Achieving wire-speed protocol processing in a multi-Gbps network using BSD UNIX and an OC-48c network interface card

We investigated the capability of BSD UNIX to achieve wire-speed protocol processing in multi-Gbps networks by using an OC-48c (2.A Gbps) network interface card. Our preliminary evaluation showed that wire-speed transmission was achieved with a Linux system, whereas the maximum throughput was limited to around 1.9 Gbps with a FreeBSD system. We quantitatively determined the cost of FreeBSD´s unique buffer management schemes, and reduced it with adaptive drivers which adapt their behavior according to the states of the host´s resources. Two adaptive methods that we tried yielded 70% packet-processing gain and 10% throughput gain.