Explaination of new feature

spawn a thread when iperf server accepts a client connect so the server can handle multiple client requests

Justification of new feature

Install iperf client on mobile devices and measure throughput via the same iperf server.

That's not really what iperf is designed for. Supporting multiple tests at the same time, while not hard, raises the possibility that the tests will interfere with each other at the server. This is particularly true in the high-performance networking environments for which iperf3 was designed. So by design, we explicitly drop connection requests that come in while a test is running.

I recommend we not address this enhancement.

Understood. Thank you for the clarification.

You can always use the iperf3 library and write you own application for this use case if you'd like.

Adding to the #3 you can always run the multiple instance of the server in multiple ports iperf3 -s -p 12345

Marking as WontFix, as this isn't really a part of iperf's design.