From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from au-smtp-delivery-117.mimecast.com (au-smtp-delivery-117.mimecast.com [103.96.23.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 31BE43B29D for ; Fri, 13 Jan 2023 07:28:01 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=auckland.ac.nz; s=mimecast20200506; t=1673612879; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Sh2t/+INAvM38TAS9bgLK9I6IcfhYf4ZMF28nFF6b0I=; b=qpT61hAojxOag6X88OiO77NQnC2mdVUrIa1hySc55yyKbnRbnceI5kmVLwnqFD/TMY8dQS e01zy+oFIKulSM8rejtNcjSOJQjgMhzHyJtPBtLAHIxkbnxOQSZAQJ1aKwDDRhGkyK1nWh Rm8UlWU9Mhtd5/yoPOtMnc13i9PLAHw= Received: from AUS01-SY4-obe.outbound.protection.outlook.com (mail-sy4aus01lp2170.outbound.protection.outlook.com [104.47.71.170]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id au-mta-90-waa7huSMOYqhtfIhpJLnKw-2; Fri, 13 Jan 2023 23:27:58 +1100 X-MC-Unique: waa7huSMOYqhtfIhpJLnKw-2 Received: from SY4PR01MB6979.ausprd01.prod.outlook.com (2603:10c6:10:142::13) by SY7PR01MB8432.ausprd01.prod.outlook.com (2603:10c6:10:1f0::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6002.10; Fri, 13 Jan 2023 12:27:56 +0000 Received: from SY4PR01MB6979.ausprd01.prod.outlook.com ([fe80::f24:6461:1e37:54ed]) by SY4PR01MB6979.ausprd01.prod.outlook.com ([fe80::f24:6461:1e37:54ed%8]) with mapi id 15.20.6002.013; Fri, 13 Jan 2023 12:27:56 +0000 Message-ID: Date: Sat, 14 Jan 2023 01:27:52 +1300 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 From: Ulrich Speidel To: starlink@lists.bufferbloat.net References: <89D796E75967416B9723211C183A8396@SRA6> <3696AEA5409D4303ABCBC439727A5E40@SRA6> In-Reply-To: X-ClientProxiedBy: SYAPR01CA0045.ausprd01.prod.outlook.com (2603:10c6:1:1::33) To SY4PR01MB6979.ausprd01.prod.outlook.com (2603:10c6:10:142::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SY4PR01MB6979:EE_|SY7PR01MB8432:EE_ X-MS-Office365-Filtering-Correlation-Id: 8e51e606-0524-468a-54cd-08daf561993e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0 X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:SY4PR01MB6979.ausprd01.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230022)(4636009)(376002)(366004)(39860400002)(346002)(136003)(396003)(451199015)(6486002)(478600001)(966005)(41300700001)(6512007)(38100700002)(86362001)(31696002)(316002)(786003)(2616005)(66556008)(26005)(66946007)(186003)(66476007)(66899015)(5660300002)(53546011)(6506007)(36756003)(2906002)(6666004)(31686004)(8676002)(6916009)(83380400001)(8936002)(45980500001)(43740500002); DIR:OUT; SFP:1101 X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?b2dzZTBUM0lmZWFEYUNpcGFwKzlCeW1zVTVNYVBmalNhUjh4RmxxN2dGQjVO?= =?utf-8?B?VGZxSmovL20wTnV2cEZJMFhQNzdmc3FDU0xMWEFhazhsRTR2eEd5a2RnQUFa?= =?utf-8?B?WjZtelFaaXhMakJsVzNNbDdHOUVrSUhiWkFrQWpBeC8zT1p5dktjZjU2RTdy?= =?utf-8?B?aklhWWhZMDRYQ1MwdmJzNlRoUlp4bG9vN3RDVkJmTzRySExoMUZUZ3BGSjFI?= =?utf-8?B?Z1dGUnhZRkNVVld0Y091UUhSbkNYdXdtM2k4RU1OZE9mY3V2RTYxelQrMGhy?= =?utf-8?B?bXlsWi9GVjNCSGphVFU0YTgzc0Q4OVczNTVpc3F4MmZYbG9ORURVcGF6SlBv?