From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: Re the default linux tcp algorithm being changed from bic to cubic. Date: Thu, 28 Sep 2006 07:16:57 -0700 Message-ID: <20060928071657.5d0cbf70@freekitty> References: <451B9ED6.9090208@nuim.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev , davem@davemloft.net, Douglas Leith Return-path: Received: from smtp.osdl.org ([65.172.181.4]:43152 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751185AbWI1O5z (ORCPT ); Thu, 28 Sep 2006 10:57:55 -0400 To: Douglas Leith In-Reply-To: <451B9ED6.9090208@nuim.ie> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, 28 Sep 2006 11:07:18 +0100 Douglas Leith wrote: > Content-Type: text/plain; charset=UTF-8; format=flowed > Content-Transfer-Encoding: 7bit > > Steve, > > I think we're all conscious of the fact that recent history contains > quite a number of proposals for changes to tcp's congestion control > algorithm for high bandwidth-delay product paths that on closer > inspection have proved problematic in one way or another. It seems to > be a hard problem to solve, so maybe that's fair enough and hopefully > we'll end up with a workable solution soon. > > Where I'm coming from here though is that bic was made the linux default > a year or so ago at a time when there were essentially no tests > available on its performance other than the infocom paper by Injong. > Subsequent tests have since highlighted a bunch of issues with bic. To > my knowledge, we're currently in a similar situation with cubic as we > were with bic back then i.e. essentially no independent tests > investigating its behaviour. > > Of course I know Injong has posted some test results, but these are > hardly independent as he's the author of both bic and cubic. Have there > perhaps been private tests carried out (e.g. by osdl) ? If so, would it > be possible to make them public ? If not, well that would be good to > know too. My tests have been limited and showed no difference. It is worthy of more discussion as to what is best. Could you rerun your tests?