I currently managed it to get a pptp-connect to my home network. now I have another little problem. NetworkManager always routes the whole network traffic over my home network if i am connected to the home network.
If i set the "Use this connection only for resources on its network" I have do manually say:
route add -net 192.168.1.0 netmask 255.255.255.0 dev ppp0
After that only the correct traffic runs over the vpn. Now my question is it possible to setup the route via the networkmanager gui?