SIST ETS 300 137:1997

SLOVENSKI STANDARD
SIST ETS 300 137:1997
01-maj-1997
Digitalno omrežje z integriranimi storitvami (ISDN) - Dopolnilna storitev: zaprta
skupina uporabnikov (CUG) - Funkcijske zmožnosti in informacijski tokovi
Integrated Services Digital Network (ISDN); Closed User Group (CUG) supplementary
service; Functional capabilities and information flows
Ta slovenski standard je istoveten z: ETS 300 137 Edition 1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST ETS 300 137:1997 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 137:1997

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SIST ETS 300 137:1997
EUROPEAN ETS 300 137
TELECOMMUNICATION May 1992
STANDARD
Source: ETSI TC-SPS Reference: T/S 22-03
ICS: 33.080
ISDN, supplementary service.
Key words:
Integrated Services Digital Network;
Closed User Group (CUG) supplementary service
Functional capabilities and information flows
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - secretariat@etsi.fr
X.400: Internet:
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 1992. All rights reserved.
New presentation - see History box

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ETS 300 137: May 1992
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.

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Contents
Foreword.5
1 Scope .7
2 Normative references .7
3 Definitions.8
4 Symbols and abbreviations.8
5 Description .9
6 Derivation of the functional model .9
6.1 Functional model description .9
6.2 Description of the functional entities.10
6.3 Relationship with a basic service .11
7 Information flows.11
7.1 Information flow diagrams.11
7.2 Definition of individual information flows.14
7.2.1 Relationship ra.14
7.2.1.1 Contents of INFORM1 .14
7.2.1.2 Contents of INFORM1 REJECT.14
7.2.2 Relationship rb.14
7.2.2.1 Contents of INFORM2 .14
7.2.2.2 Contents of INFORM2 REJECT.14
7.2.3 Relationship rc . 15
7.2.4 Relationship rd.15
7.2.4.1 Contents of ENQUIRY1.15
7.2.5 Relationship re.15
7.2.5.1 Contents of ENQUIRY2.15
7.2.6 Relationship ry .16
8 SDL diagrams for functional entities.17
8.1 FE1.17
8.2 FE2.18
8.3 FE3.21
8.4 FE4.22
8.5 FE5.25
8.6 FE6.26
9 Functional Entity Actions (FEAs).26
9.1 FEAs of FE1.27
9.2 FEAs of FE2.27
9.3 FEAs of FE3.27
9.4 FEAs of FE4.28
9.5 FEAs of FE5.28
9.6 FEAs of FE6.29
10 Allocation of functional entities to physical locations.30
History.31

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Foreword
This European Telecommunication Standard (ETS) has been produced by the Signalling Protocols &
Switching (SPS) Technical Committee of the European Telecommunications Standards Institute (ETSI) and
was adopted having passed through the ETSI standards approval procedure.
In accordance with CCITT Recommendation I.130 [1], the following three level structure is used to
describe the supplementary telecommunications services as provided by European public
telecommunications operators under the pan-European Integrated Services Digital Network (ISDN):
- Stage 1: is an overall service description, from the user's stand-point;
- Stage 2: identifies the functional capabilities and information flows needed to support the service
described in stage 1; and
- Stage 3: defines the signalling system protocols and switching functions needed to implement the
service described in stage 1.
This ETS details the stage 2 aspects (functional capabilities and information flows) needed to support the
Closed User Group (CUG) supplementary service. The stage 1 and stage 3 aspects are detailed in ETS
300 136 (1992) and ETS 300 138 (1992), respectively.

