Ah, that did the trick. Thank you!
/edit
last question: as seen here (@0,66 KB/sec)
I have a constant downstream of 0,3 - 0,7 kB/sec even if I don't download anything from LAN or internet. I think this is some sort of keep-alive information between my computer and the server.
Is there any way to tell RAS G&S that it shouldn't count this static traffic? I think not, right?