• To mitigate the gate issue, some vendors have
split the TCP stack:
– TCP Segmentation & Flow Control performed by ASIC
– Error recovery performed by host
• only creates a CPU load if TCP errors occur
A potential solution for the ASIC complexity challenges:
Implement TCP segmentation and flow control functions in an ASIC
while implementing TCP error handling functions in the software protocol
Significantly reduces size and complexity of iSCSI ASIC because error
handling is more complex than flow control.
Significantly improves performance as long as error rate remains low.
The first vendor to use this approach reports having achieved full wire-
speed throughput with only 9-10% CPU utilization, versus 50-90% for
standard Gigabit Ethernet NICs.