标准摘要
[中文适用范围]： 本国际标准规定了在专用综合业务网络（PISN）内连接在一起的专用综合业务网络交换机（PINX）之间的 Q 参考点支持简单对话补充业务（SS-SD）的信令协议。 补充服务 SD 使用户能够通过交换键盘与另一个用户或应用程序进行通信，并通过 PISN 透明地显示信息。 Q 参考点在 ISO/IEC 11579-1 中定义。 服务规范按照 ETS 300 387 中指定的方法分三个阶段制定。 本国际标准包含 Q 参考点的第 3 阶段规范，并满足 ISO/IEC 21407 中第 1 阶段和第 2 阶段规范确定的要求。 SS-SD 的信令协议在用于基本电路交换呼叫控制的信令协议之上运行（如 ISO/IEC 11572 中所规定），并使用通用过程的某些方面来控制 ISO/IEC 11582 中规定的补充服务。 该国际标准还规定了额外的信令协议要求，以支持 SS-SD 和其他补充服务和 ANF 之间 Q 参考点的交互。 本国际标准适用于可以互连形成 PISN 的 PINX。 [外文原描述]： ISO/IEC 21408:2003 specifies the signalling protocol for the support of the Simple Dialog supplementary service (SS-SD) at the Q reference point between Private Integrated services Network eXchanges (PINXs) connected together within a Private Integrated Services Network (PISN). 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. The Q reference point is defined in ISO/IEC 11579-1. Service specifications are produced in three stages and according to the method specified in ETS 300 387. ISO/IEC 21408:2003 contains the stage 3 specification for the Q reference point and satisfies the requirements identified by the stage 1 and stage 2 specifications in ISO/IEC 21407. The signalling protocol for SS-SD operates on top of the signalling protocol for basic circuit switched call control, as specified in ISO/IEC 11572, and uses certain aspects of the generic procedures for the control of supplementary services specified in ISO/IEC 11582. ISO/IEC 21408:2003 also specifies additional signalling protocol requirements for the support of interactions at the Q reference point between SS-SD and other supplementary services and ANFs. ISO/IEC 21408:2003 is applicable to PINXs which can interconnect to form a PISN.
英文名称Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Inter-exchange signalling protocol - Simple dialog supplementary service