
and
basically we did everything we could
just to to get the people
using the encrypted wi-fi and still 40
decided i know
yolo
[Laughter]
well maybe the next year we see a
decrease in this number it would be
quite fun
actually
the obligatory username statistics
because as you know you can choose any
name you want
number seven isn't is an improvement
from last year it was on
number 11.
device statistics um this time linux has
one
together
um and traffic statistics uh we saw an
average of three gigabit per second um
coming from the wi-fi which well at the
sum of received and transmitted data
um peak of 4.5 gigabits
um
so one and two were the most busy areas
of obvious obviously um
they had the peak of 1.75 gigabits
per second um so we in
in this in this deployment we see a much
higher average bandwidth use
a bandwidth usage per user than a normal
rollout of this size so it means
you guys are much more active on the
internet for some reason
yeah and uh we can see this in this
pretty graph too
that's the the airtime usage on five
gigahertz and sol one
so basically everything is you in use
we don't have any spare spare frequency
ends anymore
and uh yeah we have to be trying
uh we're actually trying to push as much
traffic as is physically possible
through those wavelengths
to those frequencies
that we that we have
uh so this year our wireless people
decided to
try uh to try to build a probe system so
they can actually
monitor the quality of the wi-fi they've
built
um well before we could just monitor
them by
do we have complaints from the users but
this time we have actual measurements
so data they've built five
open wt devices with wpa supplicant
installed and then they've run
automated tests on them for icmp ping
checks
can we get a dhcp lease let's try to
download this file via http and see how
long it takes
things like that so what you can see is
well the the download speed was limited
to 15 megabits per second
and during night time when the rooms
were empty um
you could actually get the speed um
but once people would come in the speed
would drop
so that's that's interesting data to
have
while designing the network for the next
event or something
we had with a bit of problems in the
wi-fi too of course
or challenges we had some performance
issues
with the e600 on the first day which
were
was adding because it was running out of
cam apparently
a lot of latency to the to the wireless
network and basically
to most of the net to the network
traffic that's going through it
uh when we moved the traffic away from
the e600
the throughput doubles basically uh
after day one so
we figure out then that we reached the
limits of the e600 what
we're telling you before already
and um we were hitting the physical
limits in
zal one two and three most of the time
with a channel utilization you just
you just saw so we either need
more spectrum or a more efficient usage
of the spectrum that we already have
and in this regard our wi-fi team is
asking
if there are some people who have
knowledge of this area
of running a wi-fi network for how many
having 20 12 000 15 000
people and with the bandwidth we're
having
uh they'd like to talk to you about how
this can be done if you have any ideas
or whatever
you can get in contact to us i mean this
doesn't
of course uh you can you can still talk
to us but we don't really need an
experience for someone who has like a
fritz box at home we still have this
experience ourselves so of course
so but we really need uh like the
experience of
engineers and people who are running
this high capacity
networks with with lots and lots lots of
users and bandwidth
and the last problem we had was the the
fast
radar detection we had this last year
already we were presenting it
talking a bit a little bit about it
basically when there's uh
some noise going in on one frequency the
wi-fi wi-fi just
just shuts down because it's thinking oh
there's uh like radar
uh from from the from the airport um
traffic control or whatever
coming in and then it shuts and it needs
to shut down
this is an um a known bug in the arubas
or something like that
i guess and um
it's still not fixed we're still still
seeing these problems
but apparently it gets better and the
newer devices which we didn't have
or didn't have that much from right 50
okay so 50 percent of the people were
able to
continue using the wi-fi when those
events come in which is not so bad
another topic is the people who we need
to thank
[Laughter]
we couldn't get a better picture sorry
so we would really like to thank the
kind folks from the
noc help desk who who always are our
firewall
they just take all your requests and
complaints and they try to help you guys
and they
forward the serious stuff to us so that
uh well we have actually time to work on
the network
so thanks for that
and on the last note um the traditional
thinking to the sponsors because
these are the companies who actually
make this event possible um
it's especially in a situation like uh
this year when we were
left without equipment um basically um
it was good to have so many companies
that you can still rely on who would
jump in or would
still provide their other stuff of their
respective areas
so thanks for that again
[Applause]
all right i think we're done are there
any questions
hey so thanks very much for the for the
