SIST ETS 300 975 E1:2003

• Abstract:

  This European Telecommunication Standard (ETS) identifies the Interwor king Functions (IWF s) and requirements for the interworking between a GSM PLMN and a Packet Switched Public Data Network/Integrated Service s Digital Network (PSPDN/ISDN) for the support of packet services in G SM PLMNs. In the GSM PLMN context the packet services are associated with bearer services and are described in GSM 02.02. The generally defined GSM PL MN user-network access as defined in the respective GSM specifications (see references) forms the basis for defining the particularities for the provision of packet services to the GSM PLMN subscribers. Network internal interfaces for the support of packet services in the pan-Eur opean ISDN are defined in ETSI standards, which are also taken as a ba sis. User-network access and network internal interfaces are defined to pro vide the packet services.

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.040.35 - Telephone networks
• ICS: 33.070.50 - Global System for Mobile Communication (GSM)
• 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 300 975 ed.1 (1997-05) - Digital cellular telecommunications system (Phase 2+) (GSM); Interworking between a Public Land Mobile Network (PLMN)and a Packet Switched Public Data Network/Integrated Services Digital Network (PSPDN/ISDN) for the support of packet switched data transmission services (GSM 09.06 version 5.0.2)

SIST ETS 300 975 E1:2003 is the Slovenian adoption of ETS 300 975 Edition 1, an ETSI European Telecommunication Standard for GSM Phase 2+ packet services. It specifies the interworking functions and call handling needed between a GSM Public Land Mobile Network (PLMN) and a Packet Switched Public Data Network/Integrated Services Digital Network (PSPDN/ISDN). In practice, it tells network operators and implementers how to route, signal, and access packet-mode services through GSM, ISDN, and PSPDN networks.

What does SIST ETS 300 975 E1:2003 specify?

SIST ETS 300 975 E1:2003 specifies the interworking of packet switched data transmission services between a GSM PLMN and a PSPDN/ISDN. It uses the normal GSM user-network access model and ETSI ISDN interfaces as the basis for packet service provision.

The standard is organized around:

• Clause 1 - scope
• Clause 2 - normative references
• Clause 3 - definitions and abbreviations
• Clause 4 - introduction
• Clause 5 - network characteristics
• Clause 6 - interworking classifications
• Clause 7 - network interworking scenarios
• Clause 8 - basic packet mode service
• Clause 9 - dedicated packet mode service

Clause 5 compares the main network types involved, while clauses 7 to 9 describe how calls are routed and set up in practice. That structure matters because the standard is mainly about how a GSM network reaches packet services, not about packet services in general.

What are the key requirements of SIST ETS 300 975 E1:2003?

Clauses 5 to 7 define the interworking model

SIST ETS 300 975 E1:2003 treats packet service support as an interworking problem between GSM, ISDN, and PSPDN networks. Clause 6 separates service interworking from network interworking, and this document focuses on network interworking.

Clause 7 gives two routing models:

• interworking through transit ISDN or PSTN networks
• direct interworking

That distinction matters because it determines where the Packet handler (PH) is logically placed, what numbering is used, and whether modem-based access or PH access is used. In direct interworking, the PH is treated as part of the GSM PLMN, and loop detection becomes a design issue if the PH is physically in another network.

Clause 8 defines basic packet mode service

SIST ETS 300 975 E1:2003 defines basic packet mode service as access to a PSPDN port or to a PH through the GSM PLMN. The service is carried by circuit connection, and the GSM PLMN is only responsible for the connection to and from the PH or PSPDN port.

For this service, the subscriber uses E.164/E.163 addressing and sets the GSM bearer capability, lower layer capability, and higher layer capability information in the SETUP message. The MSC-A then selects the appropriate interworking function and establishes the circuit connection. In practice, this means the mobile network sets up the path, while the packet network or PH handles the packet service details.

Clause 8 also covers:

• mobile originated calls on the home PLMN and on a visited PLMN
• mobile terminated calls
• mobile originated mobile terminated calls
• subscriber profiles passed transparently through the GSM PLMN
• the role of the Basic MSisdn in calling party information

Clause 8.7 separates transparent and non-transparent operation

SIST ETS 300 975 E1:2003 allows both transparent and non-transparent mode for the PSPDN port scenario, but the PH scenario uses only non-transparent mode. That matters because the network must choose the correct lower-layer handling before the call is set up.

