ETSI TS 182 024 V2.1.1 (2008-08)

Telecommunications and Internet Converged Services and Protocols for Advanced Networking (TISPAN); Hosted Enterprise Services; Architecture, functional description and signalling

DTS/TISPAN-02041-NGN-R2

General Information

• Status: Published
• Publication Date: 19-Aug-2008
• Technical Committee: TISPAN 2 - TISPAN Architecture
• Current Stage: 12 - Completion
• Due Date: 22-Jul-2008
• Completion Date: 20-Aug-2008

Standards Content (Sample)

ETSI TS 182 024 V2.1.1 (2008-08)
Technical Specification


Telecommunications and Internet converged Services and
Protocols for Advanced Networks (TISPAN);
Hosted Enterprise Services;
Architecture, functional description and signalling

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2 ETSI TS 182 024 V2.1.1 (2008-08)



Reference
DTS/TISPAN-02041-NGN-R2
Keywords
centrex, IMS
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3 ETSI TS 182 024 V2.1.1 (2008-08)
Contents
Intellectual Property Rights.5
Foreword.5
1 Scope.6
2 References.6
2.1 Normative references.6
2.2 Informative references.8
3 Definitions and abbreviations.8
3.1 Definitions.8
3.2 Abbreviations.8
4 Overview.9
5 Architecture.10
5.1 Functional Architecture.10
5.1.1 Overview.10
5.1.2 Involved functional entities - originating session .11
5.1.3 Involved functional entities - terminating session .12
5.2 Architecture involving heterogeneous core networks .12
6 Procedures.12
6.1 Registration.12
6.2 Originating session procedures.13
6.3 Terminating session procedures .14
6.4 Emergency communications.14
6.5 Capabilities provided to an enterprise .14
6.5.1 General.14
6.5.2 Routeing capabilities.15
6.5.2.1 Overview.15
6.5.2.2 Break-in.15
6.5.2.3 Break-out.15
6.5.3 Communication admission control .15
6.5.4 Anonymous communication rejection .15
6.6 Private Numbering.15
6.6.1 General.15
6.6.2.1 General.16
6.6.2.2 UE without dial string processing capabilities .16
6.6.2.3 UE with dial string processing capabilities .16
6.7 Group Management.17
6.8 Supplementary service control.17
7 Use of Transport Functions .17
7.1 Use of RACS.17
7.2 Use of NASS .17
7.3 Use of transport processing functions .17
8 Security issues.18
9 Management Issues .18
9.1 Configuration/provisioning issues.18
9.1.1 UPSF.18
9.1.2 User Equipment.18
9.1.3 AGCF.18
9.1.4 Charging issues.18
Annex A (informative): Processing of dial strings by the UE.20
A.1 Single private numbering plan .20
ETSI

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4 ETSI TS 182 024 V2.1.1 (2008-08)
A.2 Multiple private numbering plans .20
Annex B (informative): Scenarios for HES extension to CS users.22
History .24

ETSI

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5 ETSI TS 182 024 V2.1.1 (2008-08)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Telecommunications and Internet
converged Services and Protocols for Advanced Networking (TISPAN).
The architecture and functionality developed in the present document are in line with the capability requirements for
hosted enterprise services developed in TS 181 019 [14].
ETSI

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6 ETSI TS 182 024 V2.1.1 (2008-08)
1 Scope
The present document describes the architecture and functionality required to support enterprise and corporate services
as IMS applications hosted in the NGN operator's network on behalf of an enterprise (Hosted Enterprise Services).
The present document also specifies the protocol requirements for the UE to attach to the NGN (in particular the IMS)
and also any protocol requirements related to application servers provided in support of hosted enterprise services.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably,
the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the
reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the
method of access to the referenced document and the full network address, with the same punctuation and use of upper
case and lower case letters.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
[1] ETSI ES 282 001: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN Functional Architecture Release 1".
[2] ETSI ES 282 007: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Subsystem (IMS); Functional architecture".
[3] ETSI TS 182 012: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IMS-based PSTN/ISDN Emulation Subsystem; Functional
architecture".
[4] ETSI ETS 300 738: "Human Factors (HF);Minimum Man-Machine Interface (MMI) to public
network based supplementary services".
[5] ETSI TS 123 228: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); IP Multimedia Subsystem (IMS); Stage 2".
[6] ETSI TS 182 009: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN Architecture to support emergency communication from
citizen to authority".
ETSI

