From: Corey Hickey <bugfood-ml@fatooh•org>
To: Christoph Paasch <christoph.paasch@uclouvain•be>
Cc: Eric Dumazet <eric.dumazet@gmail•com>,
netdev@vger•kernel.org, Phil Oester <kernel@linuxace•com>,
Benjamin Hesmans <benjamin.hesmans@uclouvain•be>
Subject: Re: [RFC 0/2] Account for duplicate ACKs with invalid SACK-blocks
Date: Mon, 19 Aug 2013 14:22:46 -0700 [thread overview]
Message-ID: <52128CA6.6090001@fatooh.org> (raw)
In-Reply-To: <1376940568-16512-1-git-send-email-christoph.paasch@uclouvain.be>
On 2013-08-19 12:29, Christoph Paasch wrote:
> There exist sequence-number rewriting middleboxes, who do not modify the
> sequence-number in the SACK-blocks.
> Duplicate acknowledgments with these (invalid) SACK-blocks will not be
> accounted in sacked_out, and thus no fast-retransmit will trigger.
> So, the only way to recover from a packet-loss is through an RTO,
> effectively killing the performance of TCP in this case.
>
> Performance-results can be seen here:
> http://tools.ietf.org/agenda/87/slides/slides-87-tcpm-11.pdf
>
> Another solution might be to simply disable SACK, as soon as an invalid
> SACK-block has been received (as suggested by Phil Oester). This however
> might be too aggressive.
>
> Christoph Paasch (2):
> Use acked_out for reno-style ack acounting instead of sacked_out
> Account acked_out in sack, if the sack is invalid
>
> include/linux/tcp.h | 1 +
> include/net/tcp.h | 17 +++++---
> net/ipv4/tcp_input.c | 103 ++++++++++++++++++++++++++++++++---------------
> net/ipv4/tcp_minisocks.c | 1 +
> net/ipv4/tcp_output.c | 6 +--
> net/ipv4/tcp_timer.c | 2 +-
> 6 files changed, 89 insertions(+), 41 deletions(-)
I tested this patchset, and, unfortunately, the behavior seems to be the
same.
I'm still planning on working with the Cisco device, when I can get some
of the network admin's time, but that won't happen immediately.
Thanks,
Corey
next prev parent reply other threads:[~2013-08-19 21:22 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-18 5:55 NAT stops forwarding ACKs after PMTU discovery Corey Hickey
2013-08-18 15:24 ` Eric Dumazet
2013-08-18 16:59 ` Corey Hickey
2013-08-18 21:23 ` Jozsef Kadlecsik
2013-08-19 0:00 ` Eric Dumazet
2013-08-19 0:03 ` Eric Dumazet
2013-08-19 8:43 ` Corey Hickey
2013-08-19 12:33 ` Christoph Paasch
2013-08-19 13:24 ` Eric Dumazet
2013-08-19 13:49 ` Christoph Paasch
2013-08-19 13:58 ` Eric Dumazet
2013-08-19 14:35 ` Phil Oester
2013-08-19 15:32 ` Eric Dumazet
2013-08-19 15:33 ` Christoph Paasch
2013-08-19 16:00 ` Eric Dumazet
2013-08-19 17:15 ` Christoph Paasch
2013-08-19 18:00 ` Phil Oester
2013-08-19 18:10 ` Eric Dumazet
2013-08-19 19:29 ` [RFC 0/2] Account for duplicate ACKs with invalid SACK-blocks Christoph Paasch
2013-08-19 19:29 ` [RFC 1/2] Use acked_out for reno-style ack acounting instead of sacked_out Christoph Paasch
2013-08-19 19:29 ` [RFC 2/2] Account acked_out in sack, if the sack is invalid Christoph Paasch
2013-08-19 21:22 ` Corey Hickey [this message]
2013-08-20 7:36 ` [RFC 0/2] Account for duplicate ACKs with invalid SACK-blocks Christoph Paasch
2013-08-22 3:32 ` David Miller
2013-08-22 4:15 ` Corey Hickey
2013-08-19 14:43 ` NAT stops forwarding ACKs after PMTU discovery Christoph Paasch
2013-08-19 20:13 ` Jozsef Kadlecsik
2013-08-19 20:43 ` Christoph Paasch
2013-08-19 21:08 ` Eric Dumazet
2013-08-19 22:07 ` Jozsef Kadlecsik
2013-08-20 4:18 ` Corey Hickey
2013-08-19 18:22 ` Corey Hickey
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