ETSI ETS 300 048 ed.1 (1992-01)

SLOVENSKI STANDARD
01-december-2003
Digitalno omrežje z integriranimi storitvami (ISDN) – Paketne nosilne storitve
(PMBS) – Nosilne storitve prek B-kanala uporabniškega dostopa, osnovne in
primarne
Integrated Services Digital Network (ISDN);ISDN Packet Mode Bearer Services (PMBS)
bearer services provided by the B-channel of the user access -basic and primary rate
Ta slovenski standard je istoveten z: ETS 300 048 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.

EUROPEAN ETS 300 048
TELECOMMUNICATION January 1992
STANDARD
Source: ETSI TC-NA Reference: T/NA1(89)29
ICS: 33.080
ISDN, bearer service
Key words:
Integrated Services Digital Network (ISDN);
ISDN Packet Mode Bearer Services (PMBS)
bearer services provided by the B-channel of the user access -
basic and primary rate
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 1992. All rights reserved.
New presentation - see History box

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ETS 300 048: January 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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ETS 300 048: January 1992
Contents
Foreword.5
1 Scope .7
2 Normative references .7
3 Definitions.8
4 Description .9
5 Procedures.9
5.1 Provision and withdrawal .9
5.2 Normal procedures.9
5.2.1 Activation, deactivation and registration.9
5.2.2 Invocation and operation .9
5.2.2.1 Virtual call procedures.9
5.2.2.1.1 Layer 1 Activation and channel
establishment.9
5.2.2.1.2 Layer 2 activation (B-channel) . 10
5.2.2.1.2.1 Method 1 - Semi-permanent layer 2.10
5.2.2.1.2.2 Method 2 - On demand layer 2.10
5.2.2.1.3 Terminal selection and identification.10
5.2.2.1.4 Call establishment .10
5.2.2.1.5 Data transfer .10
5.2.2.1.6 Terminating the call . 10
5.2.2.1.7 Layer 2 deactivation .10
5.2.2.1.8 Layer 1 deactivation and channel
release.11
5.2.2.2 Permanent virtual circuit procedures. 11
5.2.2.2.1 Layer 1 activation and channel
establishment.11
5.2.2.2.2 Layer 2 activation.11
5.2.2.2.3 Terminal selection and identification.11
5.2.2.2.4 Call establishment .11
5.2.2.2.5 Data transfer .11
5.2.2.2.6 Terminating the call .11
5.2.2.2.7 Layer 2 deactivation .11
5.2.2.2.8 Layer 1 deactivation and channel
release.11
5.2.3 Interrogation and Editing.11
5.3 Exceptional procedures .12
5.3.1 Activation, deactivation and registration.12
5.3.2 Invocation and operation .12
5.3.2.1 Virtual call.12
5.3.2.2 Permanent virtual circuit .12
5.3.3 Interrogation and editing .12
6 Network capabilities for charging .12
7 Interworking.13
7.1 Interworking between Public Networks.13
7.2 Interworking between Private and Public ISDNs.13
8 Interaction with supplementary services .13

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ETS 300 048: January 1992
9 Attributes and values of attributes (including the provision of individual bearer services) .13
9.1 Attributes and values .13
9.2 Provision of individual bearer services.15
Annex A (normative): Standard service profile.16
Annex B (normative): User facilities.17
Annex C (informative): Bibliography.18
History .19

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ETS 300 048: January 1992
Foreword
This European Telecommunication Standard (ETS) has been produced by the Network Aspects (NA)
Technical Committee of the European Telecommunications Standards Institute (ETSI). It describes the
stage one requirements of the ISDN Packet Mode Bearer Service (PMBS) provided on the B-channel of
the user access. Services using the D-channel are covered in ETS 300 049.
The requirements described in this ETS are applicable only to those services within Europe and are based
upon CCITT Recommendation I.232 [8].
The service description corresponds to case B (B-channel) of ETS 300 007 [7] (the European equivalent to
CCITT Recommendation I.462/X.31 case B).
The requirements for stage three of this service are contained in ETS 300 007 [7].
Annexes A and B are normative. Annex C is informative.