great work
um just two quick questions on the wi-fi
in in
in sal eins how many access points did
you have in halle irons in in total
and i was just wondering per access
point were using only a single channel
per access point or can the access
points
have several channels at the same time
on thanks
arya i want to go on that
here's our wi-fi man and so we were
using
18 access points in style one and um
though those were using uh pretty much
all of the uh
20 megahertz wide five gigahertz
channels
so they were on different channels yes
so each access point has one five
gigahertz radio so it
will uh use up one twenty bankers
channel
i guess that's also the controller
solution right they i mean they see each
other and they distribute the
or did we assign it definitely exactly
okay
i'm being told there's another question
from the signal angel
is that correct yeah
the most interesting question is how did
you get peering with deutsche telekom
it was actually transit not not just
peering um
yeah well we asked some forks
okay so it's not reproducible
well we hope to reproduce it next year
but we'll see yeah you can
i can't
i have another one which is
[Music]
why is the wikidown
i'd like to stress this this year again
we do not run events that see the cd
and i guess the last question from the
internet
is what funny thing did some users do
against the monitoring system
uh some blah i don't remember there was
some
weird packets that put heavy load in the
machine or something
sim flat apparently okay it's in flat
easy
yeah hi um a few years ago
nadia henninger and i did a study where
we found
thousands and thousands of devices all
over the internet
that had weak rsa encryption keys for
like ssh and tls because of bad random
number generators and we could
compromise
all of them for that reason and um i'm
i'm wondering whether right you guys can
can help us with this because um a very
large fraction of them were fritz boxes
[Applause]
we're returning all our fritz boxes so
we don't have to do anything with
switchboxes anymore
um do you think next year you could uh
discourage use of the unencrypted wi-fi
more by giving the ssid
a less innocuous name like open instead
and call it like unencrypted or
insecure or something safe yeah we can
try that we
we do have some success uh discouraging
people from
using the 2.4 gigahertz networks by
giving it the
legacy or even slow name or something
so that works yeah we can probably do
better but than that
wireless questions specifically hall one
to get the network working
do you run the access points at full
power or do you have to reduce it to
make the cells smaller
yeah we have to reduce the transmit
power so we get cells that
overlap the least as possible thank you
i was wondering next year would it be
possible to get better wi-fi coverage in
the bathrooms
you know the funny thing is this was on
our list for this year
so i'm not quite sure what failed there
but well we're sorry
we are aware and we're sorry yeah
do you try to turn off the unencrypted
network
uh well we didn't try that we know what
would happen but
we don't really want to but we would
like to discourage users
um but we still want to provide a
connectivity
for people who i know it's it's a hacker
event right so if you want you
should be able to s well have your data
sniffed or whatever
okay one more question from the signal
angle
yeah how many abuse messages did you get
i'm sorry i don't have this number this
year this time around
kai is coming off our abuse handling
person is coming
hello hello scroll scroll uh 248 males
were like 95
automated about port scans because it's
still
just used for stupid pod scan the
network most of the time and
we had i think roughly 10 calls where
one was more or less serious and the
other ones were like really unimportant
and easy to fix i've got one of those
calls someone has sent a spam email
which is of course not a good thing to
do but yeah
okay we're done
okay
okay all right um who's next
blank stairs
yeah that looks like a voc review
so if have any people left the room do
we have
new free seats i see two over here one
over here because we have people
standing in the back so they can find a
seat
[Laughter]
all right um yeah just you know
keep coming keep finding the three seats
people keep their hands up
all right then please give it up for the
walk preview
all right hi um is this on
is it oh yeah now it is okay so um
some of you might know last year we were
more or less virus operation center
with half our team like falling victim
to the
congress lawyer we tried to do better
this year
and um
well more or less worked uh we have like
a few
sore throats but no casualties this year
so i think we did all right
so the setup was more or less similar to
last year we we had um
in the uh in each of the halls we had
like two
to three cameras three and the two first
two halls and
two in hall six and whole g uh
being mostly mixed or being mixed with
hardware video mixers and lots of
equipment in between
which mostly came from which mostly was
made by
blackmagic design so video mixers
signal conversion like converting hdmi
to sdi
and scaling and stuff and
backup recording to ssds and so on
we got requests to like talk more about
how the actual signal flow
looked like so i included one of the
pictures and
from hall 2.
