openvpn and system overhead

[Wojciech Puchar]

> because of unavoidable and big overhead due to constant context switching
> from user land to kernel land and back. Be it openvpn or another userland daemon.
>
> You need either some netmap-based solution or kernel-side vpn like IPsec (maybe with l2tp).

well it has to cooperate with multitude of clients like windoze, 
point&click routers etc. that's why openvpn.