Technical Report TR/52
Computer Supported Telecommunications Applications

(June 1990)

This Technical Report defines an architectural framework suitable as a basis for the development of standards in the area of Computer-Supported Telecommunications Applications (CSTA). This edition of the report introduces a client-server Architectural Model and defines an Operational Model of the Switching Function acting as the server. This model is used as a basis for the definition of Switching Function Services.

The architectural framework focuses on the provision of an application interface between a Switching Function and a Computing Function. This application interface is not associated with a specific user-network interface or network-network interface. CSTA is not intended to incorporate direct support for the user-to-network interface, applications may incorporate support of user-to-network interfaces separately from CSTA but this is not within the scope of CSTA.

This report covers the following subject areas for the Switching Function as server:

• types of CSTA application currently envisioned;
• overall system operational and functional requirements met within the framework;
• a functional architecture as it relates to a Telecommunications Application environment viewed as a whole;
• types of CSTA configurations envisaged;
• an operational architecture defined in terms of the Switching Function objects visible to, and capable of being acted on, by the Computing Functions;
• the individual Switching Function Services needed to support the CSTA applications envisaged;
• examples of some possible state transition scenarios as they relate to the Switching Function server interface to the Computing Function;
• the distribution of CSTA application functionality between the Switching and Computing Functions;
• Application Layer structure;
• the interconnection architectures existing to support the Application layer structure; and
• security and management within a distributed CSTA application domain.

The architecture provisionally described in this report is consolidated in the Standard ECMA-179 which also describes the Services provided by this architecture.