SSH EN 301 798 V1.1.1:2000

Services and Protocols for Advanced Networks (SPAN); Anonymous Call Rejection (ACR) Supplementary Service; Service description

Scope

The present document provides the definition, administrative aspects and operation for the Anonymous Call Rejection
Supplementary service. Whilst the service description is generic there may be stage 2 and 3 requirements or other
requirements for specific networks. Where there are identified issues for specific networks these will be indicated either
in the relevant place in the text or in an annex.
The present document specifies a service as instructed by article 8, clause 3 of the EC Telecomms Data Protection
Directive (97/66/EC [1]) - see annex E for the relevant extract from this directive.
The ACR supplementary service applies to Public Telecommunication Networks e.g. PSTN and ISDN.
The purpose of a generic service description is to enable future implementation to work in a similar manner for the view
of the user.
At which point in the network the actual rejection of incoming call will take place is subject to national regulations and
network considerations. The ACR supplementary service could be realized in two ways, either as a network based
solution (of which the activation, deactivation and interrogation procedures are described in the present document) or as
a user based solution using the basic call procedure which implementation is left to user's equipment manufacturer.
1) Network based solution: a service offered as part of a function within the public network for all incoming calls
for which the calling line identification is not available because of restriction according to the CLIR
supplementary service [3] and [5].
2) User based solution: a service offered as part of a function within the end-user equipment for all incoming calls
or to be decided by the end-user per incoming call for which the calling line identification is not available
because of restriction according to the CLIR supplementary service [3] and [5].
NOTE: If the presentation of the calling party number is restricted by network reasons the ACR supplementary
service shall not apply.