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ETS 300 048: January 1992
1 Scope
This European Telecommunication Standard (ETS) defines the stage one of the Packet Mode Bearer
Service (PMBS) provided by the B-channel of the user access 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 ETS makes use of ETS 300 007 [7], which is a stage 3 ETS, in order to provide a description of the
procedures. This mechanism would not normally be used in a stage 1 standard.
This ETS does not define details of the interworking requirements of private ISDNs with the public ISDN.
In addition this ETS specifies the base functionality where the service is provided to the user via a private
ISDN.
This ETS 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.
Charging principles are outside the scope of this ETS.
The ISDN Virtual Call (VC) and Permanent Virtual Circuit (PVC) bearer service category provide the
unrestricted transfer (without alteration) of user information in a packetised manner over a virtual circuit
between reference points via the basic and primary rate access. Each of the reference points can be
either an S or coincident S and T reference point.
NOTE: Network operators can also provide information transfer with the same attributes where
the reference point is T.
ISDN VC and PVC bearer service category is described in CCITT Recommendation I.232 [8].
This ETS is applicable to the stage three standards for the ISDN PMBS. The term "stage three" is 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, as a capability or possibility), this shall be
reflected in the text of the relevant stage three standards.
Furthermore, conformance to this ETS is met by conforming to the stage three standards with the field of
application appropriate to the equipment being implemented. Therefore no method of testing is provided
for this ETS.
2 Normative references
This ETS 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 ETS
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
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".

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ETS 300 048: January 1992
[4] CCITT Recommendation X.25 (1988): "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".
[5] ETS 300 125 (1991): "Integrated Services Digital Network (ISDN); User-network
interface data link layer specification. Application of CCITT Recommendations
Q.920/I.440 and Q.921/I.441".
[6] CCITT Recommendation X.1 (1988): "International user classes of service in
public data networks and Integrated Service Digital Networks (ISDNs)".
[7] ETS 300 007 (1991): "Integrated Services Digital Network (ISDN); Support of
packet-mode terminal equipment by an ISDN".
[8] CCITT Recommendation I.232 (1988): "Packet mode bearer services
categories".
[9] CCITT Recommendation E.164 (1988): "Numbering plan for the ISDN era".
3 Definitions
For the purposes of this ETS, the following definitions apply:
Integrated Services Digital Network (ISDN): See CCITT Recommendation I.112 [2], § 2.3, definition
308.
service; telecommunication service: See CCITT Recommendation I.112 [2], § 2.2, definition 201.
supplementary service: See CCITT Recommendation I.210 [3], § 2.4.
virtual call: See CCITT Recommendation X.25 [4], § 3.
permanent virtual circuit: See CCITT Recommendation X.25 [4], § 3.
service profile: See CCITT Recommendation X.25 [4].
packet handler: See ETS 300 007 [7].
semipermanent: See ETS 300 007 [7], Clause 7.
party number: As ISDN number, a number conforming to the numbering plan and structure specified in
CCITT Recommendation E.164 [9]
party subaddress: See CCITT Recommendation E.164 [9], § 11.2.