In non-transparent mode, the MT and the IWF select Layer 2 Relay/Radio Link Protocol (L2R/RLP) capabilities. The X.25 data link layer is terminated at the L2R toward the terminal and reconstructed at the IWF toward the transit network. For packet-handler access, the standard also describes LAPB address handling and the treatment of XID information before the link is established.

Clause 9 defines dedicated packet mode service

SIST ETS 300 975 E1:2003 defines dedicated packet mode service as the shortest possible connection from the GSM PLMN to the PH. It supports only mobile originated calls.

This service differs from the basic mode in several ways:

• the mobile subscriber does not use the E.164 address of the PH
• the subscriber uses a short code
• only a default service profile is supported for non-registered subscribers
• customized X.31 Case A service profiles are not supported
• OSI Network Layer Service is required

Clause 9 also states that the PH and the PLMN operator may need a pre-arrangement so that mobile originated calls are accepted. For roaming support, the standard uses a common access procedure so that the service behaves consistently across different networks.

Clause 9.5 adds charging and supplementary-services handling

SIST ETS 300 975 E1:2003 allows charging information to be generated in the PH, including volume-related and duration-related charging where needed. It also says that interworking of GSM PLMN supplementary services with PSPDN optional user facilities is not provided.

The supplementary-service points that do apply are:

• call barring of all outgoing calls
• advice of charge, for the circuit-switched portion only

That matters because operators cannot assume that packet-network options map directly to GSM supplementary services.

What terms does SIST ETS 300 975 E1:2003 define?

• Interworking Function (IWF) - The function that bridges GSM PLMN call handling with PSPDN or ISDN packet access.
• Packet handler (PH) - The packet access point used for ISDN-based packet services and related interworking arrangements.
• Home PLMN (HPLMN) - The GSM PLMN where the mobile subscriber has the subscription.
• Visited PLMN (VPLMN) - The GSM PLMN where the roaming subscriber is currently registered.
• Packet Handler Interface (PHI) - The interface between the MSC and the PH used in the packet-handling scenarios.
• Service profile - The set of network default and user-selectable attributes chosen for a particular DTE identity.
• Loop detection - The situation where a call that left the originating network appears again in that same network.

Who uses SIST ETS 300 975 E1:2003?

This standard is used by GSM network operators, ISDN and PSPDN operators, and equipment vendors that implement MSC, IWF, PH, and routing functions. It is also relevant to engineers who design roaming support, packet access, and interworking between GSM and fixed networks.

In practice, users include:

• mobile network planners defining roaming and routing behavior
• interworking and switch engineers configuring MSC-A and PH connections
• packet-network operators supporting X.31, X.32, or PH access
• terminal and modem implementers working with packet-mode services
• charging and service-operations teams handling calling, billing, and profiles

What changed in SIST ETS 300 975 E1:2003 from the previous edition?

The foreword states that this ETS is a GSM technical specification version 5 and that it incorporates GSM Phase 2+ enhancements and features into the version 4 GSM technical specification. It also states that it evolved from GSM 300 603 + Amendment 1, identified as GSM 09.06 version 4.5.0.

Which standards are used with SIST ETS 300 975 E1:2003?

Standard	What it contributes
GSM 01.04	Abbreviations and acronyms used in the GSM series
GSM 02.02	Bearer services supported by a GSM PLMN
GSM 02.03	Teleservices supported by a GSM PLMN
GSM 03.03	Numbering, addressing, and identification
GSM 03.70	Routeing of calls to and from PDNs and the GSM PLMN
GSM 04.08	Mobile radio interface layer 3 signaling
GSM 07.01	Terminal Adaptation Functions for mobile stations
GSM 07.03	Terminal Adaptation Functions for synchronous bearer capabilities
GSM 09.07	General interworking requirements with ISDN or PSTN
ETS 300 099	Packet-mode terminal support and the Packet Handler Interface
X.25, X.31, X.32	Packet-mode data access and interworking procedures

What does the SIST ETS 300 975 E1:2003 document contain?

The document contains the network model, the interworking classifications, and the call procedures needed for packet services in GSM PLMNs. Figures 1 to 6 show transit-network access, direct interworking, roaming cases, and dedicated packet mode scenarios.

