ISO/IEC TR 10000-2:1998

TECHNICAL ISO/IEC
REPORT TR 10000-2
Fifth edition
1998-11-01
Information technology — Framework and
taxonomy of International Standardized
Profiles —
Part 2:
Principles and Taxonomy for OSI Profiles
Technologies de l'information — Cadre et taxinomie des profils normalisés
internationaux —
Partie 2: Principes et taxinomie pour profils OSI
Reference number
B C
Contents
FOREWORD . iv
INTRODUCTION.v
1 SCOPE.1
2 REFERENCES.1
3 DEFINITION .1
4 ABBREVIATIONS.2
4.1 General abbreviations . 2
4.2 Abbreviations used in Profile identifiers. 2
5 THE OSI TAXONOMY: PRINCIPLES.2
5.1 General. 2
5.2 The Class concept for OSI Profiles. 3
5.3 Relationship between OSI Profiles. 3
5.3.1 A/T and B/U Boundaries. 3
5.3.2 A/F and B/F Boundaries . 3
5.4 The Group concept for OSI Lower Layer Profiles. 5
5.5 Profile classes. 5
5.5.1 Transport Profiles . 5
5.5.1.1 Principles . 5
5.5.1.2 Transport Profile Identifier . 5
5.5.1.3 Connection-mode Transport Service: profile class T. 6
5.5.1.4 Connectionless-mode Transport Service: Profile class U . 6
5.5.1.5 Interworking between Transport Profile Groups. 6
5.5.1.6 Introduction to the Taxonomy of Subnetwork Profiles . 7
5.5.1.6.1 Packet Switched Data Network. 8
5.5.1.6.2 Digital Data Circuit. 8
5.5.1.6.3 Analogue Telephone Circuit . 8
5.5.1.6.4 Integrated Services Digital Network . 8
5.5.1.6.5 Local Area Networks . 8
5.5.1.6.6 Frame Relay Data Networks . 8
5.5.2 Relay Profiles. 9
5.5.2.1 Principles . 9
5.5.2.2 Relay Profile Identifier. 9
5.5.3 Application Profiles . 9
5.5.3.1 Principles . 9
5.5.3.2 Common Upper Layer Requirements. 10
5.5.3.3 Application Profile Identifier . 10
5.5.3.4 Introduction to the Taxonomy of Application Profiles. 10
5.5.3.4.1 File Transfer, Access and Management . 10
5.5.3.4.2 Message Handling. 10
5.5.3.4.3 Directory . 11
5.5.3.4.4 Virtual Terminal. 11
5.5.3.4.5 OSI Management . 11
5.5.3.4.6 Transaction Processing. 12
©  ISO/IEC 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or
utilized in any form or by any means, electronic or mechanical, including photocopying and micro-
film, without permission in writing from the publisher.
ISO/IEC Copyright Office • Case postale 56 • CH-1211 Genève 20 • Switzerland
Printed in Switzerland
ii
©
ISO/IEC
5.5.3.4.7 Remote Database Access.12
5.5.3.4.8 Manufacturing Messaging .12
5.5.3.4.9 Library and Documentation .12
5.5.3.4.10 Document Filing and Retrieval.12
5.5.3.4.11 Interactive Manipulation of ODA Documents.13
5.5.4 Interchange Format and Representation Profiles.13
5.5.4.1 Principles.13
5.5.4.2 Interchange Format and Representation Profile Identifier.13
5.5.4.3 Introduction to the Taxonomy of Interchange Format and Representation Profiles .14
5.5.4.3.1 Open Document Format.14
5.5.4.3.2 Computer Graphics Metafile Interchange Format .14
5.5.4.3.3 SGML Interchange Format.14
5.5.4.3.4 Directory Data Definitions.14
5.5.4.3.5 Virtual Terminal Environment.14
5.5.4.3.6 Character Sets.15
6 TAXONOMY OF PROFILES . 15
6.1 Transport Profiles.15
6.1.1 Taxonomy of Subnetworks.15
6.1.2 Transport Groups.16
6.2 Relay Profiles .17
6.2.1 Relaying the Network Internal Layer Service, as defined in ISO/IEC 10028.17
6.2.2 Network Layer Protocol Relaying .17
6.2.3 Relaying the MAC Service.17
6.2.4 CO/CL Interworking.17
6.3 Application Profiles.17
6.3.1 File Transfer, Access and Management.17
6.3.2 Message Handling .17
6.3.3 Directory.18
6.3.3.1 Edition 1988 .18
6.3.3.2 Edition 1993 .18
6.3.4 Virtual Terminal .18
6.3.5 OSI Management.18
6.3.6 Transaction Processing.19
6.3.7 Remote Database Access.19
6.3.8 Manufacturing Messaging .19
6.3.9 Library and Documentation.19
6.3.10 Document Filing and Retrieval.20
6.3.11 Interactive Manipulation of ODA Documents.20
6.4 Interchange Format and Representation Profiles.20
6.4.1 Open Document Format .20
6.4.2 Computer Graphics Metafile Interchange Format .20
6.4.3 SGML Interchange Format.20
6.4.4 Directory Data Definitions .20
6.4.4.1 Edition 1988 .20
6.4.4.2 Edition 1993 .21
6.4.5 Virtual Terminal Environment.21
6.4.6 Character Sets.21
