—Software packet forwarding has been used for a long time in general purpose operating systems. While interesting for prototyping or on slow links, it is not considered a viable solution at very high packet rates, where various sources of overhead (particularly, the packet I/O mechanisms) get in the way of achieving good performance. Having recently developed a novel framework for packet I/O on general purpose operating systems, we have investigated how much the removal of this bottlenecks can improve the performance of software packet processing. The problem is of interest because software switches/routers are widely used, and they are becoming inadequate with the increasing use of