Subject: Re: TCP/SACK support.
To: Kentaro A. Kurahone <>
From: Jonathan Stone <>
List: tech-kern
Date: 01/06/2005 15:00:50
In message <>,
"Kentaro A. Kurahone" writes:

>On Thu, Jan 06, 2005 at 11:31:27AM -0800, Jonathan Stone wrote:


>Hmmm, ok.  I've only written the receiver path at (the easier side), from
>what I understand writing the sender path is considerably more work, especially
>in a way that is fast on links with large congestion windows[0].
>I was going to look at how FreeBSD/PSC did the sender side and port/adapt as
>neccecary.  No need to gratuitously reinvent the wheel afterall.


Yes, thats the part I was getting at. I have been lucky enough to
benefit from some private conversations with some very well-informed
people. I can summarise my own conclusions for you offlist in private
email, if you wish.

>Kentaro A. Kurahone
>SIGUSR1 Research and Development
>[0]: I see references to Tom Kelly (Scalable TCP)'s work regarding a SACK fast
>path that supposedly addresses a lot of these issues.

As in the CCR article from 2003? Wasn't that for Linux?  I'd have to
check the paper and the Linux code to see how relevant it is.