SIST EN 300 257 V1.3.1:2005

SIST EN 300 257 V1.3.1:2005 is the Slovene adoption of ETSI EN 300 257 V1.3.1, published through SIST as a European telecommunications standard. It specifies the inter-exchange signalling protocol for the call diversion supplementary service in Private Integrated Services Network (PISN), and it is based on ISO/IEC 13873 (2003) with ETSI modifications. The standard is aimed at people designing, implementing, testing, or buying PISN signalling that must support call diversion across exchanges.

What does SIST EN 300 257 V1.3.1:2005 specify?

SIST EN 300 257 V1.3.1:2005 specifies the signalling protocol used at the Q reference point to support call diversion supplementary services in PISN. In practice, it tells implementers how inter-exchange signalling should behave when calls are forwarded or deflected between network elements.

The foreword places the standard in the PISN series and says that the protocol forms part of the PSS1 protocol, informally known as QSIG. It also names the supplementary services covered by the protocol: Call Forwarding Unconditional (SS-CFU), Call Forwarding Busy (SS-CFB), Call Forwarding No Reply (SS-CFNR), and Call Deflection (SS-CD).

The document is organized as an endorsement of ISO/IEC 13873 (2003) with ETSI modifications. The visible structure includes the foreword, the endorsement notice, clause 3 on references, and the document history.

What are the key requirements of SIST EN 300 257 V1.3.1:2005?

SIST EN 300 257 V1.3.1:2005 applies the ISO/IEC 13873 protocol text with specific ETSI changes. The most important practical point is that implementers must follow the modified version, not the unaltered ISO/IEC text.

Protocol scope and support

The standard defines the signalling needed for call diversion in PISN at the Q reference point. That matters because interoperability depends on both exchanges using the same call diversion signalling behavior.

The foreword ties the protocol to PSS1, also called QSIG. For engineers and testers, that means this document belongs to the broader private-network inter-exchange signalling family.

Version changes identified in the scope

This version contains correction of errata, ASN.1 migration, and a new procedure for delayed sending of DiversionLeg1. In practice, these are the details that affect message encoding and call-diversion procedure handling in implementations and conformance tests.

Reference handling in clause 3

Clause 3 states how references are to be interpreted. Specific references stay fixed to the cited edition, while non-specific references use the latest version. That matters in procurement and verification because it tells you whether later updates automatically apply.

Updated normative references

Clause 3 adds a set of ETSI normative references at the end of the clause and replaces the ISO/IEC references throughout the text with the ETSI equivalents. This gives the call diversion protocol its companion standards for basic services, bearer services, reference configuration, generic supplementary-service support, and related supplementary-service specifications.

Terminology update

Clause 3 also replaces the phrase "this International Standard" with "the present document". That keeps the endorsed European text internally consistent and avoids ambiguity about which document is being cited.

What terms does SIST EN 300 257 V1.3.1:2005 define?

• PISN - Private Integrated Services Network, the network environment for which the signalling protocol is written.
• Q reference point - the interface location where the call diversion signalling protocol applies.
• PSS1 - the protocol family of which this call diversion signalling forms part.
• QSIG - the informal name used for the PSS1 protocol in the foreword.
• SS-CFU - Call Forwarding Unconditional, one of the supplementary services supported by the protocol.
• SS-CFB - Call Forwarding Busy, one of the supplementary services supported by the protocol.
• SS-CFNR - Call Forwarding No Reply, one of the supplementary services supported by the protocol.
• SS-CD - Call Deflection, one of the supplementary services supported by the protocol.

Who uses SIST EN 300 257 V1.3.1:2005?

SIST EN 300 257 V1.3.1:2005 is used by telecommunications engineers, PISN equipment manufacturers, switch and gateway designers, and interoperability test teams. It is also relevant for quality managers and buyers who need to confirm that a private network can support call diversion services between exchanges.

What changed in SIST EN 300 257 V1.3.1:2005 from the previous edition?

SIST EN 300 257 V1.3.1:2005 endorses ISO/IEC 13873 (2003) and applies ETSI modifications. The scope identifies three changes: correction of errata, ASN.1 migration, and a new procedure for delayed sending of DiversionLeg1.

Which standards are used with SIST EN 300 257 V1.3.1:2005?

What does the SIST EN 300 257 V1.3.1:2005 document contain?

The document contains the ETSI endorsement notice for ISO/IEC 13873 (2003), the national transposition dates, the IPR notice, copyright notice, and the publication history. Clause 3 gives the rules for specific and non-specific references and inserts the ETSI normative references that replace the ISO/IEC citations.

It also includes a reference-mapping table that replaces ISO/IEC 11572, 11574, 11579-1, 11582, 13868, 13869, 13870, and 13872 with the corresponding ETSI documents. The foreword identifies the supported supplementary services and explains where the protocol sits in the PISN and OSI framework.