Network Speed Test

Use ttcp to test network speed (01/24/14)

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ttcp is installed in /home/jingchen/bin/ttcp

- Test network speed between lcls-opi09 and lcls-opi10 (on a 100Mbps link)

on lcls-opi10 (receive side)

ttcp -f M -r -s -n 204800  

on lcls-opi09 (send side)  

ttcp -f M -t -s  -n 204800 172.27.8.81

204800 is number of buffers sent; buffer length is 8192 Bytes: i.e., total of 1677721600 bytes (1677MB) sent to 172.27.8.81 (lcls-opi10)

Result:

ttcp-t: 1677721600 bytes in 142.34 real seconds = 11.24 MB/sec +++ The speed of the nework between lcls-opi09 and lcls-opi10 is  11.24 MB/sec

(or 11.24 x 8 = 89 Mbps)                                                 

- Test network speed  between lcls-builder and lcls-srv05 (on a 1Gbps link)

[jingchen@lcls-srv05 ~]$ ttcp -f M -r -s -n 204800                         

[jingchen@lcls-builder ~]$ ttcp -f M -t -s  -n 204800 172.27.8.29          

Result:

ttcp-t: 1677721600 bytes in 14.38 real seconds = 111.25 MB/sec +++

(or 111.25 x 8 = 890 Mbps)                                       

The results make sense, as lower than the link speed.