ETSI TS 101 818-1 V1.1.1 (2000-07)

Integrated Services Digital Network (ISDN); Digital Subscriber Signalling System No. one (DSS1); Trunk Hunting (TH) supplementary service; Part 1: Protocol specification

DTS/SPAN-05172-1

Digitalno omrežje z integriranimi storitvami (ISDN) – Protokol digitalne naročniške signalizacije št. 1 (DSS1) – Dopolnilna storitev: iskanje prenosnika v skupini (TH) – 1. del: Specifikacija protokola

General Information

• Status: Published
• Publication Date: 17-Jul-2000
• Technical Committee: SPAN 5 4 - Supplementary services
• Current Stage: 12 - Completion
• Due Date: 26-Jun-2000
• Completion Date: 18-Jul-2000
• Ref Project: SIST-TS ETSI/TS 101 818-1 V1.1.1:2005 - Integrated Services Digital Network (ISDN); Digital Subscriber Signalling System No. one (DSS1); Trunk Hunting (TH) supplementary service; Part 1: Protocol specification

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
01-januar-2005
'LJLWDOQRRPUHåMH]LQWHJULUDQLPLVWRULWYDPL,6'1±3URWRNROGLJLWDOQHQDURþQLãNH
VLJQDOL]DFLMHãW'66±'RSROQLOQDVWRULWHYLVNDQMHSUHQRVQLNDYVNXSLQL7+±
GHO6SHFLILNDFLMDSURWRNROD
Integrated Services Digital Network (ISDN); Digital Subscriber Signalling System No. one
(DSS1); Trunk Hunting (TH) supplementary service; Part 1: Protocol specification
Ta slovenski standard je istoveten z: TS 101 818-1 Version 1.1.1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST-TS ETSI/TS 101 818-1 V1.1.1:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
ETSI TS 101 818-1 V1.1.1 (2000-07)
Technical Specification
Integrated Services Digital Network (ISDN);
Digital Subscriber Signalling System No. one (DSS1);
Trunk Hunting (TH) supplementary service;
Part 1: Protocol specification

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
2 ETSI TS 101 818-1 V1.1.1 (2000-07)
Reference
DTS/SPAN-05172-1
Keywords
ISDN, DSS1, supplementary service, TH,
protocol
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.:[phone] Fax:[phone]
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
Individual copies of the present document can be downloaded from:
http://www.etsi.org
The present document may be made available in more than one electronic version or in print. In any case of existing or
perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF).
In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network
drive within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at http://www.etsi.org/tb/status/
If you find errors in the present document, send your comment to:
[e-mail]
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 2000.
All rights reserved.
ETSI

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
3 ETSI TS 101 818-1 V1.1.1 (2000-07)
Contents
Intellectual Property Rights.4
Foreword .4
1 Scope.5
2 References.5
3 Definitions and abbreviations .6
3.1 Definitions.6
3.2 Abbreviations .7
4 Description .7
5 Operational Requirements.7
5.1 Provision and Withdrawal .7
5.2 Requirements on the originating network side.8
5.3 Requirements on the destination network side .8
6 Coding requirements .8
6.1 Coding of the Facility information element components.8
7 State Definitions.10
8 Signalling Procedures at the coincident S and T reference point .10
9 Procedures for interworking with private ISDNs.10
9.1 Activation, deactivation and interrogation.10
9.1.1 Temporary Hunt Group withdrawal.11
9.1.1.1 Normal operation .11
9.1.1.2 Exceptional procedures .12
9.1.2 Cancellation of Temporary Hunt Group withdrawal.12
9.1.2.1 Normal operation .12
9.1.2.2 Exceptional procedures .13
9.1.3 Interrogation .14
9.2 Invocation and Operation .14
9.2.1 Normal operation.14
9.2.2 Exceptional procedures.14
10 Interactions with other networks.14
11 Interaction with other supplementary services.14
12 Parameter values (timers).14
13 Dynamic description (SDL diagrams).15
Annex A (informative): Examples of Signalling flows.22
History.23
ETSI