= =?utf-8?B?RjZYakNWcTBkYzhMd1FId2srVFEvS2NabkpZTENsWktwT3hkeW1BSjR1WkVo?= =?utf-8?B?bGRoSWVmazhMY3I3VmpwZS8rTlh5aUtyYVZKUWkwODh2OWlsZTVYblhEVGVN?= =?utf-8?B?WVQzR0FDRVg2OUZ1RVlUVzl2OTgvemxKaXBheDJVdUdCa0tPMWNuY3NXd2wv?= =?utf-8?B?QUhKQTZhZDRoN2xucHBjRmp6Mkk1YTV5ZTN5M2N1UGc1Z29tdFFhbjV2a1kv?= =?utf-8?B?V2REWGhHTXBhcWRoR0dCQkIxK2JjVzFwRTA4OVlsUFhTNFlNZ1Q0SGJKVkkw?= =?utf-8?B?eFZRT0ViL1NvVEN5Vk9mRm1sbUhVQURHeFZQdVUwVHNMcWh6djhFN0xSczM5?= =?utf-8?B?SnFTalp3UnZ4d3NoTW4zb2JlWXRlREErdk1kcmEwQzhTMzR0Q052NE9majRW?= =?utf-8?B?RlRSMFlhdmVyY2FXZnFWSEYrYm9saEVYYW8vcXdMalFyckFvbVluTEtwSENM?= =?utf-8?B?Q0lhb1owdy9PV09NOFNpRkhvUEhJa1dZOGZxQmQ2cFAwbjB1Z21kRHF0a3BX?= =?utf-8?B?a3NmTy8yRFE2cGQreGlDTXMybmRVc3NVQm11M1ErOFpSWi9TMUZLUGhkQ0JZ?= =?utf-8?B?bEEyOEtFcnhZMkZyc0hBU2pSdDlRZ3d6N0hTN1J5NVorYXVNMWpzRFFZTm5Y?= =?utf-8?B?akNSL1BBd1dOL0VkQkZkMmVjOG5KRjloU3RHTG92bE4rTVgvMG1wY1M3Ty9E?= =?utf-8?B?NjVibjRKK2tVR2VsTG5iS0pQNG9hQmREcUpTSjQ0ckJFckFsQVVubjVFb3FC?= =?utf-8?B?YzNnQ0pqeE9SamdCV3FHS2l3VnFKNDZ6VDMxY3ZRZVlrUmtOVTkwRklpbXBQ?= =?utf-8?B?bXlDZUYxV3Mvdks0elhiUGQ0U2cxSEhVS2pQR0pXNzRGc2tJenBDYWlBU1Rk?= =?utf-8?B?YnBJTHowbDRHQ0JUM1d0QncvNlJWYTNFajNxWHUrbnVxUVlncHA4RUFGbHNr?= =?utf-8?B?WDl2WUN0OHhrODRENkhpMlBRUW4vZkdjZk92V1ZtYnFyU05vU1RXZXUyZWFF?= =?utf-8?B?OElXeEJWQ1pGb3pITlowclJwb0IzdTl5VFZjMGZzWVJVMUFCb3BLb2ZnbUcw?= =?utf-8?B?NHVRdzh0d0ovckprQlBicm54VEc5ZlFPdC9sSUZmdVl3czh1VFRzc1dEYjV4?= =?utf-8?B?d1RIUFlDekUycGRVVm1XNmhSV29KcDJaS0U0WmdXM2JsMXJpM1g3Ukt1Witn?= =?utf-8?B?MXExTjF6dTZKa0VyakJ2dlFEQ2lzcFY5NWl1R29QNkJ5YmIvaUNOc0t2UDlj?= =?utf-8?B?QUl2Z0hIMUtxQVRyOEwwa3JiT1ZwM0xEMGJLQjZxd0lsL0JUYjBMdFBjV2dG?= =?utf-8?B?STNXYWxHcm8wa1NOOEZ1eFNpdjg0MEJMaGFETnI5Y2dnZHRrQmhnUEhMbkNz?= =?utf-8?B?RW9aNWFJTkx3RW1ybUVOeE5aWEpZYjk3M21INUV2L0swOXFzQklIWDZySGI4?= =?utf-8?B?cjAxUzVVcSs0U1hmVlR5ajFrNFhHbW5vRWlWaXJEYzlCcVlQcXZtZEFPUXZP?= =?utf-8?B?TS8xeGNGRmxqek5xS29BeXlyZmNSZkJTRXVtSmtVSHhzZ3ZWZE9NL1VhU1Fx?= =?utf-8?B?K2tOVDhjUzdmRWZORUhMSm54cTVxTXZRZ2J3dzExTHkyVk5UT1NacSs0dllD?= =?utf-8?B?Z2xmNlNiNlRIZjkxbTBzM2kvaU5Ib2I3bFpTa1F2dFFlZEphOU5WRTd4dmJI?= =?utf-8?B?aU1iNUtBanFleGdURHNIU285eERWM1FISTB6bW5XSlZSUTFwbDAwN1hVeUZn?= =?utf-8?B?YXBCdW91Yi8wNzhQcGM5cjBhUTRhdVBRanVzTEhoUmpmQS9MQ2JJRXJ5THU4?= =?utf-8?B?NHc9PQ==?= X-OriginatorOrg: auckland.ac.nz X-MS-Exchange-CrossTenant-Network-Message-Id: 8e51e606-0524-468a-54cd-08daf561993e X-MS-Exchange-CrossTenant-AuthSource: SY4PR01MB6979.ausprd01.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Jan 2023 12:27:56.0477 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: d1b36e95-0d50-42e9-958f-b63fa906beaa X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Gu9etIteewNspc7WNBCgyzYLjbyb2Vxn5W/7+JwGXqtszKlGVbSjJ7whssIYx6Z48+796YTz9RIwDT6roc3ng8tA+vX02wL9IhsT/SUtTrs= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SY7PR01MB8432 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: auckland.ac.nz Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Starlink] insanely great waveform result for starlink X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Jan 