SIST EN 300 356-6 V3.1.3:2003

SIST EN 300 356-6 V3.1.3:2003 is the Slovenian identical adoption of EN 300 356-6 V3.1.3 from ETSI. It specifies the stage-three signalling system protocols and switching functions for the Connected Line Identification Restriction (COLR) supplementary service on the ISDN User Part (ISUP) version 3 international interface. It is written for telecom operators, network and switch implementers, and test engineers who need to support COLR in international ISDN interconnections.

What does SIST EN 300 356-6 V3.1.3:2003 specify?

SIST EN 300 356-6 V3.1.3:2003 specifies the stage-three aspects of the COLR supplementary service for the pan-European Integrated Services Digital Network (ISDN) using Signalling System No.7 and ISUP. In practice, that means it focuses on protocol procedures and switching functions, not on the user-level service description.

The document is part 6 of a multi-part EN for ISUP version 3. The foreword lists the related parts for basic services, other supplementary services, and the PICS, TSS&TP, ATS and PIXIT specifications for basic and supplementary services. For COLR, the service description and functional capabilities are covered in ETS 300 095 and ETS 300 096, while this part covers the signalling and switching behavior.

What are the key requirements of SIST EN 300 356-6 V3.1.3:2003?

SIST EN 300 356-6 V3.1.3:2003 defines how COLR is supported over the international interface and what parts of the behavior remain in scope for the signalling system. The practical point is that implementers need to align protocol handling at the international gateway and local exchanges with the modified ISUP text.

Stage-three scope and limits

The standard says the document covers stage three, meaning protocol procedures and switching functions needed to support COLR. It also states that additional protocol requirements for delivery via a non-ISDN telecommunications network are outside its scope, as are additional protocol requirements for the national signalling interface. For implementers, this separates international ISUP behavior from national or non-ISDN adaptations.

Service behavior

COLR gives the connected party the ability to stop presentation of its ISDN number to the calling party. The standard states that COLR applies to all telecommunication services. In practice, this means the service logic must be available regardless of the particular call service being used.

Use of national-use items

Although the standard applies only to the international interconnection, it keeps the functions, formats, codes and actions at originating and destination local exchanges. Items marked for national use are retained for informative purposes in the international-interface specification. Where those items are supported inside a national network and operator network, they are expected to be supported in that same way, and an international gateway exchange is expected to support both the national and international network if the national signalling system behaves differently.

Reference model

The standard uses the three-stage ISDN service description model from CCITT Recommendation I.130. Stage 1 is the service description, stage 2 covers functional capabilities and information flows, and stage 3 covers signalling and switching. For users of this part, that tells you exactly which layer of the overall service definition you are implementing.

Modified referenced protocols

The text replaces several references in ITU-T Recommendation Q.731, clause 6, with ETSI or EN versions. This matters because an implementation of this part has to follow the modified references, not the unmodified source recommendations.

What terms does SIST EN 300 356-6 V3.1.3:2003 define?

• Integrated Services Digital Network (ISDN) - the telecommunication network type for which the service is specified.
• ISDN User Part (ISUP) - the Signalling System No.7 user part used for the international interface in this standard.
• Connected Line Identification Restriction (COLR) - the supplementary service that lets the connected party prevent presentation of its ISDN number.
• Signalling System No.7 (SS7) - the signalling system carrying the ISUP procedures.
• Digital Subscriber Signalling System No. one (DSS1) - the referenced subscriber-side signalling protocol family used in related COLR material.
• Stage 1 / Stage 2 / Stage 3 - the service-description levels from user view to functional flow to signalling and switching.
• Protocol Implementation Conformance Statement (PICS) - a conformance document type listed in the related parts of the EN series.

Who uses SIST EN 300 356-6 V3.1.3:2003?

SIST EN 300 356-6 V3.1.3:2003 is used by telecommunications operators, switching-system vendors, network engineers and conformance testers. They use it when designing or verifying international ISDN interconnection behavior for COLR, especially at gateways and exchange interfaces.

It is also relevant to standards and protocol teams working with ETSI ISUP and related ISDN supplementary services. The foreword places it within the ETSI Technical Committee Signalling Protocols and Switching work.

What changed in SIST EN 300 356-6 V3.1.3:2003 from the previous edition?

The history shows the publication sequence from ETS 300 356-6 V3.1.1, through V3.1.2, to V3.1.3, with the present version published in August 1998. This edition is the current published form identified in the document history.

Which standards are used with SIST EN 300 356-6 V3.1.3:2003?

• CCITT Recommendation I.130 - gives the three-stage method used to describe telecommunication services.
• ETS 300 095 - provides the COLR service description at stage 1.
• ETS 300 096 - provides the COLP and COLR functional capabilities and information flows at stage 2.
• ETS 300 098-1 - provides the DSS1 protocol specification for COLR.
• ETS 300 121 - provides the ISUP version 1 basis for international ISDN interconnections.
• EN 300 356-1 - provides the modified ISUP basic services referenced in clause 6.
• EN 300 356-2 - provides the modified ISUP supplementary services reference used in clause 6.
• EN 300 403-1 - provides the modified Q.931 network layer protocol reference.

What does the SIST EN 300 356-6 V3.1.3:2003 document contain?

The document contains the service scope, a normative references clause, and a set of global modifications to ITU-T Recommendation Q.731, clause 6. One table maps the references used in Q.731 clause 6 to their modified ETSI or EN replacements.

It also keeps the stage-three COLR text for the international interface and marks where national-use items are retained for information. That makes the document useful for implementation, gateway behavior, and protocol review rather than for describing end-user service features.