Table 2 compares the characteristics of GSM PLMN, ISDN, and PSPDN networks. Table 3 gives the GSM profile for layer 3 and layer 2 attributes and parameters used for dedicated packet mode service.

The body of the standard also describes setup signaling, addressing rules, roaming behavior, X.31 Case A and Case B handling, LAPB and X.25 behavior, and charging and supplementary-service interactions.

SLOVENSKI STANDARD
01-december-2003
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Digital cellular telecommunications system (Phase 2+) (GSM); Interworking between a
Public Land Mobile Network (PLMN)and a Packet Switched Public Data
Network/Integrated Services Digital Network (PSPDN/ISDN) for the support of packet
switched data transmission services (GSM 09.06 version 5.0.2)
Ta slovenski standard je istoveten z: ETS 300 975 Edition 1
ICS:
33.040.35 Telefonska omrežja Telephone networks
33.070.50 Globalni sistem za mobilno Global System for Mobile
telekomunikacijo (GSM) Communication (GSM)
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 300 975
TELECOMMUNICATION May 1997
STANDARD
Source: ETSI TC-SMG Reference: DE/SMG-040906Q
ICS: 33.020
Key words: Digital cellular telecommunications system, Global System for Mobile communications (GSM)
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
Digital cellular telecommunications system (Phase 2+);
Interworking between a Public Land Mobile Network (PLMN) and
a Packet Switched Public Data Network/Integrated Services
Digital Network (PSPDN/ISDN) for the support of packet
switched data transmission services
(GSM 09.06 version 5.0.2)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
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 1997. All rights reserved.

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ETS 300 975 (GSM 09.06 version 5.0.2): May 1997
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 300 975 (GSM 09.06 version 5.0.2): May 1997
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .9
4 Introduction.10
5 Network characteristics .10
5.1 Characteristics of GSM PLMNs.10
5.2 Characteristics of PSPDNs.11
5.3 Characteristics of ISDN .11
5.4 Characteristics of the packet service provided by the PH .11
5.5 Characteristics of the packet service provided by a PH assuming the role of an AU or
by X.32.11
6 Interworking classifications .11
6.1 Service interworking.11
6.2 Network interworking .11
7 Network interworking scenarios .12
7.1 General .12
7.2 Interworking through transit networks.12
7.3 Direct Interworking.13
8 Basic packet mode service .13
8.1 General .13
8.2 Service provided by the GSM PLMN network.14
8.3 Mobile originated calls .14
8.3.1 Subscriber on home PLMN .14
8.3.2 Subscriber on visited PLMN .14
8.4 Mobile terminated calls .16
8.4.1 Subscriber on home PLMN .16
8.4.2 Subscriber on visited PLMN .16
8.5 Mobile originated mobile terminated calls.16
8.6 Subscriber profiles .16
8.7 GSM bearer services quality of service .16
9 Dedicated packet mode service.17
9.1 General .17
9.2 General application rules .18
9.3 Specific application of rules for dedicated packet mode service .18
9.4 Mobile originated calls .19
9.4.1 General.19
9.4.2 Short code .20
9.5 Particular packet access functionality.20
History.21

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ETS 300 975 (GSM 09.06 version 5.0.2): May 1997
Foreword
This European Telecommunication Standard (ETS) has been produced by the Special Mobile Group
(SMG) Technical Committee (TC) of the European Telecommunications Standards Institute (ETSI).
This ETS identifies the Interworking Functions (IWFs) and requirements for the interworking between a
GSM Public Land Mobile Network (PLMN) and a Packet Switched Public Data Network/Integrated
Services Digital Network (PSPDN/ISDN) for the support of packet services in GSM PLMNs within the
digital cellular telecommunications system (Phase 2/Phase 2+).
This ETS is a GSM technical specification version 5, which incorporates GSM Phase 2+
enhancements/features to the version 4 GSM technical specification. The ETS from which this Phase 2+
ETS has evolved, is Phase 2 GSM ETS 300 603 + Amendment 1 (GSM 09.06 version 4.5.0).
The specification from which this ETS has been derived was originally based on CEPT documentation,
hence the presentation of this ETS may not be entirely in accordance with the ETSI/PNE Rules.
The contents of this ETS are subject to continuing work within TC-SMG and may change following formal
TC-SMG approval. Should TC-SMG modify the contents of this ETS it will then be resubmitted for OAP by
ETSI with an identifying change of release date and an increase in version number as follows:
Version 5.x.y
where:
y the third digit is incremented when editorial only changes have been incorporated in the
specification;
x the second digit is incremented for all other types of changes, i.e. technical enhancements,
corrections, updates, etc.
Transposition dates
Date of adoption: 4 April 1997
Date of latest announcement of this ETS (doa): 31 August 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 28 February 1998
Date of withdrawal of any conflicting National Standard (dow): 28 February 1998

