tx_timestamping Example

Onload User Guide (UG1586)

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1.2 English

This demonstrates the tx_timestamping example application.

From Onload 8.1 onwards this example defaults to using Linux format timestamps for TCP. Use the --stream option to instead use the Onload proprietary format.


Server1 sets the EF_TX_TIMESTAMPING environment variable and starts the tx_timestamping application:

# EF_TX_TIMESTAMPING=3 onload ./tx_timestamping --proto tcp --ioctl eth4
oo:tx_timestamping[16139]: Using OpenOnload 201509 Copyright 2006-2015 Solarflare Communications, 2002-2005 Level 5 Networks [4]
TCP listening on port 9000
 TCP connection accepted
Accepted SIOCHWTSTAMP ioctl.
Selecting hardware timestamping mode.
Packet 1 - 27 bytes
Timestamp for 27 bytes:
First sent timestamp 1453436034.615029223
Last sent timestamp 0.000000000


Server2 uses the Linux netcat utility to send a packet to server1 which is then echoed back to the sender:

# nc <server1 ip> 9000
abcdefghijklmnopqrstuvwxyz  (echoed back from server 1)