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1 Scope
This standard defines stage two of the Closed User Group (CUG) supplementary service for the pan-
European Integrated Services Digital Network (ISDN) as provided by European public telecommunications
operators. Stage two identifies the functional capabilities and the information flows needed to support the
service description. The stage two description also identifies user operations not directly associated with a
call (see CCITT Recommendation I.130 [1]).
This standard is specified according to the methodology specified in CCITT Recommendation Q.65 [2].
This standard does not formally describe the relationship between this supplementary service and the
basic call, but where possible this information is included for guidance.
In addition this standard does not specify the requirements where the service is provided to the user via a
private ISDN. This standard does not specify the requirements for the allocation of defined functional
entities within a private ISDN; it does however define which functional entities may be allocated to a private
ISDN.
This standard does not specify the additional requirements where the service is provided to the user via a
telecommunications network that is not an ISDN.
The CUG supplementary service enables users to form groups to and from which access is restricted. A
specific user may be a member of one or more closed user groups. Members of a specific closed user
group can communicate among themselves but not, in general, with users outside the group.
The CUG supplementary service is applicable to all telecommunication services.
This standard is applicable to the stage three standards for the ISDN CUG supplementary service. The
term "stage three" is also defined in CCITT Recommendation I.130 [1]. Where the text indicates the
status of a requirement (i.e. as strict command or prohibition, as authorisation leaving freedom, or as a
capability or possibility) this shall be reflected in the text of the relevant stage three standards.
Furthermore, conformance to this standard is met by conforming to the stage three standards with the field
of application appropriate to the equipment being implemented. Therefore no method of testing is provided
for this standard.
2 Normative references
This standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to, or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references the latest
edition of the publication referred to applies.
[1] CCITT Recommendation I.130 (1988): "Method for the characterisation of
telecommunication services supported by an ISDN and network capabilities of an
ISDN".
[2] CCITT Recommendation Q.65 (1988): "Stage 2 of the method for the
characterisation of services supported by an ISDN".
[3] CCITT Recommendation I.112 (1988): "Vocabulary of terms for ISDNs".
[4] CCITT Recommendation Q.71 (1988): "ISDN 64 kbit/s circuit mode switched
bearer services".
[5] ETS 300 136 (1992): "Integrated Services Digital Network (ISDN); Closed User
Group (CUG) supplementary service; Service description".

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[6] CCITT Recommendation Q.85 (1988): "Community of interest supplementary
services".
[7] CCITT Recommendation I.210 (1988): "Principles of telecommunication services
supported by an ISDN and the means to describe them".
3 Definitions
For the purposes of this standard, the following definitions apply:
Closed user group (CUG) index: see ETS 300 136 [5], Clause 3.
Closed user group call: see ETS 300 136 [5], Clause 3.
Closed user group interwork code: is a code to uniquely identify the closed user group inside the
network.
Closed user group with incoming access: see ETS 300 136 [5], Clause 3.
Closed user group with incoming and outgoing access: see ETS 300 136 [5], Clause 3.
Closed user group with outgoing access: see ETS 300 136 [5], Clause 3.
Closed user group: see ETS 300 136 [5], Clause 3.
CUG-domain: a CUG domain is an area of common CUG interlock codes. The domain internal CUG
interlock codes need not be released via the boundary of the domain. A closed user group application may
span over several domains. Both domains shall treat the other domain's closed user group as a single
member of its own closed user group.
Incoming calls barred within a CUG: see ETS 300 136 [5], Clause 3.
Integrated Services Digital Network (ISDN): see CCITT Recommendation I.112 [3], § 2.3, definition
308.
Outgoing calls barred within a CUG: see ETS 300 136 [5], Clause 3.
Service; telecommunications service: see CCITT Recommendation I.112 [3], § 2.2, definition 201.
Supplementary service: see CCITT Recommendation I.210 [7], § 2.4.
4 Symbols and abbreviations
CC Call Control, typically and LE
CCA Call Control Agent, typically and TE
CUG Closed User Group
DB Data Base
DDI Direct Dialling In
FEA Functional Entity Actions
IA Incoming Access
ICB Incoming Calls Barred

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ISDN Integrated Services Digital Network
LE Local Exchange
MSN Multiple Subscriber Numbering
OA Outgoing Access
OCB Outgoing Calls Barred
PCUG Preferential CUG
PTN Private Telecommunications Network
TE Terminal Equipment
5 Description
Not applicable.
6 Derivation of the functional model
6.1 Functional model description
The functional model for the CUG supplementary service shall be as shown in figures 1 and 2.
The functional model for the application of the CUG supplementary service within a single CUG domain
shall as be shown in figure 1.
�˜˜˜¿        �˜˜˜¿
‡FE3‡        ‡FE5‡
�˜´˜�        �˜´˜�
‡          ‡
rd‡          ‡re
‡          ‡
�˜˜˜¿  ra  �˜`˜¿    rb    �˜`˜¿  rc  �˜˜˜¿
‡FE1ˆ˜˜˜˜˜˜˜˜·FE2ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·FE4ˆ˜˜˜˜˜˜˜˜·FE6‡
�˜˜˜�    �˜˜˜�        �˜˜˜�    �˜˜˜�
Figure 1