7 CONFORMANCE OF OSI PROFILES. 22
A A. 23
NNEX
Bibliography.23
iii
©
ISO/IEC
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
In the field of information technology, ISO and IEC have established a joint technical committee,
ISO/IEC JTC 1.
The main task of technical committees is to prepare International Standards, but in exceptional
circumstances a technical committee may propose the publication of a Technical Report of one of the
following types:
 type 1, when the required support cannot be obtained for the publication of an International
Standard, despite repeated efforts;
 type 2, when the subject is still under technical development or where for any other reason there
is the future but not immediate possibility of an agreement on an International Standard;
 type 3, when a technical committee has collected data of a different kind from that which is
normally published as an International Standard ("state of the art", for example).
Technical Reports of types 1 and 2 are subject to review within three years of publication, to decide
whether they can be transformed into International Standards. Technical Reports of type 3 do not
necessarily have to be reviewed until the data they provide are considered to be no longer valid or
useful.
ISO/IEC TR 10000-2, which is a Technical Report of type 3, was prepared by Joint Technical
Committee ISO/IEC JTC 1, Information technology.
This fifth edition cancels and replaces the fourth edition (ISO/IEC TR 10000-2:1995), which has been
technically revised.
ISO/IEC TR 10000 consists of the following parts, under the general title Information technology -

Framework and taxonomy of International Standardized Profiles:
 Part 1: General principles and documentation framework
 Part 2: Principles and Taxonomy for OSI Profiles
 Part 3: Principles and Taxonomy for Open System Environment Profiles
Other parts to be defined as necessary.
iv
©
ISO/IEC
Introduction
The context of Functional Standardization is one part of the overall field of Information
Technology standardization activities covering
• Base standards, which define fundamentals and generalized procedures. They
provide an infrastructure that can be used by a variety of applications, each of which
can make its own selection from the options offered by them.
• Profiles, which define conforming subsets or combinations of base standards used to
provide specific functions. Profiles identify the use of particular options available in the
base standards, and provide a basis for the development of uniform, internationally
recognized, conformance tests.
• Registration mechanisms, which provide the means to specify detailed
parameterization within the framework of the base standards or profiles.
Within ISO/IEC JTC 1, the process of Functional Standardization is concerned with the
methodology of defining profiles, and their publication in documents called "International
Standardized Profiles" (ISPs) in accordance with procedures contained in the Directives of
JTC 1. The scope of Information Technology standardization to which this process is being
applied is that which corresponds to the generally understood, but loosely defined, concept of
“Open Systems“. The objective is to facilitate the specification of IT systems characterized by
a high degree of interoperability and portability of their components.
In addition to ISO/IEC TR 10000, the secretariat of the Special Group on Functional
Standardization maintains a standing document (SD-4) entitled "Directory of ISPs and Profiles
contained therein". This is a factual record of which ISPs exist, or are in preparation, together
with an executive summary of each profile. It is subject to regular updating by the Secretariat
of ISO/IEC JTC 1/SGFS.
v
©
TECHNICAL REPORT  ISO/IEC ISO/IEC TR 10000-2:1998(E)
Information technology — Framework and taxonomy of
International Standardized Profiles —
Part 2:
Principles and Taxonomy for OSI Profiles
also provide additional information, including the status of the
1 Scope
identified profiles.
