On Mon, 3 Nov 2008 17:19:52 -0500
"Sangtae Ha" [off-list ref] wrote:

Hi all,

We had rather extensive testings with one MacOSX receiver of the
latest Leopard release.
As we had one macbook pro available in the lab, all the testing
results are with the one receiver.
Based on the tested results, MacOSX also doesn't break the algorithm.

Please see the results at the following:

http://netsrv.csc.ncsu.edu/wiki/index.php/TCP_Testing#Testing_with_MacOSX

One thing I observed with FreeBSD and MacOS receivers is that
even though we set the large send and recv buffer and run the iperf
with the large fixed memory,
without manually setting the window scale parameter to a higher value,
the receiver window is limited to 64K << 3 (which is the default of MacOSX).

Because of that, I had to set the window scailing parameter from 3 to
13 manually.
This also affects SACK not triggering with the default window scale factor of 3.
Linux certainly doesn't have this problem.

Probably, MacOSX and FreeBSD may need some updates for this issue.

Thank you for all your feedbacks,

Sangtae

Thanks for the pro-active testing.