私有综合服务网络（PISN）是一种专用的通信网络，用于在组织内部提供各种通信服务，如电话、传真、电子邮件等。PISN的设计和实现需要考虑到各种因素，如网络拓扑、通信协议、安全性等。为了提高PISN的互操作性和可靠性，ISO/IEC 20116:2004标准规定了消息中心监控和邮箱识别的功能模型和信息流。

消息中心监控是PISN中的一项重要服务，它允许用户监控消息中心的状态和活动。ISO/IEC 20116:2004标准规定了消息中心监控的功能模型和信息流，包括监控消息中心的状态、获取消息中心的活动报告、设置消息中心的参数等。这些功能可以帮助用户更好地管理消息中心，提高通信效率和可靠性。

邮箱识别是PISN中的另一项重要服务，它允许用户识别和管理邮箱。ISO/IEC 20116:2004标准规定了邮箱识别的功能模型和信息流，包括识别邮箱的类型、获取邮箱的信息、设置邮箱的参数等。这些功能可以帮助用户更好地管理邮箱，提高通信效率和可靠性。

ISO/IEC 20116:2004标准的实施可以提高PISN的互操作性和可靠性，使得不同厂商的PISN可以相互通信和协作。此外，该标准还可以帮助用户更好地管理PISN，提高通信效率和可靠性。

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 -- Circuit-mode basic call control -- 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 -- Circuit-mode supplementary services -- Part 2: Protocol specification
- ISO/IEC 11579-3:1995 Information technology -- Telecommunications and information exchange between systems -- Private Integrated Services Network -- Inter-exchange signalling protocol -- Circuit-mode procedures for call establishment, supplementary services and call clearing -- Part 3: Call clearing
- ISO/IEC 11579-4:1995 Information technology -- Telecommunications and information exchange between systems -- Private Integrated Services Network -- Inter-exchange signalling protocol -- Circuit-mode procedures for call establishment, supplementary services and call clearing -- Part 4: Call transfer
- ISO/IEC 11579-5:1995 Information technology -- Telecommunications and information exchange between systems -- Private Integrated Services Network -- Inter-exchange signalling protocol -- Circuit-mode procedures for call establishment, supplementary services and call clearing -- Part 5: Call diversion