From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hagen Paul Pfeifer Subject: Re: [RFC] netem: correlated loss generation (v3) Date: Thu, 20 May 2010 02:43:30 +0200 Message-ID: <20100520004330.GF5146@nuttenaction> References: <4BD84428.30904@uniroma2.it> <20100517205621.036a06e0@nehalam> <20100519214239.GD5146@nuttenaction> <4BF46B90.1000806@uniroma2.it> <20100519230433.GE5146@nuttenaction> <20100519171733.71c24539@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stefano Salsano , David Miller , Fabio Ludovici , netdev@vger.kernel.org, netem@lists.linuxfoundation.org To: Stephen Hemminger Return-path: Received: from alternativer.internetendpunkt.de ([88.198.24.89]:48263 "EHLO geheimer.internetendpunkt.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752854Ab0ETAnc (ORCPT ); Wed, 19 May 2010 20:43:32 -0400 Content-Disposition: inline In-Reply-To: <20100519171733.71c24539@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: * Stephen Hemminger | 2010-05-19 17:17:33 [-0700]: >The old model was useful, but it really didn't do correlated loss. >For legacy, the old syntax will go through the same code and generate >the same result. Is this really necessary? The right thing is to fix the broken behavior! If the new patch provides this, great. Imaging a network analysis for a PhD dissertation based on a broken correlation algorithm - the whole results are misleading and wrong. No one deserves this ... ;-) If the current algorithm is broken then the mechanism must be fixed. Preserve compatibility is counterproductive in this case. >tc qdisc change dev eth0 root netem > loss 2 10 # compat syntax > loss random 2 10 # same as above > loss deterministic file # loss model based on bitmap > loss state p13 [p31 [p32 [p23 [p14]]]] # 4 state > loss model p [r [1-h [1-k]]] # gilbert elliot model > >Any suggestions for better syntax are appreciated. Not at the moment, looks clear and understandable. Cheers, Hagen -- Hagen Paul Pfeifer || http://jauu.net/ Telephone: +49 174 5455209 || Key Id: 0x98350C22 Key Fingerprint: 490F 557B 6C48 6D7E 5706 2EA2 4A22 8D45 9835 0C22