本国际标准定义了专用综合业务网（PISN）交换中的映射功能 需要连接到公共（或第三方提供的）网络的虚拟专用网络（VPN）功能 设备 映射功能需要提供接口在C或T参考点的物理终止，以及 将Q参考点处的用户信道和信令信息流映射到适当的信道或时隙 在C或T参考点。 在T参考点，假设D通道上使用的协议是DSS1的增强版。 这些协议 建议Q.931和Q.932的附件Q和附件X分别给出了改进措施。 本国际标准中规定的映射功能适用于连接到VPN的PINX，该VPN支持 PISN信息在访问和/或PISN服务之间流动。 ISO/IEC 11579-1中定义了C和Q参考点。T参考点在ITU-T中定义 记录I.411。 本国际标准涵盖的C或T参考点的接口类型为ISDN主要速率接口 以及基本的访问接口。

This International Standard defines the mapping functions in exchanges of private integrated services networks (PISN) required for their attachment to Virtual Private Network (VPN) functionality of public (or third party provided) network equipment. Mapping functions are required to provide for the physical termination of the interface at the C or T reference points, and for the mapping of user channels and signalling information flows at the Q reference point to the appropriate channels or timeslots at the C or T reference point. At the T reference, point it is assumed that the protocol used on the D channel is the enhanced version of DSS1. These protocol enhancements are given in Annex Q and Annex X of Recommendations Q.931 and Q.932 respectively. The mapping function specified in this International Standard are applicable to PINXs connected to a VPN that supports either PISN information flows between accesses and/or PISN services. The C and Q reference points are defined in ISO/IEC 11579-1. The T reference point is defined in ITU-T Rec. I.411. The types of interfaces at the C or T reference point covered by this International Standard are the ISDN primary rate interface and the basic access interface.