SIST EN 301 656 V1.2.1:2005

SIST EN 301 656 V1.2.1:2005 is the Slovenian adoption of ETSI EN 301 656 V1.2.1, a European Telecommunications Standard for Private Integrated Services Network (PISN) inter-exchange signalling. It specifies the signalling protocol at the Q reference point for the Call Priority Interruption (CPI) and Call Priority Interruption Protection (CPIP) supplementary services. The document endorses ISO/IEC 15992 (2003) with ETSI modifications.

What does SIST EN 301 656 V1.2.1:2005 specify?

SIST EN 301 656 V1.2.1:2005 specifies how the PISN inter-exchange signalling protocol supports CPI and CPIP supplementary services. In practice, it is the ETSI-endorsed version of ISO/IEC 15992 (2003), adapted for use in the ETSI framework.

The document is organized as an endorsement notice for the ISO/IEC text. Its front matter identifies the standard, then the endorsement notice applies the ISO/IEC elements with specific modifications. Clause 3 updates the way references are handled and adds ETSI normative references, and a later instruction replaces ISO/IEC references throughout the text with ETSI documents.

The foreword places the protocol in the wider PISN series, notes that the series uses ISDN concepts, and says the series conforms to the OSI framework. It also states that the protocol is part of PSS1, informally known as QSIG.

What are the key requirements of SIST EN 301 656 V1.2.1:2005?

SIST EN 301 656 V1.2.1:2005 is mainly a standards endorsement with targeted reference changes, so the key requirements are the protocol scope and the replacement rules that make the ISO/IEC text usable as an ETSI standard.

• The protocol applies at the Q reference point for CPI and CPIP.
  This tells implementers where the signalling runs and which supplementary services are covered, so interoperability work can focus on the right interface and service behavior.

• The document endorses ISO/IEC 15992 (2003) with modifications.
  In practice, users follow the ISO/IEC content, but they must apply the ETSI-specific changes recorded in the endorsement notice.

• Clause 3 defines how references are interpreted.
  The text distinguishes specific references, which stay fixed to the cited edition, from non-specific references, which take the latest version. That matters when selecting supporting standards for design or test documentation.

• Clause 3 adds ETSI normative references [16] to [25].
  These references bring in the supporting PISN, bearer-service, supplementary-service, and Additional Network Feature standards needed to implement the protocol in a complete network context.

• The text replaces ISO/IEC references with ETSI references throughout.
  This gives a one-to-one map from the ISO/IEC document to the ETSI versions that should be used in European deployments.

• The phrase “this International Standard” is replaced by “the present document.”
  This is a wording change, but it matters when quoting requirements or writing conformity documents, because the ETSI standard becomes the active reference text.

• The protocol forms part of PSS1, informally known as QSIG.
  That places the work in the broader PISN signalling family, which helps engineers align it with related exchange signaling functions.

What terms does SIST EN 301 656 V1.2.1:2005 define?

SIST EN 301 656 V1.2.1:2005 uses these key terms and abbreviations.

• Private Integrated Services Network (PISN) - the private network type covered by the standard series, based on integrated services concepts.
• Call Priority Interruption (CPI) - the supplementary service named in the title and supported by the specified signalling protocol.
• Call Priority Interruption Protection (CPIP) - the paired supplementary service that the protocol also supports.
• Q reference point - the interface at which the inter-exchange signalling protocol operates.
• PSS1 protocol - the wider protocol family that the foreword says includes this document’s protocol; it is informally known as QSIG.
• Integrated Services Digital Network (ISDN) - the concept base used by the PISN series.
• Open Systems Interconnection (OSI) - the framework to which the series conforms.

Who uses SIST EN 301 656 V1.2.1:2005?

SIST EN 301 656 V1.2.1:2005 is used by engineers and integrators working on PISN exchanges, inter-exchange signalling, and supplementary service support. It is also relevant to quality teams and test labs that need to verify CPI and CPIP behavior against the referenced ETSI and ISO/IEC companion documents. Buyers and specifiers in private telecommunication networks can use it to identify the signalling standard behind a requested call-priority service.

Which standards are used with SIST EN 301 656 V1.2.1:2005?

SIST EN 301 656 V1.2.1:2005 names these companion standards in its normative references and reference substitutions.

What does the SIST EN 301 656 V1.2.1:2005 document contain?

SIST EN 301 656 V1.2.1:2005 contains an endorsement notice, a clause on references, a list of inserted normative references, and a table that replaces ISO/IEC references with ETSI equivalents. It also changes the wording “this International Standard” to “the present document.” For implementers, the most useful part is the reference mapping, because it shows which supporting ETSI standards to use alongside the endorsed ISO/IEC text.