ETSI ETS 300 426 ed.1 (1995-09)

SLOVENSKI STANDARD
SIST ETS 300 426 E1:2005
01-maj-2005
Zasebno telekomunikacijsko omrežje (PTN) – Medcentralni signalizacijski protokol
- Dopolnilna storitev: vpad v klic
Private Telecommunication Network (PTN); Inter-exchange signalling protocol; Call
intrusion supplementary service
Ta slovenski standard je istoveten z: ETS 300 426 Edition 1
ICS:
33.040.35 Telefonska omrežja Telephone networks
SIST ETS 300 426 E1:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ETS 300 426 E1:2005

---------------------- Page: 2 ----------------------

SIST ETS 300 426 E1:2005
EUROPEAN ETS 300 426
TELECOMMUNICATION September 1995
STANDARD
Source: ETSI TC-ECMA Reference: DE/ECMA-00053
ICS: 33.040.10, 33.040.30
Key words: PTN, supplementary service
Private Telecommunication Network (PTN);
Inter-exchange signalling protocol
Call intrusion supplementary service
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1995. All rights reserved.

---------------------- Page: 3 ----------------------

SIST ETS 300 426 E1:2005
Page 2
ETS 300 426: September 1995
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

---------------------- Page: 4 ----------------------

SIST ETS 300 426 E1:2005
Page 3
ETS 300 426: September 1995
Contents
Foreword .7
1 Scope.9
2 Conformance .9
3 References.9
4 Definitions.10
4.1 External definitions .10
4.2 Busy.10
4.3 Conference type connection .10
4.4 Established call.10
4.5 Forced release.10
4.6 Impending intrusion warning notification.10
4.7 Inter-PTNX link .11
4.8 Intruding call .11
4.9 Isolation.11
4.10 Path retention.11
4.11 Served user .11
4.12 Wanted user.11
4.13 Unwanted user.11
4.14 Unwanted user PTNX .11
4.15 Wait on busy.11
5 List of acronyms.11
6 Signalling protocol for the support of SS-CI.12
6.1 SS-CI description .12
6.2 SS-CI operational requirements.12
6.2.1 Requirements on the Originating PTNX.12
6.2.2 Requirements on the Terminating PTNX.12
6.2.3 Requirements on a Transit PTNX.12
6.2.4 Requirements on the unwanted user PTNX .12
6.3 SS-CI coding requirements.13
6.3.1 Operations.13
6.3.2 Notifications.16
6.3.3 Information elements .17
6.3.3.1 Facility information element.17
6.3.3.2 Notification indicator information element.17
6.3.3.3 Other information elements .17
6.3.4 Messages.17
6.4 SS-CI state definitions.17
6.4.1 States at the Originating PTNX .17
6.4.1.1 State CI-Idle.17
6.4.1.2 State CI-Wait-Ack .17
6.4.1.3 State CI-Orig-Invoked .18
6.4.1.4 State CI-inForcedRelease-Request .18
6.4.1.5 State CI-Isolation-Request.18
6.4.1.6 State CI-inWOB-Request.18
6.4.1.7 State CI-Orig-Isolated.18
6.4.1.8 State CI-isForcedRelease-Request.18
6.4.1.9 State CI-isWOB-Request.18
6.4.1.10 State CI-Orig-WOB .18
6.4.1.11 State CI-Wait-Ack-WOB.18

