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Sun, 18 Nov 2012

22:17:38 18 Nov 2012
(Posted by: Holger Levsen)

Wireless setup for DebConf7

Only in the beginning of May it became clear that we need a new wireless sponsor this year, which quite quickly was found:, which is a german grassroot movement, connecting people and communities with mesh networks.

As some of them are also upstream OpenWRT developers, we didn’t only get 19 accesspoints, but I also got quite some intensive training, which resulted in this wikipage with quite extensive documentation and a nice 3D map, how+where+why to place accesspoints.

So we’ll use the Kamikaze version of OpenWRT, whereever possible. Despite it’s name, Kamikaze is the new stable release of OpenWRT, the successor of WhiteRussian.

The accesspoints will be simply running in bridge mode (and using DHCP to get their IP and not running a DHCP server themselves) and provide unencrypted wireless (authentification via chillispot, you’ll have to login once via a webfrontend, then your MAC address will be recorded and you don’t need to login again) on the ESSID DebConf7. We’ll have 802.11b+g everywere and additionally 802.11a in some places.

We calculated that for Teviot we’ll need approximatly 15 accesspoints and three extra for the hackcenter we’ll be using at night. As we got 19 from freifunk, we should have enough. But I like to have some more, to be on the safe side and to be able to replace the least powerful ones with better ones.

If you can bring an accesspoint that runs OpenWRT, please send a short mail to We prefer OpenWRT, so we can easily include them into our monitoring with munin and because it’s a PITA to deal with lots of different web interfaces for administration (and look up lots of different manuals on different webpages…). If you really want to bring an AP which doesn’t run OpenWRT, make sure the config described above is possible and please pre-configure it like that.

You can check if your accesspoint can run OpenWRT, a modell with broadcom or atheros chips would be best, simply because I already have preconfigured images. Alternativly, the above mentioned wikipage has instructions how to build an image. (And I have a build environment on my laptop. But that’s easy to setup.)

On a personal note, I intend not to be much involved in the wireless setup this year after unpacking the hardware, there is a nice admin team this year and I want to concentrate on the video team and our work there.

And last but not least, but again: don’t just plug your AP into the network in Teviot. God might kill a kitten, and we might loose our uplink if you do :-)