From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Heffner Subject: Re: 2.6.17: networking bug?? Date: Tue, 13 Jun 2006 21:25:34 -0400 Message-ID: <448F658E.9090903@psc.edu> References: <448F0D4B.30201@rtr.ca> <20060613.142603.48825062.davem@davemloft.net> <448F32E1.8080002@rtr.ca> <20060613.152301.26928146.davem@davemloft.net> <448F3EF5.50701@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , netdev@vger.kernel.org Return-path: Received: from mailer1.psc.edu ([128.182.58.100]:14273 "EHLO mailer1.psc.edu") by vger.kernel.org with ESMTP id S964867AbWFNBZz (ORCPT ); Tue, 13 Jun 2006 21:25:55 -0400 To: Rick Jones In-Reply-To: <448F3EF5.50701@hp.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Rick Jones wrote: >> One final word about window sizes. If you have a connection whose >> bandwidth-delay-product needs an N byte buffer to fill, you actually >> have to have an "N * 2" sized buffer available in order for fast >> retransmit to work. > > Is that as important in the presence of SACK? With SACK you do need up to N * 2, but no more. With New Reno, you potentially need ~ N * (number of losses) or it will time out... yuck. SACK is a good thing. :) -John