SIST I-ETS 300 442 E1:2003

• Abstract:

  To specify functional modules including relevant human factors of a videotelephone reference terminal supporting one or two B-channels in the ISDN

• 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 I-ETS 300 442 ed.1 (1995-12) - Integrated Services Digital Network (ISDN); Videotelephony teleservice; Terminal characteristics

SIST I-ETS 300 442 E1:2003 is the Slovenian adoption of ETSI I-ETS 300 442 Edition 1. It specifies the electrical, functional, visual and acoustic characteristics of ISDN videotelephony terminals, including functional modules and relevant human factors, for terminals that use one or two B-channels. It is aimed at videotelephony terminal equipment at the basic access of the coincident S and T interface, so designers and testers can check whether a terminal can interwork as intended.

What does SIST I-ETS 300 442 E1:2003 specify?

SIST I-ETS 300 442 E1:2003 specifies the technical characteristics of videotelephony terminals on the ISDN basic access. It also covers videotelephony functions in multimedia and multiservice terminals, but it is not a type-approval document and it does not set mandatory attachment requirements.

The document is organized into clauses on scope, normative references, definitions, abbreviations, attachment requirements, system description, terminal-network characteristics, end-to-end characteristics, power feeding, physical modules, multipoint aspects and data communication. Annex A is normative and gives the test specification. Annex B is informative and lists related literature.

Annex	What it covers
A (normative)	Test specification, including test environment, power supply limits, interface conditions, accuracy, audible alerting module tests and DTMF measurements.
B (informative)	Bibliography of related ETSI, ITU-T, CCITT and IEC documents, plus draft and work-item references.

What are the key requirements of SIST I-ETS 300 442 E1:2003?

• Clause 6 requires all terminals to support the videotelephony teleservice and the telephony 3,1 kHz teleservice. Terminal types Xb2/3 and Xb5 also have to support the telephony 7 kHz teleservice. In practice, a terminal cannot be treated as a complete videotelephony terminal if it only works for video and not for the basic voice services that users expect.

• Clauses 7.1 to 7.3 require the call control functions at the user-network interface to match the cited basic call control and DSS1 specifications. The standard ties conformance to the tests in the referenced ETS and I-ETS documents. That matters because setup, clearing, channel handling and signalling behavior must work consistently on ISDN networks.

• Clause 7.4 sets rules for supplementary services. Where MSN/Subaddressing is used, the terminal must perform address checks when selection information is stored, and off-line programming and erasing of that information shall be available to the user. Conference services, call manipulating services and call diversion services have extra constraints linked to operating mode, coding and compatibility checking, so the terminal has to manage service interaction rather than just passing calls through.

• Clause 7.4 also links charging and multi-call behavior to the two-channel case. Advice of Charge (AOC-S, AOC-D, AOC-E) applies on a per-call basis, and if an additional channel is established, the terminal shall invoke the service for that call as well. This is important for billing displays and for terminals that split communication over two B-channels.

• Clauses 7.5 and 7.6 deal with dialling and network tones. A terminal with manual number entry shall support overlap sending, and network tones or announcements on the initial B-channel shall be audible to the user. Local generation of tones is allowed as an option, in normal mode or mixed mode, so the terminal can still inform the user when the network does not provide tones.

• Clauses 8.3 and 8.5 define the main audio, video and DTMF behavior. Handset audio shall implement PCM coding according to G.711, including both A-law and μ-law. Optional speech coding can use G.728 or G.722, video coding shall meet H.261, and DTMF signalling is optional but, if provided, must support the standard digit set and the specified signal behavior.

• Clause 9 covers power feeding and the restricted power condition. A terminal may be designated for restricted power use if it meets the stated requirements, and in that case it shall at least support telephony 3,1 kHz. This matters for installations where power is limited or the network expects a designated terminal response.

