On 01/04/2010 08:54 AM, Jack Z wrote:
Then I used Wireshark to grab the traces of iSCSI and iperf and I
found lots of iSCSI PDUs were divided into TCP segments of 1448 bytes
but with iperf TCP segments could be as large as 65000+ bytes.

I first thought this was because of the small default value (8192) for
MaxRecvDataSegmentLength. So I increased that value to 262144. But in
a later test with 16ms rtt, I found the iSCSI throughput was only
improved by 0.7 MB/s and a lot of iSCSI PDUs were still divided into
1448 byte long TCP segments... So I think MaxRecvDataSegmentLength may
not be the reason.

Are you using jumbo frames?
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