From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-1" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 029C121F1EE for ; Tue, 28 Apr 2015 04:49:34 -0700 (PDT) Received: from hms-beagle.lan ([134.2.89.70]) by mail.gmx.com (mrgmx001) with ESMTPSA (Nemesis) id 0MbfnB-1Z3Dp02u1t-00J65q; Tue, 28 Apr 2015 13:49:23 +0200 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) From: Sebastian Moeller In-Reply-To: Date: Tue, 28 Apr 2015 13:49:19 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: References: <5537CDB7.60301@orange.com> <1429722979.18561.112.camel@edumazet-glaptop2.roam.corp.google.com> <5537DA20.1090008@orange.com> <5537DE4D.8090100@orange.com> <553882D7.4020301@orange.com> <1429771718.22254.32.camel@edumazet-glaptop2.roam.corp.google.com> <6C0D04CF-53AA-4D18-A4E4-B746AF6487C7@gmx.de> <87wq123p5r.fsf@toke.dk> <2288B614-B415-4017-A842-76E8F5DFDE4C@gmx.de> <553B06CE.1050209@superduper.net> <14ceed3c818.27f7.e972a4f4d859b00521b2b659602cb2f9@superduper.net> <0C930D43-A05B-48E2-BC01-792CAA72CAD1@gmx.de> <1D70AD75-F177-4146-A4D6-2FD6DB408B63@gmx.de> To: Mikael Abrahamsson X-Mailer: Apple Mail (2.1878.6) X-Provags-ID: V03:K0:arwwZYUZYEUXuLjYkoF7mvZk3DL4tixVXwBElvpmq8H0aEb83qh d/d61jDP3izvHdlPA8JtcMOsMylpfItpU/lSvMQDZ1mGW17SX3BvpAsWzlQcHZtnJlJxPNL U8gw0cjinQj9cMkokXLETmpAnwA8OXkP5M6TPeCM2NseFSyyt2iX++AEjsuPYYYIivPG1ed U95w5LQ/2W0BkusINg3yg== X-UI-Out-Filterresults: notjunk:1; Cc: bloat Subject: Re: [Bloat] DSLReports Speed Test has latency measurement built-in X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Apr 2015 11:50:03 -0000 Hi Mikhail, On Apr 28, 2015, at 13:04 , Mikael Abrahamsson wrote: > On Tue, 28 Apr 2015, David Lang wrote: >=20 >> Voice is actually remarkably tolerant of pure latency. While 60ms of = jitter makes a connection almost unusalbe, a few hundred ms of = consistant latency isn't a problem. IIRC (from my college days when ATM = was the new, hot technology) you have to get up to around a second of = latency before pure-consistant latency starts to break things. >=20 > I would say most people start to get trouble when talking to each = other when the RTT exceeds around 500-600ms. >=20 > I mostly agree with = http://www.cisco.com/c/en/us/support/docs/voice/voice-quality/5125-delay-d= etails.html but RTT of over 500ms is not fun. You basically can't have a = heated argument/discussion when the RTT is higher than this :P =46rom "Table 4.1 Delay Specifications=94 of that link we = basically have a recapitulation of the ITU-T G.114 source, one-way mouth = to ear latency thresholds for acceptable voip performance. The rest of = the link discusses additional sources of latency and should allow to = come up with a reasonable estimate how much of the latency budget can be = spend on the transit. So in my mind an decent thresholds would be (150ms = mouth-to-ear-delay - sender-processing - receiver-processing) * 2. Then = again I think the discussion turned to relating buffer-bloat inured = latency as jitter source, so the thresholds should be framed in a = jitter-budget, not pure latency ;). Best Regards Sebastian >=20 > --=20 > Mikael Abrahamsson email: swmike@swm.pp.se