SIST EN 301 656 V1.1.1:2005

SIST EN 301 656 V1.1.1:2005 is the Slovenian adoption of ETSI EN 301 656 for Private Integrated Services Network (PISN) signalling. It specifies the QSIG inter-exchange protocol at the Q reference point to support Call priority interruption supplementary service and Call priority interruption protection supplementary service between Private Integrated services Network eXchanges (PINX) within a PISN.

What does SIST EN 301 656 V1.1.1:2005 specify?

SIST EN 301 656 V1.1.1:2005 specifies the signalling protocol used between PINXs in a PISN when QSIG is used at the Q reference point. In practical terms, it tells implementers how the network exchanges must support call priority interruption and call priority interruption protection.

The document is built as an ETSI European Standard based on ISO/IEC 15992 (1998), with ETSI modifications applied throughout the text. The foreword places it in the PISN service and signalling series and identifies QSIG as the protocol used for this purpose, known in international standards as PSS1.

The text shown in the endorsement notice highlights the parts that were adapted for the EN version. Clause 3 is the main normative reference section, and the body uses reference substitutions and terminology changes to align the ISO/IEC text with ETSI/EN references.

What are the key requirements of SIST EN 301 656 V1.1.1:2005?

SIST EN 301 656 V1.1.1:2005 is mainly a protocol specification, so its key requirements are the rules for using the adapted QSIG signalling text and the references it depends on. For a reader implementing or checking interoperability, the important point is which companion standards must be followed and how the document’s references are interpreted.

Reference handling rules in clause 3

Clause 3 states how references are to be read:

• a specific reference stays fixed to the cited edition
• a non-specific reference takes the latest version
• a non-specific ETS reference may also refer to later EN versions with the same number

In practice, this matters when you decide which edition of a companion standard to implement or test against.

ETSI additions to the normative references

Clause 3 adds the standards that the protocol depends on, including EN 300 171, EN 300 172, EN 301 265, EN 301 655, ETS 300 239, ETS 300 259, ETS 300 261, ETS 300 357, ETS 300 387, and ETS 300 475-1. These provide the related PISN service models, signalling protocols, supplementary-service framework, and reference configuration used by the call priority interruption protocol.

Reference substitutions throughout the text

The document replaces several ISO/IEC references with the corresponding ETSI EN or ETS document numbers. That means an implementation or compliance review should follow the ETSI-cited documents, not the original ISO/IEC numbers, when using this standard.

Terminology alignment

Throughout the text, the term “International Standard” is replaced by “EN”. In practice, that keeps the protocol text aligned with the European Standard context and avoids ambiguity when reading the adapted clauses.

Marking of modifications

The endorsement notice says new or modified text is marked with sidebars, and underlining or strike-out is used where needed. That helps reviewers see exactly what changed from the base ISO/IEC text.

What terms does SIST EN 301 656 V1.1.1:2005 define?

• PISN - Private Integrated Services Network, the network environment for the signalling protocol.
• PINX - Private Integrated services Network eXchange, the network exchange that participates in the inter-exchange signalling.
• Q reference point - The interface point between PINXs where QSIG signalling is applied.
• QSIG - The Q interface signalling protocol used for PISN inter-exchange signalling; the foreword says it is known as PSS1 in international standards.
• SS-CPI - Call priority interruption supplementary service, the service supported by the protocol.
• SS-CPIP - Call priority interruption protection supplementary service, the companion service named in the title.
• PSS1 - Private integrated Signalling System no.1, the name used for QSIG in international standards.

Who uses SIST EN 301 656 V1.1.1:2005?

SIST EN 301 656 V1.1.1:2005 is used by engineers and vendors working on PISN signalling between exchanges. It is relevant for designers of PBX/PINX systems, telecom network implementers, and test teams checking QSIG interoperability.

It also matters to quality managers and buyers who need to confirm that a product or network supports the specified supplementary services at the Q reference point. In practice, it is the document you use when aligning implementation, integration, and interoperability work for call priority interruption in a PISN.

What changed in SIST EN 301 656 V1.1.1:2005 from the previous edition?

SIST EN 301 656 V1.1.1:2005 is the ETSI EN version of ISO/IEC 15992 (1998) with ETSI modifications. The changes stated in the document are:

• added normative references in clause 3
• replacement of several ISO/IEC references with EN or ETS references
• replacement of the term “International Standard” with “EN”
• marking of modified text with sidebars, underlining, and strike-out where needed

Which standards are used with SIST EN 301 656 V1.1.1:2005?

• EN 300 171 - gives the functional models and information flows for control aspects of circuit-mode basic services.
• EN 300 172 - specifies inter-exchange signalling for circuit-mode basic services.
• EN 301 265 - covers the call interception additional network feature.
• EN 301 655 - specifies the functional model and information flows for Call Priority Interruption and Call Priority Interruption Protection supplementary services.
• ETS 300 239 - provides the generic functional protocol for supplementary services.
• ETS 300 259 - covers the path replacement additional network feature.
• ETS 300 261 - covers call transfer supplementary service.
• ETS 300 357 - covers diversion supplementary services.
• ETS 300 387 - gives the method for specifying basic and supplementary services.
• ETS 300 475-1 - gives the reference configuration for PTN exchanges.

What does the SIST EN 301 656 V1.1.1:2005 document contain?

The document contains the ETSI-adapted version of ISO/IEC 15992 for QSIG support of call priority interruption services. It includes the clause on normative references, the ETSI reference substitution table, and the editorial rules used to adapt the base international text into an EN.

It also contains the protocol content needed to support signalling between PINXs at the Q reference point. For implementers and testers, that means the standard serves as the specification to follow when designing, validating, or checking service behavior for these supplementary services.