From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from uplift.swm.pp.se (swm.pp.se [212.247.200.143]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 9A12021F25F for ; Sun, 25 May 2014 17:18:33 -0700 (PDT) Received: by uplift.swm.pp.se (Postfix, from userid 501) id 93EBD9C; Mon, 26 May 2014 02:18:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=swm.pp.se; s=mail; t=1401063510; bh=gW9fyv/Ga5hd8vBG5yS7lMJQxlwyfCe5BmHFNx+G180=; h=Date:From:To:Subject:In-Reply-To:References:From; b=4ebm0NPcPGTugW6sLVpV7GZZxXFoX0EGaCnZtQDn1qNj43cOSU8R6ulsXpWTQMZ1K 0VKwdpSbw3aH8oB2o/Cyr4MlNaUx4o5sRCRs5fz6jziiLRBRlzfkQE/yRWuOcYfyb2 VZ1ai4WqOMwl/ZyiYQQjB4AzujJ/cVIW/u1mEap8= Received: from localhost (localhost [127.0.0.1]) by uplift.swm.pp.se (Postfix) with ESMTP id 8832F9A for ; Mon, 26 May 2014 02:18:30 +0200 (CEST) Date: Mon, 26 May 2014 02:18:30 +0200 (CEST) From: Mikael Abrahamsson To: cerowrt-devel@lists.bufferbloat.net In-Reply-To: <1401048053.664331760@apps.rackspace.com> Message-ID: References: <1401048053.664331760@apps.rackspace.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) Organization: People's Front Against WWW MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Subject: Re: [Cerowrt-devel] Ubiquiti QOS X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 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, 26 May 2014 00:18:34 -0000 On Sun, 25 May 2014, dpreed@reed.com wrote: > The optimum buffer state for throughput is 1-2 packets worth - in other > words, if we have an MTU of 1500, 1500 - 3000 bytes. Only the bottleneck No, the optimal state for througbut is to have huge buffers and have them filled. The optimal state for interactivity is to have very small buffers. FQ_CODEL tries to strike a balance between the two at 10ms of buffer. PIE does the same around 20ms. In order for PIE to work properly I'd say you need 50ms of buffering as a minimum, otherwise you're going to get 100% tail drop and multiple sequential drops occasionally (which might be desireable to keep interactivity good). My comment about 50ms is that you seldom need a lot more. -- Mikael Abrahamsson email: swmike@swm.pp.se