The purpose of this part of ISO/IEC TR 10000 is to provide
principles and a classification scheme for OSI profiles which may
be or have been submitted for ratification as International
2 References
Standardized Profiles (ISPs).
ISO/IEC 9646-6:1994, Information technology - Open Systems
ISO/IEC TR 10000-1 defines the concept of profiles which are
Interconnection - Conformance testing methodology and
documented in ISPs. OSI profiles are a subset of OSE profiles.
framework - Part 6: Protocol profile test specification. {ITU-T Rec.
ISO/IEC TR 10000-3 defines the concept of OSE profiles and,
X.295 (1995)}
along with ISO/IEC TR 10000-1, gives guidance to organizations
making proposals for Draft ISPs, on the nature and content of the
ISO/IEC 9646-7:1995, Information technology - Open Systems
documents they are producing.
Interconnection - Conformance testing methodology and
framework - Part 7: Implementation Conformance Statements.
The existence of a profile classification in this part of
{ITU-T Rec. X.296 (1995)}
ISO/IEC TR 10000 does not reflect a judgment by
ISO/IEC JTC 1/SGFS that a profile is required for such capability.
ISO/IEC TR 10000-1:1998, Information technology - Framework
It merely provides a capability to identify uniquely such a function
and taxonomy of International Standardized Profiles - Part 1:
and to enable evaluation of PDISPs.
General principles and documentation framework.
Since profiles will be proposed according to needs identified to
ISO/IEC TR 10000-3:1998, Information technology - Framework
SGFS and according to the progress of international base
and taxonomy of International Standardized Profiles - Part 3:
standardization, the Taxonomy will be periodically updated or have
Principles and Taxonomy for Open System Environment Profiles.
new parts added in order to reflect the progress reached. It is also
recognized that there will be proposals for the extension of the
Taxonomy to cover functions which were not identified during A number of other ISO, IEC, and ISO/IEC JTC 1 Standards and
preparation of this edition of ISO/IEC TR 10000. These extensions ITU-T Recommendations are quoted in examples which do not
may be identified by a variety of proposers and involve simple constitute provisions of this part of ISO/IEC TR 10000.
extensions to the existing Taxonomy or the addition of new func-
tional areas not currently covered by ISO/IEC TR 10000. The
inclusion of such extensions is administered following the proce-
3 Definition
dures elaborated by SGFS.
For the purposes of this part of ISO/IEC TR 10000, the following
A distinction has been made between a profile and an ISP
definition applies.
documenting one or more profiles. The Taxonomy is only
concerned with profiles, but further information is given in the
3.1  Group: A set of OSI profiles that are compatible, in the sense
"Directory of ISPs and Profiles contained therein" as to which ISP
that an IT implementing one profile from a Group can interwork,
contains the documentation of a profile.
according to OSI, with another IT system implementing a different
profile from the same Group, in terms of the operation of the
This Directory is maintained as an SGFS standing document SD-4
protocols specified within these profiles.
(see Annex A). For each draft profile submitted to SGFS, it will

1 This part of ISO/IEC TR 10000 defines only a taxonomy for OSI based
communication profiles; the issue of the placement of other communication
profiles is not addressed.
