From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x22b.google.com (mail-lj1-x22b.google.com [IPv6:2a00:1450:4864:20::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id D8A833B29D for ; Thu, 11 Jun 2020 12:15:01 -0400 (EDT) Received: by mail-lj1-x22b.google.com with SMTP id 9so7602895ljv.5 for ; Thu, 11 Jun 2020 09:15:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=JVGQYaLgSVWKBokD2EBbvhG/LQcKv/VSnpSZj4UbcTg=; b=lcuhB6iVoVM41ngk5svTZcqEfE+GmXyfPSIkmxWoOlOssFTW2yNyNTld/zHnJxEAcp Tvqk3HYYVKFG4HN476DN/lWZ+kezfvYG9J754XfWdG2ZYy/WSjUpCtm1xYBW1UCdJ03y 8UugBHSrs1ZrK0l4QQdrYlg2FiWepj1z6LrkK3Mx6uG773AD3QEf5W+Nle+Jur6IEC0K WlfJxosFe5o1AwLfgxRf6E0a8W+oNROeXoBALV7nasYgcnqlNWsHvw5o1iJjPfALRGG4 F7bQQbPjFOb6ULWV0hvxleEGyHjmu80lxvnY3RZLJV/AjSQ07j1cot2YZvkGtwYSPSSR gGxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=JVGQYaLgSVWKBokD2EBbvhG/LQcKv/VSnpSZj4UbcTg=; b=WCxJ2vNyLTJva+T1EDKM3/vkh7NO42W6cc++Bnfp5UsSkkeznMieTpDt1YwDjC9Iz5 Bb+A6PgiIcCDF/aqXfo75358mK9QEP96wkeQQNLNh9tmfNyTeFvtxS50p5wTGfMl7+RE WPz11ET8fhRHqAwtVhFMfmvT8G8u9M8RzIUGl9nhv2WAiwKazJGdEpWXLUjGQxilRwuG AY1D2ioqgu8AFuSjTChiYvP9Ts9j08LM+VvUVaP41o0bU5kW7plWsccRrvgPFm/17/vr UT5yYyUQVI9a8JFSwyLzBQZrZBbQrKEWR+O/9kBh33S3Zx7bm4uM0gN6t6axtoJyabn/ 0HFw== X-Gm-Message-State: AOAM531sZVXuTiITXbP2E52884ZfdhB57gbOFT75wRNk65TvkDFxCx/Y 61BmoLh6nRh3VrEpSYYT9lw= X-Google-Smtp-Source: ABdhPJwDoQpBhaGSz8gu43y2b3UAGco2qlRkqm4CXxtRTHW7Oy71yJEWpu2zCx1AJnWYQCjYVgyTWw== X-Received: by 2002:a2e:9ac4:: with SMTP id p4mr5203500ljj.446.1591892100764; Thu, 11 Jun 2020 09:15:00 -0700 (PDT) Received: from jonathartonsmbp.lan (83-245-237-14-nat-p.elisa-mobile.fi. [83.245.237.14]) by smtp.gmail.com with ESMTPSA id i22sm811175ljb.50.2020.06.11.09.14.59 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 11 Jun 2020 09:15:00 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.5\)) From: Jonathan Morton X-Priority: 3 (Normal) In-Reply-To: <1591891396.41838464@apps.rackspace.com> Date: Thu, 11 Jun 2020 19:14:57 +0300 Cc: Dave Taht , bloat Content-Transfer-Encoding: quoted-printable Message-Id: References: <1591891396.41838464@apps.rackspace.com> To: "David P. Reed" X-Mailer: Apple Mail (2.3445.9.5) Subject: Re: [Bloat] FW: [Dewayne-Net] Ajit Pai caves to SpaceX but is still skeptical of Musk's latency claims 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, 11 Jun 2020 16:15:02 -0000 > On 11 Jun, 2020, at 7:03 pm, David P. Reed = wrote: >=20 > So, what do you think the latency (including bloat in the satellites) = will be? My guess is > 2000 msec, based on the experience with Apple on = ATT Wireless back when it was rolled out (at 10 am, in each of 5 cities = I tested, repeatedly with smokeping, for 24 hour periods, the ATT = Wireless access network experienced ping time grew to 2000 msec., and = then to 4000 by mid day - true lag-under-load, with absolutely zero lost = packets!) > =20 > I get that SpaceX is predicting low latency by estimating physical = distance and perfect routing in their LEO constellation. Possibly it is = feasible to achieve this if there is zero load over a fixed path. But = networks aren't physical, though hardware designers seem to think they = are. > =20 > Anyone know ANY reason to expect better from Musk's clown car parade? Speaking strictly from a theoretical perspective, I don't see any reason = why they shouldn't be able to offer latency that is "normally" below = 100ms (to a regional PoP, not between two arbitrary points on the = globe). The satellites will be much closer to any given ground station = than a GEO satellite, the latter typically adding 500ms to the path due = mostly to physical distance. All that is needed is to keep queue delays = reasonably under control, and there's any number of AQMs that can help = with that. Clearly ATT Wireless did not perform any bufferbloat = mitigation at all. I have no insight or visibility into anything they're *actually* doing, = though. Can anyone dig up anything about that? - Jonathan Morton