Napatech Link-Capture™ Software Overview

Received frames are transferred from the SmartNIC to the host memory (host buffers) in the user space using direct memory access (DMA).

How Link-Capture™ Software works

Figure 1. Napatech Link-Capture™ Software overview

Traffic is forwarded from the SmartNIC to the host memory in the user space using DMA.

As shown in the figure, delivered frames using direct memory access (DMA) in the host memory (host buffers) are accessible via data channels (network streams) using NTAPI in the application. You can configure the number of host buffers, the size of host buffers and the NUMA node in the /opt/napatech3/config/ntservice.ini file. Default values are set as follows:

HostBuffersRx = [4,16,-1]                # [x1, x2, x3], ...

Four 16-Mbyte RX host buffers are specified by default. The last value indicates that the NUMA node is taken from the NUMAnode parameter which is set as follows:

NumaNode = -1

This means that the driver attempts to determine the NUMA node location of the SmartNIC.

For more information on configuration parameters in the /opt/napatech3/config/ntservice.ini file, see ntservice ini file in DN-0449.

Note: After changes are made in the ntservice.ini file, ntservice must be stopped and restarted for changes to take effect as follows.

/opt/napatech3/bin/ntstop.sh
/opt/napatech3/bin/ntstart.sh