...

[  5]   7.00-8.00   sec  59.6 MBytes   500 Mbits/sec  0.004 ms  0/43172 (0%)

[  5]   8.00-9.00   sec  59.6 MBytes   500 Mbits/sec  0.006 ms  46/43211 (0.11%)

[  5]   9.00-10.00  sec  59.6 MBytes   500 Mbits/sec  0.006 ms  0/43128 (0%)

[  5]  10.00-11.00  sec  59.5 MBytes   499 Mbits/sec  0.005 ms  124/43196 (0.29%)

[  5]  11.00-12.00  sec  59.6 MBytes   500 Mbits/sec  0.004 ms  0/43126 (0%)

...

[  5]  13.00-14.00  sec  59.5 MBytes   499 Mbits/sec  0.004 ms  0/43106 (0%)

[  5]  14.00-15.00  sec  59.7 MBytes   500 Mbits/sec  0.005 ms  32/43237 (0.074%)

[  5]  15.00-16.00  sec  59.5 MBytes   499 Mbits/sec  0.005 ms  0/43095 (0%)

...

[  5]  31.00-32.00  sec  59.6 MBytes   500 Mbits/sec  0.005 ms  0/43172 (0%)

[  5]  32.00-33.00  sec  59.6 MBytes   500 Mbits/sec  0.004 ms  19/43178 (0.044%)

[  5]  33.00-34.00  sec  59.6 MBytes   500 Mbits/sec  0.005 ms  0/43166 (0%)

[  5]  34.00-35.00  sec  59.6 MBytes   500 Mbits/sec  0.004 ms  7/43155 (0.016%)

[  5]  35.00-36.00  sec  59.6 MBytes   500 Mbits/sec  0.004 ms  0/43171 (0%)

...

[  5]  49.00-50.00  sec  59.6 MBytes   500 Mbits/sec  0.005 ms  0/43153 (0%)

[  5]  50.00-51.00  sec  59.5 MBytes   499 Mbits/sec  0.005 ms  45/43150 (0.1%)

[  5]  51.00-52.00  sec  59.7 MBytes   501 Mbits/sec  0.005 ms  0/43210 (0%)

...

[  5]   0.00-60.04  sec  0.00 Bytes  0.00 bits/sec  0.004 ms  273/2586968 (0.011%)

This particular test exhibited 6 seconds (Trials) with loss during a 60 second Test, or one loss event every 10 seconds on average. However, many of the Trials with loss occur in a pattern of Loss, no-Loss, Loss over three consecutive Trials.  Loss-free intervals were 9, 15, 17, 3, and 8 seconds in length.  This testing was conducted at about 70% of the RFC2544 Throughput level.

Related papers:

https://www.net.in.tum.de/fileadmin/bibtex/publications/papers/SPECTS15NAPIoptimization.pdf

...