2023 12:28:02 -0000 On 13/01/2023 6:13 pm, Ulrich Speidel wrote: > > From Auckland, New Zealand, using a roaming subscription, it puts me=20 > in touch with a server 2000 km away. OK then: > > > IP address: nix six. > > My thoughts shall follow later. OK, so here we go. I'm always a bit skeptical when it comes to speed tests - they're really=20 laden with so many caveats that it's not funny. I took our new work=20 Starlink kit home in December to give it a try and the other day finally=20 got around to set it up. It's on a roaming subscription because our=20 badly built-up campus really isn't ideal in terms of a clear view of the=20 sky. Oh - and did I mention that I used the Starlink Ethernet adapter,=20 not the WiFi? Caveat 1: Location, location. I live in a place where the best Starlink=20 promises is about 1/3 in terms of data rate you can actually get from=20 fibre to the home at under half of Starlink's price. Read: There are few=20 Starlink users around. I might be the only one in my suburb. Caveat 2: Auckland has three Starlink gateways close by: Clevedon (which=20 is at a stretch daytrip cycling distance from here), Te Hana and Puwera,=20 the most distant of the three and about 130 km away from me as the crow=20 flies. Read: My dishy can use any satellite that any of these three can=20 see, and then depending on where I put it and how much of the southern=20 sky it can see, maybe also the one in Hinds, 840 km away, although that=20 is obviously stretching it a bit. Either way, that's plenty of options=20 for my bits to travel without needing a lot of handovers. Why? Easy: If=20 your nearest teleport is close by, then the set of satellites that the=20 teleport can see and the set that you can see is almost the same, so you=20 can essentially stick with the same satellite while it's in view for you=20 because it'll also be in view for the teleport. Pretty much any bird=20 above you will do. And because I don't get a lot of competition from other users in my area=20 vying for one of the few available satellites that can see both us and=20 the teleport, this is about as good as it gets at 37S latitude. If I'd=20 want it any better, I'd have to move a lot further south. It'd be interesting to hear from Jonathan what the availability of home=20 broadband is like in the Dallas area. I note that it's at a lower=20 latitude (33N) than Auckland, but the difference isn't huge. I notice=20 two teleports each about 160 km away, which is also not too bad. I also=20 note Starlink availability in the area is restricted at the moment -=20 oversubscribed? But if Jonathan gets good data rates, then that means=20 that competition for bird capacity can't be too bad - for whatever reason. Caveat 3: Backhaul. There isn't just one queue between me and whatever I=20 talk to in terms of my communications. Traceroute shows about 10 hops=20 between me and the University of Auckland via Starlink. That's 10=20 queues, not one. Many of