thank you for that interesting link.
unfortunately the solution turning mobile data off didn't worked for me.
I also tried static IP instead of DHCP - no success.
one strange thing, as already mentioned: LAN traffic to my computer works perfectly with max speed. (copying files e.g.)
so, wifi works in principle. It's about internet traffic only.
but which kind of software/hardware is able to distinguish between internet- and local traffic?
Nexus 10, ParanoidAndroid
Phone: LG G2, stock KK 4.4.2 DE VF rooted