ETSI ETS 300 183 ed.1 (1992-10)

Integrated Services Digital Network (ISDN); Conference call, add-on (CONF) supplementary service; Service description

T/NA1(89)25

Digitalno omrežje z integriranimi storitvami (ISDN) – Dopolnilna storitev: konferenčni klic, postopno vzpostavljanje (CONF) – Opis storitve

General Information

• Status: Published
• Publication Date: 05-Nov-1992
• Technical Committee: NA 1 - User Interfaces, Services and Charging
• Current Stage: 12 - Completion
• Due Date: 30-Oct-1992
• Completion Date: 06-Nov-1992
• Ref Project: SIST ETS 300 183 E1:2003 - Integrated Services Digital Network (ISDN); Conference call, add-on (CONF) supplementary service; Service description

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ETS 300 183 E1:2003
01-december-2003
'LJLWDOQRRPUHåMH]LQWHJULUDQLPLVWRULWYDPL,6'1±'RSROQLOQDVWRULWHY
NRQIHUHQþQLNOLFSRVWRSQRY]SRVWDYOMDQMH&21)±2SLVVWRULWYH
Integrated Services Digital Network (ISDN); Conference call, add-on (CONF)
supplementary service; Service description
Ta slovenski standard je istoveten z: ETS 300 183 Edition 1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST ETS 300 183 E1:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 183 E1:2003

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SIST ETS 300 183 E1:2003
EUROPEAN ETS 300 183
TELECOMMUNICATION October 1992
STANDARD
Source: ETSI TC-NA Reference: T/NA1(89)25
ICS: 33.080
ISDN, supplementary service
Key words:
Integrated Services Digital Network (ISDN);
Conference call, add-on (CONF) supplementary service
Service description
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 - [e-mail]
X.400: Internet:
Tel.: [phone] - Fax: [phone]
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 300 183: October 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 .8
6 Procedures.9
6.1 Provision and withdrawal .9
6.2 Normal procedures .9
6.2.1 Activation, deactivation and registration.9
6.2.2 Erasure.9
6.2.3 Invocation and operation .9
6.2.3.1 Beginning the conference from the idle state .9
6.2.3.2 Beginning the conference from an active call.9
6.2.3.3 Managing the conference .10
6.2.3.4 Actions available to conferees.10
6.2.3.5 Notification of participants .11
6.2.4 Interrogation .11
6.3 Exceptional procedures .11
6.3.1 Activation, deactivation and registration.11
6.3.2 Erasure.11
6.3.3 Invocation and operation .11
6.3.4 Interrogation .11
7 Intercommunication considerations.12
7.1 Interworking with non ISDNs.12
7.2 Interworking with private ISDNs.12
8 Interaction with other supplementary services .12
8.1 Advice of charge services.12
8.1.1 Charging information at call set-up time.12
8.1.1.1 Conference controller .12
8.1.1.2 Conferees .13
8.1.2 Charging information during the call.13
8.1.2.1 Conference controller .13
8.1.2.2 Conferees .14
8.1.3 Charging information at the end of a call.15
8.1.3.1 Conference controller .15
8.1.3.2 Conferees .16
8.2 Call waiting.16
8.3 Call hold .16
8.4 Explicit call transfer.16
8.5 Number identification services.16
8.5.1 Calling line identification presentation .16
8.5.2 Calling line identification restriction .16
8.5.3 Connected line identification presentation.16
8.5.4 Connected line identification restriction.16
8.6 Closed user group.17
8.7 Completion of calls to busy subscriber .17
8.8 Conference services .17

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8.8.1 Conference call, add-on. 17
8.8.2 Meet-me conference. 17
8.9 Direct dialling in . 17
8.10 Diversion services . 17
8.10.1 Call forwarding unconditional. 17
8.10.2 Call forwarding busy . 17
8.10.3 Call forwarding no reply . 17
8.10.4 Call deflection . 17
8.11 Freephone. 18
8.12 Malicious call identification. 18
8.13 Multiple subscriber number . 18
8.14 Subaddressing . 18
8.15 Terminal portability. 18
8.16 Three party. 18
8.17 User-to-user signalling . 18
Annex A (informative): Management of active and held calls . 20
A.1 Introduction. 20
A.2 Functionality available to the served user controlling more than one call. 20
History. 21

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ETS 300 183: October 1992
Foreword
This European Telecommunication Standard (ETS) has been produced by the Network Aspects (NA)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
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 standpoint;
- 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 standard details the stage 1 aspects (overall service description) for the Conference call, add-on
(CONF) supplementary service. The stage 2 and stage 3 aspects are detailed in ETS 300 184 (1992) and
ETS 300 185 (1992), respectively.

