Integrated Services Digital Network (ISDN); Application of the Bearer Capability (BC), High Layer Compatibility (HLC) and Low Layer Compatibility (LLC) information elements by terminals supporting ISDN services

Inclusion of BC, LLC, HLC codings for new basic telecommunication services.

Digitalno omrežje z integriranimi storitvami (ISDN) - Aplikacija informacijskih elementov: nosilna zmožnost (BC), združljivost zgornjih plasti (HCL) in združljivost spodnjih plasti (LLC) pri terminalih, ki podpirajo storitve ISDN

General Information

Status
Published
Publication Date
31-Mar-2005
Withdrawal Date
30-Sep-2003
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Apr-2005
Due Date
01-Apr-2005
Completion Date
01-Apr-2005

Buy Standard

Technical report
TP ETSI/ETR 018 E4:2005
English language
77 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TP ETSI/ETR 018 E4:2005
01-april-2005
Digitalno omrežje z integriranimi storitvami (ISDN) - Aplikacija informacijskih
elementov: nosilna zmožnost (BC), združljivost zgornjih plasti (HCL) in združljivost
spodnjih plasti (LLC) pri terminalih, ki podpirajo storitve ISDN
Integrated Services Digital Network (ISDN); Application of the Bearer Capability (BC),
High Layer Compatibility (HLC) and Low Layer Compatibility (LLC) information elements
by terminals supporting ISDN services
Ta slovenski standard je istoveten z: ETR 018 Edition 4
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST-TP ETSI/ETR 018 E4:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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

SIST-TP ETSI/ETR 018 E4:2005

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

SIST-TP ETSI/ETR 018 E4:2005
ETSI ETR 018
TECHNICAL November 1995
REPORT Fourth Edition
Source: ETSI TC-SPS Reference: RTR/SPS-05058
ICS: 33.080
ISDN, DSS1, coding, BC, LLC, HLC, IE
Key words:
Integrated Services Digital Network (ISDN);
Application of the Bearer Capability (BC),
High Layer Compatibility (HLC) and
Low Layer Compatibility (LLC) information elements
by terminals supporting ISDN services
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 1995. All rights reserved.

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

SIST-TP ETSI/ETR 018 E4:2005
Page 2
ETR 018: November 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-TP ETSI/ETR 018 E4:2005
Page 3
ETR 018: November 1995
Contents
Foreword .7
Introduction.7
1 Scope .9
2 References.9
3 Abbreviations.10
4 General principles applicable to all services .11
5 Impact of interworking situations.12
5.1 Incoming calls from non-ISDNs .12
5.2 BC and LLC application guidelines .12
6 Request and recognition of a basic telecommunication service in an ISDN environment .13
6.1 Request and recognition of a circuit-mode bearer service .13
6.1.1 Circuit-mode 64 kbit/s 8 kHz structured bearer service category usable for
speech information transfer.13
6.1.1.1 Request by a calling terminal equipment.13
6.1.1.2 Compatibility at the called terminal equipment .14
6.1.2 Circuit-mode 64 kbit/s unrestricted 8 kHz structured bearer service
category.15
6.1.2.1 Request by a calling terminal equipment.15
6.1.2.2 Compatibility at the called terminal equipment .15
6.1.3 Circuit-mode 64 kbit/s 8 kHz structured bearer service category usable for
3,1 kHz audio information transfer .16
6.1.3.1 Request by a calling terminal equipment.16
6.1.3.2 Compatibility at the called terminal equipment .16
6.1.4 Circuit-mode multiple-rate unrestricted 8 kHz structured bearer service
category.17
6.1.4.1 Request by a calling terminal equipment.17
6.1.4.2 Compatibility at the called terminal equipment .17
6.2 Packet mode bearer service categories .18
6.2.1 Virtual call bearer services (support of X.25 terminal equipment allowing
access to the ISDN virtual circuit service (ITU-T Recommendation X.31,
Case B)) .18
6.2.1.1 Access through the B-channel.18
6.2.1.1.1 Request by a calling terminal
equipment .18
6.2.1.1.2 Compatibility at the called terminal
equipment .18
6.2.1.2 Access through the D-channel .19
6.2.1.2.1 Request by a calling terminal
equipment .19
6.2.1.2.2 Compatibility at the called terminal
equipment .19
6.3 Request and recognition of a teleservice.20
6.3.1 Telephony 3,1 kHz teleservice .20
6.3.1.1 Request by a calling terminal equipment.20
6.3.1.2 Compatibility at the called terminal equipment .21
6.3.2 Telefax G4 service (using circuit-mode bearer capability) .22
6.3.2.1 Request by a calling terminal equipment.22
6.3.2.2 Compatibility at the called terminal equipment .24

