ATIS/ANSI 1000643.1998(R2008)

This standard is one of a series that defines and describes supplementary services within the context of an Integrated Services Digital Network (ISDN). This supplementary service may be made available on a demand or subscription arrangement. The interaction of this supplementary service with other ISDN services is also included. The purpose of the standard is to allow maximum compatibility among network- and user-owned telecommunications equipment in order to increase the attractiveness and usefulness of ISDN-based capabilities.