how does iperf3 calculate bitrate? Is retransmission data included?

[liujian-930212]

Let's say iperf3 server send 100G bits to client during 60s, and 20G bits are retransmission data, 80G bits are effective data. So the bitrate will be 100Gb/60s or 80Gb/60s

Thanks

[davidBar-On]

It will be 80Gb/60s. iperf3 take into account only the data it sends, i.e. 80G in this example. Retransmissions are done by the TCP stack and are not visible to iperf3.

[bmah888]

Also note that iperf3 only counts payload bytes...overheads such as Ethernet/IP/TCP headers are not included.