私有综合服务网络（PISN）是一种专用的通信网络，它提供了一系列的通信服务，包括语音、数据和视频等。PISN通常用于企业内部通信，它可以提高通信效率和安全性，同时也可以降低通信成本。呼叫转移是PISN中的一项重要功能，它可以将来电转移到其他终端，以便用户在不同的终端上接听来电。

ISO/IEC 13865:2003标准规定了呼叫转移补充服务的功能模型和信息流。该标准定义了呼叫转移的各种情况和操作，包括无条件呼叫转移、有条件呼叫转移和无应答呼叫转移等。无条件呼叫转移是指所有来电都会被转移到指定的终端，有条件呼叫转移是指只有符合一定条件的来电才会被转移，无应答呼叫转移是指当用户未能在规定时间内接听来电时，来电会被转移到指定的终端。

ISO/IEC 13865:2003标准还规定了与呼叫转移相关的信息流和信令。信息流是指在呼叫转移过程中传输的语音、数据和视频等信息，信令是指用于控制呼叫转移过程的信号。该标准规定了各种信息流和信令的格式和内容，以确保呼叫转移的正确执行。

ISO/IEC 13865:2003标准的实施可以提高PISN的通信效率和灵活性，同时也可以提高通信的安全性和可靠性。该标准适用于所有基于数字传输的PISN，包括ISDN、PSTN和VoIP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