From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from resqmta-po-06v.sys.comcast.net (resqmta-po-06v.sys.comcast.net [IPv6:2001:558:fe16:19:96:114:154:165]) (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 2B6523B2A4 for ; Fri, 4 Dec 2020 14:27:17 -0500 (EST) Received: from resomta-po-10v.sys.comcast.net ([96.114.154.234]) by resqmta-po-06v.sys.comcast.net with ESMTP id lG1DkiUCBznyAlGjcklDIK; Fri, 04 Dec 2020 19:27:16 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcastmailservice.net; s=20180828_2048; t=1607110036; bh=3kcMpBNva0ngQ6Q5AAwdTZRYwkPzBR059oCFpIOJSG0=; h=Received:Received:Received:Date:From:To:Subject:Message-ID: MIME-Version:Content-Type; b=dgewCunBCfn9JRiI05Kn6gVScjfzVdSA5en87KVH+9a9XyjZw9CbV2J7Fvxv5Icoy a6EZrEyW80HqQbX9CNSGYbEfJbGTWllK30jkCLYWg9HnK0fYyKORwkSJJyx2EbbWtE /zUZOMunf9RT12hI2Uq3qgdtGUNxjmVjqODHeAcGze+sEEkPQXhyqLzoxCbtdt6rWg JrR3pyTh6dwPsa/G1XtfFA7BC3J7HSat19rDceHX0JqHYi+QRAABN9QfkfDnu/m1Pp TUswAy51WHmsmhZVbCmTWj/1K8hQbd+GY9Lmn2JmR5Etuv39Q8zAco9FAHog5EDr5s inM0IMorUoDcw== Received: from home.sewingwitch.com ([IPv6:2601:644:881:42b0::3f1]) by resomta-po-10v.sys.comcast.net with ESMTPA id lGjXk952Eiib4lGjbkY20r; Fri, 04 Dec 2020 19:27:15 +0000 X-Xfinity-VMeta: sc=0.00;st=legit 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 0B4JQSjf027853 for ; Fri, 4 Dec 2020 11:26:28 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 home.sewingwitch.com 0B4JQSjf027853 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sewingwitch.com; s=default; t=1607109988; bh=3kcMpBNva0ngQ6Q5AAwdTZRYwkPzBR059oCFpIOJSG0=; h=Date:From:To:Subject:From; b=A20RUaD/cjrIXumgMfNjWSq5pUeUUPNlq/kk9ERGkpf6KsbU2vYbD/hgtrrBCuryT oZcFzqSCgHzx6PJZufkhCjBcPhSAj0PXRUX6QrdL36VtlYJGCHl1JyVBXzmf3J3yUG XFCoLQGv+sgvUBokhknETBSrX7eHdXegjnj3i03s= Date: Fri, 04 Dec 2020 11:26:27 -0800 From: Kenneth Porter To: bloat Message-ID: <6096417F0109590F3C6DD6A1@[172.27.17.193]> X-Mailer: Mulberry/4.1.0a3 (Win32) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline; size=1975 X-Scanned-By: MIMEDefang 2.84 on 10.96.0.132 Subject: [Bloat] Xfinity Flex streaming box starves on cake? 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: Fri, 04 Dec 2020 19:27:17 -0000 I suspect that my Xfinity Flex box has too small an internal buffer and is starving when fed by my cake-enabled OpenWrt router. For the last few weeks, I've been streaming Amazon Prime Video shows and movies and the box tends to go to black screen after 5-10 minutes of viewing, followed by a jump to the Flex main menu (which selects which streaming service to view). I thought perhaps the box was overheating or that there was a bug in the Amazon app that caused it to crash to the home screen. This week the same thing happened when I watched a show on HBO Max. On a hunch, I disabled SQM on the router and was able to watch an hour of TV with no interruption, using a different service on successive nights. My next test will be to re-enable SQM and try viewing to see if I get a black screen and crash to home screen again. Sometimes instead of a black screen I get a "problem with connection" message. So my theory is that the Flex box has too little buffer to handle hiccups in the feed, and is depending on a deep buffer in the Xfinity modem. Except that I have the modem set to bridge mode so I can disable its DHCP server and let my LAN server handle DHCP and DNS and other services. My SQM config follows: config queue 'eth1' option itarget 'auto' option etarget 'auto' option linklayer 'none' option interface 'eth1.2' option debug_logging '0' option verbosity '5' option qdisc 'cake' option qdisc_advanced '1' option squash_dscp '1' option squash_ingress '1' option qdisc_really_really_advanced '1' option script 'layer_cake.qos' option iqdisc_opts 'docsis wash besteffort nat ingress' option eqdisc_opts 'docsis ack-filter nat' option ingress_ecn 'NOECN' option egress_ecn 'NOECN' option download '170000' option upload '9000' option enabled '1'