ISO/IEC 21409:2001

INTERNATIONAL ISO/IEC
STANDARD 21409
First edition
2001-08-15
Information technology —
Telecommunications and information
exchange between systems — Corporate
telecommunication networks — Signalling
interworking between QSIG and H.323 —
Generic functional protocol for the support
of supplementary services
Technologies de l'information — Télécommunications et échange
d'information entre systèmes — Réseaux de télécommunications
corporatifs — Signalisation de travail entre QSIG et H.323 — Protocole
fonctionnel général pour le support des services supplémentaires
Reference number
©
ISO/IEC 2001
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ii
Contents
Foreword iv
Introduction v
1 Scope 1
2 Conformance 1
3 Normative references 1
4 Definitions 2
4.1 External definitions 2
4.2 Other definitions 2
4.2.1 Call, Basic call 2
4.2.2 Corporate telecommunication Network (CN) 2
4.2.3 Gateway 2
4.2.4 IP network 2
4.2.5 Private Integrated Services Network (PISN) 2
4.2.6 Receiving side 2
4.2.7 Sending side 2
4.2.8 Side 2
5 Acronyms 2
6 Service description 3
6.1 The architecture of the two networks 3
6.2 Generic procedures: Capabilities 4
6.3 Protocol model 5
6.4 Interworking of supplementary services 6
7 Protocol interworking – Messages and information elements 7
8 Protocol interworking – Content of information elements 8
8.1 Content mapping from QSIG to H.323 8
8.2 Content mapping from H.323 to QSIG 9
8.3 Mapping of generic elements 10
8.3.1 Mapping of addressing elements from QSIG to H.323 10
8.3.2 Mapping of addressing elements from H.323 to QSIG 12
8.3.3 Mapping of embedded information elements 13
8.3.4 Mapping of manufacturer specific information from QSIG to H.323 13
8.3.5 Mapping of manufacturer specific information from H.323 to QSIG 13
8.3.6 Mapping of names from QSIG to H.323 13
8.3.7 Mapping of names from H.323 to QSIG 14
8.4 Handling of ROSE APDUs 14
Annex A - ICS Proforma 15
© ISO/IEC 2001 – All rights reserved
iii
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. Draft
International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights.
ISO and IEC shall not be held responsible for identifying any or all such patent rights.
International Standard ISO/IEC 21409 was prepared by ECMA (as ECMA-307) and was adopted, under a special “fast-track
procedure”, by Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with its approval by national
bodies of ISO and IEC.
Annex A forms a normative part of this International Standard.
© ISO/IEC 2001 – All rights reserved
iv
Introduction
This International Standard is one of a series of Standards defining the interworking of services and signalling protocols
deployed in Corporate telecommunication Networks (CNs). The series uses telecommunication concepts as developed by
ITU-T and conforms to the framework of International Standards on Open Systems Interconnection as defined by ISO/IEC.
This International Standard defines the signalling protocol interworking for the generic functional procedures in support of
Supplementary Services and/or Additional Network Features (ANFs) between a Private Integrated Services Network (PISN)
and a private telecommunications network based on the Internet Protocol (IP). It is further assumed that the protocol for the
PISN is that defined for the Q reference point (QSIG) and the protocols for the IP based network are based on ITU-T
Recommendation H.323.
This International Standard is based upon the practical experience of ECMA member companies and the results of their active
and continuous participation in the work of ISO/IEC JTC 1, ITU-T, ETSI and other international and national standardization
bodies. It represents a pragmatic and widely based consensus.
© ISO/IEC 2001 – All rights reserved
v
INTERNATIONAL STANDARD ISO/IEC 21409:2001(E)
Information technology — Telecommunications and information exchange
between systems — Corporate telecommunication networks — Signalling
interworking between QSIG and H.323 — Generic functional protocol for
the support of supplementary services
1Scope
This International Standard specifies signalling interworking between “QSIG” and “H.323” in support of generic functional
procedures for supplementary services within a Corporate telecommunication Network (CN).
“QSIG” is a signalling protocol that operates at the Q reference point between Private Integrated Services eXchanges (PINX)
within a Private Integrated Services Network (PISN). The Q reference point is defined in ISO/IEC 11579-1. A PISN provides
circuit-switched basic services and supplementary services to its users. QSIG is specified in other Standards, in particular
ISO/IEC 11572 (call control in support of basic services), ISO/IEC 11582 (generic functional protocol for the support of
supplementary services) and a number of standards specifying individual supplementary services.
“H.323” is a set of signalling protocols for the support of voice or multimedia communication within a packet network, in
particular a packet network that uses the Internet Protocol (IP) as its network layer protocol (IP network). H.323 signalling
protocols operate between endpoints in an IP network, either indirectly via one or more gatekeepers, or directly. An endpoint
can be a terminal or a gateway to another network. H.323 is an “umbrella” recommendation, referring to various ITU-T
recommendations, in particular Recommendations H.225.0 and H.245 (basic communication capabilities) and
Recommendation H.450.1 (generic functional protocol for the support of supplementary services).
NOTE - H.450.1 applies to the 1998 version of H.323 (also known as H.323 version 2) and to later versions.
