A method for transmitting data packets of a data traffic between a sending device (10, 80) and a receiving device (80, 10) via a VPN client (200) and a VPN server (500) over a network using a secure encapsulation of the data packets, the method comprising the steps of determining a Quality of Service, QoS, parameter for the data packets of said data traffic, selecting, for the data packets, either a first tunnel (91) connecting the VPN client (200) and the VPN server (500) or a second tunnel (92) connecting the VPN client (200) and the VPN server (500) based on determined Quality of Service.