them will have cross traffic. So it's a bit=20 hard to tell where our packets really get to wait or where they get=20 dropped. The insidious bit here is that a lot of them will be between 1=20 Gb/s and 10 Gb/s links, and with a bit of cross traffic, they can all=20 turn into bottlenecks. This isn't like a narrowband GEO link of a few=20 Mb/s where it's obvious where the dominant long latency bottleneck in=20 your TCP connection's path is. Read: It's pretty hard to tell whether a=20 drop in "speed" is due to a performance issue in the Starlink system or=20 somewhere between Starlink's systems and the target system. I see RTTs here between 20 ms and 250 ms, where the physical latency=20 should be under 15 ms. So there's clearly a bit of buffer here along the=20 chain that occasionally fills up. Caveat 4: Handovers. Handover between birds and teleports is inevitably=20 associated with a change in RTT and in most cases also available=20 bandwidth. Plus your packets now arrive at a new queue on a new=20 satellite while your TCP is still trying to respond to whatever it=20 thought the queue on the previous bird was doing. Read: Whatever your=20 cwnd is immediately after a handover, it's probably not what it should be. I ran a somewhat hamstrung (sky view restricted) set of four Ookla=20 speedtest.net tests each to five local servers. Average upload rate was=20 13 Mb/s, average down 75.5 Mb/s. Upload to the server of the ISP that=20 Starlink seems to be buying its local connectivity from (Vocus Group)=20 varied between 3.04 and 14.38 Mb/s, download between 23.33 and 52.22=20 Mb/s, with RTTs between 37 and 56 ms not correlating well to rates=20 observed. In fact, they were the ISP with consistently the worst rates. Another ISP (MyRepublic) scored between 11.81 and 21.81 Mb/s up and=20 between 106.5 and 183.8 Mb/s down, again with RTTs badly correlating=20 with rates. Average RTT was the same as for Vocus. Note the variation though: More or less a factor of two between highest=20 and lowest rates for each ISP. Did MyRepublic just get lucky in my=20 tests? Or is there something systematic behind this? Way too few tests=20 to tell. What these tests do is establish a ballpark. I'm currently repeating tests with dish placed on a trestle closer to=20 the heavens. This seems to have translated into fewer outages / ping=20 losses (around 1/4 of what I had yesterday with dishy on the ground on=20 my deck). Still good enough for a lengthy video Skype call with my folks=20 in Germany, although they did comment about reduced video quality. But=20 maybe that was the lighting or the different background as I wasn't in=20 my usual spot with my laptop when I called them. --=20 **************************************************************** Dr. Ulrich Speidel School of Computer Science Room 303S.594 (City Campus) The University of Auckland u.speidel@auckland.ac.nz http://www.cs.auckland.ac.nz/~ulrich/ ****************************************************************