The wide deployment of IP technologies has driven the development of IP-based solutions for wireless networks, like the IP-based Radio Access Networks (RAN). Such wireless networks have different characteristics than traditional IP networks, imposing very strict requirements on Quality of Service (QoS) solutions. Current QoS solutions are not able to satisfy these requirements. This paper describes the prototype implementation of a QoS-framework, called Resource Management in Differentiated Services (RMD), which aimes to correct this situation. RMD is a framework offereing scalable fine-grained QoS guarantees in Differentiated Services (DiffServ) networks. It extends the DiffServ architecture with new admission control and resource reservation concepts in a scalable way.