ISO/IEC 13874:2003

INTERNATIONAL ISO/IEC
STANDARD 13874
Third edition
2003-04-01
Information technology —
Telecommunications and information
exchange between systems — Private
Integrated Services Network —
Inter-exchange signalling protocol —
Path Replacement additional network
feature
Technologies de l'information — Télécommunications et échange
d'information entre systèmes — Réseau privé à intégration de
services — Protocole de signalisation d'échange — Caractéristique
de réseau additionnelle de remplacement de chemin

Reference number
©
ISO/IEC 2003
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©  ISO/IEC 2003
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ii © ISO/IEC 2003 — All rights reserved

Contents
Foreword v
Introduction vi
1 Scope 1
2 Conformance 1
3 Normative references 1
4 Terms and definitions            2
4.1 External definitions 2
4.2 Other definitions 2
4.2.1 Branching PINX 2
4.2.2 Cooperating PINX 3
4.2.3 End PINX 3
4.2.4 Preceding PINX 3
4.2.5 Replaced connection 3
4.2.6 Requesting PINX 3
4.2.7 Retained connection 3
4.2.8 Subsequent PINX 3
Inviting PINX
4.2.9 3
5 List of acronyms 3
6 Signalling protocol for the support of ANF-PR 3
6.1 ANF-PR description 3
6.2 ANF-PR operational requirements 4
6.2.1 Requirements on the Cooperating PINX 4
6.2.2 Requirements on the Requesting PINX 4
6.2.3 Requirements on a Transit PINX 4
Requirements on the Inviting PINX
6.2.4 5
6.3 ANF-PR coding requirements 6
6.3.1 Operations 6
6.3.2 Information elements 9
6.3.3 Messages 10
6.4 ANF-PR state definitions 10
6.4.1 States at the Requesting PINX 10
6.4.2 States at the Cooperating PINX 10
6.4.3 States at a Transit PINX on the retained path, including the branching PINX 11
6.4.4 States at the Inviting PINX 11
6.5 ANF-PR signalling procedures 11
6.5.1 Actions at the Requesting PINX 11
6.5.2 Actions at the Cooperating PINX 12
6.5.3 Actions at a Cooperating/Requesting PINX in the case of a trombone connection 13
6.5.4 Actions at a Transit PINX 13
6.5.5 Actions at Inviting PINX 13
6.6 ANF-PR optional signalling procedures for retention of part of the old connection 14
Actions at the Requesting PINX
6.6.1 14
© ISO/IEC 2003 – All rights reserved iii

6.6.2 Actions at the Cooperating PINX 14
6.6.3 Actions at a Transit PINX on the retained connection 14
6.6.4 Actions at a Transit PINX on the new connection or replaced connection 16
6.6.5 Actions at Inviting PINX on the retained connection 16
6.7 ANF-PR impact of interworking with public ISDNs 16
6.8 ANF-PR impact of interworking with non-ISDNs 16
6.9 Protocol interactions between ANF-PR and other supplementary services and ANFs 16
6.9.1 Interaction with Calling Name Identification Presentation (SS-CNIP) 16
6.9.2 Interaction with Connected Name Identification Presentation (SS-CONP) 16
6.9.3 Interaction with Completion of Calls to Busy Subscriber (SS-CCBS) 17
6.9.4 Interaction with Completion of Calls on No Reply (SS-CCNR) 17
6.9.5 Interaction with Call Transfer (SS-CT) 17
Interaction with Call Forwarding Unconditional (SS-CFU)
6.9.6 18
6.9.7 Interaction with Call Forwarding Busy (SS-CFB) 18
6.9.8 Interaction with Call Forwarding No Reply (SS-CFNR) 18
6.9.9 Interaction with Call Deflection (SS-CD) 18
6.10 ANF-PR parameter values (timers) 18
6.10.1 Timer T1 18
6.10.2 Timer T2 18
6.10.3 Timer T3 18
Timer T4
6.10.4 19
Annexes
A - Protocol Implementation Conformance Statement (PICS) proforma 20
B - Imported ASN.1 definitions 27
C - Examples of message sequences 28
D - Specification and Description Language (SDL) representation of procedures 36
E - ASN.1 definitions according to ITU-T Recs. X.208 / X.209 42
iv © ISO/IEC 2003 – All rights reserved

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the
specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the
development of International Standards through technical committees established by the respective organization to deal with
particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In
the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by
the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires
approval by at least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and
IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 13874 was prepared by ECMA (as ECMA-176) and was adopted, under a special “fast-track procedure”, by Joint
Technical Committee ISO/IEC JTC 1, Information technology, in parallel with its approval by national bodies of ISO and IEC.
This third edition cancels and replaces the second edition (ISO/IEC 13874:1999), which has been technically revised.
© ISO/IEC 2003 – All rights reserved v

Introduction
This International Standard is one of a series of Standards defining services and signalling protocols applicable to Private
Integrated Services Networks (PISNs). The series uses ISDN concepts as developed by ITU-T and conforms to the framework
of International Standards for Open Systems Interconnection as defined by ISO/IEC.
This International Standard specifies the signalling protocol for use at the Q reference point in support of the Path Replacement
additional network feature. The protocol defined in this Standard forms part of the PSS1 protocol (informally known as QSIG).
This International Standard is based upon the practical experience of ECMA member companies and the results of their active
and continuous participation in the work of ISO/IEC JTC 1, ITU-T, ETSI and other international and national standardization
bodies. It represents a pragmatic and widely based consensus.
vi © ISO/IEC 2003 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 13874:2003(E)

