Abstract: With the development of the next generation Internet, the existing router architecture faces many problems, such as performance，complexity and power consumption. With the increasing of network size, how to implement a low-power forwarding is a challenge in green and high-performance router design. In this paper, we consider building a FIS mechanism based on forwarding in switching idea. The memory requiring and accessing are reduced by blurredly forwarding and piping switching. The multilevel line framework in FIS is made by many slow processing units. It can obtain higher performance and lookup speed through cosmically running. Simultaneously, it can reduce the complexity of hardware implementation. Energy model of FIS and FBS is established. We propose different modeling methodologies for node switches, internal buffers and interconnect wires inside switch fabric architectures. In this paper four switch fabric architectures are analyzed under different traffic throughput and different numbers of ingress/egress ports. Experiments using real-life routing tables demonstrate that our FIS solution can reduce the power of routing lookup by 12.5% than FBS clearly. This framework and analysis can be applied to the architectural exploration for low power high performance network router designs.