Re: [aqm] [tcpm] TCP ACK Suppression

Joe Touch <touch@isi.edu> Sat, 10 October 2015 00:39 UTC

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To: David Lang <david@lang.hm>
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From: Joe Touch <touch@isi.edu>
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Subject: Re: [aqm] [tcpm] TCP ACK Suppression
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On 10/9/2015 5:22 PM, David Lang wrote:
> You don't want to acknowlege it, but TCP is broken in the face of
> excessive buffering. 

Arguably, buffering was broken and failed to provide the feedback to TCP
(see next paragraph)

> TCPM isn't fixing that, grassroots efforts are
> developing the fixes and AQM is formalizing the results.

TCPM fixed it in 2001 by providing the flags for ECN, which was enabled
by default in Windows since 2012. ALTQ support for ECN has been around
for nearly that long.

What's changed? Not the TCP reaction (except in extreme cases such as
for datacenters) but the router algs. And getting the router algs into
routers - esp. home devices.

> TCP is also broken in the face of current and within-the-next-year
> future wifi technologies. AQM helps some here, and there is again
> outside efforts to address the problem. TCPM hasn't done anything that
> I've heard of other than possibly say that the network technology is
> broken and shouldn't be used.

You might start tracking the TCPM list. We've been talking today about
how to reduce the ACKs by direct action of the source.

Joe