NDT-DEV email list created

Revision: 590
Author:   

Date:     Fri Sep  2 04:43:43 2011
Log:      Feedback based modifications in the C2S and S2C throughput tests  
sections.
http://code.google.com/p/ndt/source/detail?r=590

Modified:
 /wiki/NDTTestMethodology.wiki

=======================================
--- /wiki/NDTTestMethodology.wiki       Fri Sep  2 03:01:06 2011
+++ /wiki/NDTTestMethodology.wiki       Fri Sep  2 04:43:43 2011
@@ -89,15 +89,15 @@
 As a first step the server binds an ephemeral port and notify the client  
about this port number.

 Next, the client connects to the server's ephemeral port. When the  
connection is successfully established, the server initializes the  
following routines:
- * libpcap routines to perform packet trace used by the Bottleneck Link  
Detection algorithm.
- * [NDTDataFormat#tcpdump_trace tcpdump trace] to dump all packets sent  
during the C2S throughput test on the newly created connection. This  
tcpdump trace dump is only started when the `-t, --tcpdump` options are set.
- * [NDTDataFormat#web100_snaplog_trace web100 snaplog trace] to dump  
web100 kernel MIB variables' values written in a fixed time (default is 5  
msec) increments during the C2S throughput test for the newly created  
connection. This snaplog trace dump is only started when the `--snaplog`  
option is set.
+ * libpcap routines to perform packet trace used by the  
[NDTTestMethodology#Bottleneck_Link_Detection Bottleneck Link Detection]  
algorithm.
+ * [NDTDataFormat#tcpdump_trace tcpdump trace] to dump all packets sent  
during the [NDTTestMethodology#C2S_Throughput_Test C2S throughput test] on  
the newly created connection. This tcpdump trace dump is only started when  
the `-t, --tcpdump` options are set.
+ * [NDTDataFormat#web100_snaplog_trace web100 snaplog trace] to dump  
web100 kernel MIB variables' values written in a fixed time (default is 5  
msec) increments during the [NDTTestMethodology#C2S_Throughput_Test C2S  
throughput test] for the newly created connection. This snaplog trace dump  
is only started when the `--snaplog` option is set.

 In the next step the client starts a 10 seconds throughput test using the  
newly created connection. The NDT client sends packets as fast as possible  
(i.e. without any delays) during the test. These packets are written using  
the 8192 Byte buffer containing a pre-generated pseudo random data  
(including only US-ASCII printable characters).

-When the 10 seconds throughput test is over, the server sends its  
calculated throughput value to the client. This throughput value is  
calculated using the following formula:
+When the 10 seconds throughput test is over, the server sends its  
calculated throughput value to the client. The throughput value is  
calculated by taking the transmitted bytes over the duration of the test.  
This value, in Bps, is then converted to kbps. This can be shown by the  
following formula:
 {{{
-THROUGHPUT_VALUE = 8 * TRANSMITTED_BYTES / 1000 / TEST_DURATION_SECONDS
+THROUGHPUT_VALUE = (TRANSMITTED_BYTES / TEST_DURATION_SECONDS) * 8 / 1000
 }}}

 === S2C Throughput Test ===
@@ -109,15 +109,15 @@
 As a first step the server binds an ephemeral port and notify the client  
about this port number.

 Next, the client connects to the server's ephemeral port. When the  
connection is successfully established, the server initializes the  
following routines:
- * libpcap routines to perform packet trace used by the Bottleneck Link  
Detection algorithm.
- * [NDTDataFormat#tcpdump_trace tcpdump trace] to dump all packets sent  
during the S2C throughput test on the newly created connection. This  
tcpdump trace dump is only started when the `-t, --tcpdump` options are set.
- * [NDTDataFormat#web100_snaplog_trace web100 snaplog trace] to dump  
web100 kernel MIB variables' values written in a fixed time (default is 5  
msec) increments during the S2C throughput test for the newly created  
connection. This snaplog trace dump is only started when the `--snaplog`  
option is set.
+ * libpcap routines to perform packet trace used by the  
[NDTTestMethodology#Bottleneck_Link_Detection Bottleneck Link Detection]  
algorithm.
+ * [NDTDataFormat#tcpdump_trace tcpdump trace] to dump all packets sent  
during the [NDTTestMethodology#S2C_Throughput_Test S2C throughput test] on  
the newly created connection. This tcpdump trace dump is only started when  
the `-t, --tcpdump` options are set.
+ * [NDTDataFormat#web100_snaplog_trace web100 snaplog trace] to dump  
web100 kernel MIB variables' values written in a fixed time (default is 5  
msec) increments during the [NDTTestMethodology#S2C_Throughput_Test S2C  
throughput test] for the newly created connection. This snaplog trace dump  
is only started when the `--snaplog` option is set.

 In the next step the server starts a 10 seconds throughput test using the  
newly created connection. The NDT server sends packets as fast as possible  
(i.e. without any delays) during the test. These packets are written using  
the 8192 Byte buffer containing a pre-generated pseudo random data  
(including only US-ASCII printable characters).

-When the 10 seconds throughput test is over, the server sends to the  
client its calculated throughput value, amount of unsent data in the socket  
send queue and overall number of sent bytes. The throughput value is  
calculated using the following formula:
+When the 10 seconds throughput test is over, the server sends to the  
client its calculated throughput value, amount of unsent data in the socket  
send queue and overall number of sent bytes. The throughput value is  
calculated by taking the transmitted bytes over the duration of the test.  
This value, in Bps, is then converted to kbps. This can be shown by the  
following formula:
 {{{
-THROUGHPUT_VALUE = 8 * TRANSMITTED_BYTES / 1000 / TEST_DURATION_SECONDS
+THROUGHPUT_VALUE = (TRANSMITTED_BYTES / TEST_DURATION_SECONDS) * 8 / 1000
 }}}

 Additionally, at the end of the S2C throughput test, the server also takes  
a web100 snapshot and sends all the web100 data variables to the client.