该国际标准规定了“QSIG”和“H.323”之间的信令互通，以支持呼叫转移 公司电信网络（CN）内的补充服务。 “QSIG”是在专用综合业务交换机(PINX)之间的Q参考点处操作的信令协议 在专用综合服务网络(PISN)内。Q参考点在ISO/IEC 11579-1中定义。PISN提供 向其用户提供电路交换基本服务和补充服务。QSIG在其他标准中有规定，特别是 ISO/IEC 11572（支持基本服务的呼叫控制）、ISO/IEC 11582（支持基本服务的通用功能协议） 补充服务）和多项规定个别补充服务的标准。ISO/IEC 13869规定了 支持通过咨询进行呼叫转移的QSIG协议，并且ISO/IEC 19460指定了支持单个呼叫转移的QSIG协议 步骤呼叫转移。 “H.323”是一组信令协议，用于支持分组网络内的语音或多媒体通信。 特别是使用因特网协议(IP)作为其网络层协议的分组网络(IP网络)。H.323信令 协议在IP网络中的端点之间运行，或者通过一个或多个网守间接运行，或者直接运行。端点 可以是终端或到另一个网络的网关。H.323是指各种ITU-T 建议，特别是建议H.225.0和H.245（基本通信能力）和 建议H.450.1（支持补充服务的通用功能协议）。建议H.450.2 指定支持呼叫转移的H.323协议。 注-H.450.2仅适用于1998年版的H.323（也称为H.323版本2）及更高版本。 如ISO/IEC 13869所支持的通过咨询的呼叫转移是一种补充服务，它使用户（用户A）能够 将该用户两个呼叫（其中至少一个必须被应答）转换为该两个用户中的另外两个用户之间的新呼叫 呼叫（用户B和C）。 ISO/IEC 19460所支持的单步呼叫转移是一种补充服务，它使用户（用户A）能够转换 将用户A和用户B之间的现有呼叫转换为用户B和用户C之间的新呼叫，而用户A不需要建立呼叫 在转移之前与用户C。 由H.450.2支持的呼叫转移是一种补充服务，它使被服务用户（用户A）能够转换现有的 与第二用户(用户B)的呼叫进入用户B和由用户A选择的第三用户(用户C)之间的新呼叫。 在呼叫转移之前没有与用户C建立呼叫。如果用户A和用户C之间已经建立了呼叫，则 称为咨询转接，相当于ISO/IEC 13869支持的呼叫转接。如果呼叫尚未 在用户A和用户C之间建立，这被称为单步呼叫转移，并且等同于支持的呼叫转移 根据ISO/IEC 19460。 QSIG和H.323之间的互通允许在PISN的用户处发起的呼叫在IP网络的用户处终止，或者 在IP网络的用户处发起并在PISN的用户处终止的呼叫。本国际标准规定如下 附加功能:_建立了两个呼叫的PISN用户，其中至少一个呼叫是去往或来自IP网络中的用户，以便能够 将这两个呼叫转换为所涉及的其他两个用户之间的新呼叫； _一个PISN用户，其与IP网络中的一个用户建立呼叫，以便能够将该呼叫转换为一个新的呼叫 在IP网络用户和由PISN用户选择的第三用户之间，该第三用户在IP网络中或在 PISN PISN用户与第二PISN用户建立呼叫以便能够将该呼叫转移到第二PISN用户之间的新呼叫 用户和由所述第一用户选择的第三用户，所述第三用户在IP网络中； _建立了两个呼叫的IP网络用户，其中至少一个呼叫是去往或来自PISN中的用户，以便能够 将这两个呼叫转换为所涉及的其他两个用户之间的新呼叫；_一个IP网络用户，其与PISN中的用户建立呼叫或从该用户建立呼叫，以便能够将该呼叫转换为新呼叫 在所述PISN用户和由所述IP网络用户选择的第三用户之间，所述第三用户要么在所述IP网络中，要么在所述IP网络中 PISN和 ISO/IEC 21410:2001(E) 2？ISO/IEC 2001？版权所有 _一个IP网络用户，其与IP网络中的第二用户建立了呼叫，以便能够将该呼叫转移到新的呼叫中 在所述第二用户和由所述第一用户选择的第三用户之间，所述第三用户在PISN中。 本国际标准适用于任何可以作为采用QSIG的PISN之间的网关的互通单元 以及采用H.323的IP网络。

This International Standard specifies signalling interworking between "QSIG" and "H.323" in support of the call transfer 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 13869 specifies the QSIG protocol in support of call transfer by consultation and ISO/IEC 19460 specifies the QSIG protocol in support of single step call transfer. "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.450.2 specifies the H.323 protocol in support of call transfer. NOTE - H.450.2 applies only to the 1998 version of H.323 (also known as H.323 version 2) and to later versions. Call transfer by consultation, as supported by ISO/IEC 13869, is a supplementary service that enables a user (user A) to transform two of that user's calls (at least one of which must be answered) into a new call between the two other users in the two calls (users B and C). Single step call transfer, as supported by ISO/IEC 19460, is a supplementary service that enables a user (user A) to transform an existing call between user A and user B into a new call between user B and user C without user A needing to establish a call with user C prior to transfer. Call transfer, as supported by H.450.2, is a supplementary service that enables the served user (user A) to transform an existing call with a second user (user B) into a new call between user B and a third user (user C) selected by user A. User A may or may not have a call established with user C prior to call transfer. If a call is already established between user A and user C, this is known as transfer by consultation and is equivalent to call transfer as supported by ISO/IEC 13869. If a call is not already established between user A and user C, this is known as single step call transfer and is equivalent to call transfer as supported by ISO/IEC 19460. 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 PISN user with two calls established, at least one of which being to or from a user in an IP network, to be able to transform those two calls into a new call between the other two users involved; _ a PISN user with a call established to or from a user in an IP network to be able to transform that call into a new call between the IP network user and a third user selected by the PISN user, that third user being either in the IP network or in the PISN; _ a PISN user with a call established to a second PISN user to be able to transfer that call into a new call between the second user and a third user selected by the first user, that third user being in an IP network; _ an IP network user with two calls established, at least one of which being to or from a user in a PISN, to be able to transform those two calls into a new call between the other two users involved; _ an IP network user with a call established to or from a user in a PISN to be able to transform that call into a new call between the PISN user and a third user selected by the IP network user, that third user being either in the IP network or in the PISN; and ISO/IEC 21410:2001(E) 2 ？ ISO/IEC 2001?All rights reserved _ an IP network user with a call established to a second user in the IP network to be able to transfer that call into a new call between the second user and a third user selected by the first user, that third user being 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.