本国际标准定义了专用综合业务网（PISN）交换中的映射功能 需要使用64 kbit/s电路模式连接被分复用为4 x 16 kbit/s的场景 用于传输PINX间信令和用户信息的通道。 注1:本国际标准旨在满足特定用户组织应用的特定需求。 然而，它也可能适用于其他地方。本国际标准中包含的要求将在未来的任何时候纳入 标准规定了一种更通用的承载条件处理方法。 为了将专用综合服务网络交换机（PINX）连接到另一个PINX，需要映射功能 使C参考点的特定接口适应Q参考点的应用程序。因此，映射函数 在C参考点对接口进行物理调整。映射函数还提供了 Q参考点处的用户信道和信令信息到C参考点处的适当信道或时隙 指向 ISO/IEC 11579-1中定义了C和Q参考点。 本国际标准涵盖的C参考点处的接口类型为64 kbit/s无限制数字信号 线路（D64U）终端设备接口，符合ITU-T Rec.G.703。 在Q参考点，映射为用户通道提供16 kbit/s服务，以支持无限制数据传输 用于支持语音传输的数字信息，以及用于信令信道的分组模式服务。应用 映射是一种静态映射，即在Q参考点和 C参考点处的接口。 与故障管理相关的管理职能不在本国际标准的范围内。 本国际标准适用于可相互连接以形成专用综合业务网络的PINX （PISN）并支持Q参考点的信令协议。

This International Standard defines the mapping functions in exchanges of Private Integrated Services Networks (PISNs) required for the utilization of scenarios in which 64 kbit/s circuit mode connections are sub-multiplexed into 4 x 16 kbit/s channels for carrying inter-PINX signalling and user information. NOTE 1 - This International Standard has been prepared to meet the specific needs of an application for a particular user organisation. However, it may also be applicable elsewhere. The requirements contained in this International Standard will be incorporated in any future standard specifying a more generic approach to bearer conditioning. In order to connect a Private Integrated Services Network Exchange (PINX) to another PINX, mapping functions are required to adapt the specific interfaces at the C reference point to the application at the Q reference point. As such, mapping functions provide for physical adaptation to the interface at the C reference point. Mapping functions also provide for the mapping of user channels and signalling information at the Q reference point to the appropriate channels or timeslots at the C reference point. The C and Q reference points are defined in ISO/IEC 11579-1. The type of interface at the C reference point covered by this International Standard is the 64 kbit/s Unrestricted Digital Leased Line (D64U) Terminal Equipment Interface, in accordance with ITU-T Rec. G.703. At the Q reference point the mapping provides a 16 kbit/s service for user channels to support the transfer of unrestricted digital information and to support the transfer of speech, and a packet mode service for the signalling channel. The applied mapping is a static mapping, i.e. there is a fixed relationship between user and signalling channels at the Q reference point and the interface at the C reference point. Management functions relating to failure management are outside the scope of this International Standard. This International Standard is applicable to PINXs that can be interconnected to form a Private Integrated Services Network (PISN) and that support signalling protocols at the Q reference point.