Classification Routing Classification N E T In terface P C I In terface P C I In terface N E T In terface Classification Classification Routing

Software/open routers, PCs (Personal Computers) running open source OSs (Operating Systems) and equipped with Ethernet Network Interface Cards (NICs), are receiving increasing attention in the research community, because they can offer multi-gigabit-persecond packet forwarding speed, performance comparable to those of low-medium end commercial routers. However, commercially available NICs lack programmability. Furthermore, the use of standard NICs implies that each packet crosses the bus twice, and is processed and routed in software by the OS, thus reducing forwarding performance. In this paper we discuss the design and the implementation of an FPGA-based NIC that permits to overcome the performance bottleneck and the lack of flexibility of commercial NICs. Performance and limitations of the proposed approach are thoroughly discussed.