zperf: Network Traffic Generator


zperf is a network traffic generator for Zephyr that may be used to evaluate network bandwidth.


  • Compatible with iPerf_2.0.5.
  • Client or server mode allowed without need to modify the source code.
  • Working with task profiler (PROFILER=1 to be set when building zperf)

Supported Boards

zperf is board-agnostic. However, to run the zperf sample application, the target platform must provide a network interface supported by Zephyr.

This sample application has been tested on the following platforms:

  • Freedom Board (FRDM K64F)
  • Quark SE C1000 Development Board
  • QEMU x86


  • iPerf 2.0.5 installed on the host machine
  • Supported board

Depending on the network technology chosen, extra steps may be required to setup the network environment.


If Zephyr acts as a client, iPerf must be executed in server mode. For example, the following command line must be used for UDP testing:

$ iperf -s -l 1K -u -V -B 2001:db8::2

For TCP testing, the command line would look like this:

$ iperf -s -l 1K -V -B 2001:db8::2

In the Zephyr console, zperf can be executed as follows:

zperf> udp.upload 2001:db8::2 5001 10 1K 1M

For TCP the zperf command would look like this:

zperf> tcp.upload 2001:db8::2 5001 10 1K 1M

If the IP addresses of Zephyr and the host machine are specified in the config file, zperf can be started as follows:

zperf> udp.upload2 v6 10 1K 1M

or like this if you want to test TCP:

zperf> tcp.upload2 v6 10 1K 1M

If Zephyr is acting as a server, set the download mode as follows for UDP:

zperf> udp.download 5001

or like this for TCP:

zperf> tcp.download 5001

and in the host side, iPerf must be executed with the following command line if you are testing UDP:

$ iperf -l 1K -u -V -c 2001:db8::1 -p 5001

and this if you are testing TCP:

$ iperf -l 1K -V -c 2001:db8::1 -p 5001

iPerf output can be limited by using the -b option if Zephyr is not able to receive all the packets in orderly manner.