so we i'll use the cursor probably
so this is where the speakers
insert or where the the speaker signal
gets inserted
which goes to a switcher which
also outputs to the projector
and can also loop back to the video
mixer which is connected to
cameras um i can't read that
oh yeah and there's a scaler for feeding
back the
output from the screen to the video
mixer as well so we can
take the info beamer which is the
thing which placed during the breaks
to and put it on the stream as well
one thing we we do which might not be
obvious if
if you haven't done video stuff before
is that we
embed the audio signal later in the
chain so
the video mixing itself happens without
the audio
and we have a central i have a slide
the next slide is about that we have a
central place where all the audio from
all the halls
gets collected and
mixed and redistributed and we only
embed the audio after
the mixing which uh makes a lot of
things easier but also
causes problems from time to time
because um
you like have it's it's not local so if
there's a problem in the hall you have
to call up to the
central central audiology we call it
and talk to them and that's
that caused some problems but we were
able to fix most of them
at least in the releases if not in the
streams
yeah so this then we split the signal to
one backup recording which is just
recording everything on ssds we
hope we don't have to use that but it
has saved us
a couple of times this year already and
we had that the previous years as well
and then they go to two separate boxes
one of which does the recording and the
other one does
the streams so yeah and this is
the control panel for the oh that's not
the control panel for the mixer
so that's hall 2 which is slightly more
complex than all g
or hall six hull one is mostly similar
oh and we also have a gopro input with
which is c1
in the front for if somebody has to or
wants to show something
uh like hardware or so on so yeah i
think i
covered everything more or less all
right
we also have that's the only picture i
got uh we have a
like i said a big audio mixer
which collects all the audio signals and
all the translation signals as well so
we can
balance the levels after uh after
the audio
mixing done by the cch itself
so we can react more quickly and do some
stuff which wouldn't be possible
otherwise like
ducking in the in the translation
streams and so on
we also did the zended centrum this year
again we we already had that last year
and we decided to do some well
experimental stuff for research we
wanted to
have a software video mixer which can do
hd
for the smaller smaller conferences we
do over the course of the year
and uh we or one of our team was
developing such a video mixer which we
call which is called voctomix
uh it is based on g streamer and we
decided well
we have to try it sometimes so well we
actually tested it before of course but
this was
really the first big conferences where
uh conference where it was
in use and it worked surprisingly well
we had some minor
hiccups but uh i think
there was no lasting damage as in all
the recordings got through
so uh if you uh if you'd like to
see how if you need uh hd uh
capable software video mixer it's open
source we can
you can go there and please send patches
and and so on
um so about the recordings um
we had uh about 133 hours worth of talks
in
all the halls together so that's um that
doesn't include a zender centrum because
that was tracked in another project in
our internal system
this is only hall 1 to gn6
we do releasing 8 in 8 formats so we do
hd releases sd releases each of those in
mp4 which is h264 and aac and webm
which is in our case vp8 and
varbis we also do audio only
releases and because
well most of you when they if you go to
media ccd and watch
the try to watch the talk in your
browser you might notice that you get
a random like either the translation or
the original
audio signal and this
this actually depends on the browser
you're using and and
uh the face of the moon and whatnot
is actually the only browser which
handles multi-language or multiple audio
tracks
in video files on the web correctly is
ia-10
so so that's pretty sad so we also have
to we also d-max
we create additional releases which only
contains single audio
tracks to to cater to broken browsers so
if you have
issues like that playing playing getting
the wrong audio or something
just download the file and try a drive
vlc or something so in the end this
amounted to
more than a thousand hours of encoding
and and actual files
ending up on on various servers
if you have uh in cpu time that's
probably about
like five or three thousand hours of
encoding time
all right um the reasoning status we
this year we were able to
we were allowed to record almost all
talks but one which was the
the play in in hall one um
when i when i made the slides we
released
we already had released 130 of those
152 talks this number is probably higher
by now
uh we'll try to get most of as many
talks as we can out
to until we have to leave and until the
the network gets
cut down so we hope that
well most of them will come out today
and the rest will hopefully come out
soon
once the our hardware has traveled to
its home again and
has we've gone to the rest of the
releasing process so
the talks which are not going to be
released today will
