$ ruby echo_server.rb &
[1] 28111
$ ruby echo_client.rb 
PID 28134: Failure! too large packet 67654656
PID 28128: Failure! incompatible marshal file format (can't be read)
	format version 4.8 required; 0.0 given

PID 28125: Failure! too large packet 67651874
PID 28144: Succeded.
PID 28147: Succeded.
PID 28192: Succeded.
PID 28176: Succeded.
PID 28167: Succeded.
PID 28186: Succeded.
PID 28152: Succeded.
PID 28150: Succeded.
PID 28131: Succeded.
PID 28170: Succeded.
PID 28137: Succeded.
PID 28173: Succeded.
PID 28164: Succeded.
PID 28179: Succeded.
PID 28182: Succeded.
PID 28139: Succeded.
PID 28158: Succeded.