-2, --dualtest Do a bidirectional test simultaneously\n\
-r, --tradeoff Do a bidirectional test individually\n\
-t, --time # time in seconds to transmit for (default 10 secs)\n\
+ or 0 for continuous\n\
-n, --num #[KM] number of bytes to transmit (instead of -t)\n\
-F, --fileinput <name> input the data to be transmitted from a file\n\
-I, --stdin input the data to be transmitted from stdin\n\