From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerrit Renker Date: Tue, 05 Dec 2006 20:19:32 +0000 Subject: CCID 3 performance - some further thoughts Message-Id: <200612052019.32837@strip-the-willow> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: dccp@vger.kernel.org I have been experimenting with CCID 3 on various computers, below is a list of observations: * I didn't use netem or anything (no loss), yet the receiver reported loss * I quite frequently got those messages from tfrc_calc_x, like tfrc_calc_x: Value of p (29) below resolution. Substituting 100 This should not happen - I believe that these p measurements are bogus and we should check if the loss rate computation is ok. * the behaviour of iperf is very unpredictable, sometimes it seems that throughput is directly related to current system load * the RTT values are almost always higher than the RTT computed by ICMP ping - highly desirable to find ways of obtaining sharper estimates * would it make sense to define an RTT cut-off value, such as e.g. 2MSL (120 seconds) and regard all RTT estimates above this value as nonsensical? E.g.: #define DCCP_SENSIBLE_RTT_VALUE_MAX 120 * USEC_PER_SEC - Gerrit