Active network technology envisions deployment of virtual execution environments within network elements, such as switches and routers. As a result, inhomogeneous processing can be applied to network traffic. To use such technology safely and efficiently, individual nodes must provide mechanisms to enforce resource limits. This implies that each node must understand the varying resource requirements for specific network traffic. This paper presents an approach to model the CPU time requirements of active applications in a form that can be interpreted among heterogeneous nodes. Further, the paper demonstrates how this approach can be used successfully to control resources consumed at an active-network node and to predict load among nodes in an active network, when integrated within the Active Virtual Network Management Prediction system.