©
ISO/IEC
4 Abbreviations 4.2 Abbreviations used in Profile
identifiers
4.1 General abbreviations
Abbr. Profile sub-class (Applications)
CGM Computer Graphics Metafile
ADF Document Filing and Retrieval
CL Connectionless-mode
ADI Directory (1988)
CLNS Connectionless-mode Network Service
ADY Directory (1993)
CLTS Connectionless-mode Transport Service
AFT File Transfer, Access and Management
CO Connection-mode
ALD Library, Documentation
CONS Connection-mode Network Service
AMH Message Handling
COTS Connection-mode Transport Service
AMM Manufacturing Messaging
CSDN Circuit Switched Data Network
AOD Interactive Manipulation of ODA Documents
CSI Communication Services Interface
ARD Remote Database Access
CSMA/CD Carrier Sense, Multiple Access / Collision Detection
ATP Transaction Processing
CULR Common Upper Layer Requirements100
AVT Virtual Terminal
DFR Document Filing and Retrieval
DSA Directory Service Agent
Abbr. Profile sub-class (Formats)
DTAM-DM Document Transfer and Manipulation - Document
FCG Computer Graphics Metafile Interchange Format
Manipulation
FCS Character Sets
DTE Data Terminal Equipment
FDI Directory Data Definitions (1988)
DUA Directory User Agent
FDY Directory Data Definitions (1993)
EDI Electronic Data Interchange
FOD Open Document Format
EDIMG EDI Messaging
FSG SGML Interchange Format
FDDI Fibre Distributed Data Interface
FVT Virtual Terminal Registered Objects
FR PVC Frame Relay Permanent Virtual Circuit
FR SVC Frame Relay Switched Virtual Call
Abbr. Profile sub-class (Lower Layers)
FRBS Frame Relay Bearer Service
TA COTS over CLNS
FRDN Frame Relay Data Network
TB COTS over CONS
FRDTS Frame Relay Data Transmission Service
TC COTS over CONS
IIF Image Interchange Facility
TD COTS over CONS
IPI Image Processing and Interchange
TE COTS over CONS
IPM Interpersonal Message
UA CLTS over CLNS
ISDN Integrated Services Digital Network
UB CLTS over CONS
ISP International Standardized Profile
RA Relaying the CLNS
LAN Local Area Network
RB Relaying the CONS
MAC Media Access Control
RC X.25 Protocol Relaying
MMS Manufacturing Message Specification
RD Relaying the MAC Service using transparent bridging
MOTIS Message Oriented Text Interchange System
RE Relaying the MAC Service using source routing
MS Message Store
RZ Relaying between CLNS and CONS
MTA Message Transfer Agent
MTS Message Transfer System
ODA Open Document Architecture
5 The OSI Taxonomy: Principles
P1 Message Transfer Protocol
P2 Interpersonal Messaging Protocol
5.1 General
P3 MTS Access Protocol
P7 MS Access Protocol
OSI profiles are primarily arranged into classes, each class
PSDN Packet Switched Data Network
representing a category of functionality of reasonable
PSTN Public Switched Telephone Network
independence from other classes. The different classes of profile
PVC X.25 Permanent Virtual Circuit
correspond to the major divisions of the taxonomy.
QOS Quality of Service
SGFS ISO/IEC JTC 1/Special Group on Functional
Within each class, a class-specific subdivision will be used.
Standardization
SGML Standardized General Markup Language
TP Transaction Processing
TPSU TP Service User
UA User Agent
2 The taxonomy substructure for the 1988 edition of the Directory
VC X.25 Virtual Call
specifications differs from the taxonomy substructure developed for the 1993
VT Virtual Terminal
edition.
©
ISO/IEC
OSI profile identifiers are structured in accordance with the F-profiles specify the characteristics and representation of various
general OSE taxonomy defined in ISO/IEC TR 10000-3. Thus, an types of information interchanged by A- and B-profiles.
OSI profile identifier comprises:
R-profiles specify Relay functionality needed to enable IT systems
using different T- or U-profiles to interwork. Interworking between
• the suffix “-C“ (for a CSI profile);
T- and U-profiles is not contemplated in any JTC 1 work.
• a root mnenomic which is a character string commencing with
Within each of these classes, sub-classes of profiles are identified
one letter that indicates the primary class of the profile;
which, again, may require further subdivision such that the
granularity of the Taxonomy meets the requirements outlined in
• an alphanumeric string that is as long as necessary to reflect
ISO/IEC TR 10000-1. This leads to a hierarchical structure of
the position of the profile within the hierarchic structure.
profile (sub-)classes which is given in full in clause “6 Taxonomy
of Profiles“.
The syntax of all but the first letter is subject to individual
definitions (see below).
For the identification of sub-classes and a further subdivision
NOTE - In the context of the general OSE taxonomy defined in ISO/IEC TR 10000-3,
within a given class, a class-dependent methodology is applied.
OSI profiles are identified as Communication Services Interface profiles by the
This is explained in the subsequent class-individual sections.
suffix “-C“. This suffix is omitted in the description of the OSI taxonomy in this
part of ISO/IEC TR 10000.
