DICOM PS3.4 2021e - Service Class Specifications

6.7 Service Class Specification

A Service Class Specification defines a group of one or more SOP Classes related to a specific function that is to be accomplished by communicating Application Entities. A Service Class Specification also defines rules that allow implementations to state some pre-defined level of conformance to one or more SOP Classes. Applications may conform to network SOP Classes as a Service Class User (SCU), Service Class Provider (SCP), User Agent or Origin Server, and to media exchange SOP Classes as a File Set Creator (FSC), File Set Reader (FSR), or File Set Updater (FSU).

Service Class Specifications are defined in this Part of the DICOM Standard.


Network interaction between peer Application Entities work on a 'client/server model.' The SCU or User Agent acts as the 'client,' while the SCP or Origin Server acts as the 'server'. For DIMSE based services the SCU/SCP roles are determined during Association establishment.

DICOM PS3.4 2021e - Service Class Specifications