NDT-DEV email list created

Revision: 597
Author:   

Date:     Fri Sep  2 07:40:47 2011
Log:      Fixes in the Duplex Mismatch Detection section.
http://code.google.com/p/ndt/source/detail?r=597

Modified:
 /wiki/NDTTestMethodology.wiki

=======================================
--- /wiki/NDTTestMethodology.wiki       Fri Sep  2 07:23:36 2011
+++ /wiki/NDTTestMethodology.wiki       Fri Sep  2 07:40:47 2011
@@ -169,7 +169,9 @@

 The NDT contains two heuristics for the duplex mismatch detection.

-A duplex mismatch is detected by the Old Duplex-Mismatch algorithm when  
all of the following conditions are met:
+A duplex mismatch is detected by the Old Duplex-Mismatch algorithm when  
the connection is congestion limited 90% of the time, the !WiFi is not  
detected, the [NDTTestMethodology#Speed_estimate speed estimate] is greater  
than 2Mibps, there is a lot of packets retransmissions and the S2C  
throughput speed is much smaller than expected.
+
+This means that all of the following conditions should be met:
  * The  
[NDTTestMethodology#'Congestion_Limited'_state_time_share 'Congestion  
Limited' state time share] *is greater than 90%*
  * The [NDTTestMethodology#Speed_estimate speed estimate] *is greater than  
2Mibps*
  * The number of segments transmitted containing at least some  
retransmitted data *is greater than 2 per second*
@@ -181,11 +183,13 @@

 If all of the above conditions are met except the last one, then the NDT  
assumes that a new duplex mismatch detection algorithm discovers the  
problem.

-The new duplex mismatch detection algorithm also discovers the problem  
when all of the following conditions are met:
+The new duplex mismatch detection algorithm also discovers the problem  
when the connection is receiver limited 90% of the time, there is a big  
difference between the S2C throughput speed and the  
[NDTTestMethodology#Web100_measured_speed web100 measured speed] and the  
packets are lost sporadically.
+
+This means that all of the following conditions should be met:
  * The throughput speed measured during the S2C test *is greater than 50  
Mbps*
  * The [NDTTestMethodology#Web100_measured_speed web100 measured speed]  
*is less than 5 Mbps*
  * The [NDTTestMethodology#'Receiver_Limited'_state_time_share 'Receiver  
Limited' state time share] *is greater than 90%*
- * The proportion of the number of multiplicative downward congestion  
window adjustments to the total number of segments sent *is less than 1%*
+ * The [NDTTestMethodology#Packet_loss packet loss] *is less than 1%*

 ==== Known limitations ====