---------------------- Page: 5 ----------------------

SIST ETS 300 426 E1:2005
Page 4
ETS 300 426: September 1995
6.4.2 States at the Terminating PTNX. 18
6.4.2.1 State CI-Idle. 18
6.4.2.2 State CI-GetCIPL-I. 18
6.4.2.3 State CI-Dest-Notify. 18
6.4.2.4 State CI-Dest-Invoked . 18
6.4.2.5 State CI-Dest-Isolated. 19
6.4.2.6 State CI-Dest-WOB. 19
6.4.2.7 State CI-GetCIPL-WOB. 19
6.4.2.8 State CI-Dest-Notify-WOB . 19
6.5 SS-CI signalling procedures for activation, deactivation and registration. 19
6.6 SS-CI signalling procedures for invocation and operation. 19
6.6.1 Actions at the Originating PTNX. 19
6.6.1.1 Procedure for invocation of SS-CI. 19
6.6.1.1.1 Normal procedure . 19
6.6.1.1.2 Exceptional procedure . 20
6.6.1.2 Optional procedure for invocation of isolation. 20
6.6.1.2.1 Normal procedure . 20
6.6.1.2.2 Exceptional procedure . 20
6.6.1.3 Optional procedure for invocation of forced release . 20
6.6.1.3.1 Normal procedure . 20
6.6.1.3.2 Exceptional procedure . 21
6.6.1.4 Optional procedure for invocation of wait on busy . 21
6.6.1.4.1 Normal procedure . 21
6.6.1.4.2 Exceptional procedure . 21
6.6.1.5 Procedure for reinvocation of intrusion during wait on busy. 21
6.6.1.5.1 Normal procedure . 21
6.6.1.5.2 Exceptional procedure . 21
6.6.1.6 Procedure for completion of SS-CI . 22
6.6.1.6.1 Normal procedure . 22
6.6.1.6.2 Exceptional procedure . 22
6.6.2 Actions at the Terminating PTNX . 22
6.6.2.1 Procedure for invocation of SS-CI. 22
6.6.2.1.1 Normal procedure . 22
6.6.2.1.2 Exceptional procedure . 23
6.6.2.2 Optional procedures for invocation of isolation . 24
6.6.2.2.1 Normal procedure . 24
6.6.2.2.2 Exceptional procedure . 24
6.6.2.3 Optional procedures for invocation of forced release. 24
6.6.2.3.1 Normal procedure . 24
6.6.2.3.2 Exceptional procedure . 24
6.6.2.4 Optional procedures for invocation of wait on busy. 24
6.6.2.4.1 Normal procedure . 24
6.6.2.4.2 Exceptional procedure . 25
6.6.2.5 Procedures for reinvocation of intrusion during wait on busy . 25
6.6.2.5.1 Normal procedure . 25
6.6.2.5.2 Exceptional procedure . 26
6.6.2.6 Procedures for completion of SS-CI. 26
6.6.2.6.1 Normal procedure . 26
6.6.2.6.2 Exceptional procedure . 26
6.6.3 Actions at the unwanted user PTNX. 27
6.6.4 Actions at a Transit PTNX . 27
6.7 SS-CI impact of interworking with public ISDNs. 27
6.8 SS-CI impact of interworking with non-ISDNs. 27
6.9 SS-CI parameter values (timers). 27
6.9.1 Timer T1.27
6.9.2 Timer T2.28
6.9.3 Timer T3.28
6.9.4 Timer T4.28
6.9.5 Timer T5.28
6.9.6 Timer T6.28

---------------------- Page: 6 ----------------------

SIST ETS 300 426 E1:2005
Page 5
ETS 300 426: September 1995
Annex A (normative): Signalling protocol for the support of path retention.29
A.1 Path retention description.29
A.2 Path retention operational requirements.29
A.2.1 Requirements on the Originating PTNX .29
A.2.2 Requirements on the Terminating PTNX .29
A.2.3 Requirements on a Transit PTNX .29
A.3 Path retention coding requirements .30
A.3.1 Operations .30
A.3.2 Information elements.30
A.3.3 Messages .30
A.4 Path retention state definitions .30
A.4.1 States at the Originating PTNX.30
A.4.1.1 PRTO-Idle .30
A.4.1.2 PRTO-Requested .30
A.4.1.3 PRTO-Retained.30
A.4.1.4 PRTO-Invoking .30
A.4.2 States at the Terminating PTNX.30
A.4.2.1 PRTT-Idle.30
A.4.2.2 PRTT-Requested.31
A.4.2.3 PRTT-Retained.31
A.4.2.4 PRTT-Invoking.31
A.5 Path retention signalling procedures for invocation and operation.31
A.5.1 Actions at the Originating PTNX .31
A.5.2 Actions at the Terminating PTNX.31
A.5.3 Actions at a Transit PTNX .32
A.6 Path retention impact of interworking with public ISDNs.33
A.7 Path retention impact of interworking with non-ISDNs .33
A.8 Path retention parameter values (timers) .33
A.9 Specification and Description Language (SDL).33
A.9.1 SDL representation of path retention at the Originating PTNX .34
A.9.2 SDL representation of path retention at the Terminating PTNX .36
Annex B (normative): Protocol Implementation Conformance Statement (PICS) proforma.38
B.1 Introduction.38
B.2 Instructions for completing the PICS proforma.38
B.2.1 General structure of the PICS proforma .38
B.2.2 Additional information .39
B.2.3 Exception information.39
B.3 PICS proforma for ECMA-203 .39
B.3.1 Implementation identification.39
B.3.2 Protocol summary.40
B.3.3 General .40
B.3.4 Procedures. .41
B.3.5 Coding.42
B.3.6 Timers .43
Annex C (informative): Examples of message sequences.44
C.1 Example message sequence for normal operation of SS-CI without path retention .45

