The present document defines the stage one of the Outgoing Call Barring-Fixed (OCB-F) supplementary service for the
pan-European Integrated Services Digital Network (ISDN) as provided by European telecommunication operators.
Stage one is an overall service description from the user s point of view (see CCITT 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
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 7 and other 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 OCB-F supplementary service enables calls belonging to certain types to be rejected when they are originated by the served user. The served user s ability to receive incoming calls is unaffected by the OCB-F supplementary service.
The OCB-F supplementary service operates according to the requirements specified by the user on provision and it
cannot be activated or deactivated under the control of the user.
NOTE: Barring of certain types of calls by the network provider due to national legislation s, regulations or for
any other reason, are out of the scope of this service.
The OCB-F supplementary service is applicable to all circuit-switched telecommunication services.
The present document is applicable to the stage two and stage three standards for the ISDN OCB-F supplementary service. The terms stage two and stage three a (...abbreviated)