ISO/IEC 21409:2001
(Main)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
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
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.
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
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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 21409:2001(E)
©
ISO/IEC 2001
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ISO/IEC 21409:2001(E)
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ISO/IEC 21409:2001(E)
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
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ISO/IEC 21409:2001(E)
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.
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ISO/IEC 21409:2001(E)
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.
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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
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ISO/IEC 21409:2001(E)
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
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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.
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ISO/IEC 21409:2001(E)
PINX A
PINX B
IPL
TE
IPL
IPL
PINX D
IPL
PINX C
TE
Figure 2 — Example of a PISN connection between two terminals
Comparing the two scenarios, the most significant difference is the absence of nodal entities in the H.323 case. Communication
is an exchange of information packets directly between two or more endpoints: A gatekeeper, if present, has certain assisting
tasks, but does not ‘switch’ any payload channels. It may, however, relay signalling information between endpoints or act upon
it on behalf of endpoints.
In the PISN case, information channels are switched by PINXs between communicating terminals for the duration of the
communication. The PINXs where the communicating terminals are attached are end PINXs, which act on user requests and are
in control of the connection through the PISN. If more than 2 PINXs are present in a call path, the intermediate PINXs act as
transit or relay nodes for both signalling and user information (payload). This role sharing – TE, end PINX, transit PINX - does
not exist in a pure H.323 conversation.
These structural differences between H.323 and PISN will in many cases result in a different allocation of supplementary
service functionality in the two environments. The possibly different function split must be taken into account when individual
supplementary services are interworked.
6.2 Generic procedures: Capabilities
Generic procedures provide the transport protocol for supplementary service control information. Supplementary service
control protocols are based on remote operations (ROSE) as defined in ITU-T Rec. X.219 / X.229 (blue book) and X.880
series.
Generic procedures for PISNs (QSIG-GF) are specified in ISO/IEC 11582. For the H.323 environment, generic procedures are
specified in ITU-T Rec. H.450.1.
The following table 1 compares the capabilities of QSIG-GF and H.450.1.
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ISO/IEC 21409:2001(E)
Table 1 — Capabilities
Capability QSIG-GF H.450.1 Remarks
Call related transport ��
Call independent connection ��
oriented transport
Call independent connectionless � - Currently not used by standardized
transport QSIG supplementary services
Network Facility Extension (NFE) �� Extended addressing capabilities in
H.450.1
Interpretation APDU ��
ROSE APDUs and procedures X.219 / 229 X.880 series In practice no relevant difference.
�
Other APDUs and procedures: DSE - Currently not used by standardized
(dialogue procedures), ACSE QSIG supplementary services
��
Manufacturer specific information 2 alternative containers in H.450.1
�
Notifications -
Messages ALERTING, ALERTING, These QSIG messages are defined in
CALL PROC., ISO/IEC 11572.
CONNECT, CONNECT, All messages for H.450.1 transport are
DISCONNECT, defined in H.225.0.
PROGRESS, PROGRESS,
RELEASE, REL.
COMP., SETUP; REL. COMP.,
SETUP;
FACILITY,
NOTIFY FACILITY These QSIG messages are defined in
ISO/IEC 11582.
Information elements Facility; User-user Element H 450.1 Supplementary
Notification information Service APDU within User-user
indicator information is the equivalent of
information element Facility
ASN.1 encoding rules X.208 X.680 series BER – Basic Encoding Rules
X.209 BER X.691 PER PER – Packed Encoding Rules
(BAV) BAV – basic aligned variant
Table 1 shows that the capabilities currently used by standardized supplementary services are supported in both environments
(exception: Notifications are currently not used in H.450. However, in many cases an equivalent operation exists in an H.450
supplementary service). An interworking or mapping is therefore generally possible although details may be different.
NOTE - The NOTIFY message is optional in H.225.0 and may be passed on by a gateway to the H.323 side, but its processing is unspecified
– it may be meaningless. In the other direction, current H.450.x services do not generate notifications.
6.3 Protocol model
QSIG-GF defines a protocol model which can be applied to H.450.1, too (see figure 3).
The shaded areas in figure 3 are specific to GF and are defined in ISO/IEC 11582. Call control and the non-shaded part of
protocol control represent the basic call protocol as defined in ISO/IEC 11572. SS-control parts are defined in individual
supplementary service standards. SCM is any suitable layer 2 protocol, dependent on the scenario in which QSIG is used.
NOTE - Some parts of the QSIG-GF protocol model, e.g. the DSE element, are omitted from figure 3 for clarity.
