ISO/IEC 13712-3:2000/Amd1:2000 – Private Integrated Services Network Reference Configuration: Additional Services Amendment

The ISO/IEC 13712 series defines the reference configuration for Private Integrated Services Networks (PISN). Part 3 (ISO/IEC 13712-3:2000) specifies the additional services that can be invoked across a PISN, building on the basic circuit-switched and packet-switched bearer services. Amendment 1:2000 introduces technical enhancements and clarifications to align the standard with evolving network requirements and to streamline the definition of supplementary services for inter-exchange signaling protocols such as QSIG. This article provides a detailed examination of the amendment’s scope, key technical provisions, implementation considerations, and compliance obligations.

Scope and Overview

ISO/IEC 13712-3:2000/Amd1:2000 falls under the JTC 1/SC 6 (Telecommunications and information exchange between systems) area. The base standard establishes a framework for describing additional services—those supplementary services that go beyond basic bearer capabilities—within a PISN reference configuration. The amendment specifically targets:

• Refinement of the functional entity (FE) models for selected supplementary services (e.g., call diversion, call hold, message waiting indication).
• Updates to the generic functional protocol (GFP) constructs used to specify inter-FE information flows.
• Introduction of new service attributes and parameters to support enhanced user control and network interworking.
• Corrections and clarifications to the Protocol Implementation Conformance Statement (PICS) proforma tables.

The amendment is intended for network operators, equipment vendors, and test laboratories that implement PISN signaling protocols conforming to the ISO/IEC 11579 and ISO/IEC 132 (QSIG) series.

Technical Requirements of the Amendment

The amendment introduces several key changes to the base standard’s technical provisions. These are grouped into three main categories: service specification updates, protocol mechanism extensions, and conformance statement revisions.

1. Service Specification Updates

For each additional service covered in the base standard, the amendment revises the operational requirements, including the state transition diagrams, FE actions, and information element (IE) definitions. Notably, the amendment adds a new supplementary service: Advanced Call Forwarding with Notification (Service ID 53). The amendment also updates the message waiting indication service (Service ID 44) to support multiple message sources.

2. Protocol Mechanism Extensions

The amendment enhances the generic functional protocol (GFP) specified in Annex A of the base standard. Table 1 summarizes the new or modified protocol data units (PDUs) introduced by the amendment:

The amendment also revises the encoding of the Feature Activation information element (IE) to include a 1-octet sub-type field, allowing more efficient negotiation of supplementary service characteristics.

3. Conformance Statement Revisions

The PICS proforma in Annex D of the base standard has been extended to include:

• New rows for the added supplementary services.
• Additional columns for amendment-specific features (e.g., notification capability, multiple source handling).
• Clarified status notations (M, O, O.n, X) to reduce ambiguity in conformance testing.

Implementation Highlights

Engineers integrating the amendment into existing PISN equipment should consider the following aspects:

• Backward Compatibility: The amendment is designed to be backward compatible with implementations that conformed to the base standard ISO/IEC 13712-3:2000. However, legacy systems that do not support the new timer values or the extended IE format may require protocol negotiation fallback mechanisms (e.g., using the Protocol Profile identification procedures defined in ISO/IEC 11579-1).
• Interworking with QSIG: The amendment harmonizes the PISN reference configuration with the QSIG supplementary service standards (ISO/IEC 13869 series). Implementers should verify that the mapping of functional entities to QSIG protocol messages follows the updated information flow tables in Annex B.
• Performance Considerations: The addition of the notification capability for call forwarding may increase the number of signaling messages during call setup. The amendment provides optional compact encoding procedures (Section 5.3.2) to reduce message overhead in bandwidth-constrained environments.

Compliance and Certification Notes

Certification against ISO/IEC 13712-3:2000/Amd1:2000 is typically required for network equipment that advertises support for PISN additional services. Key compliance points:

• Normative References: The amendment updates the list of normative references. Most notably, it now cites ISO/IEC 13869-1:2000 (QSIG – Basic Call) and ISO/IEC 11579-2:1999 (PISN – Inter-exchange signaling protocol). Implementers must ensure that their system complies with these referenced standards at the indicated edition levels.
• Test Laboratory Accreditation: Testing should be performed by a laboratory accredited under ISO/IEC 17025. The amendment recommends the use of abstract test suites (ATS) based on the TTCN-3 language for automated testing of the protocol extensions.
• Statement of Compliance: A supplier’s declaration of conformity must explicitly list which amendment features are implemented and whether optional features (e.g., the SuspendResumeAck enhancement) are supported. The declaration should reference the completed PICS proforma from Annex D as amended.

Network operators planning to deploy systems conforming to this amendment should also consider the migration road map provided by the relevant regional PISN profile (e.g., ETSI TIPHON, ITU-T Q.1762 series).

Frequently Asked Questions

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