Ethernet is converging, according to chip developer Broadcom which has demonstrated a single chip Gigabit controller including a TOE (TCP offload engine) and the logic needed to run four different functions in one network adapter. It said the chip would allow even low-end servers to use iSCSI and clustering without the need for expensive dedicated hardware or performance-sapping software.

As well as the TOE for data networking, the Broadcom NetXtreme II chip can calculate and decode iSCSI packets for storage networking, it offloads the remote DMA (RDMA) work involved in Ethernet-based clustering, and it has a sideband interface for system management.

"We have added a lot of logic and processing power to do protocol processing and handle DMA," said Allen Light, Broadcom's product marketing manager. "Ethernet is pervasive now, but in the past putting all these functions on one chip caused too much overhead. We have learned it has to be a single device, no more than 20 by 20mm, and with no external components."

He said that the chip should sell in quantity for under $40 a piece, similar to current controller chips. It is full duplex so it can handle a 2Git/s data rate and should provide an economic alternative to fitting a second specialist card for storage networking or clustering.

HP has already signed up for an earlier version of the NetXtreme II, which it is building into converged TOE data networking and iSCSI cards. HP said that these NC370F and NC370T multifunction PCI-X network adapters will be generally available by the end of June.

Light said that the chip can be considered "as three logical devices, each with its own setup and parameters. It will perform at a level comparable to a dedicated iSCSI adapter, and from a switching perspective nothing changes."

The next aim is to get all these functions working together on a single 10Gig Ethernet port, he added: "We've not announced anything, but we believe in this technology and we have other 10Gig offerings, so it's reasonable to expect it."