(ASE) Software in the presentation layer of the OSI seven layer model which provides an abstracted interface layer to service application protocol data units (APDU). Because applications and networks vary, ASEs are split into common services and specific services.

Examples of services provided by the common application service element (CASE) include remote operations (ROSE) and database concurrency control and recovery (CCR).

The specific application service element (SASE) provides more specialised services.