Overview
SIST EN 301 923 V1.1.1:2005 is a Slovenian adoption of the European Standard for Private Integrated Services Network (PISN) inter-exchange signalling protocol, specifically focusing on Call Identification and Call Linkage Additional Network Feature (ANF), as aligned with ISO/IEC 21889 (2001), with modifications. This standard defines how calls are uniquely identified throughout their route within a PISN and how logically linked calls can be tracked and managed. The provision of this ANF is essential for supporting advanced supplementary services and ensuring interoperability within complex, multi-exchange PISN environments.
Key Topics
- Global Call Identification (GID): Enables assigning a unique identifier to each call, which is maintained end-to-end between PISN exchanges (PINXs), enhancing call traceability and network management.
- Thread Identification: Allows linking together multiple calls that are logically connected, a vital feature for advanced telephony services such as call transfer and conferencing.
- Leg Identification: Facilitates identification of different segments (legs) of a call, supporting complex routing and supplementary services.
- Support for CSTA: Designed to facilitate the Computer Supported Telecommunications Applications (CSTA - ECMA-269) within a networked PISN, enhancing integration with computer-based communication systems.
- Protocol Scope: Specifies signalling at the Q reference point as part of the PSS1 (QSIG) protocol suite, ensuring compatibility and interoperability for inter-exchange communications in Private Integrated Services Networks.
Applications
The standard is especially relevant in environments where advanced call handling and supplementary services are mission-critical. Its practical value includes:
- Enterprise Telephony Systems: Supports organizations with large, distributed PISNs requiring reliable call management, auditing, and tracking across multiple geographic locations.
- Service Providers: Enables telecom providers to deliver value-added services (such as call transfer, conferencing, and call logging) with consistent identification and linkage of calls.
- Network Operations: Simplifies troubleshooting, monitoring, and auditing by ensuring all calls and associated events can be uniquely and consistently identified.
- Integration with IT Systems: Assists in merging telephony with IT through CSTA integration, unlocking unified communications, automated call handling, and enhanced reporting.
- Compliance & Security: Facilitates regulatory compliance by providing auditable call records, aiding in legal intercept, fraud prevention, and privacy enforcement.
Related Standards
To ensure full interoperability within PISNs, SIST EN 301 923 V1.1.1:2005 references and is closely aligned with several other European and international standards:
- EN 300 189: Addressing for PISN [ISO/IEC 11571, modified]
- EN 300 172: Inter-exchange signalling protocol; Circuit-mode basic services [ISO/IEC 11572, modified]
- EN 300 171: Service description, functional capabilities, and information flows [ISO/IEC 11574, modified]
- EN 300 239: Generic functional protocol for supplementary services [ISO/IEC 11582, modified]
- EN 301 922: Call identification and call linkage feature specification [ISO/IEC 21888, modified]
- EN 301 265, EN 300 366, EN 300 257: Various supplementary services protocols for call completion, call diversion, and call interception.
- CSTA (ECMA-269): Protocol support for Computer Supported Telecommunications Applications.
Summary
Implementing SIST EN 301 923 V1.1.1:2005 supports robust, scalable, and interoperable telephony operations in private integrated networks. Its comprehensive approach to call identification and linkage underpins advanced business communications and enables seamless supplementary service delivery across interconnected exchanges. This standard is vital for modern enterprise telephony, ensuring clarity, control, and efficiency in complex telecommunication environments.
