Tehuti, founded in Israel with U.S. headquarters in Austin, has been quietly pursuing a TCP-layer acceleration strategy that fits between MAC-accelerated network interface cards, and dedicated TCP offload engines.

"We could not claim to be the fastest co-processing solution at Layer 4, but we realized we could gain a lot of mileage in the 10-Gigabit Ethernet community for showing cost-effective traffic acceleration for small footprint and low power dissipation," said Tehuti vice president of marketing Blaine Kohl.

Tehuti has bypassed work on PCI-X to focus directly on PCI-Express board designs. Kohl said an important factor driving the Silicom design win was the fact that Tehuti uses open drivers for the PCI bus and TCP/IP protocol stack. Many TCP offload engines rely on custom software developed between application and TCP interface, which makes it difficult to port the co-processors across operating systems and protocol stacks. Tehuti's chip relies on a streamlined dual-port design with open interfaces on multiple layers.

Protocols accelerated by the embedded OptiStrata accelerator engine include checksum, error offload, TCP reassembly, connection search and fetch, and driver overhead. The accelerator itself uses a memory-less architecture, though the chip has a memory controller for off-chip access to DDR2 memory. Also integrated on the chip are TCP caches and TCP search blocks feeding the OptiStrata accelerator, and host-bus registers, queues, and DMA for PCI-Express.

Like many TCP accelerator companies, Tehuti will offer its own board-level products with XFP and CX4 interfaces, adding SFP+ when the fiber standard is finished. But single-chip solutions will remain a primary focus for Tehuti, and Kohl said the company will be careful not to compete with customers like Silicom as it adds adapter and add-in board products to its repertoire.