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ETS 300 975 (GSM 09.06 version 5.0.2): May 1997
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ETS 300 975 (GSM 09.06 version 5.0.2): May 1997
1 Scope
This European Telecommunication Standard (ETS) identifies the Interworking Functions (IWF's) and
requirements for the interworking between a GSM PLMN and a Packet Switched Public Data
Network/Integrated Services Digital Network (PSPDN/ISDN) for the support of packet services in GSM
PLMNs.
In the GSM PLMN context the packet services are associated with bearer services and are described in
GSM 02.02. The generally defined GSM PLMN user-network access as defined in the respective GSM
specifications (see references) forms the basis for defining the particularities for the provision of packet
services to the GSM PLMN subscribers. Network internal interfaces for the support of packet services in
the pan-European ISDN are defined in ETSI standards, which are also taken as a basis.
User-network access and network internal interfaces are defined to provide the packet services.
2 Normative references
This 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 ETS only when incorporated in it by amendment or revision. For undated references, the
latest edition of the publication referred to applies.
[1] GSM 01.04 (ETR 350): "Digital cellular telecommunications system (Phase 2+);
Abbreviations and acronyms".
[2] CCITT 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".
[3] CCITT Recommendation X.31: "Support of packet mode terminal equipment by
an ISDN".
[4] CCITT Recommendation X.32: "Interface between data terminal equipment
(DTE) and data circuit-terminating equipment (DCE) for terminals operating in
the packet mode and accessing a packet switched telephone network or an
integrated services digital network or a circuit switched public data network".
[5] ETS 300 007: "Integrated Services Digital Network (ISDN); Support of
packet-mode terminal equipment by an ISDN".
[6] ETS 300 099: "Integrated Services Digital Network (ISDN); Specification of the
Packet Handler access point Interface (PHI)".
[7] ETS 300 102: "Integrated Services Digital Network (ISDN); User-network
interface layer 3 Specifications for basic call control Specification Description
Language (SDL) diagrams".
[8] ETR 010: "ISDN Standards Management (ISM); The ETSI basic guide on the
European integrated services digital network".
[9] GSM 02.02 (ETS 300 904): "Digital cellular telecommunications system
(Phase 2+); Bearer Services (BS) supported by a GSM Public Land Mobile
Network (PLMN)".
[10] GSM 02.03 (ETS 300 905): "Digital cellular telecommunications system
(Phase 2+); Teleservices supported by a GSM Public Land Mobile Network
(PLMN)".
[11] GSM 02.04 (ETS 300 918): "Digital cellular telecommunications system
(Phase 2+); General on supplementary services".