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1 Scope
This standard defines the stage one of the Conference call, add-on (CONF) supplementary service for the
pan-European Integrated Services Digital Network (ISDN) as provided by European public
telecommunications operators. Stage one is an overall service description from the user's point of view
(see CCITT Recommendation I.130 [1]), but does not deal with the details of the human interface itself.
This standard defines the interworking requirements of private ISDNs with the public ISDN.
In addition, this standard specifies the base functionality where the service is provided to the user via 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 but does include interworking requirements of other
networks with the public ISDN.
Interactions with supplementary services not listed in Clause 8 are outside the scope of this standard.
Charging principles are outside the scope of this standard.
The CONF supplementary service enables a user to participate in, and control, a simultaneous
communication involving a number of users.
The CONF supplementary service is applicable to all circuit-switched telecommunications services
carrying speech.
This standard is applicable to the stage two and three standards for the ISDN CONF supplementary
service. The terms "stage two" and "stage three" are 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 two and three standards.
Furthermore, conformance to this standard is met by conforming to the stage three standard 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 standard 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 the
telecommunication services supported by an ISDN and network capabilities of
an ISDN".
[2] CCITT Recommendation I.112 (1988): "Vocabulary of terms for ISDNs".
[3] CCITT Recommendation I.210 (1988): "Principles of telecommunication
services supported by an ISDN and the means to describe them".
[4] CCITT Recommendation Q.9 (1988): "Vocabulary of switching and signalling
terms".

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3 Definitions
For the purposes of this standard, the following definitions apply:
Integrated Services Digital Network (ISDN): see CCITT Recommendation I.112 [2], § 2.3, definition
308.
Service; telecommunications service: see CCITT Recommendation I.112 [2], § 2.2, definition 201.
Supplementary service: see CCITT Recommendation I.210 [3], § 2.4.
Served user: the user to whom the CONF supplementary service is provided.
Basic access: see CCITT Recommendation Q.9 [4], § 1, definition 1551.
Primary rate access: see CCITT Recommendation Q.9 [4], § 1, definition 1552.
Conference: a call having the capability of involving a number of users who can communicate
simultaneously.
Conference controller: the (served) user who invokes the CONF supplementary service and controls the
addition and removal of conferees.
Conferee: any user involved in the conference, other than the conference controller.
Party: any user participating in the conference.
Private communication: a communication between the conference controller and another user who may
be a past/potential conferee. This communication is entirely separate from the conference.
(Existing) active call: a call for which the connection has been established.
Idle state: in this state, the user invokes the CONF supplementary service without an associated call.
4 Symbols and abbreviations
ISDN Integrated Services Digital Network
CONF Conference call, add-on
PSTN Public Switched Telephone Network
5 Description
The CONF supplementary service shall apply to the basic access and to the primary rate access.
The CONF supplementary service enables a user to participate in and control a simultaneous
communication involving a number of users.
The CONF supplementary service can be invoked from the idle state. As a network option, the CONF
supplementary service can be invoked from an existing active call.
When the CONF supplementary service is invoked, conference resources are allocated to the served
user. In the case of invocation from an active call, this call will be connected to the conference resources.