hopefully happen in the next one or two
weeks tops
um yeah so you can go to mediacc.e
or we also publish the talks on youtube
all right streaming on the other hand um
it was pretty similar to last year we
dropped
finally we we felt comfortable dropping
rtmp
so only hls and webm with the majority
of the
the viewers actually going to webm
because uh
browsers the only browsers which
natively support hls are apple
device so that was about
10 to 20 percent i think and this will
also be able to offer hd pass on all
relays like
for the website itself but also for the
stream people
came to us for the past few years and
requested that so we built that
this year and that was mainly possible
thanks to that's encrypt because we have
lots of servers and like going
either getting like huge amounts of
wildcard certificates or
going to uh
going to the process of getting like 50
different certificates
by copy pasting csrs somewhere just
isn't fun so let's encrypt made that
easy for us that was quite nice
so this is how uh how cdn looked like
the servers you see in the bottom that's
17 if i didn't miss
count is the ones which were serving
streams
to the users this is our source which is
in in in in a collocation space here in
in cch and we have a distribution layer
which uh just handles the
load uh of actually pushing the data to
the edge relays
because one edge relay gets fed
with approximately 300 megabits just
the all the streams so we can't
do 17 times
300 from just one server so that's where
we have this distribution layer
one of those was in two of those servers
were in
in the united states actually so people
coming from the united states
were pushed to a local server we also
had a server in inside this building
and also went to pushing
people from the 3233
to that local server to ensure that you
don't have
or you have like less less round trip
time
more or less peak thief is still a thing
so you can see peak thief over there
that was
like five and a half thousand viewers in
hall one
we also have a little peak jeopardy over
here
yeah so we ended up serving
almost 20 gigabits of streams
at the peak and well less than an
average so something like 10 gigabits
which was
10 gigabits on average during a normal
day which was quite a bit more than last
year
so uh yeah um
one of the reasons is that we actually
enforced hd by default last year we
we had hd as an upgrade path so to say
and well that seemed to have worked we
pushed more than 100 terabytes of stream
data to
users altogether and as it turns out
streaming to
deutsche telecom isn't really fun
we had to actually push
telecom customers to a specific subset
of servers which
had less than shitty peering to a
telecom
so um
yeah and actually most of the telecom
traffic was served from
cch itself via the knocklink so thanks
for that
that has helped a lot
so there are a few other teams which are
well not exactly the
video team but related so i i collected
some statistics from them as well
so first as the subtitling team which
this year again did live subtitling in
halls one and two
and they subtitled 82 talks which was
all of them
and the number of characters they typed
was 2 million
14 021
they had about i didn't get these
numbers in time for the slides so i'll
just say them they had like 60 angels
which did that so that was great as well
and i was speaking about angels we had
like video angels manning the cameras
and the video mixers and so on
that was about 250 so
well done thank you
i tried to call the translation team but
uh
their phone just uh didn't uh didn't uh
uh
they didn't answer the phone so i pulled
this these statistics out of our
recording system uh so these are not
complete but they give you a rough idea
how how how
the translations were distributed so we
had uh
three german talks which weren't
translated and nine english talks
but comparing that with uh 105 english
talks which were translated to german
and
19 german talks which were translated to
english that's a pretty good
ratio i think yeah
and
and also this is uh i think it's the
first time we actually released uh uh
uh a video with uh three audio tracks so
that's
uh originally german translated to
english and also translates to uh
switch schwitzer douche
uh that was the uh yesterday's hacker
jeopardy if i'm not mistaken so if you
want to watch that
all right so if you want to know more
details about the
how the post processing works and so on
you can go to our wiki
um the setup described there is not
exactly what we do on congress but
many of the parts are still the same so
there's some documentation there and
there's also talk from frostcon linked
which explains some of that so see you
at easter hack
and have a nice day
[Music]
all right
so we're going to start switching
speakers already
and might do one or two very quick
questions because we are running low on
time so if you have a question
i mean signalrange will go ahead you
already have a mic
the first question from the internet is
still buffering
what were the audio problems during the
opening event
[Music]
um
uh he would be able to explain more
about that but um
the audio problems during opening can
you
yeah some some magic happened and uh it
didn't
do the magic anymore so um
yeah any other questions here
um yeah uh did you think about uh
broadcasting the streams on dvpt
or yeah we thought about that like we we