Information technology — Telecommunications and information
exchange between systems — Private Integrated Services Network —
Inter-exchange signalling protocol — Path Replacement additional
network feature
1Scope
This International Standard specifies the signalling protocol for the support of the Path Replacement additional network feature
(ANF-PR) at the Q reference point between Private Integrated services Network eXchanges (PINXs) connected together within
a Private Integrated Services Network (PISN).
ANF-PR is a feature which applies to an established call, allowing that call's connection between PINXs to be replaced by a
new connection.
The Q reference point is defined in ISO/IEC 11579-1.
Service specifications are produced in three stages and according to the method specified in ETS 300 387. This International
Standard contains the stage 3 specification for the Q reference point and satisfies the requirements identified by the stage 1 and
stage 2 specifications in ISO/IEC 13863.
The signalling protocol for ANF-PR operates on top of the signalling protocol for basic circuit switched call control, as
specified in ISO/IEC 11572, and uses certain aspects of the generic procedures for the control of supplementary services
specified in ISO/IEC 11582.
This International Standard also specifies additional signalling protocol requirements for the support of interactions at the Q
reference point between ANF-PR and other supplementary services and ANFs.
This International Standard is applicable to PINXs which can interconnect to form a PISN.
2 Conformance
In order to conform to this International Standard, a PINX shall satisfy the requirements identified in the Protocol
Implementation Conformance Statement (PICS) proforma in annex A.
3 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the
edition cited applies. For undated references, the latest edition of the referenced document (including any amendments)
applies.
ISO/IEC 11571:1998, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Networks - Addressing
ISO/IEC 11572:2000, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Circuit mode bearer services - Inter-exchange signalling procedures and protocol
ISO/IEC 11574:2000, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Circuit-mode 64 kbit/s bearer services - Service description, functional capabilities and
information flows
ISO/IEC 11579-1:1994, Information technology - Telecommunications and information exchange between systems - Private
integrated services network - Part 1: Reference configuration for PISN Exchanges (PINX)
ISO/IEC 11582:2002, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Generic functional protocol for the support of supplementary services - Inter-exchange
signalling procedures and protocol
ISO/IEC 13863:1998, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Specification, functional model and information flows - Path replacement additional network
feature
© ISO/IEC 2003 – All rights reserved 1

ISO/IEC 13869:2003, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Inter-exchange signalling protocol - Call Transfer supplementary service
ISO/IEC 15056:1997, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Inter-exchange signalling protocol - Transit counter additional network feature
ETS 300 387:1994, Private Telecommunication Network (PTN); Method for the specification of basic and supplementary
services
ITU-T Rec. I.112:1993, Vocabulary of terms for ISDNs
ITU-T Rec. I.210:1993, Principles of telecommunication services supported by an ISDN and the means to describe them
ITU-T Rec. Q.950:2000, Supplementary services protocols, structure and general principles
ITU-T Rec. Z.100:1999, Specification and description language (SDL)
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1 External definitions
This International Standard uses the following terms defined in other documents:
− ANF-PR user (ISO/IEC 13863)
− Application Protocol Data Unit (APDU) (ISO/IEC 11582)
− Basic Service (ITU-T Rec. I.210)
− Call, Basic Call (ISO/IEC 11582)
− Connection (ISO/IEC 13863)
− Incoming Gateway PINX (ISO/IEC 11572)
− Interpretation APDU (ISO/IEC 11582)
− Network Facility Extension (NFE) (ISO/IEC 11582)
− New Connection (ISO/IEC 13863)
− Old Connection (ISO/IEC 13863)

− Originating PINX (ISO/IEC 11572)
− Outgoing Gateway PINX (ISO/IEC 11572)
− Private Integrated Services Network (PISN) (ISO/IEC 11579-1)
− Private Integrated services Network eXchange (PINX) (ISO/IEC 11579-1)
− Signalling (ITU-T Rec. I.112)
− Supplementary Service (ITU-T Rec. I.210)
− Supplementary Services Control Entity (ISO/IEC 11582)
− Terminating PINX (ISO/IEC 11572)
− Transit PINX (ISO/IEC 11572)
− Trombone Connection (ISO/IEC 13863)
− User (except in the context of ANF-PR user) (ISO/IEC 11574)
4.2 Other definitions
4.2.1 Branching PINX
The Transit PINX at which the retained connection finishes and the new connection starts.
2 © ISO/IEC 2003 – All rights reserved

4.2.2 Cooperating PINX
The end PINX which initiates the establishment of the new connection towards other end PINX involved in the call.
4.2.3 End PINX
Within the context of a call, a PINX which is not acting as a Transit PINX, i.e., an Originating PINX, a Terminating PINX, an
Incoming Gateway PINX or an Outgoing Gateway PINX.
4.2.4 Preceding PINX
The adjacent PINX in the direction of the Cooperating PINX, relative to a particular PINX involved in the old connection.
NOTE 1 - This can be the Cooperating PINX itself or a Transit PINX.
4.2.5 Replaced connection
That part of the old connection which is not retained and is replaced by the new connection.
4.2.6 Requesting PINX
The end PINX which invokes ANF-PR and towards which the new connection is routed.
4.2.7 Retained connection
That part of the old connection which is retained and not replaced by the new connection.
4.2.8 Subsequent PINX
The adjacent PINX in the direction of the Requesting PINX, relative to a particular PINX involved in the old connectio
...