本国际标准规定了补充业务简单对话框（SS-SD），适用于各种基本业务 由专用综合服务网络（PISN）支持的服务。ISO/IEC 11574规定了基本服务。 补充业务SD允许用户通过交换键盘和数据与另一个用户或应用程序通信 在PISN上透明地显示信息。 根据ETS 300 387中描述的方法，服务规范分三个阶段制定。 这个国际 标准包含SS-SD的第1阶段和第2阶段规范。第一阶段规范（第6条）规定了 PISNs用户看到的补充服务。第2阶段规范（第7条）规定了涉及的功能实体 在补充业务中，信息在它们之间流动。

This International Standard specifies the supplementary service Simple Dialog (SS-SD), which is applicable to various basic services supported by Private Integrated Services Networks (PISNs). Basic services are specified in ISO/IEC 11574. Supplementary service SD enables a user to communicate with another user or application by the exchange of keypad and display information transparently over a PISN. Service specifications are produced in three stages, according to the method described in ETS 300 387. This International Standard contains the stage 1 and stage 2 specifications of SS-SD. The stage 1 specification (clause 6) specifies the supplementary service as seen by users of PISNs. The stage 2 specification (clause 7) specifies the functional entities involved in the supplementary service and the information flows between them.