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

SIST-TP ETSI/ETR 018 E4:2005
Page 4
ETR 018: November 1995
6.3.3 Syntax-based videotex teleservice . 26
6.3.3.1 Access to the syntax-based videotex teleservice using an
end-to-end circuit-switched connection. 26
6.3.3.1.1 Request by a calling terminal
equipment . 26
6.3.3.1.2 Compatibility at the called terminal
equipment . 28
6.3.3.2 Access to the syntax-based videotex teleservice via a
PSPDN access unit (ITU-T Recommendation X.31,
Case A) . 30
6.3.3.2.1 Request by a calling terminal
equipment . 30
6.3.3.2.2 Compatibility at the called terminal
equipment . 31
6.3.3.3 Access to the syntax-based videotex teleservice using a
packet-switched connection through the B-channel . 32
6.3.3.3.1 Request by a calling terminal . 32
6.3.3.3.2 Compatibility at the called terminal
equipment . 32
6.3.3.4 Access to the syntax-based videotex service using a
packet-switched connection through the D-channel . 33
6.3.3.4.1 Request by a calling terminal using
the D-channel. 33
6.3.3.4.2 Compatibility at the called terminal
equipment . 33
6.3.4 Telephony 7 kHz teleservice. 34
6.3.4.1 Request by a calling terminal equipment . 34
6.3.4.2 Compatibility at the called terminal equipment. 35
6.3.5 Videotelephony teleservice. 36
6.3.5.1 Codings required for the service specified in ETS 300 264 36
6.3.5.1.1 First connection. 36
6.3.5.1.2 Second connection. 39
6.3.5.2 Codings required for short term procedures . 41
6.3.5.2.1 Request by a calling terminal
equipment . 41
6.3.5.2.2 Compatibility at the called terminal
equipment . 43
6.3.6 Facsimile group 2/3 service. 45
6.3.6.1 Request by a calling terminal equipment . 45
6.3.6.2 Compatibility at the called terminal equipment. 45
6.3.7 File Transfer & Access Management (FTAM) teleservice. 46
6.3.7.1 Request by a calling terminal equipment . 46
6.3.7.2 Compatibility at the called terminal equipment. 48
6.3.8 Eurofile transfer teleservice . 50
6.3.8.1 Request by a calling terminal. 50
6.3.8.2 Compatibility at the called terminal equipment. 52
7 Coding examples applicable to specific user applications. 54
7.1 Specific user applications of the circuit-mode 64 kbit/s unrestricted 8 kHz structured
bearer service. 54
7.1.1 Support of terminal adapters V.110/X.30 . 54
7.1.1.1 Synchronous mode of operation . 54
7.1.1.1.1 Request by a calling terminal
equipment . 54
7.1.1.1.2 Compatibility at the called terminal
equipment . 56
7.1.1.2 Asynchronous mode of operation . 58
7.1.1.2.1 Request by a calling terminal
equipment . 58
7.1.1.2.2 Compatibility at the called terminal
equipment . 60

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

SIST-TP ETSI/ETR 018 E4:2005
Page 5
ETR 018: November 1995
7.1.2 Support of X.25 terminal equipment allowing access to PSPDN via an
access unit (ITU-T Recommendation X.31, Case A).62
7.1.2.1 Rate adaption using X.31 HDLC flag stuffing.62
7.1.2.1.1 Request by a calling terminal
equipment .62
7.1.2.1.2 Compatibility at the called terminal
equipment .63
7.1.2.2 Rate adaption corresponding to CCITT
Recommendations V.110/X.30.64
7.1.2.2.1 Request by a calling terminal
equipment .64
7.1.2.2.2 Compatibility at the called terminal
equipment .65
7.1.3 Support of teletex terminals using circuit-mode 64 kbit/s unrestricted
8 kHz-structured bearer capability.66
7.1.3.1 Request by a calling terminal equipment.66
7.1.3.2 Compatibility at the called terminal equipment .68
7.2 Specific user applications of the circuit mode 64 kbit/s 8 kHz structured bearer service
category usable for 3,1 kHz audio information transfer .70
7.2.1 Voice band data via modem.70
7.2.1.1 Request by a calling terminal equipment.70
7.2.1.2 Compatibility at the called terminal equipment .72
8 Interworking with non-European ISDNs supporting restricted 64 kbit/s transfer capability.73
8.1 Request by a calling terminal connected to a network supporting 64 kbit/s unrestricted
digital information transfer .73
8.2 Compatibility at the called terminal equipment connected to a network supporting
64 kbit/s unrestricted digital information transfer .73
8.3 Request by a calling terminal connected to a non-European network supporting
64 kbit/s restricted digital information transfer .74
8.4 Compatibility at the called terminal equipment connected to a non-European network
using restricted digital information transfer.74
9 Codings in the case where non-ISDNs are involved.75
9.1 Calls from PSTN to ISDN .75
9.2 Calls from PSPDN to ISDN.75
9.3 Calls from CSPDN to ISDN .75
Annex A: Bibliography .76
History.77

