From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baruch Even Subject: Re: TCP congestion control for fast, short-distance networks ? Date: Wed, 4 Apr 2007 19:11:21 +0300 Message-ID: <20070404161121.GB32019@galon.ev-en.org> References: <20070403091656.769e5368@localhost.localdomain> <200704032113.l33LDVhp025035@expredir6.cites.uiuc.edu> <20070404080743.5e67245a@localhost.localdomain> <8C944E41FEE84B1-244-BFF@FWM-D41.sysops.aol.com> <20070404153911.GA32019@galon.ev-en.org> <8C944E930D99B5D-244-E4B@FWM-D41.sysops.aol.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: shemminger@linux-foundation.org, netdev@vger.kernel.org To: davef1624@aol.com Return-path: Received: from rrcs-24-123-59-149.central.biz.rr.com ([24.123.59.149]:48796 "EHLO galon.ev-en.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753512AbXDDQLW (ORCPT ); Wed, 4 Apr 2007 12:11:22 -0400 Content-Disposition: inline In-Reply-To: <8C944E930D99B5D-244-E4B@FWM-D41.sysops.aol.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org * davef1624@aol.com [070404 19:03]: > Thanks - so you are suggesting we enable 802.3 flow-control / pause-frames? > (it's currently disabled) I do, but do test it before you bet on it. I've never tested such a scenario but from my experience the lower the rtt the lesser are the problems that the high speed algorithms are trying to solve. Baruch > > -----Original Message----- > From: baruch@ev-en.org > To: davef1624@aol.com > Cc: shemminger@linux-foundation.org; netdev@vger.kernel.org > Sent: Wed, 4 Apr 2007 8:39 AM > Subject: Re: TCP congestion control for fast, short-distance networks ? > > * davef1624@aol.com [070404 18:29]: > >Hello, > > > >We are currently using both 1 Gb & 10 Gb links, that interconnect > several > servers that are very *local* to > >each other. > >Typical RTT times range from 0.2 ms - 0.3 ms. > > > >We are currently using TCP reno - is there a more suitable congestion > control > algorithm for our > >application, > >especially using the 10 Gb links ? > >(Most of the High-Speed TCP algorithms seem suitable for large RTT, > long-distance networks). > > I'm not aware of any tests for high speed links with very low RTTs, but > I suspect that the new algorithms will not change much, if the > connections you have are indeed local than the Ethernet pause mechanism > is more effective for the flow control you need. > > Baruch