Abrupt Release is a term of the communication control layer (Session Layer) of the OSI reference model. Tasks of this layer include connection establishment, execution and connection termination. Normally, the connection is only properly terminated after the data traffic has ended (orderly release or graceful release), i.e. the termination command is disregarded as long as data is still in transit. A sudden connection termination, the so-called Abrupt Release or Abnormal End, usually leads to irretrievable data loss and possibly to severe disruptions of the connections to be established afterwards.