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The expanded functional model used for interworking between CUG domains shall be as shown in figure 2.
           �˜˜˜¿            �˜˜˜¿
˜˜˜         ‡FE3‡            ‡FE5‡
 ^         �˜´˜�            �˜´˜�
 ‡          ‡              ‡re
 ‡         rd‡              ‡
Domain A        ‡              ‡
 ‡          ‡              ‡
 ‡  �˜˜˜¿  ra  �˜`˜¿     rb      �˜`˜¿ ry
 ‡  ‡FE1ˆ˜˜˜˜˜˜˜˜˜·FE2ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·FE4ˆ˜˜˜˜˜˜˜¿
 ‡  �˜˜˜�     �˜˜˜�            �˜˜˜�    ‡
 *      �˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜�
 ‡      ‡   �˜˜˜¿            �˜˜˜¿
 ‡      ‡   ‡FE3‡            ‡FE5‡
Domain B    ‡   �˜´˜�            �˜´˜�
 ‡      ‡    ‡              ‡
 ‡      ‡    ‡              ‡
 ‡      ‡   rd‡              ‡re
 ‡      ‡    ‡              ‡
 ‡      ‡   �˜`˜¿     rb      �˜`˜¿ ry
 ‡      �˜˜˜˜˜·FE2ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·FE4ˆ˜˜˜˜˜˜¿
 ‡         �˜˜˜�            �˜˜˜�   ‡
 *      �˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜�
 ‡      ‡   �˜˜˜¿            �˜˜˜¿
Domain C    ‡   �˜´˜�            �˜´˜�
 ‡      ‡    ‡              ‡
 ‡      ‡   rd‡              ‡re
 ‡      ‡    ‡              ‡
 ‡      ‡    ‡              ‡
 ‡      ‡   �˜`˜¿     rb      �˜`˜¿ rc �˜˜˜¿
 v      �˜˜˜˜˜·FE2ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·FE4ˆ˜˜˜˜˜·FE6‡
           �˜˜˜�            �˜˜˜�   �˜˜˜�
Figure 2
6.2 Description of the functional entities
The functional entities for the CUG supplementary service shall be:
FE1 originating CUG agent;
FE2 outgoing CUG determination;
FE3 outgoing CUG control;
FE4 incoming CUG determination;
FE5 incoming CUG control;
FE6 destination CUG agent.

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6.3 Relationship with a basic service
The relationship of the functional model for the CUG supplementary service with a basic call may be as
shown in figure 3.
NOTE: The basic call model is defined in CCITT Recommendation Q.71 [4], § 2.1, with the
exception that r1 represents an outgoing call relationship and r3 represents an incoming
call relationship.
        �˜˜˜¿            �˜˜˜¿
        ‡FE3‡            ‡FE5‡
        �˜´˜�            �˜´˜�
         ‡              ‡
        rd‡              ‡re
         ‡              ‡
         ‡              ‡
�˜˜˜¿  ra   �˜`˜¿     rb      �˜`˜¿  rc  �˜˜˜¿
‡FE1ˆ˜˜˜˜˜˜˜˜˜˜·FE2ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·FE4ˆ˜˜˜˜˜˜˜˜·FE6‡
�`˜˜´�  r1  �˜`˜´˜�   r2 �˜˜˜¿ r2  �˜`˜´˜� r3 �˜`˜´˜�
‡CCAˆ˜˜˜˜˜˜˜˜˜·CC ˆ˜˜˜˜˜˜˜˜˜˜˜·CC ˆ˜˜˜˜˜˜˜·CC ˆ˜˜˜˜˜˜˜˜·CCA‡
�˜˜˜�     �˜˜˜�      �˜˜˜�    �˜˜˜�    �˜˜˜�
Figure 3
7 Information flows
7.1 Information flow diagrams
The information flows for the CUG supplementary services shall be as shown in figures 4, 5, 6, 7 and 8.
Figures 5 and 8 show a portion of the flows appropriate to a call across multiple domains.
                        rb              rc
                 �˜ - - - - - - - - - - - ˜¿   �˜ - - - - - - - - - ˜¿
    �˜˜˜˜˜¿   ra   �˜˜˜˜˜¿   rd   �˜˜˜˜˜¿    �˜˜˜˜˜¿  re  �˜˜˜˜˜¿    �˜˜˜˜˜¿
    ‡ FE1 ‡- - - - - - -‡ FE2 ‡- - - - - - ‡ FE3 ‡    ‡ FE4 ‡- - - - ‡ FE5 ‡    ‡ FE6 ‡
    �´˜˜˜´�       �´˜˜˜´�      �´˜˜˜´�    �´˜˜˜´�    �´˜˜˜´�    �´˜˜˜´�
  211 ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
  >>>>‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
INFORM1 ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
------->ˆ˜˜˜·        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
req.  ‡910‡211 SETUP 221 ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡>>>>‡- - >‡>>>>‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡  req.ind  ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡  INFORM1   ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜>ˆ˜˜˜·       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡  req.ind   ‡920‡ ENQUIRY1  ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜>ˆ˜˜˜·     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡ req.ind   ‡930‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡ ENQUIRY1  ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ˆ˜˜˜·<˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜·     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡921‡ resp.conf  ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡221  SETUP  ‡  ‡   241 ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡>>>>‡- - - - -‡  ‡- ->‡>>>>‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡   req.ind ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡922‡   INFORM2 ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜·  ˆ˜˜˜˜˜˜˜˜>ˆ˜˜˜·     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡  req.ind  ‡  ‡     ‡940‡ ENQUIRY2 ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜¯˜˜>‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡ req.ind ‡950‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡ ENQUIRY2 ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ˆ˜˜˜·<˜˜˜˜˜˜˜˜˜¯˜˜˜·     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡941‡resp.conf ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡241 SETUP‡  ‡   251‡  ‡251
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡>>>>‡- - -‡  ‡- - ->‡>>‡  ‡>>>>
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡ req.ind ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ‡942‡ INFORM1 ‡  ‡     ‡  ‡
    ‡  ‡        ‡  ‡       ‡  ‡     ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜·  ˆ˜˜˜˜˜˜˜˜>ˆ˜˜˜·
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡ req.ind ‡  ‡     ‡960‡INFORM1
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ˆ˜˜˜¯˜˜˜˜˜˜>
    ‡  ‡        ‡  ‡       ‡  ‡     ‡  ‡     ‡  ‡     ‡  ‡ind.
Figure 4