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

SIST-TP ETSI/ETR 018 E4:2005
Page 6
ETR 018: November 1995
Blank page

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

SIST-TP ETSI/ETR 018 E4:2005
Page 7
ETR 018: November 1995
Foreword
This ETSI Technical Report (ETR) has been produced by the Signalling Protocols and Switching (SPS)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
ETRs are informative documents resulting from ETSI studies which are not appropriate for European
Telecommunication Standard (ETS) or Interim European Telecommunication Standard (I-ETS) status. An
ETR may be used to publish material which is either of an informative nature, relating to the use or the
application of ETSs or I-ETSs, or which is immature and not yet suitable for formal adoption as an ETS or
an I-ETS.
This fourth edition of ETR 018 replaces the third edition issued in January 1995.
The following modifications have been made as compared to the third edition:
- examples for the use of the File Transfer & Access Management (FTAM) teleservice have been
added (see subclause 6.3.7);
- examples for the use of the Eurofile transfer teleservice have been added (see subclause 6.3.8).
Further enhancements of this ETR will (most likely) become necessary. Candidates for inclusion in a
future edition are e.g.:
- an adjustment of the examples for the use of the FTAM teleservice following a possible amendment
of ETS 300 403-1;
- examples to document the user signalling bearer service;
- examples to document the teleaction teleservice;
- examples to support channel aggregation as an application of the 64 kbit/s unrestricted bearer
service.
Introduction
This ETR specifies the coding of the information elements Bearer Capability (BC), High Layer
Compatibility (HLC) and Low Layer Compatibility (LLC) to be used by terminals supporting the ISDN
telecommunication services so far specified within ETSI and operating in the demand mode. It is based on
ITU-T Recommendation Q.931 (1993) as modified by ETS 300 403-1, including its relevant annexes (B, I
and J).
For each service it is specified which field values the calling user is requested to send and which field
values the called user could expect to receive in a pure ISDN environment (clauses 6 and 7). Clause 8
specifies the codings to be used in the case of inter-working with non European ISDNs supporting
restricted 64 kbit/s transfer capability. Furthermore, interworking with the Public Switched Telephone
Network (PSTN) is also covered (subclause 9.1).
Unless otherwise stated, the use of the term "terminal" refers to customer's terminal apparatus which may
be a Terminal Equipment type 1 (TE1), a Terminal Adapter (TA) together with a Terminal Equipment
type 2 (TE2) or a Network Termination type 2 (NT2) as defined in ITU-T Recommendation I.411.
The terms "terminal" and "user" are used interchangeably.
The exact bit patterns correlated with the named field values can be found in the following subclauses of
ETS 300 403-1:
- in subclause 4.5.5 for the Bearer capability information element;
- in subclause 4.5.17 for the High layer compatibility information element; and
- in subclause 4.5.19 for the Low layer compatibility information element.

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

SIST-TP ETSI/ETR 018 E4:2005
Page 8
ETR 018: November 1995
Generally, the information elements BC, HLC and LLC serve the following purposes:
At the calling side, the network checks that the bearer service requested by the calling user in the Bearer
capability information element matches with the bearer service provided to that user by the network (see
ETS 300 403-1, annex B).
At the called side, the called user performs network-to-user compatibility checking based on the content of
the BC-information element, and user-to-user compatibility checking based on the content of the HLC-
and LLC- information elements (see ETS 300 403-1, annex B).

