Overview
ISO/IEC 15053:2003 - Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Call Interception additional network feature (ANF‑CINT) - defines how a Private Integrated Services Network (PISN / PINX) performs call interception. The standard specifies stage 1 (user-visible behaviour) and stage 2 (functional model and information flows) for ANF‑CINT. It describes when calls that cannot be completed under certain conditions are redirected to a pre‑defined intercepted‑to user, and what notifications and functional interactions are required.
Key topics and technical requirements
- Scope: ANF‑CINT applies to basic services defined in ISO/IEC 11574 and is a PISN‑instigated Additional Network Feature (ANF).
- Staged specifications:
- Stage 1 (clause 6) - feature seen by users: invocation conditions, parameters (e.g., intercepted‑to number), notification rules, activation/registration behaviour.
- Stage 2 (clause 7) - functional model: functional entities (FEs), information flows, FE actions and behaviour, allocation to physical equipment.
- Invocation conditions / interception causes (implementation options include): busy user, no reply (timeout during alerting), incoming barred destination, invalid number, network congestion, route restriction, mobile user not registered, call transfer timeouts, and others.
- Interception modes:
- Immediate interception - redirect when a precluding condition is detected before alerting/waiting.
- Delayed interception - redirect after a timeout in alerting or waiting on busy; PISN may retain the called leg until intercepted‑to user alerts.
- Notification requirements:
- The intercepted‑to user must be notified of interception cause and called number/name if available.
- The calling user must be informed the call was intercepted and, where allowed (subject to CLIR/CNIR), receive intercepted‑to user identity.
- Conformance: To claim conformance to ISO/IEC 15053:2003, a stage 3 standard (signalling protocols / equipment behaviour) must support the relevant aspects of clauses 6 and 7.
Applications and who uses it
- PISN / PBX vendors implementing private telephony features (ANF‑CINT) for enterprises.
- Telecom equipment manufacturers and system integrators designing call control, redirection and supplementary‑service interworking.
- Network operators and service designers specifying interception behaviour for attendants, call centres, security routing, and emergency handling.
- Standards developers creating stage 3 signalling protocols and conformance test suites.
Related standards
- ISO/IEC 11574 (basic services / basic call model)
- ISO/IEC 11579‑1 (PISN reference configuration)
- ISO/IEC 11571 (PISN addressing)
- ETS 300 387 (method for ANF specification)
- Relevant ITU‑T recommendations (I.112, I.210, I.221, Z.100)
This concise specification is essential when you need standardized behaviour, functional decomposition and information‑flow models for call interception in private integrated telephony networks.