We are currently performing tests over a wireless network and are having some issues trying to get the correct configuration of iperf3.
Our server side command line is as follows iperf3 -s -p 5101
Our client side is iperf3 -u -t 120 -b 150M -p 5101 -i 0.1
My expectation is that the client would attempt to send 150M across the wireless link; however, the link is only 100M and therefore the server would only receive 100M and the remainder of the packets would be dropped. However, what we see is that the sender reduces its bitrate down to the link availability with the sent bitrate fluctuating depending on the link quality.
Our questions 1) is this expected behaviour? 2) how do we prevent this behaviour? 3) is there something else going on outside of iPerf that could cause this?
Client side version is Ubuntu 16.04 compiled iPerf 3.7+ server side is Ubuntu 18.04 package manager version 3.1.3.