?????????
????nttcp ?μ?tcp??????????????Linux????
???????????
????nttcp [ local options ] partner-host [ partner-host ] ... [ remote options ]
??????????
????nttcp????????TCP??UDP???UDP???????????????á?nttcp??????????????????????????????????????????????????????????nttcp -i????????????????partner-host????????????IP??????????????????????????д????????????￡??????????????????2048??buffer????????????С?4KB?????8M?????????????????????????????????????????????????????????е????????????????????????????????
???????????
????-r
???????崫?????????????????????????????????????????????????
????-t
???????崫??????????????????????????????????????????????????????????
????-T
??????????????
????-u
???????UDPЭ?????TCPЭ?饗????TCPЭ?飩??
????-g
????????????????????????????????????????select??gettimeofday?????????????????????????????????????????????????????????????У???????????????????????TCP?????????????????????????????write?????????????????????豸???????????????
????-v
???????????????????????????????????????
????-D
???????????????TCP_NODELAY????????????????κ?wirte???????????
????-f format string
????????????????????????OUTPUT??
????-n number of buffer
??????η????buffer??????????2048????
????-l length of a buffer
????????buffer???С??????????????????С????????4096KB??
????-x fixed length of data
????????????????????????????????????-n????-l ??????????????????????????????????buffers*length = fixed data length??
????-w
??????????????????buffer size?????????????????????????16KB??
????-c
??????????????????????????????????????????????????100??????????????????
????-s
??????????UDP?????????????????stream pattern.
????-S seed string
?????????????????????????-S??????????-c??
????-p port number
???????????????????????5037??
????-i
???????????????????????
????-R number of getpid() calls
?????????????????κε????????????????getpid()???????????????????????????????????????????
????-m
????????IP????????????-t??-u??????
?????????
??????????????????????????????????????н??????????н?????????????????????????н????????????????????????е?????????“l”(local)????????е?????????“r”(remote);????????“-T”???????????б????С????????????????????

????????CPU?????CPU s???????(CPU-C/s)???????????????????????Real???????????????儷?????????????????п??????????????????????????
????n prints the buffer count. Integer value.
????c prints the number of calls. Integer value.
????rt prints the real time in s. Float value.
????rbr prints the real bit rate in MBit/s. Float value.
????rcr prints the real call rate in calls/s. Float value.
????ct prints the cpu time in s. Float value.
????cbr prints the cpu bit rate in MBit/s. Float value.
????ccr prints the cpu call rate in calls/s. Float value.
????The default format is produced with the following format string:
????"%9b%8.2rt%8.2ct%12.4rbr%12.4cbr%8c%10.2rcr%10.2ccr"