ÖNORM EN 300090 V 1.2.1

The present document defines the stage one of the Calling Line Identification Restriction (CLIR) supplementary service for the pan-European Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators. Stage one is an overall service description from the users point of view (see ITU-T Recommendation I.130 [1]), but does not deal with the details of the human interface itself. The present document defines the interworking requirements of private ISDNs with the public ISDN. In addition the present document specifies the base functionality where the service is provided to the user via a private ISDN. The present document does not specify the additional requirements where the service is provided to the user via a telecommunications network that is not an ISDN but does include interworking requirements of other networks with the public ISDN. Interactions with supplementary services not listed in clause 8 are outside the scope of the present document. Charging principles are outside the scope of the present document. The CLIR supplementary service enables the calling party to prevent presentation of its ISDN number to the called party. The CLIR supplementary service is applicable to all telecommunications services. The present document is applicable to the stage two and stage three standards for the ISDN CLIR supplementary service. The terms "stage two" and "stage three" are also defined in ITU-T Recommendation I.130 [1]. Where the text indicates the status of a requirement, (i.e. as strict command or prohibition, as authorizetion leaving freedom, as a capability or possibility), this shall be reflected in the text of the relevant stage two and stage three standards. Furthermore, conformance to the present document is met by conforming to the stage three standards with the field of application appropriate to the equipment being implemented. Therefore no method o (...abbreviated)