From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neal Cardwell Subject: Re: [PATCH net] sctp: not allow to set rto_min with a value below 200 msecs Date: Tue, 29 May 2018 12:03:46 -0400 Message-ID: References: <20180525191319.GB392@hmswarspite.think-freely.org> <71FD541D-25FE-4100-980B-C3A0CEAF6CD4@lurchi.franken.de> <20180527010059.GA15798@neilslaptop.think-freely.org> <20180528194315.GB3788@localhost.localdomain> <20180529114111.GA24144@hmswarspite.think-freely.org> <559FFFDD-E508-4936-9544-CACE606AF40F@lurchi.franken.de> <20180529154514.GC3788@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: Michael Tuexen , nhorman@tuxdriver.com, Dmitry Vyukov , lucien.xin@gmail.com, Netdev , linux-sctp@vger.kernel.org, David Miller , dsa@cumulusnetworks.com, Eric Dumazet , syzkaller@googlegroups.com To: marcelo.leitner@gmail.com Return-path: Received: from mail-wm0-f44.google.com ([74.125.82.44]:40666 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934933AbeE2QEF (ORCPT ); Tue, 29 May 2018 12:04:05 -0400 Received: by mail-wm0-f44.google.com with SMTP id x2-v6so34697043wmh.5 for ; Tue, 29 May 2018 09:04:05 -0700 (PDT) In-Reply-To: <20180529154514.GC3788@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, May 29, 2018 at 11:45 AM Marcelo Ricardo Leitner < marcelo.leitner@gmail.com> wrote: > - patch2 - fix rtx attack vector > - Add the floor value to rto_min to HZ/20 (which fits the values > that Michael shared on the other email) I would encourage allowing minimum RTO values down to 5ms, if the ACK policy in the receiver makes this feasible. Our experience is that in datacenter environments it can be advantageous to allow timer-based loss recoveries using timeout values as low as 5ms, e.g.: https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf https://tools.ietf.org/html/draft-wang-tcpm-low-latency-opt-00 cheers, neal