From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp119.iad3a.emailsrvr.com (smtp119.iad3a.emailsrvr.com [173.203.187.119]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 44E2E3B2A4 for ; Mon, 13 Jan 2020 12:56:40 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=g001.emailsrvr.com; s=20190322-9u7zjiwi; t=1578938199; bh=w8rq9qBtq3N8aXrIlRJ182pYRrzpJNxRvQVKWykUh3k=; h=Date:Subject:From:To:From; b=JiR+Swrz9zBCiaGYudIGPwA8FKWLqHxcYeeVMTWXpvwJcW5dNmA/jOaQntFSFXw8/ c/7fhWqaIFCEucpF/QoPh3+D+9lr4sqJc+yWgl9ehnmrAn83hNHgudh1SWrU6gO3iM JgHATxTl6XY85oorqsqO0x2haosE2YBSkKniEqhA= Received: from app67.wa-webapps.iad3a (relay-webapps.rsapps.net [172.27.255.140]) by smtp31.relay.iad3a.emailsrvr.com (SMTP Server) with ESMTP id B2F0E21FE1; Mon, 13 Jan 2020 12:56:39 -0500 (EST) X-Sender-Id: dpreed@deepplum.com Received: from app67.wa-webapps.iad3a (relay-webapps.rsapps.net [172.27.255.140]) by 0.0.0.0:25 (trex/5.7.12); Mon, 13 Jan 2020 12:56:39 -0500 Received: from deepplum.com (localhost.localdomain [127.0.0.1]) by app67.wa-webapps.iad3a (Postfix) with ESMTP id 9F32B60104; Mon, 13 Jan 2020 12:56:39 -0500 (EST) Received: by apps.rackspace.com (Authenticated sender: dpreed@deepplum.com, from: dpreed@deepplum.com) with HTTP; Mon, 13 Jan 2020 12:56:39 -0500 (EST) X-Auth-ID: dpreed@deepplum.com Date: Mon, 13 Jan 2020 12:56:39 -0500 (EST) From: "David P. Reed" To: "Dave Taht" Cc: "cerowrt-devel" MIME-Version: 1.0 Content-Type: text/plain;charset=UTF-8 Content-Transfer-Encoding: quoted-printable Importance: Normal X-Priority: 3 (Normal) X-Type: plain In-Reply-To: References: Message-ID: <1578938199.64982240@apps.rackspace.com> X-Mailer: webmail/17.2.4-RC Subject: Re: [Cerowrt-devel] starlink as a mesh network 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: Mon, 13 Jan 2020 17:56:40 -0000 Fun, but it is all just a dynamic geometry game. =0A=0AIt's worth rememberi= ng that Congestion Control will be a huge problem here. It's far from obvio= us that current TCP congestion control (which assumes all packets in a virt= ual circuit traverse the same path in a very deep way indeed) will do the j= ob. Thus there is a serious risk of congestion collapse if windows larger t= han one packet are allowed to operate.=0A=0ASo the Dijkstra algorithm reach= ability is not at all predictive of how this network will respond once it h= as a moderate load percentage on any path (over 10% of average link capacit= y).=0A=0AGlad it's being funded by billionaires who may have a long timefra= me in mind.=0A=0AIridium took a much different approach, focused on 14 kb/s= ec constrant-rate virtual circuits (compressed voice).=0A=0AMy guess is tha= t, just as in the Internet, nobody understands bufferbloat, or deeply under= stands the TCP congestion control approach's limitations. And I bet they wi= ll throw in "differential service" as if it were a solved problem, and mayb= e network layer multicast, too. Why not create a huge mess based on assumin= g you can just figure it out after the satellites are up?=0A=0AAre there an= y queueing theory and control theory folks among the leadership here? There= are few in the IETF, and few in the cellular community, too, who can explo= re a completely new topology...=0A=0AOn Sunday, January 12, 2020 7:59am, "D= ave Taht" said:=0A=0A> Mark ignores retries and loss= . I'm really far from confident this can=0A> be avoided, however perhaps wi= th multiple terminals retransmitting...=0A> =0A> http://nrg.cs.ucl.ac.uk/mj= h/starlink/hotnets19.pdf=0A> =0A> And it's still a bear to cross an ocean.= =0A> =0A> --=0A> Make Music, Not War=0A> =0A> Dave T=C3=A4ht=0A> CTO, TekLi= bre, LLC=0A> http://www.teklibre.com=0A> Tel: 1-831-435-0729=0A> __________= _____________________________________=0A> Cerowrt-devel mailing list=0A> Ce= rowrt-devel@lists.bufferbloat.net=0A> https://lists.bufferbloat.net/listinf= o/cerowrt-devel=0A> =0A