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

SIST-TP ETSI/ETR 018 E4:2005
Page 9
ETR 018: November 1995
1 Scope
This ETSI Technical Report (ETR) provides supplementary information on the usage of the compatibility
information elements Bearer Capability (BC), High layer Compatibility (HLC) and Low Layer Compatibility
(LLC) for individual telecommunication services. It considers the telecommunications services as they are
specified for public Integrated Services Digital Networks (ISDNs). It does not specify additional codings of
the compatibility information elements which might be required to support the request and provision of
telecommunication services by private networks.
Since some bearer services can be used to support various user applications, additional information on
such applications is specified:
- in subclause 7.1 for the circuit-mode 64 kbit/s unrestricted 8 kHz structured bearer service;
- in subclause 7.2 for the circuit-mode 64 kbit/s 8 kHz structured 3,1 kHz audio bearer service.
The specific objective of this ETR is to provide guidance on the correct usage of ETS 300 403-1 [7]
codepoints to the different ETSI Technical Committees or Technical Subcommittees dealing with services,
ISDN terminals, Terminal Adapters (TAs) and documents on testing. This ETR shall help to assure inter-
operability of terminals supporting the same telecommunication service and shall enable terminals to
operate on different public ISDNs.
The typical codings specified in clause 6 should be supported by all users and networks supporting the
corresponding telecommunications service. Other variants of these codings may be supported in addition,
however, these variants might not provide for world-wide interoperability and might not guarantee terminal
interchangeability.
The coding examples given in clause 7 are not exhaustive. They illustrate typical user applications
involving bit rate adaption schemes where ETSI standardized interfaces are used.
Clause 8 is devoted to examples showing the interworking of European ISDNs with non-European ISDNs
supporting restricted 64 kbit/s transfer capability.
Finally, clause 9 presents codings when interworking with non-ISDNs occurs.
2 References
This ETR incorporates by dated or undated reference, provisions from other publications. These
references are cited at the appropriate places in the text and the publications listed hereafter. For dated
references, subsequent amendments to or revisions of any of these publications apply to this ETR only
when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies.
[1] ETS 300 080: "Integrated Services Digital Network (ISDN); ISDN lower layer
protocols for telematic terminals".
[2] ETS 300 103 (1990): "Integrated Services Digital Network (ISDN); Support of
CCITT Recommendation X.21, X.21 bis and X.20 bis based Data Terminal
Equipments (DTEs) by an ISDN; Synchronous and asynchronous terminal
adaption functions".
[3] ETS 300 218 (1993): "Integrated Services Digital Network (ISDN); Syntax-based
Videotex lower layers protocols for ISDN packet mode
(CCITT Recommendation X.31 Case A and Case B)".
[4] ETS 300 264 (1993): "Integrated Services Digital Network (ISDN);
Videotelephony teleservice; Service description".
[5] ETS 300 383 (1995): "Integrated Services Digital Network (ISDN); File transfer
over the ISDN; EUROFILE transfer profile".

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

SIST-TP ETSI/ETR 018 E4:2005
Page 10
ETR 018: November 1995
[6] ETS 300 388 (1995): "Integrated Services Digital Network (ISDN); File Transfer
Access & Management (FTAM) over ISDN based on simple file transfer profile".
[7] ETS 300 403-1: "Integrated Services Digital Network (ISDN); Digital Subscriber
Signalling System No. one (DSS1); User-network interface layer 3 specification
for basic call control; Part 1: Protocol specification [ITU-T Recommendation
Q.931 (1993), modified]".
[8] ITU-T Recommendation F.184: "Operational provisions for the international
public facsimile service between subscriber stations with group 4 facsimile
machines (telefax 4)".
[9] CCITT Recommendation F.200: "Teletex service".
[10] CCITT Recommendation F.220: "Service requirements unique to the
processable mode number one (PM1) used within the teletex service".
[11] CCITT Recommendation F.230: "Service requirements unique to the mixed
mode (MM) used within the teletex service".
[12] CCITT Recommendation T.90 (1992): "Characteristics and protocols for
terminals for telematic services in ISDN".
[13] CCITT Recommendation V.110 (1992): "Support of data terminal equipments
with V-Series type interfaces by an Integrated Services Digital Network (ISDN)".
[14] ITU-T Recommendation X.25: "Interface between data terminal equipment
(DTE) and data circuit-terminating equipment (DCE) for terminals operating in
the packet mode and connected to public data networks by dedicated circuit".
[15] ITU-T Recommendation X.30 (1992): "Support of X.21, X.21 bis and X.20 bis
based data terminal equipments (DTEs) by an Integrated Services Digital
Network (ISDN)".
[16] ITU-T Recommendation X.31 (1993): "Support of packet mode terminal
equipment by an ISDN".
[17] ITU-T Recommendation X.75: "Packet-switched signalling system between
public networks providing data transmission services".
3 Abbreviations
For the purposes of this ETR, the following abbreviations apply:
AU Access Unit
BC Bearer Capability
CSPDN Circuit Switched Public Data Network
FTAM File Transfer Access & Management
HDLC High Level Data Link Control
HLC High Layer Compatibility
ISDN Integrated Services Digital Network
LLC Low Layer Compatibility
MSN Multiple Subscriber Number
NIC Network Independent Clock
NT Network Termination
PSPDN Packet Switched Public Data Network
PSTN Public Switched Telephone Network
SAPI Service Access Point Identifier
SUB Subadressing
TA Terminal Adapter
TE Terminal Equipment

