SIST ETS 300 056/A1 E1:2003

• Abstract:

  This amendment considers the interaction with CFNR and CD.

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.080 - Integrated Services Digital Network (ISDN)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI ETS 300 056/A1 ed.1 (1996-09) - Integrated Services Digital Network (ISDN); Call Waiting (CW) supplementary service; Service description

SIST ETS 300 056/A1 E1:2003 is the Slovenian standard that reproduces ETS 300 056/A1 Edition 1 from ETSI. It covers the Integrated Services Digital Network (ISDN) Call Waiting (CW) supplementary service and clarifies how CW behaves when call forwarding no reply and call deflection are involved.

What does SIST ETS 300 056/A1 E1:2003 specify?

SIST ETS 300 056/A1 E1:2003 specifies an amendment to the ISDN Call Waiting (CW) supplementary service description. Its scope is limited to the interaction with call forwarding no reply and call deflection, so it is mainly about how diverted calls and waiting-call notifications are handled in those cases.

The document is organized as an amendment to ETS 300 056 (1991). The foreword explains the purpose, and the amendment text inserts or replaces wording in clause 7, subclause 8.10.3, and subclause 8.10.4. For a reader, that means the standard is meant to be applied together with the base CW service description, not read as a full standalone service specification.

What are the key requirements of SIST ETS 300 056/A1 E1:2003?

SIST ETS 300 056/A1 E1:2003 adds clarifications on when a CW notification is allowed, when it is blocked, and what happens if a call is diverted. The main practical point is that network behavior depends on the interaction between CW and the diversion services already active on the call.

Notification to the calling user

Clause 7 says that if an ISDN user does not want a call waiting notification sent to the calling user, that requirement may not always be met. The example given is voice notification when the calling user is outside the called user’s ISDN. In practice, this warns operators that notification control can depend on network boundaries and the signaling path.

Interaction with call forwarding no reply

Subclause 8.10.3 says that if subscriber B has call forwarding no reply (CFNR) active, a waiting call is still offered as described in the standard. If the CFNR timer expires before the call is answered, CFNR is invoked, the call is forwarded, and CW ceases. This tells implementers that CW and CFNR can both apply, but CFNR takes over once its timer expires.

The same subclause says that if the forwarding user subscribes to “No” for the option “Calling user receives notification that the call has been forwarded,” then no CW notification shall be sent to the calling user from the forwarded-to user. In multiple diversions, CW notification is only sent if all diverting users allow notification that the call has been forwarded. A forwarded call can also invoke CW.

Interaction with call deflection

Subclause 8.10.4 says that when user B receives the call waiting indication, user B can invoke call deflection. If call deflection after alerting is used and the diverting user has subscribed to “No” for “Calling user receives notification that the call has been deflected,” then no CW notification shall be sent to the calling user from the deflected-to user. In multiple diversions, notification is only sent if all diverting users allow notification that the call has been deflected. A deflected call can also invoke CW.

What terms does SIST ETS 300 056/A1 E1:2003 define?

SIST ETS 300 056/A1 E1:2003 uses a small set of service terms consistently in its amendment text.

• Integrated Services Digital Network (ISDN) - the digital network environment in which the CW supplementary service operates.
• Call Waiting (CW) - the supplementary service covered by the base document and clarified by this amendment.
• Call forwarding no reply (CFNR) - a diversion service that forwards a call when user B does not answer in time.
• Call deflection (CD) - a diversion service that user B can invoke after alerting to send the call elsewhere.
• Calling user - the user originating the call who may receive or not receive CW-related notification.
• Called user / subscriber B - the user receiving the call and the person whose diversion and waiting-call behavior is described.
• Forwarded-to user / deflected-to user - the destination user who may be involved in CW notification after diversion.

Who uses SIST ETS 300 056/A1 E1:2003?

SIST ETS 300 056/A1 E1:2003 is used by telecom standards engineers, ISDN network operators, switch and service platform vendors, and test teams that need to implement or verify CW behavior. It is also relevant to quality managers and buyers who need to check how supplementary services interact before specifying or accepting an ISDN service implementation.

The document is especially useful for tasks such as service configuration, interworking checks, and conformance testing of diverted-call behavior. It helps people decide how the network should behave when CW meets CFNR or CD.

What changed in SIST ETS 300 056/A1 E1:2003 from the previous edition?

SIST ETS 300 056/A1 E1:2003 reproduces Amendment 1 to the first edition of ETS 300 056 (1991). The amendment changes two subclauses to clarify the interaction of CW with call forwarding no reply and call deflection, especially the rules for notification to the calling user.

Which standards are used with SIST ETS 300 056/A1 E1:2003?

The base document named with this amendment is ETS 300 056 (1991), which this amendment modifies. That base standard provides the original service description for ISDN Call Waiting, while this amendment adds the interaction rules for CFNR and CD.

What does the SIST ETS 300 056/A1 E1:2003 document contain?

SIST ETS 300 056/A1 E1:2003 contains a foreword, amendment instructions, and document history. The amendment text is concentrated in clause 7, subclause 8.10.3, and subclause 8.10.4, where it adds wording on notification limits and on how CW behaves during forwarded or deflected calls.

It is a short technical amendment rather than a full service specification. In practice, it is used to interpret or test edge cases in ISDN supplementary service interaction, especially where more than one diversion mechanism may apply to the same call.

SLOVENSKI STANDARD
01-december-2003
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Integrated Services Digital Network (ISDN); Call Waiting (CW) supplementary service;
Service description
Ta slovenski standard je istoveten z: ETS 300 056/A1 Edition 1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

ETS 300 056
AMENDMENT A1
September 1996
Source: ETSI TC-NA Reference: RE/NA-010047
ICS: 33.020
Key words: ISDN, CW, supplementary service
This amendment A1 modifies
the European Telecommunication Standard ETS 300 056 (1991)
Integrated Services Digital Network (ISDN);
Call Waiting (CW) supplementary service;
Service description
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
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Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail]
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 1996. All rights reserved.

Page 2
ETS 300 056: October 1991/A1: September 1996
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 3
ETS 300 056: October 1991/A1: September 1996
Foreword
This amendment to ETS 300 056 (1991) has been produced by the Network Aspects (NA) Technical
Committee of the European Telecommunications Standards Institute (ETSI).
This amendment contains changes to two subclauses of ETS 300 056 (1991) to clarify the interaction
situation for the Call Waiting (CW) supplementary service in relation to the call forwarding no reply and
call deflection supplementary services.
Transposition dates
Date of adoption of this amendment: 6 September 1996
Date of latest announcement of this amendment (doa): 31 December 1996
Date of l
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