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
4 ETSI TS 101 818-1 V1.1.1 (2000-07)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://www.etsi.org/ipr).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Services and Protocols for
Advanced Networks (SPAN).
The present document is part 1 of a multi-part standard covering the Digital Subscriber Signalling System No. one
(DSS1) protocol specification for the Integrated Services Digital Network (ISDN) Trunk Hunting (TH) supplementary
service, as described below:
Part 1: "Protocol specification";
Part 2: "Protocol Implementation Conformance Statement (PICS) proforma specification";
Part 3: "Test Suite Structure and Test Purposes (TSS&TP) specification for the user";
Part 4: "Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT)
proforma specification for the user";
Part 5: "TSS&TP specification for the network";
Part 6: "ATS and partial PIXIT proforma specification for the network".
In accordance with CCITT Recommendation I.130 [6], the following three level structure is used to describe the
supplementary telecommunication services as provided by European public telecommunications operators under the
pan-European 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.
The present document details the stage 3 aspects (signalling system protocols and switching functions) needed to
support the Trunk Hunting supplementary service. The stage 2 aspects of the Trunk Hunting supplementary service have
not been specified.
ETSI

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
5 ETSI TS 101 818-1 V1.1.1 (2000-07)
1 Scope
The present document specifies the stage three of the Trunk Hunting (TH) supplementary service for the pan-European
Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators at the T
reference point or coincident S and T reference point (as defined in CCITT Recommendation I.411 [12] ) by means of
the Digital Subscriber System No. one (DSS1). Stage three identifies the protocol procedures and switching functions
needed to support a telecommunications service (see CCITT Recommendation I.130 [6]).
In addition, the present document specifies the protocol requirements at the T reference point where the service is
provided to the user via an intermediate private ISDN.
The present document does not specify the additional protocol requirements where the service is provided to the user via
a telecommunications network that is not an ISDN.
The TH supplementary service enables calls to a single ISDN number to be offered to a free access in a group of
accesses to which a private ISDN is connected (T reference point).
The principles for the selection of a free channel within an access are a network provider matter as part of the basic call
procedures and so are outside the scope of the present document.
The TH service is applicable to all circuit-switched telecommunication services.
Further parts of EN 301 484 [13] specify the method of testing required to identify conformance to the present
document.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
• A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same
number.
[1] ETSI EN 300 195-1: "Integrated Services Digital Network (ISDN); Supplementary service
Interactions; Digital Subscriber Signalling System No. one (DSS1) protocol; Part 1: Protocol
Specification".
[2] ETSI EN 300 196-1: "Integrated Services Digital Network (ISDN); Generic functional protocol for
the support of supplementary services; Digital Subscriber Signalling System No. one (DSS1)
protocol; Part 1: Protocol specification".
[3] ETSI EN 300 403-1: "Integrated Services Digital Network (ISDN); Digital Subscriber Signalling
System No. one (DSS1) protocol; Signalling network layer for circuit-mode basic call control;
Part 1: Protocol specification [ITU-T Recommendation Q.931 (1993), modified]".
[4] ITU-T Recommendation I.112: "Vocabulary of terms for ISDNs".
[5] ITU-T Recommendation I.210: "Principles of telecommunication services supported by an ISDN
and the means to describe them".
[6] CCITT Recommendation I.130: "Method for the characterization of telecommunication services
supported by an ISDN and network capabilities of an ISDN".
[7] ITU-T Recommendation I.221 (1993): "Common specific characteristics of services".
ETSI

