High Level Synchronization Services of OSI (Open Systems Interconnection): Commitment, Concurrency and Recovery

摘要

The Commitment, Concurrency and Recovery (CCR) application-oriented protocol for Open Systems Interconnection is discussed. It offers service elements in support of successful coordination and completion of distributed application activities in the presence of network failures and system crashes. The user requirements for such a protocol are outlined. It is concluded that these requirements are met by the OSI CCR service. An ad hoc protocol that provides the CCR service and uses the Session service is formally specified by application of the formal description technique LOTOS. Based on this exercise, conclusions with respect to the current definition of the OSI CCR protocol are drawn.