help urgently needed!

Sven Nielsen post
Sat Feb 23 14:14:01 PST 2008

hi everyone,

we are supposed to roll out about 20 new access points on our first test
site in a few days, however, I haven't quite got them working yet.
The APs are small Alix mainboards equipped with two Atheros miniPCI
cards (madwifi driver). System is minimal Debian stable.

bridgeutils version is 1.2
hostapd version is 0.5.5 
(both from stable debian package)

The current major problem at hand is as follows:

Most important scenario for this test site is this:

Asterisk Voip server <--> AP <--> Mobile SIP client (Nokia E65 / E51)
(Everything in one LAN)

We are using a bridge setup, with e.g. br0 containing eth0 and ath0 on
the APs.

Using no, WPA, or WPA2 encryption (with PSK) the mobile clients connect
with no problem, they register to Asterisk Voip server, I can start a
call, I can browse the internet on the mobiles, too. 

However, using CCMP algorithm in hostapd I cannot ping or reach the
mobiles, neither from LAN nor from AP directly, but mobiles can reach
PCs behind AP (wired) with no problem.

Using no encryption, everything is _almost_ fine. Ping loss pinging the
mobiles is about 6% at most.

Using TKIP, it seems to work at first, like with no encryption (network
reachable from both sides of AP), but after a few calls (udp
connections), it is the same as with CCMP. Mobile clients can reach the
net without problems, but the wireless clients are not reachable through
the AP.

And finally the weirdest: as long as call is actively transmitting
(active UDP connection), the mobile client is fully reachable! with no
ping loss at all, no matter what encryption is used! But, it vanishes
instantly when the call ends.

I wrecked my brain for 3 days now, it might be something with mtu sizes
different for eth0 and ath0 (1500 vs 2290) it might be related to MAC
addresses, it might be something totally different. 

Any help greatly appreciated, really! ;-)

I can compose detailed information and logs instantly if someone thinks
he might know the solution to this.

Best Regards
Sven Nielsen

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