Specifying the Time Stamp Method

Time-Stamping and Time Synchronization

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Intel® PAC
Napatech SmartNIC
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User Guide

In this section

This section describes how to specify the time stamp method.

Time stamp method

The TimestampMethod parameter has two values: EOF and SOF. EOF determines that received frames are time-stamped when the last byte is received, and that the last byte of a frame is transmitted according to the time stamp in the descriptor. SOF determines that received frames are time-stamped when the first byte is received, and that the first byte of a frame is transmitted according to the time stamp in the descriptor. For NT200A02 SmartNICs running on a test and measurement image, the setting also determines if the time stamp value, when a time stamp is injected into a transmitted frame, is the time when the first byte of the frame is put on the wire, or the time when the last byte of the frame is put on the wire. SOF is not supported by NT40E3-4-PTP running on the capture/replay image, by NT40A01-4×10/1-SLB nor by the Intel® Programmable Acceleration Card with Intel® Arria® 10 GX FPGA.

Note: Using different settings of TimestampMethod for capturing data and later for transmitting the same data, will result in inaccuracies.

ntservice.ini code line

The syntax for the ntservice.ini code line specifying the time stamp method is:

'TimestampMethod' '=' ( 'SOF' | 'EOF' )

Example:

TimestampMethod=EOF

Default value

This table shows the default value.

Parameter Default Value
TimestampMethod EOF