scope:

This European Telecommunication Standard (ETS) specifies procedures to support supplementary services for Broadband Integrated Services Digital Network (B-ISDN) Capability Set 1 (CS1) applications defined for the pan-European B-ISDN as provided by the European public telecommunications operators by means of the Signalling System No.7 protocol for the B-ISDN User Part (B-ISUP). Additional protocol requirements, which have to be specified in the case where services are provided to the user via a telecommunication network that is not a B-ISDN, are not part of this ETS.