Level5 Networks this week is expected to launch its inaugural product - a Gigabit Ethernet server adapters; but there's a twist to these network interface cards, the start-up says.

Level5 says its EthernetFabric adapters can match the performance of advanced data center server interconnects, such as Infiniband or remote direct memory access - which bypass server bus architecture, letting corporate applications run faster - but remain compatible with standard server operating system configurations and commodity Ethernet switch infrastructures. Such advanced interconnect gear typically requires proprietary hardware and changes to server operating system software, the vendor adds.

As opposed to TCP/IP offload cards or processors on NICs, which run a TCP/IP software stack on hardware, EthernetFabric technology distributes the TCP/IP network software stack among various applications running on a server. With this "personal" IP stack, each application gets a direct, unshared path to the EthernetFabric network. The vendor says this removes latency and extra CPU processing that happens when an application makes a request to the network software stack running on a server operating system.

Level5 says the EthernetFabric adapters offer a greater than 2X speed advantage over standard Gigabit Ethernet NICs, while costing one-third as much as technologies such as Infiniband or iWarp. For example, Alacritech makes a dual-port RDMA Gigabit NIC for $1,500; Level5's card costs around $500.

With such advanced interconnect technologies, "you have to rewrite the operating system so that it supports the bypass architecture," says Dan Karr, CEO of Level5. "That presents costs in time for development, as well as the cost of upgrading every server on the network."

The first products from Level5 will include single- and dual-port Gigabit Ethernet EthernetFabric adapters that work with Linux servers - either 2.4 or 2.6 kernel versions. A Windows server adapter is due by year-end. Drivers for Unix servers can be developed on a per-customer demand basis.

In addition to providing quicker access to network hardware for applications, Level5 says the EthernetFabric architecture also provides better redundancy and network bandwidth than other multi-port Ethernet cards, or trunked single-port cards.

Tying standard Ethernet NICs together via 802.3 link aggregation gives the appearance of a multi-Gigabit pipe, but application flows cannot span multiple links, Karr says. EtherFabric connections can run application flows over multiple ports without requiring special trunking configurations on switch hardware, he adds.

Level5 competes with vendors such as Alacritech Chelsio, Intel and Netirion in the advanced server interconnect market.

The dual-port 1G bit/sec EthernetFabric card costs $500.

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