Napatech Support
================

PF_RING has native support for Napatech adapters, the Napatech library
needs to be installed under /opt/napatech3 in order to enable the 
Napatech module at runtime.

Prerequisite
------------

Napatech drivers and SDK installed. Latest Napatech SDK is available for download at https://www.napatech.com/downloads/.

Note: as of PF_RING 6.6 dynamic linking is used and you are able to use
any ntanl driver version.

After installing the Napatech SDK, please make sure the driver is loaded with:

.. code-block:: console

   /opt/napatech3/bin/ntload.sh 
   /opt/napatech3/bin/ntstart.sh 

Installation
------------

In order to get up and running with Napatech when installing from source code,
run the following commands:

.. code-block:: console

   cd PF_RING/kernel && make && sudo insmod pf_ring.ko
   cd ../userland/lib && ./configure && make
   cd ../libpcap && ./configure && make
   cd ../examples && make
   sudo ./pfcount -i nt:0

Please note that installing from repository, all applications are already compiled with Napatech support

Capturing Traffic
-----------------

In order to open a port from the Napatech adapter you should specify nt:<PORT>, example:

.. code-block:: console

   pfcount -i nt:0

In order to open a stream you should specify nt:stream<ID>, example:

.. code-block:: console

   pfcount -i nt:stream0

Streams with port aggregation or distribution (similar to RSS) can be created using the ntpl tool (ntpl -e "<command>")

Note: it is possible to open the same stream from multiple applications at the same time (the slowest consumer will
affect the others!). Instead it is not possible to open a port multiple times (as the port is reassigned to a new 
stream every time you open it). In case of multiple applications, it is possible to set the host buffer allowance (please
refer to the Napatech documentation for this setting) by using the PF_RING_PACKET_CAPTURE_PRIO environment variable (with a 
value between 1 and 100, 80 is usually recommended).

Streams Configuration
---------------------

Command example for ports (2 and 3) aggregation on a single stream (1):

.. code-block:: console

   /opt/napatech3/bin/ntpl -e "Delete = All"
   /opt/napatech3/bin/ntpl -e "Assign[streamid=1] = port == 2,3"

Command example for load balancing of all ports across 16 streams:

.. code-block:: console

   /opt/napatech3/bin/ntpl -e "Delete = All"
   /opt/napatech3/bin/ntpl -e "HashMode = Hash2TupleSorted"
   /opt/napatech3/bin/ntpl -e "Assign[StreamId=(0..15)] = All"

Command example for load balancing port 0 across 4 streams:

.. code-block:: console

   /opt/napatech3/bin/ntpl -e "Delete = All"
   /opt/napatech3/bin/ntpl -e "HashMode = Hash2TupleSorted"
   /opt/napatech3/bin/ntpl -e "Assign[StreamId=(0..3)] = port == 0"

Command example for merging two ports and load balancing them across 24 streams where the first 12 streams are bond on node 0 and the remaining 12 on numa node 1

.. code-block:: console

   /opt/napatech3/bin/ntpl -e "Delete=All"
   /opt/napatech3/bin/ntpl -e "HashMode = Hash5TupleSorted"
   /opt/napatech3/bin/ntpl -e "Setup[NUMANode=0]=Streamid==(0..11)"
   /opt/napatech3/bin/ntpl -e "Setup[NUMANode=1]=Streamid==(12..23)"
   /opt/napatech3/bin/ntpl -e "Assign[streamid=(0..23)]=port==0,1"

Adapter configuration for n2disk
--------------------------------

In order to use the Napatech adapter with n2disk the configuration file /opt/napatech3/config/ntservice.ini should contain:

.. code-block:: text

   TimestampFormat = PCAP_NS
   PacketDescriptor = PCAP
   HostBufferSegmentSizeRx = 4

Napatech and Packet Copy
------------------------

If you use the PF_RING (non-ZC) API packets are read in zero-copy. Instead
if you use PF_RING ZC API, a per-packet copy takes place, which is required to move
payload data from Napatech-memory to ZC memory. Keep this in mind!

Transmission Support
--------------------

In order to use Napatech in transmission you need to make sure you have
configured TX properly. Edit /opt/napatech3/config/ntservice.ini and
make sure you have the following sections configured

.. code-block:: text

   [Adapter0]
   ..
   HostBuffersTx = [4,16,0]
   ..

[Debug]
RntcTxEnable=1

Hardware Filtering
------------------

Napatech NICs support full-blown hardware filtering  out of the box. Thanks
to nBPF we convert BPF expressions to hardware filters. This feature is
supported transparently, and thus all PF_RING/libpcap-over-PF_RING can benefit
from it.

Example: 

.. code-block:: console

   pfcount -i nt:3 -f "tcp and port 80 and src host 192.168.1.1"

As Napatech hardware filters are very advanced, filtering happens all in hardware.