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     �˜˜˜˜˜¿    ry     �˜˜˜˜˜¿
     ‡ FE4 ‡- - - - - - - - - ‡ FE2 ‡
     �´˜˜˜´�         �´˜˜˜´�
(NOTE)  ‡940‡          ‡  ‡
     ‡941‡231  SETUP   231‡  ‡
     ‡942‡>>>>‡- - - - ->‡>>>>‡  ‡
     ‡  ‡   req.ind    ‡  ‡
     ‡  ‡          ‡  ‡
     ‡  ‡   INFORM1    ‡  ‡
     ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜>ˆ˜˜˜·
     ‡  ‡   req.ind    ‡920‡
     ‡  ‡          ‡  ‡
NOTE: A call to this point is covered in figure 4.
Figure 5: Chaining of CUG domains
Successful CUG calls between different CUG domains showing information flows across relationship ry
according to the functional model given in figure 2.
    �˜˜˜˜˜¿   ra   �˜˜˜˜˜¿    rd    �˜˜˜˜˜¿
    ‡ FE1 ‡- - - - - - - ‡ FE2 ‡- - - - - - - - - ‡ FE3 ‡
    �´˜˜˜´�       �´˜˜˜´�         �´˜˜˜´�
  211 ‡  ‡        ‡  ‡          ‡  ‡
  >>>>‡  ‡        ‡  ‡          ‡  ‡
INFORM1‡  ‡        ‡  ‡          ‡  ‡
req.  ‡  ‡        ‡  ‡          ‡  ‡
˜˜˜˜˜˜>ˆ˜˜˜·        ‡  ‡          ‡  ‡
    ‡910‡211 SETUP  221‡  ‡          ‡  ‡
    ‡  ‡>>>>‡- - ->‡>>>>‡  ‡          ‡  ‡
    ‡  ‡  req.ind   ‡  ‡          ‡  ‡
    ‡  ‡        ‡  ‡          ‡  ‡
(NOTE) ‡  ‡  INFORM1   ‡  ‡          ‡  ‡
    ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜>ˆ˜˜˜·          ‡  ‡
    ‡  ‡  req.ind   ‡920‡   ENQUIRY1    ‡  ‡
    ‡  ‡        ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜>ˆ˜˜˜·
    ‡  ‡        ‡  ‡  req.ind     ‡930‡
    ‡  ‡        ‡  ‡          ‡  ‡
    ‡  ‡        ‡  ‡   ENQUIRY1    ‡  ‡
    ‡  ‡        ˆ˜˜˜·<˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜·
    ‡  ‡        ‡921‡  resp.conf    ‡  ‡
    ‡  ‡ SETUP REJECT ‡923‡          ‡  ‡
    ‡  ‡<<<<‡<- - -‡<<<<‡  ‡          ‡  ‡
    ‡  ‡  req.ind   ‡  ‡          ‡  ‡
    ‡  ‡        ‡  ‡          ‡  ‡
    ‡  ‡ INFORM1 REJECT ‡924‡          ‡  ‡
INFORM1ˆ˜˜˜·<˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜·          ‡  ‡
REJECT ‡911‡  req.ind   ‡  ‡          ‡  ‡
 <˜˜˜˜¯˜˜˜·        ‡  ‡          ‡  ‡
ind.  ‡  ‡        ‡  ‡          ‡  ‡
NOTE: Depending on the progress of the basic call INFORM1 REJECT will be sent
simultaneously with the appropriate basic call clearing information flow.
Figure 6: Unsuccessful CUG calls - case 1: own CUG domains