5.3 Relationship between OSI Profiles
5.2 The Class concept for OSI Profiles
The schematic illustration in Figure 1 brings together examples of
In order to decouple representation of information or objects from the relationships which exist between OSI profiles, particularly the
communication protocols, and application-related protocol from three main subdivisions of the Taxonomy, and the combinations
subnetwork types, OSI and OSI-related profiles are divided into which can be made between profiles from different classes.
the following classes:
5.3.1 A/T and B/U Boundaries
T - Transport profiles providing connection-mode Transport
Service
Actual use of an A- or B-profile requires that an IT system operate
it in combination with a T- or U-profile, in order to provide a
U - Transport profiles providing connectionless-mode
particular application protocol over a particular subnetwork type.
Transport Service
The separation of A- and B-profiles from T- and U-profiles is
represented by an A/T or B/U boundary. This relationship is
R - Relay profiles
illustrated vertically in Figure 1. The location of a set of A-profiles
above a set of T-profiles, separated by a common A/T boundary,
A - Application profiles requiring connection-mode Transport
represents the possibility of combining any pair of A- and
Service
T-profiles, one from each of the two classes.
B - Application profiles requiring connectionless-mode
A similar situation exists for the B- and U-profiles. The A/T
Transport Service
boundaries correspond to the OSI Connection-mode Transport
Service, and the B/U-boundaries to the OSI Connectionless-mode
F - Interchange format and representation profiles
Transport Service. The possibility of making the combination
arises from the fact that a T- or U-profile is specified to provide the
Other classes may be required.
OSI Transport Service and an A- or B-profile is specified to use
the OSI Transport Service.
Transport profiles of classes T and U specify how the two modes
of OSI Transport Service are provided over the two modes of OSI
5.3.2 A/F and B/F Boundaries
Network Service, and over specific subnetwork types, such as in-
dividual types of LANs, PSDNs, etc. In this way they isolate the
The combination of an A- or B-profile with one or more F-profiles
A/B-profiles and F-profiles from network technology.
will be selected by the user to meet the functional requirements in
each case. The various general possibilities are illustrated by the
T- and U-profiles are further subdivided into Groups.
vertical relationships in Figure 1. The location of one or more
See “5.4 The Group concept for OSI Lower Layer Profiles“ for
F-profiles above one or more A-/B-profiles, represents the
details.
possibility of combining profiles from each class.
Application profiles of classes A and B specify communications
Unlike the A/T and B/U boundaries, the A/F and B/F boundaries
protocol support for particular application types over the two
are not characterized by a single service definition.
modes of OSI Transport Service, respectively.
©
ISO/IEC
©
ISO/IEC
The Application Layer base standards require, implicitly or working between IT systems conforming to them is made possible
explicitly, the structure of information carried or referenced by by LAN bridges and/or Network Layer relays.
them to be specified for each instance of communication. The
combination of A-/B-profiles with one or more F-profiles will be A Group is identified by labels of the form YXnnn, where Y is the
selected by the user to meet the functional requirements in each class identifier and X is a letter identifying the Group.
case. However, the choice may be subject to constraints which
can be expressed within either A-/B-profiles, F-profiles, or both.
5.5 Profile classes
In other A-/B-profiles, the Application Layer base standards
themselves constrain the choice of presentation context.
5.5.1 Transport Profiles
Constraints may also exist within an F-profile, arising either from
5.5.1.1 Principles
its base standard, or as a result of profile creation. These
constraints will limit the A-/B-profiles which can be used to transfer
Transport profiles define the use of protocol standards from OSI
the information.
layers 1 to 4, to provide the OSI Transport Service.
In summary, therefore, there are three forms of constraints
A primary distinction is made between Transport profiles, based
affecting the combination of A-/B- and F-profiles:
on the mode of Transport Service offered:
a) the choice of information to be transferred may be
 Connection-mode Transport Service:
constrained by the Application Layer base standards, and
profile class T
possibly further constrained by the A-/B-profile;
 Connectionless-mode Transport Service:
b) some interchange and representation base standards may
profile class U
limit transfer to particular Application base standards; this
choice may be further constrained by the F-profiles;
For the Transport profile classification within each class, the
following methodology is applied:
c) the combinations are not constrained by base standards,
but may be constrained by either A-/B- or F-profiles to
a) As a first level distinction the Group concept
achieve some general function.
