From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from uplift.swm.pp.se (swm.pp.se [212.247.200.143]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 2F3C43B2A4 for ; Thu, 25 Feb 2021 08:49:26 -0500 (EST) Received: by uplift.swm.pp.se (Postfix, from userid 501) id D04B0AF; Thu, 25 Feb 2021 14:49:24 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=swm.pp.se; s=mail; t=1614260964; bh=kQ+Gi3T8885aGMyfDoE43sLeOGajqOubgR3GYWK8hso=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=cqBgXJG/B7CNQNytpB9tzkVjYKqnbDgnDbWT11mmgEnFGVAEricD4mtyN6fRV09oX eZvpdCGK848SAyJKKoMBbJZl/EOLXql1FGALBUf/Bda+EktPSqR7WjB51bwXRDMdxX xwcpNNj1RHfDS/jG2Pvye+r8TN73z9UFTWrTQ8xc= Received: from localhost (localhost [127.0.0.1]) by uplift.swm.pp.se (Postfix) with ESMTP id CC35D9F; Thu, 25 Feb 2021 14:49:24 +0100 (CET) Date: Thu, 25 Feb 2021 14:49:24 +0100 (CET) From: Mikael Abrahamsson To: Simon Barber cc: Sina Khanifar , sam@waveform.com, bloat In-Reply-To: <177d9698ff0.27a9.e972a4f4d859b00521b2b659602cb2f9@superduper.net> Message-ID: References: <177d80af608.27a9.e972a4f4d859b00521b2b659602cb2f9@superduper.net> <177d9698ff0.27a9.e972a4f4d859b00521b2b659602cb2f9@superduper.net> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) Organization: People's Front Against WWW MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Subject: Re: [Bloat] Updated Bufferbloat Test X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 25 Feb 2021 13:49:26 -0000 On Thu, 25 Feb 2021, Simon Barber wrote: > The ITU say voice should be <150mS, however in the real world people are > a lot more tolerant. A GSM -> GSM phone call is ~350mS, and very few > people complain about that. That said the quality of the conversation is > affected, and staying under 150mS is better for a fast free flowing > conversation. Most people won't have a problem at 600mS and will have a > problem at 1000mS. That is for a 2 party voice call. A large group > presentation over video can tolerate more, but may have issues with > talking over when switching from presenter to questioner for example. I worked at a phone company 10+ years ago. We had some equipment that internally was ATM based and each "hop" added 7ms. This in combination with IP based telephony at the end points that added 40ms one-way per end-point (PDV buffer) caused people to complain when RTT started creeping up to 300-400ms. This was for PSTN calls. Yes, people might have more tolerance with mobile phone calls because they have lower expectations when out and about, but my experience is that people will definitely notice 300-400ms RTT but they might not get upset enough to open a support ticket until 600ms or more. -- Mikael Abrahamsson email: swmike@swm.pp.se