• Clause 10 covers the physical modules and user alerts. The handset has no prescribed shape, but the audible alerting module has to meet loudness, timing and frequency-spectrum requirements, and an incoming call indication may also be visual. For a buyer or engineer, this is the part that affects whether the terminal is audible, recognisable and usable in day-to-day operation.

What terms does SIST I-ETS 300 442 E1:2003 define?

• Integrated Services Digital Network (ISDN) - The network environment for which the terminal characteristics are specified.
• Videotelephony teleservice - The service for which the terminal is designed, as described in ETS 300 264.
• Multimedia terminal - A terminal that simultaneously supports two or more media.
• Multiservice terminal - A terminal that supports two or more teleservices.
• Handsfree terminal - A terminal that uses a loudspeaker with an amplifier as the telephony receiver and can be used without a handset.
• Loudspeaking terminal - A handset terminal that uses a loudspeaker with an amplifier as the telephony receiver.
• Restricted power condition - The power mode identified by reversed polarity of the phantom voltage at the S or coincident S and T reference point.
• Dual Tone Multi Frequency (DTMF) - The tone-signalling method used for dialling and signalling over the connected B-channel.

Who uses SIST I-ETS 300 442 E1:2003?

SIST I-ETS 300 442 E1:2003 is used by manufacturers of ISDN videotelephones, designers of multimedia and multiservice terminals, test laboratories, and quality or purchasing teams that need to check terminal capabilities against a defined ISDN profile.

• Design engineers use it to choose supported teleservices, coding options, alerting behavior and supplementary-service handling.
• Test houses use Annex A and the referenced test documents to verify call control, audio behavior, DTMF and alerting functions.
• Buyers and quality managers use it to compare terminals that support one or two B-channels, optional loudspeaking or data functions, and restricted power operation.
• Interop and network engineers use it when checking that a terminal will work with ISDN call control, supplementary services, inband signalling and optional multipoint functions.

Which standards are used with SIST I-ETS 300 442 E1:2003?

SIST I-ETS 300 442 E1:2003 relies on service descriptions, signalling, coding, test and measurement standards from ETSI, ITU-T, CCITT and IEC. The table below groups the main references and related companion documents by what they contribute.

Reference	What it contributes
ETS 300 264 [1]	Service description for the videotelephony teleservice.
CCITT G.701, I.112, I.230, I.240, P.10 [2]-[6]	Vocabulary used for definitions of transmission, ISDN, bearer services, teleservices and telephone quality terms.
ETS 300 111 [7] and ETS 300 263 [8]	Service descriptions for the telephony 3,1 kHz and telephony 7 kHz teleservices.
ETS 300 012 [9]	Basic user-network interface, layer 1, test principles, power supply limits and S/T reference-point connection.
ETS 300 145 [10]	Videotelephone system description, multipoint minimums and inband signalling context.
ETS 300 102-1 [11] and ETS 300 267-1 [12]	Basic call control and DSS1 protocol requirements for videotelephony and 7 kHz telephony.
I-ETS 300 245-1 [13] and I-ETS 300 245-7 [18]	Telephony terminal characteristics and locally generated information tones.
G.711 [16], G.722 [14], G.728 [22]	Audio coding laws and optional speech coding methods.
I-ETS 300 322 [15]	Test suite support for signalling and basic call control checks.
ETS 300 182-1 [17]	Advice of Charge DSS1 protocol.
ETS 300 144 [19] and ETS 300 143 [20]	Inband signalling frame structure and procedures.
I-ETS 300 302-1 [21]	Electroacoustic characteristics for handset PCM operation.
ITU-T H.261 [23]	Video codec requirements for audiovisual services.
ITU-T T.122, T.123, T.125 [24]-[26]	Multipoint communication and optional data communication protocol stack.
IEC 651 [27] and IEC 225 [28]	Sound-level meter and octave-band filter methods used in Annex A.
ETS 300 085 [29]	Attachment requirements for handset terminals and restricted power designated-terminal behavior.
I-ETS 300 302-2, I-ETS 300 302-3, I-ETS 300 302-4	Related companion parts for loudspeaking/handsfree, wideband handset and wideband coding topics.
prETS 300 678 and prI-ETS 300 654	Draft companion work on videoconference service description and interim D-channel signalling.
CCITT Q.23 and CCITT P.35	Reference material for DTMF push-button signalling and handset characteristics.
ETS 300 001 and DI/TE-04114	Related references for precise timing/level definitions and data communication work items.
I-ETS 300 245-5, TBR 3 and TBR 8	Related documents for wideband handset telephony and ISDN attachment requirements.

