iperf 是一個網路效能測試工具。Iperf可以測試最大TCP和UDP頻寬效能，具有多種引數和UDP特性，可以根據需要調整，可以報告頻寬、延遲抖動和資料包丟失。在嵌入式開發的過程中經常需要用到這個工具，下面我們演示一下如何利用這個工具來測兩臺機器之間的資料傳輸速度：
分別在兩臺待測機器中安裝iperf，我使用的是ubuntu

sudo apt-get install iperf3

然後其中一臺作為客戶端，一臺作為伺服器，通過客戶端連線伺服器來實現測速：

伺服器端

iperf3 -s

客戶端

iperf3 -c xxxxxx(這裡是伺服器端ip) -b 100M -t 20
 

結果

[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  46.7 KBytes   382 Kbits/sec                  
[  4]   1.00-2.00   sec  29.7 KBytes   243 Kbits/sec                  
[  4]   2.00-3.00   sec  28.3 KBytes   232 Kbits/sec                  
[  4]   3.00-4.00   sec  29.7 KBytes   243 Kbits/sec
 
                  
[  4]   4.00-5.00   sec  29.7 KBytes   243 Kbits/sec                  
[  4]   5.00-6.00   sec  28.3 KBytes   232 Kbits/sec                  
[  4]   6.00-7.00   sec  29.7 KBytes   243 Kbits/sec                  
[  4]   7.00-8.00   sec  28.3 KBytes   232 Kbits/sec                  
[  4]   8.00-9.00   sec
 
  29.7 KBytes   243 Kbits/sec                  
[  4]   9.00-10.00  sec  28.3 KBytes   232 Kbits/sec                  
[  4]  10.00-11.00  sec  29.7 KBytes   243 Kbits/sec                  
[  4]  11.00-12.00  sec  28.3 KBytes   232 Kbits/sec                  
[  4]  12.00-13.00  sec  29.7 KBytes   243 Kbits/sec                  
[  4]  13.00-14.00  sec  28.3 KBytes   232 Kbits/sec                  
[  4]  14.00-15.00  sec  28.3 KBytes   232 Kbits/sec                  
[  4]  15.00-16.00  sec  29.7 KBytes   243 Kbits/sec                  
[  4]  16.00-17.00  sec  29.7 KBytes   243 Kbits/sec                  
[  4]  17.00-18.00  sec  28.3 KBytes   232 Kbits/sec                  
[  4]  18.00-19.00  sec  25.5 KBytes   208 Kbits/sec                  
[  4]  19.00-20.00  sec  26.9 KBytes   220 Kbits/sec                  
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-20.00  sec  1.64 MBytes   689 Kbits/sec    0             sender
[  4]   0.00-20.00  sec   976 KBytes   400 Kbits/sec                  receiver