In the H.450.1 case call control and protocol control include H.225.0 and possibly H.245 signalling (the latter is not required
by H.450.1 per se) . The signalling carriage mechanism is an IP protocol stack, usually TCP (and/or UDP) on top of IP. The
shaded areas are GF specific and are implicitly contained in H.450.1 (and partly in H.225.0).
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SS-Control #1
�
Coordination
�
Call
�
Function
Control �
SS-Control #n
ROSE
GFT Control
Control
Protocol
Signalling Carriage
M echanism (SCM )
Figure 3 — Protocol model
6.4 Interworking of supplementary services
The interworking function (IWF) sits above the application service elements (ASE), which comprise the coordination function,
ROSE and SS Control. The gateway has to support both protocol versions of the supplementary service syntactically and
semantically. It represents on each side one of the functional roles specified for the supplementary service (usually a different
one on each side � for example, the gateway may look like the terminating PINX on its PISN side and like the originating
endpoint on its H.323 side). Depending on the individual supplementary service, the gateway may have to provide functions
that are interworking specific, in addition to the procedures specified by the supplementary service itself.
This International Standard specifies generic requirements for the IWF. For a given supplementary service additional
requirements of the IWF can be specified separately, e.g., in another standard.
PINX Gateway
H.323 Term inal
Interworking Function (IW F)
SS-Control /
ASE ASE SS-Control / ASE ASE
SS-Control / SS-Control /
ROSE / Coord.
ROSE / Coord. ROSE / Coord.
ROSE / Coord.
Function
Function Function Function
QSIG GFT Control
QSIG GFT Control H.450 GFT Control
H.450 GFT Control
QSIG Protocol Control H.225.0 Protocol Control
QSIG Protocol Control
H.225.0 Protocol Control
Signalling Carriage
Signalling Carriage IP Stack
IP Stack
M echanism (SCM )
M echanism (SCM )
Figure 4 — Interworking
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7 Protocol interworking – Messages and information elements
When providing interworking for a specific supplementary service, each side of a gateway shall act according to the
requirements of the supplementary service protocol in force on that side. In addition, the gateway shall provide the interworking
function that controls and co-ordinates the two sides of the gateway.
NOTE - This means the gateway will act as source PINX or as destination PINX on its QSIG side, and as source endpoint or as destination
endpoint on its H.323 side.
In the absence of more specific rules mandated by a supplementary service specific interworking specification, a gateway shall:
— if the content - e.g. APDU(s) of supplementary service operation(s) - of a received message is understood and can be
passed on (in the form of equivalent information), behave in accordance with the rules of table 2, by carrying out the —
required action when a given condition occurs. Each condition applies to either the receipt of an H.323 message from an
entity in the IP network or the receipt of a QSIG message from a PINX;
— if the content is understood but cannot be passed on, discard the information and act in accordance with the rules of the
supplementary service concerned;
— if an invoke APDU of an unrecognised operation is encountered, act according to the interpretation APDU; in the absence
of an interpretation APDU, send back a reject APDU ‘unrecognisedOperation’.
NOTE 1 - The rules below cover both call related and call independent signalling.
NOTE 2 - It is recommended that supplementary service specific interworking standards take these rules as a basis and modify them or add
to them only when necessary.
NOTE 3 - It is not precluded that an implementation handles additional cases by refining these rules, e.g. sending a FACILITY message if
the intended basic call control message is not appropriate at the time. Such behaviour is outside the scope of this International Standard.
