=echo.c=
machine: self.read -> self.write. 2 hrs, no "da da sheng"

=aread/aplay=
machine1 -> machine2: m1.read -> m2.write. sr: 16000, S16_LE, 1 ch.

=pc test=
pc 1 -> linux notebook 2, plus vm development server. 2hr, no da da sheng.

=two terminal=
server: 10.0.1.45 <br/>
two terminals, talk has "da da sheng"