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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Yuchung Cheng <ycheng@google.com>
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Date: Sun, 05 Aug 2012 20:40:37 +0200
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Cc: codel@lists.bufferbloat.net
Subject: Re: [Codel] [RFC PATCH] codel: ecn mark at target
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On Sun, 2012-08-05 at 11:14 -0700, Yuchung Cheng wrote:
> On Sun, Aug 5, 2012 at 10:35 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> > On Sun, 2012-08-05 at 19:26 +0200, Eric Dumazet wrote:
> >
> >> It could be a flaw in linux implementation, I admit we had so many bugs
> >> that it could very well be still buggy.
> >
> > And at first glance, the following tcpdump seems suspect : We can see
> > all ACK are delayed by about 40 ms
> but RFC 3168 (sec 6.1.3) does not mandate immediate ACKs for ECE
> marked ones? is this because ECN response is per round-trip?
> 

We should IMHO not delay ACKS, exactly like we react to a dropped
packet.

If not specified in RFC 3168, it seems a forgotten point.