My planned work on networking stack

Mark Allman mallman at
Tue Mar 2 07:35:42 PST 2004

> TCP buffer sizing involves mainly two areas.  One is good RTT
> measurements to be able to estimate the bw*delay product well and the
> other is information about memory (mbuf) usage in the networking
> system to do the right thing if memory gets low.

Why try to measure the bw*delay?  Why not use the trick from PSC's
autotuning paper whereby you just try to ensure that the socket buffer
size is always some multiple (2-4, I think) of the congestion window?
I.e., so the congestion window dictates the performance and the socket
buffer is not a factor.

Of course, you have to figure out what to do to all the connections
when there is not enough memory for such socket buffer sizes.

But, fundementally, that seems like a much better approach to me.

And, thanks for taking this all on!  It sounds wonderful!


Mark Allman -- ICIR --

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