What does the SIST I-ETS 300 442 E1:2003 document contain?

The document contains a main body of functional and interface requirements, plus a detailed Annex A test specification. Annex A gives the test environment, power-supply limitations, test equipment interface rules, allowed alternative methods, and accuracy targets for electrical, acoustic and timing measurements.

Annex A also gives measurement set-ups for the audible alerting module, including the anechoic test arrangement and the method used to calculate average sound pressure, as well as DTMF measurement methods for frequency, level and timing. The main body includes the DTMF signalling scheme in table form, the conditions for audible network tones, and the rules for local tone generation, alerting, restricted power operation and optional data communication.

SLOVENSKI STANDARD
01-december-2003
Digitalno omrežje z integriranimi storitvami (ISDN) – Daljinske storitve:
videotelefonija – Terminalske karakteristike
Integrated Services Digital Network (ISDN); Videotelephony teleservice; Terminal
characteristics
Ta slovenski standard je istoveten z: I-ETS 300 442 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.

INTERIM
EUROPEAN I-ETS 300 442
TELECOMMUNICATION December 1995
STANDARD
Source: ETSI TC-TE Reference: DI/TE-04112
ICS: 33.080
ISDN, videotelephony teleservice, terminal characteristics
Key words:
Integrated Services Digital Network (ISDN);
Videotelephony teleservice;
Terminal characteristics
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 1995. All rights reserved.
New presentation - see History box

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I-ETS 300 442: December 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.

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I-ETS 300 442: December 1995
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions.9
4 Abbreviations.9
5 Attachment requirements.10
6 System description.10
7 Terminal-network characteristics .10
7.1 Call control functions for the videotelephony teleservice.10
7.2 Call control functions for the telephony 3,1 kHz teleservice .10
7.3 Call control functions for the telephony 7 kHz teleservice .10
7.4 Support of supplementary services in the ISDN .10
7.4.1 General.10
7.4.2 Supplementary services, Multiple Subscriber Number/Subaddressing .10
7.4.2.1 Address checking .10
7.4.2.2 No selection information stored.11
7.4.2.3 Programming.11
7.4.3 Support of conference supplementary services .11
7.4.4 Call manipulating supplementary services.11
7.4.5 Call diversion supplementary services .11
7.4.6 Advice of Charge supplementary services (AOC-S, AOC-D, AOC-E).12
7.4.6.1 Protocols and procedures.12
7.4.6.2 Additional channel .12
7.4.7 Other supplementary services.12
7.5 Overlap and en-bloc sending.12
7.6 Information tones .12
7.6.1 Transmission of tones and announcement from the network .12
7.6.2 Generation of tones by the terminal .13
8 End-to-end characteristics .14
8.1 General .14
8.2 Inband signalling .14
8.3 Audio characteristics.14
8.3.1 Handset function .14
8.3.1.1 PCM coding .14
8.3.1.2 3,1 kHz bandwidth coding at 16 kbit/s .14
8.3.1.3 7 kHz bandwidth SB-ADPCM coding.15
8.3.2 Loudspeaking and handsfree functions .15
8.3.2.1 PCM coding .15
8.3.2.2 3,1 kHz bandwidth coding at 16 kbit/s .15
8.3.2.3 7 kHz bandwidth SB-ADPCM coding.15
8.4 Video characteristics.15
8.5 Dual Tone Multi Frequency (DTMF) signalling .15
8.5.1 General.15
8.5.2 Connection to the B-channel .15
8.5.3 Signalling frequencies .16
8.5.4 Frequency deviation .16
8.5.5 Level.16
8.5.6 Timing.16

