Common Application Service Elements (CASE) are common application service elements (ASE) that provide basic mechanisms for the application layer.
CASE is a standard consisting of many parts, the most important of which is the Application Control Service Element (ACSE), which provides control functions for applications. Other general service elements include Commitment, Concurrency, and Recovery Service Element (CCRSE), Reliable Transfer Service Element (RTSE), and Remote Operation Service Element (ROSE).
CASE covers the requirements and commitment to standard application processes for a given connection and coordinates the concurrent use of these processes. Unlike Application Service Elements (ASE), Common Application Service Elements (CASE) support common application services.