Replyfrom202.103.96.68:bytes=32time=50msTTL=241
           Replyfrom202.103.96.68:bytes=32time=50msTTL=241
           Replyfrom202.103.96.68:bytes=32time=50msTTL=241
           Requesttimedout.
           ………………
           Replyfrom202.103.96.68:bytes=32time=50msTTL=241
           Replyfrom202.103.96.68:bytes=32time=50msTTL=241
           Pingstatisticsfor202.103.96.68:
           Packets:Sent=50,Received=48,Lost=2(4%loss),Approximate
           roundtriptimesinmilli-seconds:
           Minimum=40ms,Maximum=51ms,Average=46ms
           从以上我就可以知道在给202.103.96.68发送50个数据包的过程当中，返回了48个，其中有两个由于未知原因丢失，这48个数据包当中返回速度最快为40ms，最慢为51ms，平均速度为46ms。

           -lsizeSendbuffersize.
           定义echo数据包大小。