Talk:WLAN

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For The Wireless Lan on the WTH we will use Channel: 1,4,7,13. We need many Channels because there is 3 to 5 thousand Hacker comes. Only less than 2-5% will use OLSR. Rop and i decided that Channel 10 is public Channel for ALL OLSR. On 5 Ghz our Soekris AccessPoints will use Dynamic Frequency Selection and only Channel 40 will be for ALL OLSR.

--Mac 18:32, 30 Jun 2005 (CEST)

Please realise that people with American wireless cards can't use channel 13. Due to circumstances I have one of those myself :) so I hope you don't make a station on 13 the main one for a bigger area!
--Niels 16:07, 13 Jul 2005 (CEST)

Why no 802.11g?

It would be great if we could have g-only base stations on separate frequencies, this would give the g-crowd much more bandwidth and even be good for the b-only people because they get the remaining b-stuff to themselves.

Having mixed b/g is not a good idea because of the overhead of having b backward compatibility.

If you want to use 802.11g you will need 3 channels between Accesspoints. We have not enough Channels on 2.4 Ghz and at the WTH. IEEE 802.11g is NOT ALLOWED. If anyone setup it and use it we will DEAUTH (DoS).

--Mac 03:16, 3 Jul 2005 (CEST)

The IETF and RIPE NCC communities may have some experiences with mixed b/g environments, but what I've heard from it, it's a hassle to get and keep working.

If you need throughput, bring a cable - there should be ample switchports!
--Niels 15:51, 13 Jul 2005 (CEST)

Previous experiences

It'd be nice if the wireless network quality would approach the level at HAL2001 rather than that of the wireless network(s) at CCC2003 or 21C3.

For example, does anybody have an idea how to counter rogue ad-hoc networks with the same SSID as the regular network? Machines running Mac OS X get majorly confused; machines running Windows XP tend to set them up if they can't get a connection to a regular access point...

I realise this isn't an easy request.
--Niels 23:20, 11 Jul 2005 (CEST)

Yes this is not so easy, but what we are doing is to monitor multiple bssid (wlanMAC) on all of the soekris aps. We are monitoring the complete 802.11 Link Layer. We can send DEAUTH Frames and with the wireless location tracking see from which place the rouge ap is coming. Also the roaming protocal IAPP 802.11F is making a complete dynamic user roaming over all soekris. We can manage user between mulitiple bssid and monitor it on the Managment Server.
On the HAL was 500 to 1000 clients in the Wireless. At the last Congress we had ca. 3100 clients. Have i answered the question good for you? Sorry but my english is not so great.
--Mac 03:47, 13 Jul 2005 (CEST)

Are you claiming this should've worked well at 21C3? Because I'm sorry to say, the wlan there was nonfunctional. Broken. Didn't work. Dead. (For me and my friends with PowerBooks.)

I'm really sorry that I am sounding so negative, I had a superb time at 21C3, maybe even because I couldn't check my e-mail every 15 minutes ;-) but wireless isn't on the list of perks I enjoyed then.

I realise HAL2001 was 3.5 years before 21C3 on the technology curve, and also spaced over a much larger area, so will likely pose very different challenges.

What may already help is not having 1,500 users packed in one amphitheatre all trying to get on the same 2-3 access points!

Either way, thanks for your answer, it's good to know that you (plural) are planning to actively work on getting rid of rogue base stations, which is predominantly a people problem. Maybe the booklet could contain a paragraph about not creating Ad-Hoc networks on your laptop, disabling the radio in your Linksys switch, etc.?

Finally, at HAL2001 I was unemployed and too poor to own a laptop, so my experiences with the wireless there are mostly second-hand.
--Niels 15:43, 13 Jul 2005 (CEST)
On 5 Ghz (OFDM) we had most time stable wireless with working roaming on the 21c3, but it was only because on 5 GHZ you can use 64 Channels. IEEE 802.11 with DSSS using only 11 channels and with 3000 clients and a default transmit power of 100mW from each client and other rouge aps, it cant be working.
--Mac 14 July 2005 01:52 (CEST)