tried that last congress
in preparation for camp and we um
ended up deciding not to do that this
year
inside the building because it's not
really all that useful and we because
in propagation of radio inside a
building is not
all that good and um the
well the idea during 31c3 was to
evaluate the
technical problems and we managed that
so we didn't do that
we were thinking about doing broadcast
like
putting an antenna on top of the
building and broadcasting to hamburg
but that didn't happen because of
lysis um well radio license issues but
we might try that next year
okay all right um i think
we're running out of time and to give
the other teams
chances to speak we're gonna move to the
gsm review
right hello hello hello
yes okay good thanks so gsm we had a
um we had a test network again this year
but um there there there's
a gsm spectrum situation in germany
at the moment so the regulatory body the
bundesnet's argentour they
in 2015 auctioned away the test
spectrum the the decked guardband that
is between the frequencies used for gsm
and the frequencies used for dect
handsets so because
this spectrum is in between the two
ranges
it's it's traditionally been held free
because
you know there might be some they might
sort of bleed into each other
anyway now it's gone it's auctioned off
and
um so we couldn't apply for a test
license well we could apply but we
wouldn't get one and it looked really
bad
it looked like we would get no spectrum
at all and so
hagal velter one of the osmo comb
developers he
he wrote a blog post about this and a
few days later
well saying in his blog post that it
seemed like we would be able to have no
network actually because of this
situation and a few days later he was
able to write another very good blog
post
saying that we would have a network
because he got um some
some some contacts from or somebody from
vodafone got in touch and said well
actually this isn't being used just yet
so it's all right for you to uh to use
it one more time they gave us permission
and we
applied at the bundesliga and we were
assigned
assigned one more test license so that
was that was great
we had seven well some of them are still
up we had seven bts's operating
in the building that's a little bit less
than we've had previous years
they were each on their own um arkan
their own frequency in the 1800
megahertz band one in the rooms
one two and g the larger room upstairs
one in the gsm room
upstairs one outside here in the foyer
and one two stories up and one
over in the hack center so we did some
new things this year
we implemented huff rate the half rate
audio codec which means that we were
able to accommodate twice as many
calls as as previously that's good
now there's also an open source working
open source implementation
of this which was indeed
finished during during congress now and
and we also operated gprs for the whole
event
uh on one time slot on each pts so
that's uh
one-eighth of the frequency capacity was
reserved for packet data and this
this uh this was used and it it worked
the the thing is so you you if you do
this you have to
you have to determine in advance how
many how much
uh frequency spectrum you're going to
allocate to
packet data versus phone calls and
that's sort of fixed it's not so easy to
do that dynamically so
um we started small and let's see what
happens so we had
some some subscribers i'll
show a graph in a bit lots of sim cards
and
no stupid bots this year that's that's
good
peak activity 66 calls
in within a minute was the maximum load
on the network
and 38 sms messages
sent within one minute the total number
of sms messages 15
939 so well done and
it seems that about 450 or so
of them didn't actually deliver uh
didn't arrive at their destination maybe
the phone was switched off for too long
or
nobody there was no subscriber with that
particular number who knows
there was some gprs traffic as well not
no gigabytes right but megabytes
at least at least something let's start
small uh
116 or so megabytes received by
the network so sent by um by devices
and 475 megabytes transmitted by the
networks are received by
the the devices and some
some pretty graphs this is a snapshot
from
from a little while ago the
the three on top i already went through
that's the number of active subscribers
and the total
number of sent messages in gprs traffic
and on the bottom you see
the the channel loads of the the the
activity
uh of each bts uh each of the seven bts
that we're using
finally so what about next year uh
we don't really know it doesn't look
that great and
um the we're it's pretty certain that
vodafone is going to be using the the
their spectrum that they've acquired
next year and um sad sad
sad panda sad face if you have
any way to to help us out
with some spectrum in downtown hamburg
between christmas and new year's in 2016
then we would love to talk to you
and and this is really this is really a
unique and important opportunity to
exercise the open source
software and hardware that we have for
cell phone technology
i know maybe you catched uh caught
harold's talk
on on the new 3g work that is slowly
coming off the ground and by next year i
i would be super excited to see that um
implemented
now um i mentioned yeah so so if you
can't help please get in touch
i mentioned sim cards as it turns out we
found
