Subject: NDT-DEV email list created
[ndt-dev] [ndt] r563 committed - Added description of the C2S Throughput Test.
- Subject: [ndt-dev] [ndt] r563 committed - Added description of the C2S Throughput Test.
- Date: Tue, 30 Aug 2011 12:45:57 +0000
Date: Tue Aug 30 05:44:49 2011
Log: Added description of the C2S Throughput Test.
--- /wiki/NDTTestMethodology.wiki Tue Aug 30 04:36:41 2011
+++ /wiki/NDTTestMethodology.wiki Tue Aug 30 05:44:49 2011
@@ -79,12 +79,24 @@
|| "3" || There was no connection to the ephemeral port within the specified time ||
=== C2S Throughput Test ===
- * A block of pseudo random data is generated on the client and stored in memory.
- * The client repeatedly transmits this data to the server for 10 seconds.
- * The server acknowledges receipt of this data and then discards it.
- * The server calculates the average throughput by dividing the number of bytes sent by the test time.
- * The server also makes measurements on a per-packet basis, calculating the capacity of the e2e path.
- * Results from the test are returned to the client at the conclusion of the test.
+The C2S throughput test tests the achievable network bandwidth from the client to the server by performing a 10 seconds memory-to-memory data transfer.
+A detailed description of all of the C2S protocol messages can be found in the [NDTProtocol#C2S_throughput_test NDT Protocol document].
+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.
+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:
+THROUGHPUT_VALUE = 8 * TRANSMITTED_BYTES / 1000 / TEST_DURATION_SECONDS
=== S2C Throughput Test ===
* A block of pseudo random data is generated on the server and stored in memory.
- [ndt-dev] [ndt] r563 committed - Added description of the C2S Throughput Test., ndt, 08/30/2011
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