From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from uplift.swm.pp.se (ipv6.swm.pp.se [IPv6:2a00:801::f]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id D67C33BA8E for ; Wed, 29 Nov 2017 07:49:25 -0500 (EST) Received: by uplift.swm.pp.se (Postfix, from userid 501) id 35131B2; Wed, 29 Nov 2017 13:49:24 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=swm.pp.se; s=mail; t=1511959764; bh=EH+scgrKLexC9U5vPgKmK8Q8pMfsgfQtm363IO2DOKg=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=Id+5NeE0H9x+HUAJdAvDayep5edBW5hZdFHOs/nhu+3AbQI/uGbU/HSGlVP6K2o7G 9XQlgHHlNK6HKZnSPwVa5BA0gXKhC8cgiIj6dKOxRmwy+0hhdL1RlRy7I/3bCp2UHz 2MIfvN9MT7srrsmVmEP/14/RDmACM7A2wHE8POXA= Received: from localhost (localhost [127.0.0.1]) by uplift.swm.pp.se (Postfix) with ESMTP id 336BCB1; Wed, 29 Nov 2017 13:49:24 +0100 (CET) Date: Wed, 29 Nov 2017 13:49:24 +0100 (CET) From: Mikael Abrahamsson To: Sebastian Moeller cc: =?ISO-8859-15?Q?Dave_T=E4ht?= , bloat In-Reply-To: <4D0E907C-E15D-437C-B6F7-FF348346D615@gmx.de> Message-ID: References: <4D0E907C-E15D-437C-B6F7-FF348346D615@gmx.de> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) Organization: People's Front Against WWW MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Subject: Re: [Bloat] benefits of ack filtering 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, 29 Nov 2017 12:49:26 -0000 On Wed, 29 Nov 2017, Sebastian Moeller wrote: > Well, ACK filtering/thinning is a simple trade-off: redundancy versus > bandwidth. Since the RFCs say a receiver should acknoledge every second > full MSS I think the decision whether to filter or not should be kept to Why does it say to do this? What benefit is there to either end system to send 35kPPS of ACKs in order to facilitate a 100 megabyte/s of TCP transfer? Sounds like a lot of useless interrupts and handling by the stack, apart from offloading it to the NIC to do a lot of handling of these mostly useless packets so the CPU doesn't have to do it. Why isn't 1kPPS of ACKs sufficient for most usecases? -- Mikael Abrahamsson email: swmike@swm.pp.se