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7 ETSI TS 182 024 V2.1.1 (2008-08)
[7] ETSI TS 187 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN Security; Security Architecture".
[8] ETSI TS 182 006: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Subsystem (IMS); Stage 2 description
(3GPP TS 23.228 Release 7, modified)".
[9] IETF RFC 3323: "A Privacy Mechanism for the Session Initiation Protocol (SIP)".
[10] IETF RFC 3325: "Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity
within Trusted Networks".
[11] ETSI TS 182 023: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Core and Enterprise NGN Interaction Scenarios and
Architectural Requirements".
[12] ETSI ES 282 002: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); PSTN/ISDN Emulation Subsystem (PES); Functional
Architecture".
[13] ETSI ES 282 010: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Charging management [Endorsement of 3GPP TS 32.240
Release 7, 3GPP TS 32.260 Release 7, 3GPP TS 32.297 Release 7, 3GPP TS 32.298 Release 7 and
3GPP TS 32.299 Release 7, modified]".
[14] ETSI TS 181 019: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Business communication requirements".
[15] ETSI ES 283 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Call Control Protocol based on Session
Initiation Protocol (SIP) and Session Description Protocol (SDP) Stage 3 [3GPP TS 24.229
[Release 7], modified]".
[16] ETSI TS 183 043: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IMS based PSTN/ISDN Emulation Stage 3 specification".
[17] ETSI TS 183 028: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Common Basic Communication procedures; Protocol
specification".
[18] ETSI TS 124 229: "Digital cellular telecommunications system (Phase 2+);Universal Mobile
Telecommunications System (UMTS);Internet Protocol (IP) multimedia call control protocol
based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP);Stage 3
(3GPP TS 24.229 version 8.2.0 Release 8)".
[19] IETF RFC 5031: "A Uniform Resource Name (URN) for Emergency and Other Well-Known
Services".
[20] ETSI TS 183 011: "Technical Specification Telecommunications and Internet converged Services
and Protocols for Advanced Networking (TISPAN); PSTN/ISDN simulation services: Anonymous
Communication Rejection (ACR) and Communication Barring (CB); Protocol specification".
[21] IETF RFC 3966: "The tel URI for Telephone Numbers".
[22] IETF RFC 3261: "SIP: Session Initiation Protocol".
[23] IETF RFC 4967: "Dial String Parameter for the Session Initiation Protocol Uniform Resource
Identifier".
[24] draft-vanelburg-sipping-private-network-indication-02.txt: "The Session Initiation Protocol (SIP)
P-Private-Network-Indication Private-Header (P-Header)".
ETSI

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8 ETSI TS 182 024 V2.1.1 (2008-08)
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
Not applicable.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in TS 181 019 [14], ES 283 003 [15] and
TS 183 043 [16] apply:
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AGCF Access Gateway Control Function
AGF Access Gateway Function
AS Application Server
BGCF Breakout Gateway Control Function
BGF Border Gateway Function
CNGCF Customer Network Gateway Configuration Function
CS Circuit Switched
CSCF Call Session Control Function
HES Hosted Enterprise Services
I-BGF Interconnection-Border Gateway Function
I-CSCF Interrogating-Call Session Control Function
IFC Initial filter Criteria
IMS IP Multimedia Subsystem
IN Intelligent Network
IP Internet Protocol
IPCAN IP Connectivity Access Network
ISC IMS Service Control
ISDN Integrated Services Digital Network
LDAP Lightweight Directory Access Protocol
MGCF Media Gateway Control Function
MGF Media Gateway Function
MRFC Multimedia Resource Function Controller
MRFP Multimedia Resource Function Processor
NASS Network Attachment SubSystem
NGCN Next Generation Corportate Network
NGN Next Generation Network
NGN Next Generation Network
P-CSCF Proxy-Call Session Control Function
PES PSTN/ISDN Emulation Subsystem
PSTN Public Switched Telephony Network
RACS Resource and Admission Control Subsystem
RG Residential Gateway
SCP Service Control Functio
S-CSCF Serving-Call Session Control Function
SGF Signalling Gateway Function
SIP Session Initiation Protocol
SLF Subscription Locator Function
SPDF Service-based Policy Decision Function
T-MGF Trunking-Media Gateway Function
ETSI

