From: "Michal Kubeček" <mkubecek@suse.cz>
To: netdev@vger.kernel.org
Cc: "John A. Sullivan III" <jsullivan@opensourcedevel.com>
Subject: Re: tc filter mask for ACK packets off?
Date: Tue, 03 Jan 2012 08:31:49 +0100 [thread overview]
Message-ID: <21734335.uCtjXOcSpA@alaris> (raw)
In-Reply-To: <1325385056.4174.51.camel@denise.theartistscloset.com>
On Saturday 31 of December 2011 21:30EN, John A. Sullivan III wrote:
> Hello, all. I've been noticing that virtually all the documentation
> says we should prioritize ACK only packets and that they can be
> identified with match u8 0x10 0xff. However, isn't the actual flag
> field only 6 bits longs and the first two belong to a previous 6 bit
> reserved field?
It's even worse, those two bits are in fact used for ECN (RFC 3168).
> If that is true, if ever those bits are set, our filters will
> unnecessarily break. Shouldn't it be match u8 0x10 0x3f?
I think so.
However, by a "ACK only" packet (worth prioritizing), I would rather
understand a packet with ACK flag without any payload, not a packet with
ACK as the only flag. For many TCP connections, all packets except
initial SYN and SYN-ACK and two FIN packets have ACK as the only flag.
So my guess is you should rather prioritize all TCP packets with no
application layer data.
Michal Kubecek
next prev parent reply other threads:[~2012-01-03 7:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-01 2:30 tc filter mask for ACK packets off? John A. Sullivan III
2012-01-03 7:31 ` Michal Kubeček [this message]
2012-01-03 9:36 ` Dave Taht
2012-01-03 10:40 ` [RFC] SFQ planned changes Eric Dumazet
2012-01-03 12:07 ` Dave Taht
2012-01-03 12:50 ` Eric Dumazet
2012-01-03 16:08 ` Eric Dumazet
2012-01-03 23:57 ` Dave Taht
2012-01-04 0:14 ` Eric Dumazet
2012-01-04 7:56 ` Dave Taht
2012-01-04 8:17 ` Eric Dumazet
2012-01-03 12:18 ` tc filter mask for ACK packets off? John A. Sullivan III
2012-01-03 12:32 ` Eric Dumazet
2012-01-03 12:45 ` John A. Sullivan III
2012-01-03 13:00 ` Dave Taht
2012-01-03 17:57 ` John A. Sullivan III
2012-01-04 0:01 ` Michal Soltys
-- strict thread matches above, loose matches on Subject: below --
2012-01-01 2:30 John A. Sullivan III
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