Table 2 — Generic Message and APDU handling requirements
Rule Condition Required action
1 Receipt of an H.323 ALERTING, CONNECT, or If a QSIG ALERTING, CONNECT, or PROGRESS
PROGRESS message containing one or more message is to be transmitted, include in this QSIG message
H4501SupplementaryService APDU(s) within the one or more Facility information element(s) with content
User-user information element equivalent to that of the H4501SupplementaryService
APDU(s)
2 Receipt of an H.323 SETUP message containing one If a QSIG SETUP message is to be transmitted, include in
or more H4501SupplementaryService APDU(s) this QSIG message one or more Facility information
within the User-user information element element(s) with content equivalent to that of the
H4501SupplementaryService APDU(s)
3 Receipt of an H.323 CALL PROCEEDING message Transmit a QSIG FACILITY message containing one or
containing one or more H4501SupplementaryService more Facility information element(s) with content
APDU(s) within the User-user information element equivalent to that of the H4501SupplementaryService
APDU(s) if the QSIG call state permits
4 Receipt of an H.323 RELEASE COMPLETE If clearing is not already in progress on the QSIG side,
message containing one or more transmit a QSIG DISCONNECT, RELEASE or RELEASE
H4501SupplementaryService APDU(s) within the COMPLETE message, whichever is appropriate for the
User-user information element QSIG call state, containing one or more Facility
information element(s) with content equivalent to that of
the H4501SupplementaryService APDU(s)
5 Receipt of an H.323 FACILITY message containing Transmit a QSIG FACILITY message containing one or
one or more H4501SupplementaryService APDU(s) more Facility information element(s) with content
within the User-user information element equivalent to that of the H4501SupplementaryService
APDU(s) if the QSIG call state permits
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6 Receipt of a QSIG ALERTING, CONNECT, or If an H.323 ALERTING, CONNECT, or PROGRESS
PROGRESS message containing one or more Facility message is to be transmitted, include within the User-user
information element(s) information element in this message one or more
H4501SupplementaryService APDU(s) with content
equivalent to that of the Facility information element(s)
7 Receipt of a QSIG SETUP message containing one or If an H.323 SETUP message is to be transmitted, include
more Facility information element(s) within the User-user information element in this message
one or more H4501SupplementaryService APDU(s) with
content equivalent to that of the Facility information
element(s)
8 Receipt of a QSIG DISCONNECT, RELEASE or If clearing has not already taken place on the H.323 side,
RELEASE COMPLETE message containing one or transmit an H.323 RELEASE COMPLETE message
more Facility information element(s), as the first call containing within the User-user information element one or
clearing message more H4501SupplementaryService APDU(s) with content
equivalent to that of the Facility information element(s)
9 Receipt of a QSIG RELEASE or RELEASE Ignore
COMPLETE message containing one or more
Facility information element(s), as a subsequent call
clearing message
10 Receipt of a QSIG FACILITY message containing a Transmit an H.323 FACILITY message containing within
call reference other than the dummy call reference the User-user information element one or more
and one or more Facility information element(s) H4501SupplementaryService APDU(s) with content
equivalent to that of the Facility information element(s) if
the H.323 call state permits
11 Receipt of a QSIG FACILITY message containing Ignore
the dummy call reference
12 Receipt of a QSIG NOTIFY message Ignore
13 Receipt of a QSIG message, other than NOTIFY, Ignore the Notification indicator information element
containing a Notification indicator information (further actions to be taken are those required by basic call
element interworking rules or by rules 1 through 10 above)
14 Receipt of an H.323 SETUP message for a call Transmit a QSIG SETUP message for a call independent
independent signalling connection signalling connection if possible (rule 2 applies if
supplementary service information is present)
15 Receipt of a QSIG SETUP message for a call Transmit an H.323 SETUP message for a call independent
independent signalling connection signalling connection if possible (rule 7 applies if
supplementary service information is present)
8 Protocol interworking – Content of information elements
8.1 Content mapping from QSIG to H.323
Unless a specific supplementary service interworking standard mandates a different mapping, a gateway, when transmitting an
H4501SupplementaryService APDU within the User-user information element as a result of receiving a QSIG Facility
information element, shall map elements in accordance with table 3 by carrying out the required action when a given condition
occurs.
In the table, “(M)” denotes a mandatory element, and “(C)” denotes a conditionally mandatory element, meaning that the
element is part of another optional element of type SEQUENCE or SET and shall be included if the enclosing element is
included.
NOTE - The QSIG Facility information element adheres to the Q.931 coding rules of separate octet groups, with some octet groups being
ASN.1 encoded, whereas the H.450.1SupplementaryService APDU is a single structure fully defined in ASN.1.
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Table 3 — Mapping from QSIG Facility information element to H.323 H4501SupplementaryService APDU
QSIG element name H.323 element name Mapping requirement
Network Facility Extension networkFacilityExtension (Note)
sourceEntity (C): sourceEntity (C): Generate as required, or map without change (type
endPINX endpoint ENUMERATED vs. type CHOICE with alternatives of
anyTypeOfPINX anyEntity type NULL).
sourceEntityAddress sourceEntityAddress Generate as required, or map from type PartyNumber to
type AliasAddress.partyNumber according to table 5.
destinationEntity (C): destinationEntity (C): Generate as required, or map without change (type
endPINX endpoint ENUMERATED vs. type CHOICE with alternatives of
anyTypeOfPINX anyEntity type NULL).
destinationEntity
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Questions, Comments and Discussion
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