Added a udev-rule which whenever a bnep[0-9]* comes up
starts an instance of my userspace-nat daemon and kills
it again when the bnep-device disappears.
I think I'm gonna stay with bluetooth connection for now.
It is simple, costs comparably little CPU-Power and when
doing a terminal session to my N900 it is much less choppy
as when I do that when Laptop and N900 see each other
via a WLAN-Access-Point at home.
And what might be interesting in addition PAN leaves
WLAN unused to e.g. connect to a public WLAN-Hotspot
and share this connection.
One drawback I see at the moment is that 2 PAN clients
connected to my N900 don't see each other at the moment
as they are living each in their private userspace network-stack.
Does anybody know if it is easily possible to get the linux-bridge
to work with stock kernel N900?
Other solution would be to have on the fly interface-adding/removal
to a single instance of the userspace-nat-daemon.
By the way I can even switch back an forth between WLAN-Hotspot
and UMTS as I'm just doing while writing this text.