(see “5.4 The Group concept for OSI Lower Layer
Profiles“) is used in the following way:
Note that, as always, in making his choice of combination, a user
must in practice take account not only of the constraints derived
A lower layer Group is a collection of profiles which:
from profiles, but also the capabilities implemented in the end
systems involved in each instance of communication, to support
• support the same combination of modes of Transport
the various profiles.
and Network Service;
5.4 The Group concept for OSI Lower
• support the same Transport Protocol Class(es);
Layer Profiles
The notion of a Group is incorporated in the classification.
The Group concept is used in the Taxonomy as follows:
b) The second level distinction between profiles, i.e. within a
A Group is a set of T- or U-profiles that are compatible in the
Group, is made according to the subnetwork type
sense that an IT system implementing one profile from the Group
supported
and another IT system implementing a profile from the same
(see “6.1.1 Taxonomy of Subnetworks“ for examples of
Group can be expected to interwork, according to OSI, to some
subnetwork types).
minimum level which is determined by the mandatory features of
the profiles in the Group.
c) Further subdivisions are made according to the
characteristics of a particular subnetwork, e.g., switched
Interworking according to OSI means end-to-end operation across
versus leased line
a single subnetwork, or across multiple subnetworks linked by
(see 6.1.1 for examples of such characteristics).
means of Network (or lower) Layer relays.
5.5.1.2 Transport Profile Identifier
An example of a Group is the set of T-profiles that provide the
Connection-mode Transport Service, using Class 4 Transport
The identifier for a profile in the lower layers is of the form:
Protocol over the Connectionless-mode Network Service, provided
by ITU-T Rec. X.233 | ISO/IEC 8473-1. This Group has members
YXabcde
which correspond to different subnetwork technologies but inter-
©
ISO/IEC
where: Group TB: 0 and 2 and 4 (see note 2)
Group TC: 0 and 2 (see note 2)
Y   = class designator, indicating the Transport Service
Group TD: 0
mode:
Group TE: 2 (see note 3)
T for Connection-mode
NOTES
U for Connectionless-mode 1 'Mandatory' means those Transport Protocol classes made mandatory by the
base standard, ISO/IEC 8073, plus any class required for Group membership.
X   = one letter indicating the lower-layer Group within the
2 The class negotiation rules to be employed are those in ITU-T
class, as defined in “5.5.1.3 Connection-mode
Recommendation X.224.
Transport Service: profile class T“ and “5.5.1.4
Connectionless-mode Transport Service: Profile
3 An IT system implementing a profile from Group TE and claiming conform-
ance to ITU-T Recommendation X.224 also has to implement transport
class U“ below.
protocol class 0.
abcde = the structured numerical identifier indicating the
subnetwork type supported in this profile. It is possible
5.5.1.4 Connectionless-mode Transport
that a further level of identifier may become necessary.
Service: Profile class U
In general, when referencing a profile, only that level of
identifier which is necessary for uniqueness needs to
be used. a) Connectionless-mode Transport Service over
Connectionless-mode Network Service:
The identifier structure is not meant to capture the
variety of details and options of OSI layer 1 such as
Group UA
attachment speeds and connectors. However, it is re-
cognized that this issue must be covered by the appro-
The Connectionless-mode Transport Service (CLTS) is provided
priate profile specification.
using the ITU-T Rec. X.234  ISO/IEC 8602 Connection-
less-mode Transport Protocol. This Group supports the mandatory
5.5.1.3 Connection-mode Transport Service: profile
operation of the ITU-T Rec. X.234  ISO/IEC 8602, over Connec-
class T
tionless-mode Network Service.
Based on functional standardization already under way in organi-
b) Connectionless-mode Transport Service over
zations represented in SGFS and on standards already
Connection-mode Network Service:
developed, the following lower layer Groups are identified as be-
ing of value. They are characterized as follows:
Group UB
a) Connection-mode Transport Service over
Connectionless-mode Network Service:
The Connectionless-mode Transport Service (CLTS) is provided
using the ITU-T Rec. X.234  ISO/IEC 8602 Connection-
Group TA
less-mode Transport Protocol. This Group supports the option of
the ITU-T Rec. X.234  ISO/IEC 8602 that operates over
The Connection-mode Transport Service (COTS) is provided over
Connection-mode Network Service.
the Connectionless-mode Network Service (CLNS) by requiring
the use of the Class 4 Transport Protocol as defined in ITU-T Rec.