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I-ETS 300 442: December 1995
9 Power feeding. 16
9.1 General conditions . 16
9.2 Restricted Power Condition. 16
9.2.1 Leakage current. 17
9.2.2 Operation of the designated terminal under Restricted Power Conditions. 17
10 Physical modules. 17
10.1 Handset. 17
10.2 Audible alerting module. 17
10.2.1 Sound pressure level . 17
10.2.2 Alerting module control. 17
10.2.2.1 Starting. 17
10.2.2.2 Stopping. 17
10.2.3 Adjustment of sound characteristics. 18
10.2.4 Frequency spectrum. 18
10.3 Indication of requested teleservice. 18
10.3.1 Audible indication. 18
10.3.2 Visual indication. 18
11 Multipoint aspects. 19
11.1 Minimum configuration for multipoint application . 19
11.2 Optional functions. 19
12 Data communication. 19
Annex A (normative): Test specification . 20
A.1 General conditions for testing. 20
A.1.1 Environment for tests . 20
A.1.2 Power supply limitations. 20
A.1.3 Test equipment interface. 20
A.1.4 Alternative test methods. 20
A.1.5 Accuracy of test equipment. 20
A.2 Audible alerting module . 20
A.2.1 Sound pressure level measurement . 20
A.2.1.1 Measurement conditions. 20
A.2.1.2 Measurement method. 20
A.2.1.3 Frequency spectrum measurement. 21
A.3 DTMF measurements. 21
A.3.1 Frequency . 21
A.3.2 Signal level . 21
A.3.3 Signal timing. 21
Annex B (informative): Bibliography . 22
History. 23

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I-ETS 300 442: December 1995
Foreword
This Interim European Telecommunication Standard (I-ETS) has been produced by the Terminal
Equipment (TE) Technical Committee of the European Telecommunications Standards Institute (ETSI).
An ETSI standard may be given I-ETS status either because it is regarded as a provisional solution ahead
of a more advanced standard, or because it is immature and requires a "trial period". The life of an I-ETS
is limited to three years after which it can be converted into an ETS, have it's life extended for a further
two years, be replaced by a new version, or be withdrawn.
Proposed announcement date
Date of adoption of this I-ETS: 17 November 1995
Date of latest announcement of this I-ETS (doa): 31 March 1996

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I-ETS 300 442: December 1995
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I-ETS 300 442: December 1995
1 Scope
This I-ETS specifies the technical characteristics (electrical, functional, visual and acoustic) for
videotelephony terminals to be used at the basic access of the coincident S and T interface of the
Integrated Services Digital Network (ISDN). The characteristics of this I-ETS are meant to specify
characteristics that are outside the scope of attachment standards or specifications, and outside the
scope of standards specifying the end-to-end characteristics for videotelephony terminals. However, this I-
ETS is not intended to be used for type approval purposes or other mandatory requirements.
This I-ETS is applicable to videotelephony terminals as well as to the videotelephony functions of
multimedia or multiservice terminals.
This I-ETS is applicable to terminal equipment supporting the videotelephony teleservice in the ISDN as
defined in ETS 300 264 [1].
The characteristics specified in this I-ETS will cover a number of functions or facilities that can be
combined to form a particular terminal.
For multimedia or multiservice terminals, other requirements or standards may apply in addition to this
I-ETS.
The requirements of this I-ETS do not apply to videoconference terminals. Requirements to
videoconference terminals are specified in other standards.
2 Normative references
This I-ETS incorporates by dated and 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 I-ETS only when incorporated in it by amendment or revision. For undated references the
latest edition of the publication referred to applies.
[1] ETS 300 264 (1994): "Integrated Services Digital Network (ISDN);
Videotelephony teleservice, Service description".
[2] CCITT Recommendation G.701 (1988): "Vocabulary of digital transmission and
multiplexing, and pulse code modulation (PCM) terms".
[3] CCITT Recommendation I.112 (1988): "Vocabulary of terms for ISDNs".
[4] CCITT Recommendation I.230 (1988): "Definition of bearer service categories".
[5] CCITT Recommendation I.240 (1988): "Definition of teleservices".
[6] CCITT Recommendation P.10 (1988): "Vocabulary of terms on telephone
transmission quality and telephone sets".
[7] ETS 300 111 (1992): "Integrated Services Digital Network (ISDN); Telephony
3,1 kHz teleservice, Service description".
[8] ETS 300 263 (1994): "Integrated Services Digital Network (ISDN); Telephony
7 kHz teleservice, Service description".
[9] ETS 300 012 (1992): "Integrated Services Digital Network (ISDN); Basic
user-network interface, Layer 1 specification and test principles".
[10] ETS 300 145 (1994): "Integrated Services Digital Network (ISDN); Audiovisual
services, Videotelephone systems and terminal equipment operating on one or
two 64 kbit/s channels".
[11] ETS 300 102-1 (1990): "Integrated Services Digital Network (ISDN);
User-network interface layer 3, Specification for basic call control".

