From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from resqmta-c2p-570641.sys.comcast.net (resqmta-c2p-570641.sys.comcast.net [IPv6:2001:558:fd00:56::9]) (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 14F2C3CB37 for ; Wed, 22 May 2024 14:58:20 -0400 (EDT) Received: from resomta-c2p-555921.sys.comcast.net ([96.102.18.229]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 256/256 bits) (Client did not present a certificate) by resqmta-c2p-570641.sys.comcast.net with ESMTPS id 9pk9sN9XBTyxh9rAJs9bBw; Wed, 22 May 2024 18:58:19 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcastmailservice.net; s=20211018a; t=1716404299; bh=iGrvjNxLpYsHCf5vmgSj5TjwBX6jw+5fzf+Uev7LyyI=; h=Received:Received:Received:Message-ID:Date:MIME-Version:Subject: To:From:Content-Type:Xfinity-Spam-Result; b=IVlOc7c5Qkz8hEMRjpZzyPzINmS4+zzUorVWo8SteqJ5wmYOlNOFUZXlx8/BqAhkU yk473ecfoYd7R3SoMkJQj3rkgQIMgRaKB2+uXD+aWhEEjI9qrd6y9QT8xWF6ObvUOT DoMPE6o8ienuqfcUcQuLKvv6lo/0vsluAA4Nu3dBIUHDnHYYgsi4Z63jNG1ZIv6hvF zdKTaYrnUWBkRCt9LgLRPq9ndru+RCjOkDV/ldsijHupwCWfqAbKtD6yUJhmXWLEY1 oaXKzJo75vZkfWUzwmtyZOgLAupbIJIcxXu5Rj/BBX0LPpnawTukLkmdLxTXJJI/si FqsXb6jYzgy9w== Received: from home.sewingwitch.com ([IPv6:2600:1700:a64d:600f:2e0:81ff:feb5:9463]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 256/256 bits) (Client did not present a certificate) by resomta-c2p-555921.sys.comcast.net with ESMTPSA id 9r7psh6pSVhRk9r7us1JWt; Wed, 22 May 2024 18:55:55 +0000 Received: from [10.96.7.39] ([10.96.7.39]) (authenticated bits=0) by home.sewingwitch.com (8.14.7/8.14.7) with ESMTP id 44MItgT2020577 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO) for ; Wed, 22 May 2024 11:55:42 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 home.sewingwitch.com 44MItgT2020577 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sewingwitch.com; s=default; t=1716404142; bh=iGrvjNxLpYsHCf5vmgSj5TjwBX6jw+5fzf+Uev7LyyI=; h=Date:Subject:To:References:From:In-Reply-To:From; b=n4LtY10Z4Dg/YYdGw3x7CfLWLagiqlg+QfLzi3iqkZbDNBDW0SnrRPu+ppVghE0Al +rRpOp58rI3qBzvixTKMyGHzs5hBxg1O4tOVFZ+UWIaE845s+fMquvKGI5+O9MqtXp ozC7ENd53H+qr1/Chn0BHG5twml4gyxidlnDZhdM= Message-ID: <258721b6-efdc-472c-b606-3192b2551bc3@sewingwitch.com> Date: Wed, 22 May 2024 11:55:41 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: bloat@lists.bufferbloat.net References: <4223FB1D3EC8265F9E30D997@[192.168.11.128]> Content-Language: en-US From: Kenneth Porter In-Reply-To: <4223FB1D3EC8265F9E30D997@[192.168.11.128]> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.96.0.132 X-CMAE-Envelope: MS4xfDfBw1qt37ANesSTQKk1SEZYTM00kq/ef5vvVdefC+na2mFAVpQ5K99DiF/yuGp9ZslFiijgEsQ5bxFcEB3g9RvYVm+q2rYwkVIF2Ih7uUptka1q7RDv GndSynwi8vV0GoCCQGvRcj9VydDKxIU1+5hiR7lkLXLA0OBjwLrC7d31qpexYHJ+jKcKvf1ZORtlsvaSIE3PU0Qns8HWbTbdDL1NKC+5lqojqnLpSmbmRtsF bLK5P/eON6V4CK7dyCwo0VyrZJipJw5A6nEixMofQfo= Subject: Re: [Bloat] A Transport Protocol's View of Starlink 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, 22 May 2024 18:58:21 -0000 The Register came out with this summary today: https://www.theregister.com/2024/05/22/starlink_tcp_performance_evaluation/ Excerpt: > Using PING, he found "minimum latency changes regularly every 15 > seconds" and surmised "It appears that this change correlates to the > Starlink user's terminal being assigned to a different satellite. That > implies that the user equipment 'tracks' each satellite for a > 15-second interval, which corresponds to a tracking angle of 11 > degrees of arc." > > During those handovers, Huston observed some packet loss – and a > significant increase in latency. "The worst case in this data set is a > shift from 30ms to 80ms," he wrote. Further: "Within each 15-second > satellite tracking interval, the latency variation is relatively high. > The average variation of jitter between successive RTT intervals is > 6.7ms. The latency spikes at handover impose an additional 30ms to > 50ms indicating the presence of deep buffers in the system to > accommodate the transient issues associated with satellite handover." > > Overall, Huston believes Starlink has "a very high jitter rate, a > packet drop rate of around one percent to two percent that is > unrelated to network congestion, and a latency profile that jumps > regularly every 15 seconds." [No need to cc me in replies, I'll read them on the mailiing list.]