root@GL-MV1000:~# iperf3 -c 45.14.107.x -u -b 20MB --get-server-output --bidir Connecting to host 45.14.107.x, port 5201 [ 5] local 100.64.189.159 port 47629 connected to 45.14.107.x port 5201 [ 7] local 100.64.189.159 port 57883 connected to 45.14.107.x port 5201 [ ID][Role] Interval Transfer Bitrate Jitter Lost/Total Datagrams [ 5][TX-C] 0.00-1.00 sec 2.38 MBytes 20.0 Mbits/sec 1735 [ 7][RX-C] 0.00-1.00 sec 2.26 MBytes 19.0 Mbits/sec 0.085 ms 96/1745 (5.5%) [ 5][TX-C] 1.00-2.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 7][RX-C] 1.00-2.00 sec 2.26 MBytes 19.0 Mbits/sec 0.112 ms 85/1733 (4.9%) [ 5][TX-C] 2.00-3.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 7][RX-C] 2.00-3.00 sec 2.21 MBytes 18.5 Mbits/sec 0.087 ms 114/1724 (6.6%) [ 5][TX-C] 3.00-4.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 7][RX-C] 3.00-4.00 sec 2.37 MBytes 19.9 Mbits/sec 0.050 ms 32/1759 (1.8%) [ 5][TX-C] 4.00-5.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 7][RX-C] 4.00-5.00 sec 2.25 MBytes 18.8 Mbits/sec 0.077 ms 99/1734 (5.7%) [ 5][TX-C] 5.00-6.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 7][RX-C] 5.00-6.00 sec 2.28 MBytes 19.1 Mbits/sec 0.129 ms 53/1714 (3.1%) [ 5][TX-C] 6.00-7.00 sec 2.39 MBytes 20.0 Mbits/sec 1737 [ 7][RX-C] 6.00-7.00 sec 2.32 MBytes 19.4 Mbits/sec 0.181 ms 64/1751 (3.7%) [ 5][TX-C] 7.00-8.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 7][RX-C] 7.00-8.00 sec 2.29 MBytes 19.2 Mbits/sec 0.108 ms 73/1742 (4.2%) [ 5][TX-C] 8.00-9.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 7][RX-C] 8.00-9.00 sec 2.25 MBytes 18.8 Mbits/sec 0.081 ms 100/1736 (5.8%) [ 5][TX-C] 9.00-10.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 7][RX-C] 9.00-10.00 sec 2.17 MBytes 18.2 Mbits/sec 0.098 ms 149/1729 (8.6%) - - - - - - - - - - - - - - - - - - - - - - - - - [ ID][Role] Interval Transfer Bitrate Jitter Lost/Total Datagrams [ 5][TX-C] 0.00-10.00 sec 23.8 MBytes 20.0 Mbits/sec 0.000 ms 0/17360 (0%) sender [ 5][TX-C] 0.00-10.07 sec 23.8 MBytes 19.9 Mbits/sec 0.195 ms 1/17360 (0.0058%) receiver Server output: ----------------------------------------------------------- Server listening on 5201 ----------------------------------------------------------- Accepted connection from 113.89.1.x, port 9728 [ 5] local 45.14.107.x port 5201 connected to 113.89.1.x port 9729 [ 6] local 45.14.107.x port 5201 connected to 113.89.1.x port 9730 [ ID][Role] Interval Transfer Bitrate Jitter Lost/Total Datagrams [ 5][RX-S] 0.00-1.00 sec 2.21 MBytes 18.5 Mbits/sec 0.090 ms 0/1608 (0%) [ 6][TX-S] 0.00-1.00 sec 2.38 MBytes 20.0 Mbits/sec 1735 [ 5][RX-S] 1.00-2.00 sec 2.38 MBytes 20.0 Mbits/sec 0.159 ms 0/1735 (0%) [ 6][TX-S] 1.00-2.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 5][RX-S] 2.00-3.00 sec 2.38 MBytes 20.0 Mbits/sec 0.123 ms 0/1736 (0%) [ 6][TX-S] 2.00-3.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 5][RX-S] 3.00-4.00 sec 2.39 MBytes 20.0 Mbits/sec 0.161 ms 0/1738 (0%) [ 6][TX-S] 3.00-4.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 5][RX-S] 4.00-5.00 sec 2.38 MBytes 20.0 Mbits/sec 0.058 ms 1/1736 (0.058%) [ 6][TX-S] 4.00-5.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 5][RX-S] 5.00-6.00 sec 2.38 MBytes 20.0 Mbits/sec 0.232 ms 0/1736 (0%) [ 6][TX-S] 5.00-6.00 sec 2.39 MBytes 20.0 Mbits/sec 1737 [ 5][RX-S] 6.00-7.00 sec 2.38 MBytes 20.0 Mbits/sec 0.066 ms 0/1736 (0%) [ 6][TX-S] 6.00-7.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 5][RX-S] 7.00-8.00 sec 2.38 MBytes 20.0 Mbits/sec 0.060 ms 0/1736 (0%) [ 6][TX-S] 7.00-8.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 5][RX-S] 8.00-9.00 sec 2.38 MBytes 20.0 Mbits/sec 0.080 ms 0/1735 (0%) [ 6][TX-S] 8.00-9.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 5][RX-S] 9.00-10.00 sec 2.39 MBytes 20.0 Mbits/sec 0.090 ms 0/1737 (0%) [ 6][TX-S] 9.00-10.00 sec 2.38 MBytes 20.0 Mbits/sec 1736 [ 5][RX-S] 10.00-10.07 sec 179 KBytes 19.8 Mbits/sec 0.195 ms 0/127 (0%) [ 6][TX-S] 10.00-10.07 sec 180 KBytes 20.0 Mbits/sec 128 - - - - - - - - - - - - - - - - - - - - - - - - - [ ID][Role] Interval Transfer Bitrate Jitter Lost/Total Datagrams [SUM][RX-S] 0.0-10.1 sec 4 datagrams received out-of-order [ 5][RX-S] 0.00-10.07 sec 23.8 MBytes 19.9 Mbits/sec 0.195 ms 1/17360 (0.0058%) receiver [ 6][TX-S] 0.00-10.07 sec 24.0 MBytes 20.0 Mbits/sec 0.000 ms 0/17488 (0%) sender [ 7][RX-C] 0.00-10.00 sec 24.0 MBytes 20.1 Mbits/sec 0.000 ms 0/17488 (0%) sender [SUM][RX-C] 0.0-10.0 sec 225 datagrams received out-of-order [ 7][RX-C] 0.00-10.07 sec 22.7 MBytes 18.9 Mbits/sec 0.098 ms 865/17367 (5%) receiver iperf Done. command explain: UDP 客户端与服务端同时双向发送包，速率为 20M比特/s 观察丢包情况 丢包信息为接收侧统计，客户端可结束后向服务端获取结果 result explain: 该 VPS 回国存在 5% 丢包，但国内去程没有丢包 so what?: 可用于非对称网络加速，比如 kcp 中可更针对性的调参，也可定制非对称的 fec