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I-ETS 300 442: December 1995
[12] ETS 300 267-1 (1994): "Integrated Services Digital Network (ISDN); Telephony
7 kHz and videotelephony teleservices, Digital Subscriber Signalling System No.
one (DSS1) protocol, Part 1: Protocol specification".
[13] I-ETS 300 245-1: "Integrated Services Digital Network (ISDN); Technical
characteristics of telephony terminals, Part 1: General".
[14] CCITT Recommendation G.722 (1988): "7 kHz audio coding within 64 kbit/s".
[15] I-ETS 300 322 (1995): "Integrated Services Digital Network (ISDN); Digital
Subscriber Signalling System No. 1 (DSS 1); Abstract Test Suite (ATS)
specification for signalling network layer protocol for circuit-mode basic call
control (user)".
[16] CCITT Recommendation G.711 (1988): "Pulse code modulation (PCM) of voice
frequencies".
[17] ETS 300 182-1 (1993): "Integrated Services Digital Network (ISDN); Advice of
Charge (AOC) supplementary service, Digital Subscriber Signalling System No.
one (DSS1) protocol, Part 1: Protocol specification".
[18] I-ETS 300 245-7 (1995): "Integrated Services Digital Network (ISDN); Technical
characteristics of telephony terminals; Part 7: Locally generated information
tones".
[19] ETS 300 144 (1994): "Integrated Services Digital Network (ISDN); Audiovisual
services, Frame structure for a 64 kbit/s to 1 920 kbit/s channel and associated
syntax for inband signalling".
[20] ETS 300 143 (1994): "Integrated Services Digital Network (ISDN); Audiovisual
services, Inband signalling procedures for audiovisual terminals using digital
channels up to 2 048 kbit/s".
[21] I-ETS 300 302-1 (1994): "Integrated Services Digital Network (ISDN);
Videotelephony teleservice; Part 1: Electroacoustic characteristics for handset
telephony function when using Pulse Code Modulation (PCM) encoding".
[22] CCITT Recommendation G.728 (1992): "Coding of speech at 16 kbit/s using
low-delay code excited linear prediction".
[23] ITU-T Recommendation H.261 (1993): "Video codec for audiovisual services at
p x 64 kbit/s".
[24] ITU-T Recommendation T.122 (1993): "Multipoint communication service for
audiographics and audiovisual conferencing service definition".
[25] ITU-T Recommendation T.123 (1994): "Protocol stacks for audiographic and
audiovisual teleconference applications".
[26] ITU-T Recommendation T.125 (1994): "Multipoint communication service
protocol specification".
[27] IEC Publication 651: "Sound level meters".
[28] IEC Publication 225: "Octave, half-octave and third-octave band filters intended
for the analysis of sound and vibrations".
[29] ETS 300 085 (1990): "Integrated Services Digital Network (ISDN); 3,1 Hz
telephony teleservice, Attachment requirements for handset terminals
(Candidate NET 33)".
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I-ETS 300 442: December 1995
3 Definitions
For the purposes of this I-ETS, the relevant definitions in CCITT Recommendations G.701 [2], I.112 [3],
I.230 [4], I.240 [5] and P.10 [6] apply along with the following:
handsfree terminal: A terminal using a loudspeaker associated with an amplifier as a telephony receiver
and which can be used without a handset. Defined in CCITT Recommendation P.10 [6].
loudspeaking terminal: A handset terminal using a loudspeaker associated with an amplifier as a
telephony receiver. Defined in CCITT Recommendation P.10 [6].
multimedia terminal: A terminal that simultaneously supports two or more media.
multiservice terminal: A terminal that supports two or more teleservices.
restricted power condition: See ETS 300 012 [9]. The condition is indicated by the reversed polarity of
the phantom voltage at the S or coincident S and T reference point.
NOTE 1: For some networks the restricted power condition may be the normal operating mode.
telephony 3,1 kHz teleservice: A description of the telephony 3,1 kHz teleservice is given in
ETS 300 111 [7], clause 5.
telephony 7 kHz teleservice: A description of the telephony 7 kHz teleservice is given in ETS 300 263
[8], clause 5.
videoconference terminal: A terminal that supports the videoconference teleservice.
NOTE 2: The videoconference teleservice is described in draft prETS 300 678 ("Integrated
Services Digital Network (ISDN); Videoconference teleservice, Service description").
videotelephony teleservice: A description of the videotelephony teleservice is given in ETS 300 264 [1],
clause 5.
4 Abbreviations
For the purposes of this I-ETS, the following abbreviations apply:
AOC-D Advice of Charge; charging information During the call
AOC-E Advice of Charge; charging information at the End of the call
AOC-S Advice of Charge; charging information at call Set-up time
CD Call Deflection
CFB Call Forwarding Busy
CFNR Call Forwarding No Reply
CFU Call Forwarding Unconditional
CH Call Hold
CONF Conference
CTR Common Technical Regulation
DTMF Dual Tone Multi Frequency
ECT Explicit Call Transfer
ISDN Integrated Services Digital Network
MLP Multi Layer Protocol
MMC Meet Me Conference
MSN Multiple Subscriber Number
SUB Subaddressing
TP Terminal Portability
3PTY Three Party
UDI-TA Unrestricted Digital Information with Tones and Announcement

