From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp89.iad3a.emailsrvr.com (smtp89.iad3a.emailsrvr.com [173.203.187.89]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 5A2EB3B25E for ; Sat, 17 Sep 2016 17:11:32 -0400 (EDT) Received: from smtp12.relay.iad3a.emailsrvr.com (localhost [127.0.0.1]) by smtp12.relay.iad3a.emailsrvr.com (SMTP Server) with ESMTP id 262B7C0155; Sat, 17 Sep 2016 17:11:32 -0400 (EDT) Received: from app18.wa-webapps.iad3a (relay-webapps.rsapps.net [172.27.255.140]) by smtp12.relay.iad3a.emailsrvr.com (SMTP Server) with ESMTP id 1BC10C0148; Sat, 17 Sep 2016 17:11:32 -0400 (EDT) X-Sender-Id: MAILER-DAEMON Received: from app18.wa-webapps.iad3a (relay-webapps.rsapps.net [172.27.255.140]) by 0.0.0.0:25 (trex/5.7.7); Sat, 17 Sep 2016 17:11:32 -0400 Received: from reed.com (localhost [127.0.0.1]) by app18.wa-webapps.iad3a (Postfix) with ESMTP id 0A9AB40065; Sat, 17 Sep 2016 17:11:32 -0400 (EDT) Received: by mobile.rackspace.com (Authenticated sender: dpreed@reed.com, from: dpreed@reed.com) with HTTP; Sat, 17 Sep 2016 17:11:32 -0400 (EDT) Date: Sat, 17 Sep 2016 17:11:32 -0400 (EDT) From: dpreed@reed.com To: "Jonathan Morton" Cc: "Maciej Soltysiak" , "cerowrt-devel@lists.bufferbloat.net" MIME-Version: 1.0 Content-Type: text/plain;charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Message-ID: <1474146692.035424358@mobile.rackspace.com> X-Mailer: mobile/4.0.0 Subject: Re: [Cerowrt-devel] BBR congestion control algorithm for TCP innet-next X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Sep 2016 21:11:32 -0000 The assumption that each flow on a path has a minimum, stable RTT fails in= wireless and multi path networks. However, it's worth remembering two things: buffering above a certain level= is never an improvement, and flows through any shared router come and go q= uite frequently on the real Internet. Thus RTT on a single flow is not a reasonable measure of congestion. ECN ma= rking is far better and packet drops are required for bounding time to reco= ver after congestion failure. The authors suffer from typical naivete by thinking all flows are for file = transfer and that file transfer throughput is the right basic perspective, = rather than end to end latency/jitter due to sharing, and fair sharing stab= ility. -----Original Message----- From: "Jonathan Morton" Sent: Sat, Sep 17, 2016 at 4:11 pm To: "Maciej Soltysiak" Cc: "Maciej Soltysiak" , "cerowrt-devel@lists.bufferb= loat.net" Subject: Re: [Cerowrt-devel] BBR congestion control algorithm for TCP innet= -next > On 17 Sep, 2016, at 21:34, Maciej Soltysiak wrote: >=20 > Cake and fq_codel work on all packets and aim to signal packet loss early= to network stacks by dropping; BBR works on TCP and aims to prevent packet= loss.=20 By dropping, *or* by ECN marking. The latter avoids packet loss. - Jonathan Morton _______________________________________________ Cerowrt-devel mailing list Cerowrt-devel@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/cerowrt-devel