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
6 ETSI TS 101 818-1 V1.1.1 (2000-07)
[8] CCITT Recommendation Z.100: "Specification and Description Language (SDL)".
[9] ITU-T Recommendation E.164: "The International public telecommunications Numbering plan".
[10] ITU-T Recommendation X.680: "Information technology – Abstract Syntax Notation One
(ASN.1): Specification of basic notation".
[11] ITU-T Recommendation X.880: "Information technology – remote operations: concepts, model
and notation".
[12] CCITT Recommendation I.411: "ISDN user-network interfaces - Reference configurations".
[13] ETSI EN 301 484: "Integrated Services Digital Network (ISDN); Line Hunting (LH)
supplementary service; Digital Subscriber Signalling System No. one (DSS1)".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Access: General term, used in the present document, denoting basic accesses and/or primary rate accesses.
Basic access: See ITU-T Recommendation I.112 [4], subclause 2.4, definition 425.
Basic call procedures: Procedures by which a call (as an instance of a basic telecommunications service) is established
and terminated.
Channels busy: See ITU-T Recommendation I.221 [7], subclause 2.1.3.
Cyclic hunting: Selection of a free access always starts at the next access after the one used last, and follows a fixed
order. When the last access in the group is reached, the search continues from the beginning of the group until all
accesses in the group have been searched.
Free access: Access for which the channels busy condition does not exist (i.e., one or more information channels are
available).
Hunt group: Number of accesses over which the TH supplementary service applies for the assigned ISDN number.
Hunt group number: The ISDN number to which the TH supplementary service is allocated and to which ISDN basic
services and supplementary services relating to the hunt group are allocated.
Hunt group withdrawal: Request by the private ISDN in order to temporarily prevent an access from receiving calls to
the hunt group (existing calls are not affected).
Integrated Services Digital Network (ISDN): See ITU-T Recommendation I.112 [4], subclause 2.3, definition 308.
ISDN number: Number conforming to the numbering plan and structure specified in
ITU-T Recommendation E.164 [9].
Primary rate access: See ITU-T Recommendation I.112 [4], subclause 2.4, definition 426.
Sequential hunting: Selection of a free access always starts with the same access and then follows a fixed order until all
accesses in the hunt group have been searched or a free access is found.
Served user: User (i.e., a private ISDN) to whom the TH service is provided.
Service; telecommunications service: See ITU-T Recommendation I.112 [4], subclause 2.2, definition 201.
Supplementary service: See ITU-T Recommendation I.210 [5], subclause 2.4.
ETSI

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
7 ETSI TS 101 818-1 V1.1.1 (2000-07)
Uniform Hunting:
NOTE: Uniform hunting is not explicitly identified but not necessarily excluded for future enhancement.
3.2 Abbreviations
For the purpose of the present document, the following abbreviations apply:
HG Hunt Group
ISDN Integrated Services Digital Network
TH Trunk Hunting
4 Description
The TH supplementary service is intended for use on accesses to which a private ISDN is connected to the public ISDN
at the T reference point.
The TH supplementary service enables calls to an ISDN number assigned to the private ISDN (i.e. the hunt group
number and any DDI number associated with the hunt group number) to be offered to a free access in a hunt group. The
hunt group can comprise basic accesses, primary rate accesses, or a mixture of these types of accesses.
The TH supplementary service applies to accesses within a hunt group that are connected to the same exchange. As a
network operator option the TH supplementary service can be used to create a multi-nodal service that allows Trunk
Hunting across accesses on multiple exchanges. The specification of the multi-nodal service is outside the scope of the
present document.
As a network option an access can be member of more than one hunt group. The maximum number of hunt groups of
which an access can be a member, shall be a network option with an upper limit of 15.
The method of selecting the access shall be either sequential, uniform or cyclic hunting.
As a service provider option, the TH supplementary service can be offered with the possibility for hunt group
withdrawal. If the option of "hunt group withdrawal" is supported by the service provider, the served user can request
that an access can be temporarily prevented from receiving calls to the hunt group.
Services can be subscribed to on the hunt group identified by the hunt group number.
5 Operational Requirements
5.1 Provision and Withdrawal
The TH supplementary service shall be provided after prior arrangement with the network provider.
The TH supplementary service shall be withdrawn at the network provider or subscriber's request.
The network option having an impact on the protocol is described in Table 1.
Table 1: Network options
Network option Values
Max number of HGs for which one access may be a member 1 to 15
As a network option, the TH supplementary service can be offered with subscription options which are provided on a
hunt group basis. The subscription options are summarized in Table 2.
If the network supports the option "hunt group withdrawal" then the subscription option for "hunt group withdrawal"
shall be available to all accesses of the hunt group.
ETSI

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

SIST-TS ETSI/TS 101 818-1 V1.1.1:2005
8 ETSI TS 101 818-1 V1.1.1 (2000-07)
Table 2: Subscription option applying for the whole hunt group
Subscription Option Values
Selection Method - sequential hunting
- cyclic hunting
- uniform hunting (see Note)
Hunt group withdrawal - available
- not available
NOTE: Uniform hunting is not explicitly identified as an option but is not necessarily excluded for
future enhancement.
If the TH supplementary service is provided without the subscription option "selection method", the network shall
determine the selection method.
If the network does not offer the subscription option "hunt group withdrawal", then the accesses cannot be withdrawn
from the hunt group by the user.
5.2 Requirements on the originating network side
The procedures at the T reference point in EN 300 403-1 [3], subclause 5.1 and the procedures of Clause 9 in the
present document shall apply.
5.3 Requirements o
...