私有综合服务网络（PISN）是一种基于数字传输技术的通信网络，它可以提供多种通信服务，如语音、数据、图像等。PISN通常由一组私有交换机和其他通信设备组成，这些设备可以通过专用线路或公共网络进行连接。PISN的主要优点是可以提供高质量的通信服务，并且可以根据用户的需求进行定制。

ISO/IEC 13872:2003标准规定了PISN中的呼叫转移补充服务。呼叫转移是一种通信服务，它可以将来电转移到另一个电话号码或语音信箱中。呼叫转移补充服务是指在呼叫转移的基础上，增加了一些额外的功能，如条件呼叫转移、无条件呼叫转移、遇忙呼叫转移等。

ISO/IEC 13872:2003标准规定了呼叫转移补充服务的功能模型和信息流。其中，功能模型描述了呼叫转移补充服务的各种功能和操作，如呼叫转移的启用、禁用、查询等。信息流描述了呼叫转移补充服务的信息交换过程，如用户向交换机发送呼叫转移请求、交换机向用户发送呼叫转移确认等。

ISO/IEC 13872:2003标准的实施可以提高PISN的通信服务质量和可靠性，同时也可以提高用户的满意度和使用体验。该标准适用于各种类型的PISN，包括企业内部通信网络、公共交换电话网络等。

相关标准
- ISO/IEC 11579-1:1995 Information technology — Telecommunications and information exchange between systems — Private Integrated Services Network — Inter-exchange signalling protocol — Part 1: Protocol specification
- ISO/IEC 11579-2:1995 Information technology — Telecommunications and information exchange between systems — Private Integrated Services Network — Inter-exchange signalling protocol — Part 2: Protocol implementation conformance statement (PICS) proforma
- ISO/IEC 11579-3:1995 Information technology — Telecommunications and information exchange between systems — Private Integrated Services Network — Inter-exchange signalling protocol — Part 3: Abstract test suite (ATS) and protocol implementation extra information for testing (PIXIT)
- ISO/IEC 11579-4:1995 Information technology — Telecommunications and information exchange between systems — Private Integrated Services Network — Inter-exchange signalling protocol — Part 4: Protocol implementation extra information for testing (PIXIT) for the network service
- ISO/IEC 11579-5:1995 Information technology — Telecommunications and information exchange between systems — Private Integrated Services Network — Inter-exchange signalling protocol — Part 5: Protocol implementation extra information for testing (PIXIT) for the supplementary services