Local Retransmission with Embedded Time Stamp

Napatech Link-Capture™ Software Features

Intel® PAC
Napatech SmartNIC
Content Type
Feature Description
Capture Software Version
Link™ Capture Software 12.11

Local retransmission with embedded time stamp appends a high-precision time stamp from the capture port to retransmitted frames.


By delivering a high-precision time stamp to downlink appliances, local retransmission with embedded time stamp minimizes the need for expensive load distribution switch ports.


The retransmitted frames are expanded to include a trailer with a time stamp, and a new FCS is calculated and added. The Unix-based time stamp format has a resolution of 1 ns and represents time as a 64-bit unsigned integer value, starting from January 1, 1970.

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Frames are expanded by 12 bytes, increasing the risk of oversubscription of the TX port and resulting packet loss.

Otherwise, limitations for local retransmission with embedded time stamp are similar to the limitations for local retransmission without embedded time stamp (see Local Retransmission).

Configuration interface

Local retransmission with time stamp is configured using NTPL.


In this NTPL example, all traffic received on port 0 is retransmitted with embedded time stamp on port 1.

Assign[DestinationPort=1; TxMetaData=TimeStamp] = Port==0