Okay i f***ed up myself.
Somehow my router didn't want to change anything so he didn't forward the port.
now i changed it and double checked it and it works

how to do it:
1) log in to your router.
2) go to the tab: "port forwarding"
3) fill in at local ip the ip of your NAS
portrange: 548-548 (open port 548)
that is the port for the afp service.
4) ADD and apply and restart if necessary and check if your router did it

5) in MAC OS LION go to finder.
6) GO->Connect to server
7) server adres:
afp://yourinternetip

now fill in your username and password. make sure you have an tough password so hard to guess

Have fun

for samba and ifs you have to look up which ports they use standard
