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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.
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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.
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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.
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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.
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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.
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.
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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.
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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.
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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.
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InfoStor January, 2002
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