ISO/IEC 14843:2003 PDF

Overview

ISO/IEC 14843:2003 specifies the inter-exchange signalling protocol for the Call Offer (SS-CO) supplementary service at the Q reference point between Private Integrated services Network eXchanges (PINXs) within a Private Integrated Services Network (PISN). Commonly implemented as part of the QSIG/PSS1 suite, this stage‑3 specification defines the message operations, notifications, state behavior and protocol interactions needed to offer a call to a busy called user and wait for that user to accept.

Key topics and technical requirements

• Service description: SS-CO enables a calling user (or on their behalf) to offer a call to a busy called user and wait for acceptance. Applicable to circuit-mode basic services.
• Protocol layering: Operates on top of basic circuit‑switched call control (see ISO/IEC 11572) and reuses generic supplementary‑service procedures from ISO/IEC 11582.
• Stage‑3 specification: Satisfies stage‑1/2 requirements from ISO/IEC 14841 and follows the ETS 300 387 service‑specification method.
• ASN.1 operations and notifications: Defines operations such as callOfferRequest, pathRetain, serviceAvailable, cfbOverride, and notifications like remoteUserAlerting (ASN.1 definitions included).
• State machines & procedures: Specifies originating, terminating and transit PINX behaviors, activation/registration, invocation and operational procedures, and timer parameters (e.g., Timer T1).
• Interactions: Explicit protocol interactions with other supplementary services and ANFs (e.g., Calling/Connected Name Presentation, Call Completion CCBS/CCNR, Call Transfer, Call Forwarding variants, Do Not Disturb, Call Intrusion, Path Replacement).
• Conformance & testing: Protocol Implementation Conformance Statement (PICS) proforma provided (Annex B) plus message sequence examples and SDL representations (Annexes C, D).

Applications and who uses this standard

• Enterprise PBX vendors / PINX manufacturers: Implement QSIG SS-CO to ensure interoperable call-offer behavior across multi-vendor PISNs.
• Telecom integrators and network architects: Design and deploy private network call completion and advanced call handling for corporate networks.
• Software engineers & protocol implementers: Use ASN.1 operation definitions and PICS proforma to develop, test and certify conformance.
• Testing labs and certification bodies: Validate inter‑exchange behavior, interactions with other supplementary services, and conformance to timing/state requirements.

Related standards

• ISO/IEC 11572 - Basic circuit‑switched call control (inter-PINX signalling)
• ISO/IEC 11582 - Generic procedures for supplementary services
• ISO/IEC 14841 - Stage 1/2 Call Offer service specification
• ISO/IEC 11579-1, ISO/IEC 11574 and other PISN/QSIG documents cited for reference

Keywords: ISO/IEC 14843:2003, SS-CO, Call Offer, QSIG, PISN, PINX, inter-exchange signalling protocol, ASN.1, PICS, supplementary service.