#33 Meaning of -P switch, how it should be modified on network devices

[Peter Orecny]

Hi, I'd like to ask you for help to identify restriction on bandwidth in one connection what I measure. If I run iperf3 with parameter -P < 4 (number of clients) between two IPs on selected TCP port, bandwidth is much lower as it is with P > 6 where bandwidth reach requested values. What parameter P really test on connection between two IPs, please? What is possible to modify on netwrok devices to eliminate this behaviour?

Thank you for your answers