From: "Injong Rhee" <redacted>
Date: Wed, 29 Oct 2008 19:14:03 -0400

quoted

This looks like a good optimization, it obviously needs more testing
because Linux always seems to find new broken hardware.  The areas
that need to be tested should include:
 * MacOs has a broken version of delayed ack that might cause
   HyStart to radically underestimate.

We tested with FreeBSD. I presume that it covers MacOS. We will look into that.

Not even close, Apple made an enormous number of local modifications
to the BSD tcp stack in their copy of the code base.

That's where the dupack behavior comes from, FreeBSD never did
that stuff.