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6 Procedures
6.1 Provision and withdrawal
The CONF supplementary service shall be provided by prior arrangement with the service provider.
The maximum number of parties allowed in a conference shall be a network option.
The CONF supplementary service shall be withdrawn by the service provider upon request by the
subscriber or for service provider reasons.
6.2 Normal procedures
6.2.1 Activation, deactivation and registration
Not applicable.
6.2.2 Erasure
Not applicable.
6.2.3 Invocation and operation
The CONF supplementary service can be invoked from the idle state. As a network option, the CONF
supplementary service can be invoked from an existing call.
NOTE: It is the responsibility of the user to ensure that the calls are compatible.
6.2.3.1 Beginning the conference from the idle state
The served user can request the CONF supplementary service. The number of parties required in the
conference can be indicated in the request.
If the number of parties is not indicated, a maximum value allowed by the network shall be used.
A successful request for the CONF supplementary service shall result in the network reserving conference
resources capable of serving the required number of parties.
6.2.3.2 Beginning the conference from an active call
As a network option, the following procedures can be used when a user already has a call on which the
connection has been established.
The served user can request the CONF supplementary service, indicating in the request that an existing
call shall be connected to the conference. The number of parties required in the conference can be
indicated in the request.
If the number of parties is not indicated, the maximum value allowed by the network shall be used.
A successful request for the CONF supplementary service shall result in the network assigning
conference resources capable of supporting the required number of parties. The other user in the call
indicated in the request for the CONF supplementary service shall be connected to the conference.
If the call indicated in the request was not held by the served user, then the served user shall be
connected to the conference. If the call indicated in the request was held by the served user, then the
conference shall be held by the served user.
The conferee shall be notified that their call has been added to the conference (see subclause 6.2.3.5).

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6.2.3.3 Managing the conference
During the conference, the served user can:
- invoke the call hold supplementary service in order to put their own connection to the conference on
hold. Whilst the conference is on hold, the remaining parties in the conference can communicate
with each other. The served user can then make a call to a potential conferee;
- create a private communication with one of the parties. The network shall place the conference on
hold for the served user. The required party shall be removed from the conference and connected
to the served user. The private communication shall be considered as a normal call. Whilst the
conference is on hold, the remaining parties can still communicate with each other;
- terminate the entire conference, i.e. all connections to the conference shall be terminated and the
conference resources shall be released;
- explicitly disconnect one party from the conference, i.e. the connection between that party and the
conference shall be terminated;
- add a conferee, to which a private communication has been established, provided the maximum
number of parties is not exceeded. For an incoming call on which the connection has already been
established, the conference controller can request that this call be added into the conference using
the add-on procedures. As a network option, this request can be accepted or rejected;
After addition of a party, the connection between the served user and the conference shall remain in
the state it was prior to the request to add the potential conferee. If the conference was on hold, the
served user shall retrieve the conference in order to participate in the conference;
- isolate a conferee. The conferee indicated by the conference controller shall be prevented from
communicating with the conference without being removed from it;
- reattach a conferee previously isolated. The conferee can communicate again with the other parties
in the conference.
If only one conferee remains, or no conferees remain, as a result of any of the above operations, the
conference shall be considered to still be in progress.
6.2.3.4 Actions available to conferees
During the conference any of the conferees can:
- invoke the call hold supplementary service in order to put their own connection to the conference on
hold; or
- release their connection to the conference.
If only one conferee remains, or no conferees remain, as a result of any of the above operations, the
conference shall be considered to still be in progress.

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6.2.3.5 Notification of participants
Each participant in the conference shall be informed by the service provider about the state of their call
when a change occurs. When a party is added to the conference, a party is explicitly disconnected from
the conference, a party is removed from the conference in order to create a private communication with
that party, a party is isolated from the conference, or a party is reattached to the conference, then all the
remaining conferees shall be informed.
Conferees shall not be informed when the conference controller holds or retrieves the whole conference.
NOTE: During an interim period of time, some networks may not support the transfer of
notifications.
6.2.4 Interrogation
Not applicable.
6.3 Exceptional procedures
6.3.1 Activation, deactivation and registration
Not applicable.
6.3.2 Erasure
Not applicable.
6.3.3 Invocation and operation
If a user tries to invoke the CONF supplementary service and the service provider cannot comply with that
request, the service provider shall deny the request and give the served user the reason for rejection.
Possible reasons for rejection are:
- the CONF supplementary service is not subscribed to;
- the requested number of conferees exceeds the maximum number allowed by the network (N);
- resources cannot be allocated.
If the service provider cannot satisfy the request to manipulate the conference (e.g. a request to add a
further conferee fails, for example, because the conference has been cleared, the maximum number of
conferees allowed has already been reached, or closed user group restrictions are not met) the served
user shall receive an indication that the request is rejected, with the reason.
If the served user attempts to invoke the CONF supplementary service using the procedures in subclause
6.2.3.2, and the network can allocate the conference resources, but cannot connect the user to the
conference for any reason, then the attempt to invoke the CONF supplementary service shall be rejected
and the conference resources shall be released.
In all cases of rejection, the served user's calls shall remain in the same state they were in before the
rejected request was received.
6.3.4 Interrogation
Not applicable.

