The Napatech Driver

Network Interface Modules

Platform
Napatech SmartNIC
Content Type
User Guide

Initialization

The Napatech driver reads the static and dynamic data of connected NIMs during start-up and of new NIMs when they are hot-plugged. A NIM is not fully functioning during such initialization periods.

NIMs with DDM interface

For NIMs with digital diagnostics monitoring (DDM) interface the Napatech driver software reads the monitoring data on a regularly basis. The NIM temperature is read and compared with the low and high alarm limits and an alarm is issued if the limits are transgressed. The warning limits are not used.

Combined 25 Gbit/s and 10 Gbit/s support

NT200A02, NT200A01 and NT50B01 SmartNICs running on 2 × 25/10 Gbit/s images and NT100A01 running on 4 × 25/10 Gbit/s images support both SFP28 and SFP+ modules (on NT200A02 and NT200A01 by using a pluggable module adapter (PMA) enabling SFP28 and SFP+ modules to be plugged into a QSFP28 port (see DN-0515)), and thereby both 25 Gbit/s and 10 Gbit/s traffic. 25 Gbit/s or 10 Gbit/s speed is selected automatically based on the SFP28/SFP+ modules in question. Any combination of SFP28 and SFP+ modules on a single SmartNIC can be used, allowing simultaneous monitoring of 25 Gbit/s and 10 Gbit/s links.

Such SmartNICs also support dual-rate SFP28 modules. For dual-rate SFP28 modules the PortSpeedMultiRate parameter in the ntservice.ini file (see DN-0449) determines if the initial speed is 25 Gbit/s or 10 Gbit/s. The default speed is 25 Gbit/s. The speed can be changed later using NTAPI or using the --speed parameter in the config tool (see DN-0449).

Example on NT200A02:

PortSpeedMultiRate = 25G, 10G

sets the port speed on port 0 to 25 Gbit/s and the port speed on port 1 to 10 Gbit/s.

Combined 10 Gbit/s and 1 Gbit/s support

NT200A02 and NT20E3-2-PTP SmartNICs running on 2 × 10/1 Gbit/s images and NT100A01, NT40A01 and NT40E3-4-PTP SmartNICs running on 4 × 10/1 Gbit/s images support both SFP+ and SFP modules (on NT200A02 by using a pluggable module adapter (PMA) enabling SFP28 and SFP+ modules to be plugged into a QSFP28 port (see DN-0515)), and thereby both 10 Gbit/s and 1 Gbit/s traffic. 10 Gbit/s or 1 Gbit/s speed is selected automatically based on the SFP+/SFP modules in question. Any combination of SFP+ and SFP modules on a single SmartNIC can be used, allowing simultaneous monitoring of 10 Gbit/s and 1 Gbit/s links.

Such SmartNICs also support dual-rate SFP+ modules. For dual-rate SFP+ modules the PortSpeedMultiRate parameter in the ntservice.ini file (see DN-0449) determines if the initial speed is 10 Gbit/s or 1 Gbit/s. The default speed is 10 Gbit/s. The speed can be changed later using NTAPI or using the --speed parameter in the config tool (see DN-0449).

Example for NT40E3-4-PTP:

PortSpeedMultiRate = 1G, 10G, 1G, 1G

sets the port speed on ports 0, 2 and 3 to 1 Gbit/s and the port speed on port 1 to 10 Gbit/s.

Forward error correction (FEC)

On NIM modules used for 25GBASE-SR, 25GBASE-LR, 25GBASE-ER, 100BASE-SR4 and 100BASE-CR4 links, forward error correction (FEC) is enabled by default. This is also the case for 25GBASE-CR links applying CA-25G-S or CA-25G-L cables. It is possible to disable FEC by setting the DisableFec parameter in the ntservice.ini file to true. The default value for this parameter is false. For 25GBASE-CR links applying CA-25G-N cables and for 100BASE-LR4 links, the parameter has no impact, and FEC is always disabled.

Elevated power levels

Some NIMs, for instance SFP+ modules or especially CFP4 modules, require an elevated power level to work properly, and if this can be met, the power level is raised. For some NIMs it can take up to 90 seconds before they are ready after the power level has been raised. No link can be expected during this period.