NOTE - An IT system implementing a profile from Group UB and claiming conformance
X.224  ISO/IEC 8073.
to the ITU-T Rec. X.234  ISO/IEC 8602 also has to implement the mandatory
operation over CLNS as required by the ITU-T Rec. X.234  ISO/IEC 8602.
NOTE - An IT system implementing a profile from Group TA and claiming conformance
to ITU-T Rec. X.224  ISO/IEC 8073 also has to implement the mandatory
transport protocol classes for operation over CONS as required by ITU-T Rec.
X.224  ISO/IEC 8073.
5.5.1.5 Interworking between Transport Profile
Groups
b) Connection-mode Transport Service over
Connection-mode Network Service
The following tables 1 and 2 show the interworking capabilities
between profiles. Table 1 shows the interworking between profiles
The Connection-mode Transport Service (COTS) is provided over
in profile class T, and table 2 shows the interworking among
the Connection-mode Network Service (CONS).
profiles in profile class U. Successful establishment of a Transport
Connection is dependent upon successful negotiation of parame-
Profiles of this characteristic are further grouped according to their
ters, some of which are not considered in the following tables.
required support of Transport Protocol class(es):
No interworking is possible between Groups in class T and U
mandatory (see note 1)
because of the different mode of Transport Service provided.
transport protocol classes
©
ISO/IEC
Entries in the tables have the following meaning: Special 1: Special restrictions for interworking exist
(see “6.2.4 CO/CL Interworking“).
Full: Full OSI interworking (an OSI relay may be
required (see “6.2 Relay Profiles“)) Special 2: Interworking between these profile types is not
contemplated in any JTC 1 work.
Restricted: Interworking capabilities are restricted in the
NOTE - Successful interworking depends not only on the satisfactory outcome of the
sense that the choice of Transport Protocol
transport protocol class negotiation but also on dynamic responses during
classes may be restricted by the static
transport initiation. Such dynamic responses can include, amongst others, re-
capability of the responder. Successful inter-
sponder reactions to the offered Quality of Service (QOS) or to the specific op-
tions requested by the initiator.
working is dependent on the satisfactory out-
come of class negotiation.
Special: Non-OSI relay required for interworking
(see also “5.5.2.1 Principles“)
Table 1 - Interworking amongst Groups in class T
Responder in Network Initiator in Group
Group Service mode TA TB TC TD TE
TA CL full special 1 special 1 special 1 special 1
TB CO special 1 full full full full
TC CO special 1 restricted full full full
TD CO special 1 restricted restricted full special 2
TE CO special 1 restricted restricted special 2 full
Table 2 - Interworking amongst Groups in class U
Responder in Initiator in Group
Group UA UB
UA full special 2
UB special 2 full
5.5.1.6 Introduction to the Taxonomy of The number of ways in which subnetworks may be implemented
Subnetwork Profiles and used is potentially very large. There are also cases where one
subnetwork type is used to access another subnetwork type which
Subnetwork types are characterized by a structured numerical has a higher network functionality. For example, an ISDN or a
identifier. The first digit of the numerical identifier classifies the FRDN may be used to access a PSDN which offers a higher
major subnetwork type being used for system interconnection functionality. The subnetwork taxonomy needs to reflect such
while the subsequent digits represent a subdivision of the combinations which are defined by ITU recommendations and
subnetwork type, indicating how use is made of the subnetwork offered by public network service providers.
type, or describing how the subnetwork is accessed. The major
subnetwork types, as identified by the first digit of the subnetwork Other subnetwork variations have been deemed to be, in practice,
identifier, are the following: less important to the goal of end system interoperability, e.g. some
electrical and physical interfaces that are prerequisites to
1 Packet Switched Data Network (PSDN) subnetwork connection establishment but transparent to data
2 Digital Data Circuit exchange. Therefore, aspects such as line speed, connector type,
3 Analogue Telephone Circuit or modem type have, in general, not been reflected in the
4 Integrated Services Digital Network (ISDN) subnetwork taxonomy. Such requirements may be included in
5 Local Area Network (LAN) actual ISPs, if considered important,
...