From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262196AbUKWFRz (ORCPT ); Tue, 23 Nov 2004 00:17:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262200AbUKWFAy (ORCPT ); Tue, 23 Nov 2004 00:00:54 -0500 Received: from adsl-63-197-226-105.dsl.snfc21.pacbell.net ([63.197.226.105]:54458 "EHLO cheetah.davemloft.net") by vger.kernel.org with ESMTP id S262212AbUKWE55 (ORCPT ); Mon, 22 Nov 2004 23:57:57 -0500 Date: Mon, 22 Nov 2004 20:40:52 -0800 From: "David S. Miller" To: Pradeep Anbumani Cc: linux-net@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: ACK Flooding Message-Id: <20041122204052.581ba69b.davem@davemloft.net> In-Reply-To: <19f134cc04112220125461595d@mail.gmail.com> References: <19f134cc04112220125461595d@mail.gmail.com> X-Mailer: Sylpheed version 0.9.99 (GTK+ 1.2.10; sparc-unknown-linux-gnu) X-Face: "_;p5u5aPsO,_Vsx"^v-pEq09'CU4&Dc1$fQExov$62l60cgCc%FnIwD=.UF^a>?5'9Kn[;433QFVV9M..2eN.@4ZWPGbdi<=?[:T>y?SD(R*-3It"Vj:)"dP Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 23 Nov 2004 09:42:18 +0530 Pradeep Anbumani wrote: > If anybody could tell me what changes had to be made to get the > desired output..the desired output is TCP as per the conventional > behaviour has to increase the transmission rate as it gets more > duplicate acknowledgements.... If you send a 100 ACKs you won't get this behavior. Once you give more ACKs than the other end has packets to send (or more than the congestion window can fit) the sender just waits for a timer based timeout before it retransmits more data. So what you code causes to happen is after the first data segment is sent, you crazily spit out 100 ACKs, the send has a tiny congestion window (now 2 segments) so at most it can send 2 packets back in response to all of those ACKs.