Modern packet processing hardware (e.g. IPv6-supported routers) demands high processing power, while it also should be power-efficient. In this paper we present an architecture for high-speed packet processing with a hierarchical chip-level power management that minimizes the energy consumption of the system. In particular, we present a modeling framework that provides an easy way to create new networking applications on an FPGA based board. The development environment consists of a modeling environment, where the new application is modeled in SystemC. Furthermore, our power management is modeled and tested against different traffic loads through extensive simulation analysis. Our results show that our proposed solution can help to reduce the energy consumption significantly in a wide range of traffic scenarios.