iSCSI adapter vendors jockeying for position

A number of network interface card (NIC) and host bus adapter (HBA) vendors are poised to enter the iSCSI market in the first half of 2002 with cards that offload TCP/IP and iSCSI protocol processing from host servers. The cards will let end users speed up storage I/O (both block-level for SAN and file-level for NAS) over standard IP networks.

For example, Adaptec is currently shipping beta versions of an iSCSI ASIC, with production shipments of the ASIC and the AEA7110C HBA due by the end of this quarter, according to Ram Jayam, vice president and general manager of Adaptec's Storage Networking Group. Adaptec has inked OEM deals for its ASIC with vendors such as ADIC, Hewlett-Packard, and Inrange.

Adaptec's board fully offloads TCP/IP and iSCSI protocol processing from the host, as opposed to boards that use a partial offload approach. Adaptec officials argue that full offload is necessary for high performance.

Last October, Agilent Technologies shipped an iSCSI development kit for OEMs, which features a common API with Agilent's Fibre Channel products, making it easier for the company's OEMs to migrate to iSCSI. Agilent plans to sample iSCSI controllers and HBAs "in the first half of the year," according to Julian Elliott, vice president of Agilent's Storage Networking Division.

In Adaptec's terminology, an "iSCSI NIC" is a traditional network interface card with the iSCSI stack running on the host computer. An "iSCSI offload NIC" is an intelligent NIC running the TCP/IP stack on a plug-in board with the iSCSI stack running on the host. An "iSCSI HBA" is a host bus adapter with a processor running the iSCSI stack and TCP/IP.
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Emulex is beta testing an iSCSI HBA with full TCP/IP offload capability. The company's first implementation will be based on an Intel XScale processor, with a design based on a custom ASIC to follow later in the year, according to Mike Smith, vice president of worldwide marketing at Emulex.

Similarly, QLogic is in final testing of its QLA4000 iSCSI HBA, which is based on an XScale processor. Like Emulex, QLogic considers this an interim product, with an ASIC-based implementation with full offload capability due around the middle of the year, according to Graeme Plant, director of QLogic's iSCSI product group.

HBA vendors generally agree about when end-user adoption of iSCSI/IP storage networks will begin. For example, QLogic's Plant expects adoption to proceed in two phases. First, end users will build IP SANs using iSCSI HBA initiators and bridging devices such as switches or routers to SCSI and Fibre Channel target devices (e.g., disk arrays and tape libraries). Plant expects this phase to begin around the middle of this year.

After that, end users can move to end-to-end iSCSI storage networks as native iSCSI target devices become available-which is expected in the second half of the year.

This article was originally published on January 01, 2002