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4 Description
This service is described for both the point-to-multipoint and point-to-point configurations. This covers the
passive bus and NT2 access arrangements.
These packet mode bearer services allow users (e.g. terminals) in a point-to-point communication
configuration to communicate via the ISDN using CCITT Recommendation X.25 [4] encoding, by means of
procedures over a B-channel in both directions continuously and simultaneously, for the duration of a call
as described in ETS 300 007 [7]. This shall be performed by means of procedures over a B-channel in
both directions continuously and simultaneously, for the duration of a call as described in ETS 300 125 [5]
(CCITT Recommendations I.462/X.31). User class 30 as described in CCITT Recommendation X.1 [6] is
supported.
NOTE: In case of access via TA, the following user classes are supported at the R-reference
point: 8-13 (see CCITT Recommendation X.1 [6])
5 Procedures
5.1 Provision and withdrawal
This service shall be either provided by prior arrangement with the service provider or be available on a
general basis.
The user can have subscription to a specific CCITT Recommendation X.25 [4] profile (essential for PVC
operation); or standard profile as described in Annex A.
5.2 Normal procedures
5.2.1 Activation, deactivation and registration
Not applicable.
5.2.2 Invocation and operation
VC and PVC procedures can be invoked and operated by a given terminal concurrently.
5.2.2.1 Virtual call procedures
If a B-channel has already been established between the terminal and the Packet Handler (PH) then
CCITT Recommendation X.25 [4] packet layer calls may be made over an active Link Access
Procedure-Balanced (LAPB) data link. If no such B-channel connection exists then channel establishment
procedures are needed to provide a communication path between the terminal and the PH.
5.2.2.1.1 Layer 1 Activation and channel establishment
Layer 1 shall be permanently active or activated on demand by the Data Terminal Equipment (DTE) or the
PH. The procedures for layer 1 activation depend on methods for layer 2 activation; see following sections.
For Primary Rate Access (PRA), layer 1 is permanently active.
A B-channel connection to the Packet Handler (PH) is either permanent or shall be established on demand.
In the latter case detailed procedures for channel establishment by the terminal or by the network are to
be found in ETS 300 007 [7] using ETS 300 102-1 signalling procedures.

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ETS 300 048: January 1992
5.2.2.1.2 Layer 2 activation (B-channel)
Two different methods of layer 2 activation can be identified:
5.2.2.1.2.1 Method 1 - Semi-permanent layer 2
A CCITT Recommendation X.25 [4] LAPB link is activated at subscription time. The network shall keep the
data link in the activated state. A permanent B-channel connection is required to the PH.
5.2.2.1.2.2 Method 2 - On demand layer 2
A LAPB link is activated, in accordance with CCITT Recommendation X.25 [4], over the B-channel. Its
activation is initiated either by the TA/TE1 or the network.
5.2.2.1.3 Terminal selection and identification
For certain applications the subscription to the Multiple Subscriber Number (MSN) or Direct Dialling In
(DDI) supplementary service is necessary for the purpose of terminal selection.
For certain applications for outgoing calls the calling party number and/or calling party subaddress shall be
sent to the network by the calling user during call set-up and used by the network as a network option for
terminal identification or selection of the user's profile.
Public networks conforming to this ETS do not provide channel negotiation.
Successive incoming calls to the same ISDN number shall be directly multiplexed on an already established
B-channel, irrespective of information contained in the CCITT Recommendation X.25 [4] called address
extension facility field.
NOTE: In the case of no notification class, the PH could make use of this information to identify
a specific B-channel (see Annex G to CCITT Recommendation X.25 [4]). This would be
a non-standard use of a facility intended to support the Open Systems Interconection
(OSI) network service and would remain a network option.
5.2.2.1.4 Call establishment
ETS 300 007 [7] procedures using ETS 300 102-1 signalling may be used to notify the user of incoming
calls when conditional notification is applicable. Networks will provide at least one of the two notification
classes defined in ETS 300 007 [7] no notification class and conditional notification class. These classes
may be provided on a subscription basis.
CCITT Recommendation X.25 [4] packet layer call establishment procedures are operated on an active
LAPB link.
NOTE: There is only one LAPB link active per B-channel.
5.2.2.1.5 Data transfer
CCITT Recommendation X.25 [4] packet layer data transfer procedures apply.
5.2.2.1.6 Terminating the call
CCITT Recommendation X.25 [4] packet layer call clearing procedures apply.
5.2.2.1.7 Layer 2 deactivation
The terminal/network should deactivate the LAPB link after clearing the last VC unless layer 2 is
semi-permanent or follow-on calls are expected.

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