---------------------- Page: 7 ----------------------

SIST ETS 300 426 E1:2005
Page 6
ETS 300 426: September 1995
C.2 Example message sequence for normal operation of SS-CI with path retention . 46
C.3 Example of unsuccessful invocation of SS-CI without path retention. 47
C.4 Examples of completion of SS-CI. 48
C.4.1 The established call is released . 48
C.4.2 The intruding call is released. 48
C.5 Examples of invocation of SS-CI options . 49
C.5.1 The Originating PTNX forced releases the unwanted user . 49
C.5.2 The Originating PTNX isolates the unwanted user . 49
C.5.3 The Originating PTNX invokes wait on busy .50
C.5.4 The Originating PTNX reinvokes intrusion during wait on busy . 51
Annex D (informative): Specification and Description Language (SDL) representation of procedures . 52
D.1 SDL representation of SS-CI at the Originating PTNX . 52
D.2 SDL representation of SS-CI at the Terminating PTNX . 59
History. 65

---------------------- Page: 8 ----------------------

SIST ETS 300 426 E1:2005
Page 7
ETS 300 426: September 1995
Foreword
This European Telecommunication Standard (ETS) has been produced by the European Computer
Manufacturers Association (ECMA) on behalf of its members and those of the European Telecommunications
Standards Institute (ETSI).
This ETS is one of a series of standards defining services and signalling protocols applicable to Private
Telecommunication Networks (PTNs). The series uses the ISDN concepts as developed by the ITU-T
(formerly CCITT) and is also within the framework of standards for open systems interconnection as defined
by ISO.
This ETS specifies the signalling protocol for use at the Q reference point in support of the Call Intrusion (CI)
supplementary service.
The ETS is based upon the practical experience of ECMA member companies and the results of their active
and continuous participation in the work of ISO, ITU-T, ETSI and other international and national
standardization bodies. It represents a pragmatic and widely based consensus.
This ETS was produced by ECMA using the ECMA guidelines for the production of standards and using the
ECMA stylesheet. In order to avoid undue delays in the approval process for this ETS it has been agreed that
this ETS will not be converted to the ETSI stylesheet.

