In one embodiment, a network system of the present invention includes at least a first router and a second router coupled to an upstream link to permit data flow from the first router to the second router across the upstream link. The second router includes a control plane and a data plane having an input port coupled to the upstream link and an output port connectable to a downstream link. The control plane includes a virtual pool having a capacity corresponding to a resource capacity of the first router and an admission control function. In response to a request to reserve resources for a flow through the data plane from the input port to the output port, the admission control function performs admission control for the upstream link by reference to resource availability within the virtual pool. In one embodiment, the request is a request to reserve resources for an Integrated Services flow, and the capacity of the virtual pool corresponds to a resource capacity of a Integrated Services service class supported by the first router.