Host Architectures
iSCSI Host Implementations
iSCSI ASICs
ƒ TCP was designed for
software implementation,
and TOE can require up to
4M gates in ASIC
iSCSI
ƒ Latest iSCSI HBAs with
TOE and SOE and IPSec
16M gates
have up to 16M gates in
ASIC
iSCSI ASICs are more complex than Fibre Channel ASICs:
TCP is a message-passing protocol designed for reliability on chaotic
networks.
TCP was designed for implementation in software (NIC drivers) and
does not easily lend itself to implementation in silicon.
Initial assessments of developing TOE ASIC technology indicated that
up to four million gates would be required, more than eight times the size
of a Fibre Channel ASIC.
The latest Dual Ported iSCSI HBAs with IPsec (Adaptec) have up to
16M gates
A large number of gates would create some challenges, including
increased heat output. More importantly, it would increase the rate of
manufacturing defects, resulting in higher production costs and higher
prices.