From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x244.google.com (mail-wm0-x244.google.com [IPv6:2a00:1450:400c:c09::244]) (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 EE9DB3BA8E for ; Sun, 26 Nov 2017 13:43:43 -0500 (EST) Received: by mail-wm0-x244.google.com with SMTP id y82so25725488wmg.1 for ; Sun, 26 Nov 2017 10:43:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=EjGv8EptCFITmtlX30t9yIBewWIdoINcLw2AoLBVJeA=; b=KUKVwHyFG5rg+tr52l23eupWgjdY51964crXQVMR7lWQaXGXJvQJB/Pa7/JkGYa4mZ BlZFcWBnkpRq0bYNAL1AosIU0oOHbMDnKZ93Wd4EVqNQepku0HzRjlM7eDlZta/jgdUA 8axG5Rwx8nrGXtzxY4idftLgOyJnW0PPyr3PtjQWALRpTwqRHIiL4QF/rMnEmpHODZUE 8V3AmEILsnjeStrjt8kSCtzLShRdVW0JXGivQ1V59x+foJeXZu9UVABEyuKDJGMicMvZ XPDGl04/InbkNyndgcEKNVRpGX2KcN/mxWBBEo+a/2SljmdKtjAR1JR1yb9wd1P6PyLM LfJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=EjGv8EptCFITmtlX30t9yIBewWIdoINcLw2AoLBVJeA=; b=Wf8fi/gtqz6xvCyJdaJz0CKzUiiHJBkkXd4a1URRAhJVcTxjeO7gtv8z+bw/T076OI Yve8Y203o1x071TpACkIrFZGwiJrdNMJq4P4c2GjmPXx0eB43sMbtlxNPtb2Aiq/gu19 xgHsW6WK1HfVW4YEZX8kHSYy0dbzNkdqsJkEStiB8vFud2kBBA2jmHnDnZsjW9zqaVcF OiskkfHsJ1JmiMS6rQx/nGTbf7M44pyKzkrngM5iUPclaZQDuyn8aewLQEzNlok3EcIj GDuRMUZBEH0igTrR0kEfWbqxiaycbK3zPGLJTbn+bKjLp6THrlrtbK68ahS8ebFZKN6S HeSw== X-Gm-Message-State: AJaThX5JSdEZY4+t7T2S2GBgi7zPG3hXm9Sl5rIOJaI6DgBbOlkLQB8E PJX1YWWpa5i8B+MCt1IjVWk= X-Google-Smtp-Source: AGs4zMYmDL13F9etqi2mFIjBQNxcLjBhN2mmFLmO9guBX3/jcBbSwEuuwMFIE9cETfnkPpZNFqq49Q== X-Received: by 10.80.143.98 with SMTP id 89mr13628573edy.273.1511721823001; Sun, 26 Nov 2017 10:43:43 -0800 (PST) Received: from zotac.xperim.be (22.49-200-80.adsl-dyn.isp.belgacom.be. [80.200.49.22]) by smtp.gmail.com with ESMTPSA id a99sm20320253edf.54.2017.11.26.10.43.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 26 Nov 2017 10:43:42 -0800 (PST) Received: from [192.168.8.172] (unknown [192.168.8.172]) by zotac.xperim.be (Postfix) with ESMTPSA id BAF2B480CD2; Sun, 26 Nov 2017 19:43:41 +0100 (CET) To: Dave Taht , Jonathan Morton Cc: bloat References: <20171124092021.DC01D40605C@ip-64-139-1-69.sjc.megapath.net> <4a37c330-cb03-23eb-f705-743c6cb30c15@gmail.com> From: Jan Ceuleers Message-ID: Date: Sun, 26 Nov 2017 19:43:41 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Subject: Re: [Bloat] Steam In Home Streaming on ath9k wifi 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: Sun, 26 Nov 2017 18:43:44 -0000 Resending with the from-address with which I'm subscribed to the list On 26/11/17 18:53, Dave Taht wrote: > On Sun, Nov 26, 2017 at 2:05 AM, Jonathan Morton wrote: >> Another explanation for latency spikes on the order of 100ms is that a >> periodic (and wholly unnecessary) scan for other APs is run, which requires >> the wifi radio to be temporarily tuned away from the currently associated >> AP's frequency. > > I'd written that up here: > > http://blog.cerowrt.org/post/disabling_channel_scans/ > > Which was improved in some release of network manager > > https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/373680 Dave, Thanks, but that's not the same problem I experienced. Yours was entirely client-side (i.e. it was behaviour of Network Manager). My problem was due to the AP asking the client to periodically perform scans (by means of hostapd's obss_interval parameter). Similar (but not the same) symptoms - different cause. Jan