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ETS 300 975 (GSM 09.06 version 5.0.2): May 1997
[12] GSM 02.86: "Digital cellular telecommunications system; Advice of charge
(AoC) Supplementary Services - Stage 1".
[13] GSM 02.88: "Digital cellular telecommunications system; Call Barring (CB)
Supplementary Services - Stage 1".
[14] GSM 03.03 (ETS 300 927): "Digital cellular telecommunications system
(Phase 2+); Numbering, addressing and identification".
[15] GSM 03.10: "Digital cellular telecommunications system (Phase 2+); GSM
Public Land Mobile Network (PLMN) connection types".
[16] GSM 03.70: "Digital cellular telecommunications system; Routeing of calls
to/from Public Data Networks (PDN) and the GSM Public Land Mobile Network
(PLMN)".
[17] GSM 04.02: "Digital cellular telecommunications system (Phase 2+); GSM
Public Land Mobile Network (PLMN) access reference configuration".
[18] GSM 04.08 (ETS 300 940): "Digital cellular telecommunications system
(Phase 2+); Mobile radio interface layer 3 specification".
[19] GSM 04.21 (ETS 300 945): "Digital cellular telecommunications system
(Phase 2+); Rate adaption on the Mobile Station - Base Station System (MS -
BSS) Interface".
[20] GSM 04.22 (ETS 300 946): "Digital cellular telecommunications system
(Phase 2+); Radio Link Protocol (RLP) for data and telematic services on the
Mobile Station - Base Station System (MS - BSS) interface and the Base Station
System - Mobile-services Switching Centre (BSS - MSC) interface".
[21] GSM 07.01 (ETS 300 913): "Digital cellular telecommunications system
(Phase 2+); General on Terminal Adaptation Functions (TAF) for Mobile
Stations (MS)".
[22] GSM 07.03 (ETS 300 915): "Digital cellular telecommunications system
(Phase 2+); Terminal Adaptation Functions (TAF) for services using
synchronous bearer capabilities".
[23] GSM 08.20: "Digital cellular telecommunications system (Phase 2+); Rate
adaption on the Base Station System - Mobile-services Switching Centre (BSS -
MSC) interface".
[24] GSM 09.03: "Digital cellular telecommunications system; Signalling
requirements on interworking between the Integrated Services Digital Network
(ISDN) or Public Switched Telephone Network (PSTN) and the Public Land
Mobile Network (PLMN)".
[25] GSM 09.07 (ETS 300 976): "Digital cellular telecommunications system
(Phase 2+); General requirements on interworking between the Public Land
Mobile Network (PLMN) and the Integrated Services Digital Network (ISDN) or
Public Switched Telephone Network (PSTN)".

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ETS 300 975 (GSM 09.06 version 5.0.2): May 1997
3 Definitions and abbreviations
Use is made of the following terms within this ETS. These terms refer to information requirements
necessary to support interworking functions, some of these terms will be identifiable with their use in other
specifications.
For the purposes of this ETS, the following definitions apply:
bearer capability information: Specific information defining the lower layer characteristics required
within the network.
lower layer capability information: Information defining the lower layer characteristics of the terminal.
higher layer capability information: Information defining the higher layer characteristics of a teleservice
active on the terminal.
protocol identifier: Information defining the specific protocols utilised for the support of data transfer by a
terminal.
service profile: Set of values of the network default and user selectable attributes selected for a
particular DTE identity.
loop detection: Detection of the situation, where a call, which has left the originating network, re-appears
at the originating network.
GSM packet mode services "Use of X.31 case A": A circuit connection shall be used for accessing the
packet service (according to ETS 300 099), with the significant characteristics of the connection identified
by the following setting of the respective parameters of the BC-IE:
- information transfer capability = unrestricted digital information;
- transfer mode = circuit mode.
The issue of "loop detection" is of no concern in the case of X.31 Case A (ETS 300 099) because the PH
inserts - irrespective of being accessed by a home or a foreign roaming subscriber - into the "calling
address" of an outgoing X.25 "call request" packet the address of the B-channel port.
GSM packet mode services "Use of X.31 case B": A packet connection shall be used for accessing the
packet service (according to ETS 300 099), with the significant characteristics of the connection identified
by the following setting of the respective parameters of the BC-IE:
- information transfer capability = unrestricted digital information;
- transfer mode = packet mode.
service number: A service number is a special E.164 number of the HPLMN which indicates to the
HPLMN that, in case of an access to a PH X.31 case B, case A/B conversion is necessary. It is translated
in the HPLMN into the actual E.164 number of the PH. The service number is used by the subscriber for
the access of the PH case B when the subscriber is in the HPLMN or in the VPLMN.
packet mode services via PSTN (X.32): A circuit connection shall be used for accessing the packet
service with the significant characteristics of the connection identified by the following setting of the
respective parameters of the Bearer Capability Information Element in access from a PLMN:
- information transfer capability = 3,1 kHz exPLMN;
- transfer mode = circuit mode.
home PLMN: That GSM PLMN where the mobile subscriber has his subscription for mobile services.
visited PLMN: That GSM PLMN on which the mobile subscriber is roamed to when leaving his home
PLMN (HPLMN) and logged-in there.
basic MSisdn: The MSisdn stored in VLR for a visiting mobile subscriber.
PSPDN port: Unit providing incoming/outgoing demand access to a PSPDN (X.32).