---------------------- Page: 9 ----------------------

SIST ETS 300 426 E1:2005
Page 8
ETS 300 426: September 1995
Blank page

---------------------- Page: 10 ----------------------

SIST ETS 300 426 E1:2005
Page 9
ETS 300 426: September 1995
1 Scope
This European Telecommunication Standard (ETS) specifies the signalling protocol for the support of
the Call Intrusion supplementary service (SS-CI) at the Q reference point between Private
Telecommunication Network Exchanges (PTNXs) connected together within a Private
Telecommunication Network (PTN).
SS-CI is a supplementary service which, on request from the calling user, enables the calling user to
establish communication with a busy called user by breaking into an established call between the
called user and a third user (unwanted user).
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 ETS contains the stage 3 specification for the Q reference point and satisfies the
requirements identified by the stage 1 and stage 2 specifications in ETS 300 425.
The signalling protocol for SS-CI operates on top of the signalling protocol for basic circuit switched
call control, as specified in ETS 300 172, and uses certain aspects of the generic procedures for the
control of supplementary services specified in ETS 300 239.
The impact on the protocol of interactions between the supplementary service specified in this ETS
and other supplementary services is outside the scope of this ETS.
This ETS is applicable to PTNXs which can interconnect to form a PTN.
2 Conformance
In order to conform to this ETS, a PTNX shall satisfy the requirements identified in the Protocol
Implementation Conformance Statement (PICS) proforma in annex B.
3 References
ISO/IEC 11579-1 Information technology - Telecommunications and information
exchange between systems - Private Integrated Services Network -
Reference configurations for PISN exchanges (PINX) (1994)
ETS 300 171 Private Telecommunication Network (PTN); Specification,
functional models and information flows; Control aspects of
circuit mode basic services (1992)
ETS 300 172 Private Telecommunication Network (PTN); Inter-exchange
signalling protocol; Circuit mode basic services (1994)
ETS 300 196 Integrated Services Digital Network (ISDN); Generic functional
protocol for the support of supplementary services; Digital
Subscriber Signalling System No. one (DSS1) protocol (1993)
ETS 300 239 Private Telecommunication Network (PTN); Inter-exchange
signalling protocol; Generic functional protocol for the support of
supplementary services (1993)
ETS 300 387 Private Telecommunications Network (PTN); Method for the
specification of basic and supplementary services
(1994)
ETS 300 415 Private Telecommunication Network (PTN); Terms and
definitions (1995)
ETS 300 425 Private Telecommunication Network (PTN); Specification,
functional model and information flows; Call intrusion
supplementary service (1995)
CCITT Recommendation I.112 Vocabulary of terms for ISDNs (1988)

---------------------- Page: 11 ----------------------

SIST ETS 300 426 E1:2005
Page 10
ETS 300 426: September 1995
CCITT Recommendation I.210 Principles of telecommunication services supported by an ISDN
and the means to describe them (1988)
CCITT Recommendation Z.100 Specification and Description Language (SDL) (1988)
4 Definitions
For the purpose of this ETS the following definitions apply.
4.1 External definitions
This ETS uses the following terms defined in other documents:
− Application Protocol Data Unit (APDU) (ETS 300 239)
− Basic Service (CCITT Recommendation I.210)
− Call, Basic Call (ETS 300 239)
− Coordination Function (ETS 300 239)
− Notification (ETS 300 239)
− Originating PTNX (ETS 300 172)
− Private Telecommunication Network Exchange (PTNX) (ETS 300 415)
− Public ISDN (ETS 300 415)
− Signalling (CCITT Recommendation I.112)
− Supplementary Service (CCITT Recommendation I.210)
− Private Telecommunication Network (ETS 300 415)
− Terminal Equipment (ETS 300 415)
− Terminating PTNX (ETS 300 172)
− Transit PTNX (ETS 300 172)
− User (ETS 300 171)
4.2 Busy
A property of a user for whom either a Network Determined User Busy or User Determined User
Busy condition exists.
4.3 Conference type connection
A connection between the served user, the wanted user and the unwanted user, where all users have
user information connection with each other.
4.4 Established call
The active call that is selected for intruding on.
4.5 Forced release
The release of the established call on request from the served user during intrusion.
4.6 Impending intrusion warning notification
A notification provided before communication is established between the served user and the
wanted user.

---------------------- Page: 12 ----------------------

SIST ETS 300 426 E1:2005
Page 11
ETS 300 426: September 1995
4.7 Inter-PTNX link
The totality of a signalling channel and a number of user information channels at the Q reference
point.
4.8 Intruding call
A call in which the served user requests call intrusion.
4.9 Isolation
The breaking of the user information connection to and from the unwanted user during intrusion.
4.10 Path retention
The retaining of the network connection between the Originating PTNX and the Terminating PTNX
so that a supplementary service (such as SS-CI) can be invoked without establishing a new
connection.
4.11 Served user
The user who requests SS-CI.
4.12 Wanted user
The called user in the intruding call.
4.13 Unwanted user
The user other than the wanted user in the established call.
4.14 Unwanted user PTNX
The PTNX of the unwanted user.
...