BY DAVE SIMPSON
One of the major hurdles facing developers and users of IP-based storage is the CPU-intensive overhead imposed by the TCP/IP protocol stack. Several network interface card (NIC) and host bus adapter (HBA) vendors have announced products that will offload TCP/IP processing onto specialized processors and firmware. Most of those cards are due by year-end. This month, Wind River began shipping technology that could give a number of those vendors faster time to market, while paving the way for IP storage based on the emerging iSCSI protocol.
Wind River's Tornado for Intelligent Network Acceleration (TINA) architecture implements the TCP/IP stack in firmware on an embedded processor that HBA or NIC developers can integrate on their cards (see Figure 1). About 80% of the solution is implemented in software, with functions such as check summing being handled in hardware. Wind River provides a reference board that includes software drivers (currently, for Linux and VxWorks, with Windows NT/2000 and Unix BSD to come), firmware, and Intel's 80200 I/O processor and XScale Microarchitecture. (Wind River plans to have versions based on the PowerPC and MIPS processors in the future.)
In addition to HBA/NIC vendors, Wind River's target customers include server/ network vendors and storage area network (SAN) component manufacturers.
Beta shipments began in May, and production shipments were scheduled for this month. The company plans to launch a version for InfiniBand in the fourth quarter.
According to Roger Frey, product marketing manager for server products at Wind River, the need for offloading TCP/IP processing is being driven by increased adoption of Gigabit Ethernet (and, next year, 10Gbps Ethernet) and by an expected shift from Fibre Channel-based SANs to IP-based SANs.
Frey says the company's goal is to get close to Gigabit Ethernet wire speeds (1Gbps or 100MBps), which would rival current-generation Fibre Channel performance. In preliminary tests, the TINA card yielded a Performance Efficiency Index rating approximately twice that of traditional NICs. (The Performance Efficiency Index was developed by PC Week-now eWeek-and measures networking throughput relative to CPU utilization.)
TINA could be used for traditional network I/O traffic, as well as for storage traffic based on the iSCSI standard, which enables block-level SCSI I/O over IP networks. (iSCSI functionality would be added by NIC or HBA vendors.)
Figure 2: The Tornado for Intelligent Network Acceleration (TINA) is based on Wind River's IxWorks real-time operating system.
TINA is based on Wind River's IxWorks real-time operating system kernel and APIs as the company's VxWorks 5.4 RTOS.
HBA vendors that have announced intentions to deliver iSCSI-based TCP/IP offload cards include Adaptec, Emulex, JNI, and QLogic. NIC vendors expected to deliver iSCSI cards include Alacritech, Intel, 3Com, and others.
At the Networld+Interop show in May, Intel demonstrated interoperability be tween a beta version of its iSCSI HBA, IBM's 200i iSCSI disk array, and Cisco's SN 5420 Storage Router. According to Blaine Kohl, director of HBA marketing at Intel, production shipments of the PRO/1000 T IP Storage Adapter are due "by the end of the year," which is when most of the other iSCSI HBAs/NICs are expected to become available.