信息技术 系统间通信和信息交换 团体电信网 QSIG 和H.323之间信号互通 呼叫变更补充业务

[中文适用范围]： 该国际标准规定了“QSIG”和“H.323”之间的信令互通，以支持企业电信网络（CN）内的呼叫转移补充服务。 “QSIG”是在专用综合业务网络（PISN）内的专用综合业务交换（PINX）之间的Q参考点处运行的信令协议。 Q 参考点在 ISO/IEC 11579-1 中定义。 PISN 为其用户提供电路交换基本服务和补充服务。 QSIG 在其他标准中进行了规定，特别是 ISO/IEC 11572（支持基本服务的呼叫控制）、ISO/IEC 11582（支持补充服务的通用功能协议）以及指定各个补充服务的许多标准。 ISO/IEC 13873 指定了支持呼叫转移服务的 QSIG 协议。 “H.323”是一组用于支持分组网络内语音或多媒体通信的信令协议，特别是使用网际协议(IP)作为其网络层协议(IP网络)的分组网络。 H.323 信令协议在 IP 网络中的端点之间运行，可以通过一个或多个网守间接运行，也可以直接运行。 端点可以是另一个网络的终端或网关。 H.323 是一个“伞”建议，指的是各种 ITU-T 建议，特别是建议 H.225.0 和 H.245（基本通信能力）以及建议 H.450.1（支持补充业务的通用功能协议）。 建议 H.450.3 规定了支持呼叫转移服务的 H.323 协议。 注 - H.450.3 仅适用于 1998 版 H.323（也称为 H.323 版本 2）和更高版本。 在 ISO/IEC 13873 (QSIG) 和 ITU-Recommendation H.450.3 (H.323) 中，呼叫转移补充业务包括无条件呼叫前转 (SS-CFU)、遇忙呼叫前转 (SS-CFB)、无应答呼叫前转(SS-CFNR) 和呼叫偏转 (SS-CD)。 这些补充服务在呼叫建立期间应用，并将传入呼叫转移到另一个目的地。 QSIG 和 H.323 之间的互操作允许源自 PISN 用户的呼叫终止于 IP 网络用户，或者源自 IP 网络用户的呼叫终止于 PISN 用户。 该国际标准提供了以下附加功能： · 源自 PISN 且目的地为 H.323 网络用户的呼叫将被 H.323 网络转移到另一个目的地； · 源自 H.323 网络、目的地为 PISN 用户的呼叫将被 PISN 转移到另一个目的地； · 发往 PISN 用户的呼叫将被转移到替代目的地，而该替代目的地位于 H.323 网络中； · 发往 H.323 网络用户的呼叫将被转移到备用目的地，而该备用目的地位于 PISN 中。 本国际标准适用于任何可以充当采用 QSIG 的 PISN 和采用 H.323 的 IP 网络之间网关的互通单元。 [外文原描述]： This International Standard specifies signalling interworking between "QSIG" and "H.323" in support of call diversion supplementary services within a Corporate telecommunication Network (CN). "QSIG" is a signalling protocol that operates at the Q reference point between Private Integrated Services eXchanges (PINX) within a Private Integrated Services Network (PISN). The Q reference point is defined in ISO/IEC 11579-1. A PISN provides circuit-switched basic services and supplementary services to its users. QSIG is specified in other Standards, in particular ISO/IEC 11572 (call control in support of basic services), ISO/IEC 11582 (generic functional protocol for the support of supplementary services) and a number of standards specifying individual supplementary services. ISO/IEC 13873 specifies the QSIG protocol in support of call diversion services. "H.323" is a set of signalling protocols for the support of voice or multimedia communication within a packet network, in particular a packet network that uses the Internet Protocol (IP) as its network layer protocol (IP network). H.323 signalling protocols operate between endpoints in an IP network, either indirectly via one or more gatekeepers, or directly. An endpoint can be a terminal or a gateway to another network. H.323 is an "umbrella" recommendation referring to various ITU-T recommendations, in particular Recommendations H.225.0 and H.245 (basic communication capabilities) and Recommendation H.450.1 (generic functional protocol for the support of supplementary services). Recommendation H.450.3 specifies the H.323 protocol in support of call diversion services. NOTE - H.450.3 applies only to the 1998 version of H.323 (also known as H.323 version 2) and to later versions. In both ISO/IEC 13873 (QSIG) and ITU-Recommendation H.450.3 (H.323), the call diversion supplementary services are Call Forwarding Unconditional (SS-CFU), Call Forwarding Busy (SS-CFB), Call Forwarding No Reply (SS-CFNR) and Call Deflection (SS-CD). These supplementary services apply during call establishment and provide diversion of an incoming call to another destination. Interworking between QSIG and H.323 permits a call originating at a user of a PISN to terminate at a user of an IP network, or a call originating at a user of an IP network to terminate at a user of a PISN. This International Standard provides the following additional capabilities: _ a call originating from a PISN and destined for a user of an H.323 network to be diverted by the H.323 network to an alternative destination; _ a call originating from an H.323 network and destined for a user of a PISN to be diverted by the PISN to an alternative destination; _ a call destined for a user of a PISN to be diverted to an alternative destination where that alternative destination is in an H.323 network; _ a call destined for a user of an H.323 network to be diverted to an alternative destination where that alternative destination is in a PISN. This International Standard is applicable to any interworking unit that can act as a gateway between a PISN employing QSIG and an IP network employing H.323.