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7 Intercommunication considerations
NOTE: In the case of a conference with conferees belonging to different networks (e.g. in
different countries or continents), a decrease in quality of service parameters for the
speech connection between those conferees may arise, e.g. long transmission delay
or unacceptable attenuation of audio signals. A network may provide some
precautions, e.g. inhibit addition to the conference of connections from which it is
known that the quality of service is near the lower limit for an individual call (e.g.
connections via satellites).
7.1 Interworking with non ISDNs
The conferees can belong to the Public Switched Telephone Network (PSTN) or any network supporting
speech.
NOTE: If interworking with non-ISDNs occurs, notification to conferees may not be possible.
7.2 Interworking with private ISDNs
A private ISDN can transfer the service invocation request (at service invocation time) to a public ISDN.
The conference as seen by the public ISDN shall then be treated as a conference requested by a user
directly connected to the public ISDN.
The conferees can belong to any private ISDN.
When a remote user is on a network different from that of the served user (e.g. one user is on a private
ISDN and the other user on a public ISDN), indications to the remote user shall be sent to the remote
user's network for forwarding to the remote user.
Two conferences in different networks (e.g. one in a private ISDN and the other in a public ISDN) can be
connected together. The served user of a conference in one network shall act as a conferee of the
conference in the other network.
8 Interaction with other supplementary services
8.1 Advice of charge services
8.1.1 Charging information at call set-up time
8.1.1.1 Conference controller
NOTE 1: Some networks may not support the advice of charge: charging information at call set-
up time supplementary service in conjunction with the CONF supplementary service,
or may only give part of the information, e.g. due to off-line processing of the charges
associated with the CONF supplementary service. In the former case an indication that
the advice of charge: charging information at call set-up time supplementary service is
not available should be given on invocation of the CONF supplementary service if the
advice of charge: charging information at call set-up time supplementary service had
been invoked.
Invocation of the CONF supplementary service from the idle state:
The conference controller can invoke the advice of charge: charging information at call set-up time
supplementary service at the same time as the CONF supplementary service is invoked. Updated
charging rate information for the whole conference shall be given to the conference controller if the
charging rate for the conference is changed, i.e. each time the rate changes, the new charge rate shall be
given by means of a single indication which shall apply to the whole conference.

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Invocation of the CONF supplementary service from an active call:
If the advice of charge: charging information at call set-up time supplementary service has been invoked
for the initial call, then it shall be invoked automatically for the whole conference.
If the advice of charge: charging information at call set-up time supplementary service has not been
invoked for the initial call, then the conference controller can invoke the advice of charge: charging
information at call set-up time supplementary service at the same time as the CONF supplementary
service is invoked.
Addition of a call to a conference:
For calls between the conference controller and potential conferees which are outside the conference, the
normal procedures for the advice of charge: charging information at call set-up time supplementary
service shall apply. When a call for which the advice of charge: charging information at call set-up time
supplementary service has been invoked, is added to the conference, then further charging rate
information shall not be given for this call.
NOTE 2: Further charging rate information for communication with the new conferee is
considered to be part of the charging rate information for the conference.
Creating a private communication with one of the parties:
In this case the private communication shall be considered as a new call between the conference
controller and the individual party. If the advice of charge: charging information at call set-up time
supplementary service has been invoked for the conference, it shall be invoked automatically for the new
call when the private communication is established.
Other operation on the conference:
No impact, i.e. neither supplementary service shall affect the operation of the other supplementary
service.
8.1.1.2 Conferees
No impact, i.e. neither supplementary service shall affect the operation of the other supplementary
service.
8.1.2 Charging information during the call
8.1.2.1 Conference controller
NOTE 1: Some networks may not support the advice of charge: charging information during the
call supplementary service in conjunction with the CONF supplementary service, or
may only give part of the information, e.g. due to off-line processing of the charges
associated with the CONF supplementary service. In the former case an ind
...