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 B643D3B2A4 for ; Wed, 13 Dec 2017 04:46:02 -0500 (EST) Received: by uplift.swm.pp.se (Postfix, from userid 501) id E0231B2; Wed, 13 Dec 2017 10:46:00 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=swm.pp.se; s=mail; t=1513158360; bh=dsuhMw2hA0EwCJDxONuW/MkCQ5dXJIHZQ1lCZfEpQVQ=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=S5hWYyEF0VFmUewRsg8htR+bm/Qw+JuDwPdn5a6NORnqsmFA996KU2F6cWUONHCdB vSqJaiopefavHBpeXIUGZ8hX74QHHXipeCb+H8EctZoPWkPra4Y+TcmedZBJjayqFh hkq05nnRBRoOoLnUCpBod5lZRCoy9hAg7T8fM/Cs= Received: from localhost (localhost [127.0.0.1]) by uplift.swm.pp.se (Postfix) with ESMTP id C6BBEB1; Wed, 13 Dec 2017 10:46:00 +0100 (CET) Date: Wed, 13 Dec 2017 10:46:00 +0100 (CET) From: Mikael Abrahamsson To: Jonathan Morton cc: David Lang , bloat In-Reply-To: Message-ID: References: <4D0E907C-E15D-437C-B6F7-FF348346D615@gmx.de> <019064B3-835C-4D59-BE52-9E86EE08CD02@gmx.de> 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] benefits of ack filtering 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: Wed, 13 Dec 2017 09:46:02 -0000 On Wed, 13 Dec 2017, Jonathan Morton wrote: > the uplink shaper is set to about a fiftieth of that. I seriously doubt > that DOCSIS is ever inherently that asymmetric. Well, the products are, because that's what the operators seems to want, probably also because that's what the customers demand. So my modem has 16x4 (16 downstream channels and 4 upstream channels), meaning built into the hardware, I have 1/4 split. Then providers typically (this is my understanding, I haven't worked professionally with DOCSIS networks) do is they have 24 downstream channels and 4 upstream channels. Older modems can have 8 downstream and 4 upstream for instance, so they'll "tune" to the amount of channels they can, and then there is an on-demand scheduler that handles upstream and downstream traffic. So I guess theoretically the operator could (if large enough) make a hw vendor create a 16x16 modem and have 32 channels total. But nobody does that, because that doesn't sell as well as having more downstream (because people don't seem to care about upstream). It just makes more market sense to sell these asymmetric services, because typically people are eyeballs and they don't need a lot of upstream bw (or think they need it). On the ADSL side, I have seen 28/3 (28 down, 3 up) for annex-M with proprietary extensions. The fastest symmetric I have seen is 4.6/4.6. So if you as an operator can choose between selling a 28/3 or 4.6/4.6 service, what will you do? To consumers, it's 28/3 all day. So people can blame the ISPs all day long, but there is still (as you stated) physical limitations on capacity on RF spectrum in air/copper, and you need to handle this reality somehow. If a lot of power is used upstream then you'll get worse SNR for the downstream, meaning less capacity overall. Symmetric access capacity costs real money and results in less overall capacity unless it's on point to point fiber. -- Mikael Abrahamsson email: swmike@swm.pp.se