From mboxrd@z Thu Jan 1 00:00:00 1970 From: jellyaaa Subject: puzzled of the congestion control window of Scalable TCP Date: Thu, 10 Jun 2010 18:15:35 -0700 (PDT) Message-ID: <28850421.post@talk.nabble.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from kuber.nabble.com ([216.139.236.158]:54454 "EHLO kuber.nabble.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760024Ab0FKBPg (ORCPT ); Thu, 10 Jun 2010 21:15:36 -0400 Received: from isper.nabble.com ([192.168.236.156]) by kuber.nabble.com with esmtp (Exim 4.63) (envelope-from ) id 1OMsqN-0000pW-4q for netdev@vger.kernel.org; Thu, 10 Jun 2010 18:15:35 -0700 Sender: netdev-owner@vger.kernel.org List-ID: I am now doing something related to the STCP (Scalable TCP). By pringking the dynamic snd_cwnd in linux (kernel 2.6.18) ,the result puzzled me . Theoryly, if any congestion occurs, the snd_cwnd = snd_cwnd * 0.875,but I haven't got the result I expected. The snd_cwnd changes like this : snd_cwnd = 1 , snd_ssthresh = 2147483647 snd_cwnd = 2 , snd_ssthresh = 2147483647 snd_cwnd = 3, snd_ssthresh = 2147483647 ...... snd_cwnd = 19022, snd_ssthresh = 2147483647 // keeping this value for several ms snd_cwnd = 1769, snd_ssthresh = 16645 // congestion occurs snd_cwnd = 1770, snd_ssthresh = 16645 ...... >>From the above data. when congestion occurs , snd_ssthresh = 16645 ~=~ 19022*0.875=16626 corresponds to the theory calculated result. no problems. but what is the mean of snd_cwnd = 1770? how this value is calculated .who (where )calculated it ? -- View this message in context: http://old.nabble.com/puzzled-of-the-congestion-control-window-of-Scalable-TCP-tp28850421p28850421.html Sent from the netdev mailing list archive at Nabble.com.