Sender                     Receiver
  |-------FCN=6,Seq=1-------->|
  |-------FCN=5,Seq=2----X    |
  |-------FCN=4,Seq=3-------->|
  |-------FCN=3,Seq=4-------->|
  |-------FCN=2,Seq=5-------->|
  |-------FCN=1,Seq=6-------->|
  |-------FCN=15,Seq=7------->| Missing Fragment Unable to reassemble
(End)