This paper describes a novel model for the provision of service composites for active routers. The service composition framework enables flexible programmability of the router’s data path through dynamically loadable software components, called ‘active components’. The composition model promotes transparent and dynamic creation of network-side services and allows independent users to partake in this process. A prototype implementation has revealed that the composition model using packet filters and a classification graph structure as a means to integrate active components into the forwarding path enables the dynamic alteration of the elements of a composite at run-time and permits scalability in the generation of such composites. Furthermore, it allows the flexible provision of a unique service profile for each packet passing through an active router. We show that the overhead of this composition model does not significantly affect the performance of the router.