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9 ETSI TS 182 024 V2.1.1 (2008-08)
UE User Equipment
UEE User Equipment Emulation
UPSF User Profile Server Function
URI Uniform Resource Identifier
URN Uniform Resource Name
VGW Voice over IP Gateway
4 Overview
Hosted Enterprise Services (HES) refers to a solution where an NGN hosts all business communication capabilities to a
set of endpoints connected to a plurality of access points to this network. This type of network solution is also known as
IP Centrex.
In the simplest configuration all endpoints are connected to a TISPAN NGN IP-CAN. Endpoints may be SIP phones or
legacy phones (Analogue or ISDN) connected to a gateway. All services by HES are provided by application servers
using standard IMS procedures. User may access services that are specific to the enterprise they belong to as well as
services available to any other IMS users.
In more complex configurations some of the endpoints may be connected to a 3GPP IPCAN and/or a circuit-switched
network, which is itself connected to the IMS via an MGCF. Endpoints connected to heterogeneous access networks
may be served by the same HES.
Endpoints served by a HES shall have the ability to setup a session, identifying the communication target by:
• a SIP URI of the form user @domain;
• an E.164 telephone number;
• a number within a private numbering plan;
• local service numbers.
With regard to supplementary services, HES have strong similarities with the provision of PSTN/ISDN simulation
services, although the actual set of services may be different. Examples of services that are enabled by the architecture
described in the present document are:
• All commonly used PSTN/ISDN services.
• IMS Multimedia Messaging, Presence and Conferencing services.
• Personal and Corporate Directory.
• Unified Voice mail.
• Operator assisted communications.
• Hot Line Calling.
• Abbreviate dialling.
• Line Hunting.
• Attended Communication Transfer.
• Blind Communication Transfer.
• Communication Pickup.
• Manager/Secretary filtering.
• Click to Dial.
• Colour Ring Back Tone.
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Other IP Networks
PSTN/ISDN
 10 ETSI TS 182 024 V2.1.1 (2008-08)
The sole purpose of the above list of services is to illustrate the type of services that are enabled by the architecture
described in the present document. This list is not intended to be exhaustive nor is it expected that all implementations
will support all of these services. The list actual of enterprise services hosted in a network is a matter for each operator
to decide.
NOTE: The present document provides a number of examples where domain names are used. It should be noted
that these are for information only and are not intended to place any constraint on the structure and
management of domain names as long as they are globally routable.
5 Architecture
5.1 Functional Architecture
5.1.1 Overview
The functional architecture for supporting access to Hosted Enterprise Services is illustrated in figure 1. This functional
architecture supports access from both SIP based endpoints and legacy endpoints.
The functional architecture for supporting access to Hosted Enterprise Services from both types of endpoints is obtained
by a combination of the Core IMS Architecture defined in ES 282 007 [2] with the addition of an AGCF as defined in
TS 182 012 [3] and ES 282 002 [12]. This should not be understood as an integration of an AGCF into the functional
architecture defined in ES 282 007 [2]. The AGCF only applies to configurations where an H.248-controlled media
gateway is required in support of legacy endpoints.
Rf/Ro
Ut
Charging
AS
(HES logic) Functions
Sh
Dh
ISC/Ma
UPSF
Iw
Rf/Ro
SLF
Cx Dx
IWF
Ib
Mw
Mx
Mx
IBCF
I/S-CSCF
Mx
Mi Ic
Mw
Mk
BGCF
P-CSCF
Gm Mr Mx
Mj
Gq-Rx Mw
Mg
MRFC
MGCF SGF
Mx
AGCF
Gq', e2 Gq'
Gq', e2, P1
3GPP IP
Mp Mn
SPDF
CAN
UE
MRFP
T-MGF
TISPAN
IP-CAN
Core Transport I-BGF

