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zperf: Network Traffic Generator


zperf is a shell utility which allows to generate network traffic in Zephyr. The tool may be used to evaluate network bandwidth.

zperf is compatible with iPerf_2.0.5. Note that in newer iPerf versions, an error message like this is printed and the server reported statistics are missing.


zperf can be enabled in any application, a dedicated sample is also present in Zephyr. See zperf sample application for details.

Sample Usage

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.