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To: Ajinkya D Kadam <ajinkya.kadam@nyu.edu>, users@dpdk.org
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From: Paul Emmerich <emmericp@net.in.tum.de>
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Date: Mon, 17 Oct 2016 00:55:51 +0200
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Subject: Re: [dpdk-users] TimeStamping Packets Generated and Received via
 Pktgen Application
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Hi,


Ajinkya D Kadam:
> If yes I would like to modify the pktgen code so that each transmitting and
> received packet is timestamped.  Right now I am exploring the example
> applications  like rxtx_callbacks which timestamps packets in DPDK, Is this
> the right direction to go ?

Check out my packet generator MoonGen
https://github.com/emmericp/MoonGen

It uses the hardware timestamping features (PTP) to do latency 
measurements in the nanosecond-range.

However, if you will run into hardware limitations if you want to 
timestamp *all* packets. This is sometimes supported on RX (e.g., i310, 
X550) but I don't know a NIC that supports this on TX.

As for the precision that is achievable: ~10ns (depending on the NIC) 
with hardware support. Software timestamping will typically result in a 
standard deviation of 200-300ns under load and there will be huge outliers.


  Paul