half a box of sim cards left over so if
you're interested in those come find me
after after the talk that's it for me i
guess we can take some questions yeah so
we're gonna
start switching speakers already and in
the meantime
take a few questions
so if you have a question in the room
run to one of the microphones
if the signal angel has one he waves his
hand like he does right now
um yeah the question a question is
were there any special uh
services provided via gprs and
were there congress wap pages still
remember that
there were no special services
implemented by
by us and there was no wap
content provided but if you're
interested in doing so please
please get in touch and and we'll we'll
make sure to set something up oh there's
one thing
one more thing i should mention about
the sim cards uh
they so the sim cards from 31c3 a year
ago
uh the ones from camp this summer and
the ones
from this event they are all java cards
and
if you're interested in acquiring the
the keys
on these cards get in touch with us we
can
we can give them to you if you want to
implement for example some
some sim toolkit applets and there's
some some source code that was released
just before congress as well
in if you're interested to work on that
okay perfect maybe one one final very
quick question
have you tried to combine the text
messages from the voiceover ip with the
sms
because that didn't work i think but
it could be interesting have we tried to
combine text messages over
over packet you mean yeah there is a
voice over ip also to call and
uh but you can also send text messages
with that protocol but uh
do you mean is it possible to send sms
you mean
text messages okay uh no we haven't
tried that there is no
no sip to 2g sip 2 sms
gateway that's also an an interesting
project if anyone wants to work on that
should be it should be pretty easy the
poc infrastructure is
is easy to integrate with okay thank you
okay perfect you are the last question
one sentence question one sentence
answer
my question is what kind of hardware was
involved in this entire network
i'm also interested in the bts
uh the hardware we used are cismo bts
cismo btss and what was the second part
of your question
that i was mostly interested in the bts
all right yeah so the the bts is a cisco
bts and
it has an ethernet connection to a
server where we're running the open bsc
open source software to control all
these seven btss
thank you okay perfect thank you and
we technically have two minutes left for
silk road but we made
might run one or two uh longer so
uh yeah please secret yeah hi
um we are part of the team that set up
this year's pneumatic tube network
but we also attended camp
some people thought we weren't there but
we actually were
our village got located or
moved to another spot so we weren't able
to build the
network we wanted part of the reason was
because there's there were security ways
that
we couldn't cross but we didn't
we tried to cross them
turns out that the clay soil in
mildenberg is actually pretty hard to
dig trenches into we also have some
statistics from camp that we couldn't
show the at the
last infrastructure review
so all in all there are about 118
capsules sent from our central node
unfortunately as most of you know there
was a little downpour at the
camp one of the last days so our
measuring hardware that we
would have loved to use at 32 c3
somewhat corroded there and
we weren't able to use it
so this year's network uh looks like
this
it's a bit larger than uh at last year's
congress
um but this year we were also able to
handle
all the traffic from a single central
node so
most of you have seen the router
upstairs so it's able
to route all the traffic to the central
node and
back to all the nodes again
so some new developments we did
for the camp we actually
wanted to collect the statistics from
all the nodes and
since we planned a large network with
nodes that are far apart we figured we
needed
some kind of two-wire bus that has to
use cheap cable
so this is somewhat
is uh two wire bars you can check out
the code and github
and the hardware schematics and this is
also this stuff
we use to control the routers
yeah yeah because of that
decentral or that central approach we
needed some communications
that's why some other guys set up some
field phones to every station
and they were heavily used even uh
especially in the mornings when the
smaller hackers were there that was
quite fun
and nah that's our router
it was really fun
it had three tubes one tube coming
one tube coming from the hack center and
three other tubes
one going to the park to get home for
its vai
and the other one was actually yeah
we'll come to that later was really fun
because of that central approach
we could provide suction as a service
so that yeah i got rid of that
noise problem we had some
yeah not no one really who
who could provide an electrical switch
so we
choose another approach
yeah and we had that third tube at the
router
that was really really fun it was good
for trolling podcasts
because it was on the stage at the
zenith centrum
that was almost everything we would love
to to have more
more people who help us if you want to
help us get everything set up come here
come here on day minus three or so and
just
help if you have nice ideas contact us
via the mailing list and
[Applause]
[Music]
you