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I-ETS 300 442: December 1995
5 Attachment requirements
Attachment requirements are outside the scope of this I-ETS.
NOTE: Information about type approval requirements can be found in annex B to this I-ETS.
6 System description
A system description of a videotelephone terminal is given in ETS 300 145 [10]. All terminals shall be
capable of supporting the videotelephony teleservice as specified in ETS 300 264 [1] and the telephony
3,1 kHz teleservice as specified in ETS 300 111 [7].
Terminal types Xb2/3 and Xb5, as defined in ETS 300 145 [10], shall also be capable of supporting the
telephony 7 kHz teleservice as specified in ETS 300 263 [8].
Conformance shall be checked by verifying that the requirements of the relevant clauses in this I-ETS, or
the requirements of standards referred to, be met.
7 Terminal-network characteristics
7.1 Call control functions for the videotelephony teleservice
The call control functions at the user-network interface shall meet the relevant requirements of
ETS 300 102-1 [11] and ETS 300 267-1 [12].
Conformance shall be checked by using the tests specified in these ETSs.
NOTE: ETS 300 267-1 [12] specifies the layer 3 requirements for the videotelephony
teleservice as described in ETS 300 263 [8]. Additional characteristics as well as short
term solutions will be described in prI-ETS 300 654 ("Integrated Services Digital
Network (ISDN); Videotelephony terminals, Interim D-channel signalling aspects").
7.2 Call control functions for the telephony 3,1 kHz teleservice
The call control functions at the user-network interface shall meet the relevant requirements of
I-ETS 300 245-1 [13] and ETS 300 102-1 [11].
Conformance shall be checked by using the tests specified in this ETS and I-ETS.
7.3 Call control functions for the telephony 7 kHz teleservice
Where the speech coding option according to CCITT Recommendation G.722 [14] is implemented, the
call control functions at the user-network interface shall meet the relevant requirements of ETS 300 102-1
[11], ETS 300 267-1 [12] and I-ETS 300 245-1 [13].
Conformance shall be checked by using the tests specified in these ETSs and I-ETS.
7.4 Support of supplementary services in the ISDN
7.4.1 General
If two B-channels are required the ISDN supplementary services shall be invoked for each call. There are
other restrictions related to the videotelephony teleservice due to coding algorithms and the inband
signalling system.
7.4.2 Supplementary services, Multiple Subscriber Number/Subaddressing
7.4.2.1 Address checking
A terminal connected to an ISDN basic access can be selected by using the Multiple Subscriber Number
(MSN) and/or Subaddressing (SUB) supplementary services, if present.

