Specifies PINX reference configuration, reference points, use of the PINX reference configuration. The configuration specified is not intended to require any specific implementation of a PINX, but only to provide guidance for the specification of PINX capabilities. It is sufficient to support ISDN-like applications and can be extended to also support non-ISDN-like application. It describes a conceptual PINX. By combining multiple PINXs to a private integrated services network it becomes applicable to a PISN.