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

SIST-TP ETSI/ETR 018 E4:2005
Page 11
ETR 018: November 1995
4 General principles applicable to all services
For all services, the following principles apply:
a) the LLC information element is transferred transparently through an ISDN between the calling entity
and the addressed entity. However, dependent on the charging principles applied, some networks
may perform checks on the length of the LLC information elements;
b) the HLC information element is transferred transparently through an ISDN between the calling entity
and the addressed entity. However, some networks may check its content, e.g., to associate a
supplementary service to a teleservice;
c) where bearer services are specified, the HLC information element will normally not be present
unless they are used to support high layer applications;
d) the coding examples consider the general case. In special terminal arrangements the user may
need to rely on address information only. In these cases, the Multiple Subscriber Number (MSN)
supplementary service shall be used;
e) a Terminal Equipment type 2 (TE2) together with a TA are assumed to provide the same
functionality as a Terminal Equipment type 1 (TE1). Therefore, a TA should not generate and send
a progress indicator when setting-up a connection. Consequently, a TA, e.g., adapting a two-wire
analogue Public Switched Telephone Network (PSTN) user-network interface to the ISDN user-
network interface will generate the BC and, if appropriate, the HLC and LLC information elements in
accordance with the type of equipment it serves at the interface at the R reference point, namely:
BC-/HLC-/LLC-codepoints used at an interface at the
Equipment connected to an interface coincident S&T reference point
at the R reference point BC HLC LLC
analogue telephone speech telephony
facsimile group 2/3 equipment 3,1 kHz audio facsimile group 2/3
voice band data equipment via modem 3,1 kHz audio modem type
For the presentation of the coding examples, the following conventions apply:
- octets 1 and 2 of the compatibility information elements, indicating the information element identifier
and length respectively, are omitted from the considerations and therefore not shown in the
examples;
- a dash instead of a field value indicates:
a) at the calling side: this field is not included in the information element;
b) at the called side: this field is not present;
- field values in brackets ( ) may or may not be included at the calling side and therefore not be
present at the called side.

---------------------- Page: 13 ----------------------

SIST-TP ETSI/ETR 018 E4:2005
Page 12
ETR 018: November 1995
5 Impact of interworking situations
5.1 Incoming calls from non-ISDNs
In the case of interworking with non-ISDNs, HLC and LLC information elements may be absent, and this
interworking is shown with the presence of the Progress indicator information element. When this occurs,
the terminal should accept the incoming call according to annex B of ETS 300 403-1 [7], i.e. it should
regard the compatibility as successful if it is compatible with the included information, which as a minimum
will be the Bearer capability information element.
5.2 BC and LLC application guidelines
In many cases, the same low layer information (e.g., the user rate and the rate adaption technique
applied) can be coded in either the BC or the LLC information element. However, the provision of
information in the one or the other information element has consequences with respect to the selection or
the denial of a network provided interworking function.
The following guidelines exist for the application of BC and LLC information elements according to annex I
of ETS 300 403-1 [7]:
Type I Information used only at the destination end to allow decision regarding terminal
compatibility. This information, if required, shall be coded into octets (3a and) 5 to 7 of the
LLC information element.
Type II Information to permit the network to select the bearer service. This information shall be
coded into:
- octets 3 and 4 of the BC information element for circuit-mode traffic;
- octets 3 and 4, 6 and 7 of the BC information element for packet-mode traffic.
Type III Information used by the addressed user to determine terminal compatibility and used by the
network to facilitate interworking with other ISDNs or other dedicated networks. This
information is encoded into octet 5 (including octets 5a-5d if appropriate) of the BC
information element.
These types of information can be used as follows:
Case 1 If the originating user wishes to transfer information end-to-end to ensure end user
compatibility without invoking network interworking, then type I information together with
type II information shall apply.
Case 2 If the originating user either requires network interworking or is willing to accept network
interworking, should it be necessary in order to complete the call, then type III information
together with type II information shall apply.
Consequently, if interworking with a PSTN, Circuit Switched Public Data Network (CSPDN) or the pan-
European mobile cellular system is supported by the network by providing the appropriate functions (i.e.
data extraction, modem pool) at the interworking unit, then those calls carrying the rate adaption
informatio
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.