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I-ETS 300 442: December 1995
Only one ISDN number or subaddress shall be allocated to the videotelephony function of a terminal.
Where two B-channels are required, the same ISDN number or subaddress shall be used for both
connections (however, see note).
If the terminal, as an option, supports the MSN and/or SUB supplementary services and information for
selection is stored, a terminal connected to an ISDN basic access shall perform address checks on the
ISDN subscriber number and/or subaddress, if present in the incoming SETUP message. These checks
are additional to the compatibility checks referred to in subclauses 7.1 to 7.3.
Conformance shall be checked by using the relevant tests specified in I-ETS 300 322 [15].
NOTE: Regions outside Europe may allocate separate numbers to the two B-channels used.
For interworking with those regions and with non-ISDN video equipment on non-ISDN
networks, it may be necessary to use different destination numbers.
7.4.2.2 No selection information stored
When no information for selection is stored, the terminal shall respond to every incoming SETUP
message if the compatibility checks specified in subclauses 7.1 to 7.3 are successful.
Conformance shall be checked by using the relevant tests specified in I-ETS 300 322 [15].
7.4.2.3 Programming
Off-line programming and erasing of information for selection (MSN and/or SUB) shall be available to the
human user.
Conformance shall be checked by inspection.
7.4.3 Support of conference supplementary services
The conference supplementary services offered by the ISDN (Meet-Me Conference (MMC), Conference
call, Add-on (CONF) or Three party (3 PTY)) may be invoked only when the terminal is operating in mode
0U and uses A-law speech coding according to CCITT Recommendation G.711 [16].
Before one of these supplementary services is invoked, the terminal shall switch to mode a0U.
Conformance shall be checked by verifying that the relevant supplementary services only can be invoked
when the terminal is working in mode a0U.
NOTE 1: The remote videotelephone terminal cannot be forced to transmit unframed, only to
receive unframed. Unless that terminal is switched to mode a0U by user action, the
speech quality will be reduced.
NOTE 2: If the remote terminal has indicated that it supports CCITT Recommendation G.711
[16] μ-law only, the invocation of these supplementary services should be prevented.
7.4.4 Call manipulating supplementary services
When invoking the call manipulating supplementary services (Call Hold (CH), Explicit Call Transfer (ECT)
or Terminal Portability (TP)), an interaction between inband signalling and D-channel signalling is needed.
The principles specified in ETS 300 145 [10] shall be used.
Before the invocation of these supplementary services, a mode a0U communication shall be established.
7.4.5 Call diversion supplementary services
Terminals that support these supplementary services (Call Forwarding Unconditional (CFU), Call
Forwarding Busy (CFB), Call Forwarding No Reply (CFNR), and Call Deflection (CD)) shall have the
capability of compatibility checking of both octet 4 and octet 4a of the HLC information element as
described in ETS 300 267-1 [12].

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