信息技术 系统间远程通信和信息交换 专用综合业务网 交换间信令协议 转接计数器附加网络特性

[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 参考点处支持转接柜台附加网络功能 (ANF-TC) 的信令协议。 ANF-TC 是一种限制呼叫建立请求可路由通过的转接 PINX 数量的功能，例如，以保护网络免遭无限循环。 Q 参考点在 ISO/IEC 11579-1 中定义。 服务规范按照 CCITT 建议 I.130 中指定的方法分三个阶段制定。 该国际标准包含 Q 参考点的第 3 阶段规范，并满足 ISO/IEC 15055 中第 1 阶段和第 2 阶段规范确定的要求。 ANF-TC 的信令协议与基本电路交换的信令协议联合运行。 呼叫控制（如 ISO/IEC 11572 中指定）和呼叫独立（面向连接）信令连接（如 ISO/IEC 11582 中指定）。 该国际标准还规定了额外的信令协议要求，以支持 ANF-TC 和其他补充业务和 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]： This International Standard specifies the signaling protocol for the support of the Transit Counter additional network feature (ANF-TC) at the Q reference point between Private Integrated Services Network Exchanges (PINXs) connected together within a Private Integrated Services Network (PISN). ANF-TC is a feature that limits the number of Transit PINXs that a call setup request may be routed through e.g., to protect the network against indefinite looping. 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 CCITT Recommendation I. 130. This International Standard 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 15055. The signaling protocol for ANF-TC operates in association with the signaling protocols for basic circuit switched call control (as specified in ISO/IEC 11572) and call independent (connection oriented) signaling connections (as specified in ISOIIEC 11582). This International Standard also specifies additional signaling protocol requirements for the support of interactions at the Q reference point between ANF-TC and other supplementary services and ANFs. This International Standard is applicable to PINXs that can interconnect to form a PISN.