Interworking between QSIG and H.323 permits a call originating at a user of a PISN to terminate at a user of an IP network, or
a call originating at a user of an IP network to terminate at a user of a PISN. In addition this International Standard enables the
participants of a call to exchange supplementary service control information in a generic way. The more specific aspects of
interworking particular supplementary services are specified in other Standards.
This International Standard is applicable to any interworking unit that can act as a gateway between a PISN employing QSIG
and an IP network employing H.323.
2 Conformance
In order to conform to this International Standard, a gateway shall satisfy the requirements identified in the Implementation
Conformance Statement (ICS) proforma in annex A.
3 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this
International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply.
However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying
the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative
document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.
ISO/IEC 11572:2000, Information technology — Telecommunications and information exchange between systems — Private
Integrated Services Network — Circuit mode bearer services — Inter-exchange signalling procedures and protocol
ISO/IEC 11579-1:1994, Information technology — Telecommunications and information exchange between systems — Private
integrated services network — Part 1: Reference configuration for PISN Exchanges (PINX)
ISO/IEC 11582:1995, Information technology — Telecommunications and information exchange between systems — Private
Integrated Services Network — Generic functional protocol for the support of supplementary services — Inter-exchange
signalling procedures and protocol
ITU-T Rec. H.225.0:1998 (or later edition), Call signalling protocols and media stream packetization for packet-based
multimedia communication systems
© ISO/IEC 2001 – All rights reserved
ITU-T Rec. H.245:1998 (or later edition), Control protocol for multimedia communication
ITU-T Rec. H.323:1998 (or later edition), Packet-based multimedia communications systems
ITU-T Rec. H.450.1:1998, Generic functional protocol for the support of supplementary services in H.323
4 Definitions
For the purposes of this International Standard, the following definitions apply.
4.1 External definitions
This International Standard uses the following terms defined in other documents:
– Endpoint (ITU-T Rec. H.323)
– Gatekeeper (ITU-T Rec. H.323)
– Private Integrated services Network eXchange (PINX) (ISO/IEC 11579-1)
– Switched Circuit Network (SCN) (ITU-T Rec. H.323)
Additionally the definitions of ISO/IEC 11582 and of ITU-T Rec. H.450.1 shall apply, as appropriate.
4.2 Other definitions
4.2.1 Call, Basic call : A call in the sense of QSIG (see ISO/IEC 11572), and a (point-to-point) conference in the sense of
H.323 (see ITU-T Rec. H.323).
NOTE - A “call” in the sense of H.323 is that segment of a (point-to-point) conference which belongs to the H.323 domain. In a multipoint
conference the H.323 segment of each conference leg is a separate call.
4.2.2 Corporate telecommunication Network (CN) : Sets of equipment [Customer Premises Equipment and/or Customer
Premises Networks] which are located at geographically dispersed locations and are interconnected to provide
telecommunication services to a defined group of users.
NOTE - A CN can comprise a PISN, a private IP network (intranet), or a combination of the two.
4.2.3 Gateway : A gateway as defined in H.323, here specifically for the purpose of interworking with a network employing
QSIG.
4.2.4 IP network : A public or private network offering connectionless packet-mode services based on the Internet Protocol
(IP) as the network layer protocol.
4.2.5 Private Integrated Services Network (PISN) : A private switched circuit network (SCN).
4.2.6 Receiving side : Within the context of a single information exchange through a gateway, the side of the gateway where
the information arrives.
4.2.7 Sending side : Within the context of a single information exchange through a gateway, the side of the gateway where the
information is transmitted.
4.2.8 Side : A single protocol stack (QSIG or H.323) within a gateway.
5 Acronyms
APDU Application Protocol Data Unit
ASE Application Service Element
CN Corporate telecommunication Network
GFT Generic Functional Transport
GK GateKeeper
ICS Implementation Conformance Statement
IE Information Element
IP Internet Protocol
IPL Inter-PINX Link
IWF InterWorking Function
© ISO/IEC 2001 – All rights reserved
LAN Local Area Network
MCU Multipoint Control Unit
PINX Private Integrated services Network eXchange
PISN Private Integrated Services Network
ROSE Remote Operations Service Element
SCM Signalling Carriage Mechanism
SCN Switched Circuit Network
SS Supplementary Service
TCP Transmission Control Protocol
TE Terminal Equipment
UDP User Datagram Protocol
6 Service description
6.1 The architecture of the two networks
An H.323 arrangement consists of two or more H.323 endpoints connected to an IP network, e.g. a local area network (LAN).
H.323 endpoints are terminals, gateways or multipoint control units (MCU). The arrangement may also contain one or more
gatekeepers (GK). The underlying network’s components (routers etc.), however, are of no concern with regard to H.323.
A gateway permits interworking with switched circuit networks (SCN), e.g. a PISN.
Gatekeeper Gateway
SCN
LAN
Terminal Terminal
Figure 1 — Example of an H.323 arrangement
A Private Integrated Services Network (PISN) consists of one or more network exchanges (PINX) with attached terminals
(TE). PINXs are inter-connected by inter-PINX links (IPLs). Communication requires a path to be set up between two TEs via
PINXs and IPLs.
© ISO/IEC 2001 – All rights reserved
PINX A
PINX B
IPL
TE
IPL
IPL
PINX D
IPL
PINX C
TE
Figure
...