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ETS 300 975 (GSM 09.06 version 5.0.2): May 1997
Table 1/GSM 09.06: Specification reference list
Term Specification where defined
CCITT, ETS GSM
Bearer service I.112, I.210, I.211 02.02
Exchange I.112
Terminal Adaptor (Functions) I.411 07 series
Interworking Function X.300 09.06, 09.07
Attributes I.112,I.140, I.211 02.01
Connection capabilities I.340 03.10
Control channel (D/Dm channel) I.412 04.03
Traffic channel (B/TCH channel) I.412 04.03
Service profile ETS 300 099 09.06
In addition to those below, abbreviations used in this ETS are listed in GSM 01.04.
AU Access Unit
Cct Circuit
CRP Call Request Packet
IWMSC MSC accessing the PH
4 Introduction
General Network Interworking Scenarios are described in GSM 09.01.
When two dissimilar networks are required to interwork in order to support a communication between two
subscribers, one on each network, a number of functions performing the interworking are required to
support the communication. Some of these are related to the differences in signalling and are dealt with in
GSM 09.03.
Examples of other aspects of interworking are:
i) the need of specific packet functions;
ii) the need of modem pools and network-based rate adaptation.
From the mobile subscriber's point of view, there have been defined two types of services within GSM
PLMNs:
- basic packet mode services:
These services provide access either to the Packet handler(PH) and/or the PSPDN Port to which
the individual subscriber is subscribed to.
- dedicated packet mode services:
These services provide access to the PH provided by the visited GSM PLMN, i.e. the "real packet
world" is entered as soon as possible.
Packet services are provided in the context of this ETS by means of the "circuit" transfer mode.
For the purposes of determining the required IWF functionality, it is necessary, however, to consider
separately each type of service i.e. the basic and the dedicated packet mode service.
5 Network characteristics
The key characteristics of networks concerned are listed in table 2/09.06.
5.1 Characteristics of GSM PLMNs
The GSM PLMN is fully defined in the GSM series of specifications.

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ETS 300 975 (GSM 09.06 version 5.0.2): May 1997
5.2 Characteristics of PSPDNs
These are defined in the relevant CCITT X series recommendations, such as X.1, X.2, X.10, X.25, and
X.75.
5.3 Characteristics of ISDN
These are defined in the CCITT I-series recommendations. The services and standards for the
pan-European ISDN are identified in ETR 010.
5.4 Characteristics of the packet service provided by the PH
The packet services supported via the packet handler interface (PHI) are defined in ETS 300 099. Support
for both the ISDN X.31 Case A and Case B are specified there.
Table 2/GSM 09.06: Key characteristics of networks concerned
Characteristics GSM PLMN ISDN PSPDN
User-network interface Digital Digital
User-network signalling GSM 04.08 I.441/I.451 X.25, X.31, X.32
User-terminal equipment MT0, Digital TE DTE
support DTE+MT1, (ISDN NT,
DTE+MT2 TE1 or TE2+TA)
see GSM 04.02 see I.441
Inter-exchange SS No.7 SS No.7 Proprietary,
signalling ISUP,TUP+, ISUP, TUP+ X.75
MAP X.75
Transmission facilities Digital Digital Digital
Exchange types Digital Digital Digital
Information transfer mode Circuit Cct or Packet
Information transfer Speech, Speech, unrestr.digital
capabilities unrestr.digital, unrestr.digital
altern. speech/ 3.1 kHz audio
fax group 3, etc. video, etc.
5.5 Characteristics of the packet service provided by a PH assuming the role of an AU or
by X.32
The packet services provided by the PH assuming the role of an AU is defined in the ETS 300 099 (X.31
Case A). The packet service provided via a modem is defined in CCITT X.32.
6 Interworking classifications
Generally the distinction is made between the service interworking and the network interworking.
6.1 Service interworking
Service interworking is required when the Teleservices at the calling and called terminals are different
(e.g. Teletex interworking with facsimile). These aspects are not dealt with in this ETS.
6.2 Network interworking
Network interworking is required whenever a GSM PLMN and a non-GSM PLMN together are involved to
provide an end to end connection and may be required in instances of GSM PLMN to GSM PLMN
connecti
...