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SIST ETS 300 137:1997
Page 13
ETS 300 137: May 1992
        rb
         �˜ - - - - - - - - - - - - - ˜¿
        �˜˜˜˜˜¿   ra   �˜˜˜˜˜¿ rd �˜˜˜˜˜¿      �˜˜˜˜˜¿ re �˜˜˜˜˜¿
        ‡ FE1 ‡- - - - - - ‡ FE2 ‡- - -‡ FE3 ‡      ‡FE4 ‡- - - ‡ FE5 ‡
        �´˜˜˜´�      �´˜˜˜´�   �´˜˜˜´�      �´˜˜˜´�   �´˜˜˜´�
        ‡  ‡       ‡  ‡    ‡  ‡     241 ‡  ‡    ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡  NOTE >>>>‡940‡ENQUIRY2‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡       ˆ˜˜˜¯˜˜˜˜˜˜˜>ˆ˜˜˜·
        ‡  ‡       ‡  ‡    ‡  ‡       ‡  ‡req.ind ‡951‡
        ‡  ‡       ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡       ‡  ‡ENQUIRY2‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡       ˆ˜˜˜·<˜˜˜˜˜˜˜¯˜˜˜·
        ‡  ‡       ‡  ‡    ‡  ‡       ‡941‡ resp. ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡       ‡943‡ conf  ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡ RELEASE 441 ‡  ‡    ‡  ‡
        ‡  ‡       ‡  ‡<<<<‡<-‡  ‡- - - - -‡<<<<‡  ‡    ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡ req.ind   ‡  ‡    ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡INFORM2 REJECT‡  ‡    ‡  ‡
        ‡  ‡       ˆ˜˜˜·<˜˜˜˜˜˜·  ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜·    ‡  ‡
        ‡  ‡  DISCONNECT ‡923‡    ‡  ‡  req.ind  ‡  ‡    ‡  ‡
        ‡  ‡ 411   421 ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
        ‡  ‡<<<<‡<- -‡<<<<‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
        ‡  ‡  req.ind  ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
        ‡  ‡INFORM1 REJECT‡924‡    ‡  ‡       ‡  ‡    ‡  ‡
        ˆ˜˜˜·<˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜·    ‡  ‡       ‡  ‡    ‡  ‡
     INFORM ‡911‡  req.ind  ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
     REJECT ‡  ‡       ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
     ind. <˜¯˜˜˜·       ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
        ‡  ‡       ‡  ‡    ‡  ‡       ‡  ‡    ‡  ‡
NOTE: A call to this point is covered in figure 4.
Figure 7: Unsuccessful CUG calls - case 2: another CUG domain
        �˜˜˜˜˜¿    ry      �˜˜˜˜˜¿ NOTE 2
    ‡ FE4 ‡- - - - - - - - - - -‡ FE2 ‡
    �´˜˜˜´�           �´˜˜˜´�
    ‡  ‡            ‡  ‡
NOTE 1 ‡940‡231   SETUP   231‡  ‡
    ‡941‡>>>>‡- - - - - - >‡>>>>‡  ‡
    ‡942‡    req.ind    ‡  ‡
    ‡  ‡            ‡  ‡
    ‡  ‡    INFORM1    ‡  ‡
    ˆ˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜>ˆ˜˜˜·
    ‡  ‡    req.ind    ‡920‡
    ‡  ‡            ‡921‡
    ‡  ‡   SETUP REJECT   ‡923‡
    ˆ˜˜˜·<<<<‡<- - - - - - ‡<<<<‡924‡
    ‡  ‡    req.ind    ‡  ‡
    ‡  ‡            ‡  ‡
    ‡  ‡  INFORM1 REJECT   ‡  ‡
INFORM 1ˆ˜˜˜·<˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜·
REJECT ‡944‡    req.ind    ‡  ‡
<˜˜˜˜˜˜˜¯˜˜˜·            ‡  ‡
ind.  ‡  ‡            ‡  ‡
    ‡  ‡            ‡  ‡
NOTE 1: A call to this point is covered in figure 4.
NOTE 2: Depending on the progress of the basic call INFORM1 REJECT will be sent
simultaneously with the appropriate basic call clearing information flow.
Figure 8: Chaining of CUG domains
Figure 8 shows unsuccessful CUG calls between different CUG domains showing information flows across
relationship ry according to the functional model given in figure 2.

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SIST ETS 300
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