This Recommendation International Standard describes the application layer protocol for OSI commitment, concurrency and recovery service element. OSI CCR provides a service by which a set of actions are grouped together to form an 'atomic action', where either the entire set of actions is performed or none is performed. The specification of Version 1 is included for completeness only. It is not anticipated that it will be used by ITU-T applications. This version differs mainly in its mapping through presentation onto the session service and, in particular, requires the use of the Session Data Separation Functional Unit.