Sender               Receiver
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-------FCN=0-------->|
          |-----FCN=1 + RCS --->| Integrity check: success
        (End)