50. NTB Sample Application
The ntb sample application shows how to use ntb rawdev driver. This sample provides interactive mode to do packet based processing between two systems.
This sample supports 4 types of packet forwarding mode.
file-trans: transmit files between two systems. The sample will be polling to receive files from the peer and save the file as
ntb_recv_file[N], [N] represents the number of received file.
rxonly: NTB receives packets but doesn’t transmit them.
txonly: NTB generates and transmits packets without receiving any.
iofwd: iofwd between NTB device and ethdev.
50.1. Compiling the Application
To compile the sample application see Compiling the Sample Applications.
The application is located in the
50.2. Running the Application
The application requires an available core for each port, plus one. The only available options are the standard ones for the EAL:
./build/ntb_fwd -c 0xf -n 6 -- -i
Refer to the DPDK Getting Started Guide for general information on running applications and the Environment Abstraction Layer (EAL) options.
50.3. Command-line Options
The application supports the following command-line options.
Set the data size of the mbufs used to N bytes, where N < 65536. The default value is 2048.
Set the packet forwarding mode as
Set number of descriptors of queue as N, namely queue size, where 64 <= N <= 1024. The default value is 1024.
Set the transmit free threshold of TX rings to N, where 0 <= N <= the value of
--nb-desc. The default value is 256.
Set the number of packets per burst to N, where 1 <= N <= 32. The default value is 32.
Set the number of queues as N, where qp > 0. The default value is 1.
50.4. Using the application
The application is console-driven using the cmdline DPDK interface:
From this interface the available commands and descriptions of what they do as follows:
send [filepath]: Send file to the peer host. Need to be in file-trans forwarding mode first.
start: Start transmission.
stop: Stop transmission.
show/clear port stats: Show/Clear port stats and throughput.
set fwd file-trans/rxonly/txonly/iofwd: Set packet forwarding mode.
quit: Exit program.