Nowadays, an increasing number of users get high-speed broadband access to the Internet. These broadband connections make new multimedia applications possible. However, such applications also introduce new Quality of Service (QoS) requirements to the network. Particularly, they require an assured bandwidth even in the case of network overload. The network itself has to provide such bandwidth assurances. This article introduces our concept of a novel network QoS device being located in network edge nodes. It provides a solution for relaxed QoS guarantees to certain flows on a congested link by focussing packet discard on selected flows. However, unlike for IntServ solutions like RSVP, our approach only requires minimal signalling and therefore provides both efficiency and scalability. We furthermore provide a quantitative performance evaluation of our QoS device by using simulations.