Figure 1: Functional architecture overview
All functional entities behave as defined in ES 282 007 [2], TS 182 012 [3] and/or ES 282 002 [12].
The service logic of the HES resides in one or more application servers. All sessions to/from a member of a HES shall
be handled by at least one application server.
SIP-based endpoints may be connected to the IMS via any IP¨CAN valid for the current specification release. A HES
may serve endpoints connected through both types of IP-CANs.
ETSI

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11 ETSI TS 182 024 V2.1.1 (2008-08)
Legacy endpoints may be connected via a media gateway or a SIP-based Voice over IP Gateway (VGW). Both types of
gateways may be part of the User Equipment (UE) or reside in the TISPAN IP-CAN. A SIP-based Voice over IP
Gateway (VGW) plays the role of a UE with regards to the P-CSCF. A media gateway is controlled by the AGCF,
which plays the combined role of a UE and a P-CSCF with regards to other CSCFs of the IMS.
TS 182 012 [3] provides a more detailed specification of the procedures that a VGW and AGCF shall support for
enabling access to IMS-supported services from legacy endpoints.
NOTE: The concepts of "Media Gateway" and AGCF are defined in both TS 182 012 [3] and ES 282 002 [12]. A
Media Gateway implements the R-MGF or A-MGF functional entities defined in ES 282 001 [1].
ES 282 002 [12] uses different names to refer to a Media Gateway depending on its location: a media
gateway located in the customer premises is referred to as a Residential Gateway (RG) while a media
gateway located in the IP-CAN is referred to as an Analogue Gateway Function (AGF).
5.1.2 Involved functional entities - originating session
Figure 2 shows the functional entities involved in an originating session.
Rf/Ro
AS
Charging
(HES logic)
Sh
Functions
ISC
UPSF
Cx
Rf/Ro
To terminating side
S-CSCF
Mw
P-CSCF
Gm Mr
Gq-Rx Mw
MRFC
Mx
AGCF
Gq', e2
Gq', e2, P1
3GPP IP
Mp
CAN
UE
MRFP
TISPAN
IP-CAN
Core Transport

Figure 2: Functional entities involved in originating sessions
NOTE: Figure 2 does not show the intermediate functions between the P-CSCF and the S-CSCF, or those
between the S-CSCF and the terminating side.
The originating side can interoperate with any other terminating side scenario.
ETSI

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12 ETSI TS 182 024 V2.1.1 (2008-08)
5.1.3 Involved functional entities - terminating session
Figure 3 shows the functional entities involved in a terminating session.
Rf/Ro
AS
Charging
(HES logic)
Sh
Functions
ISC
UPSF
Cx
Rf/Ro
From originating side
S-CSCF
Mw
P-CSCF
Mr Gm
Mw Gq-Rx
MRFC
AGCF
Gq', e2
Gq', e2, P1
3GPP IP
Mp
CAN
UE
MRFP
TISPAN
IP-CAN
Core Transport

Figure 3: Functional entities involved in terminating sessions
NOTE: Figure 3 does not show the intermediate functions between the P-CSCF and the S-CSCF, or those
between the S-CSCF and the originating side.
The terminating side can interoperate with any other originating side scenario.
5.2 Architecture involving heterogeneous core networks
A HES can serve a set of endpoints some of which being connected to the IMS and some others being connected to
Circuit-Switched (CS) networks. Example scenarios are shown in annex B.
6 Procedures
6.1 Registration
Registration procedures comply with TS 182 006 [8] or TS 182 012 [3] depending on the type of endpoint.
NOTE: Registration procedures for endpoints not connected directly to a 3GPP or TISPAN IP CAN are outside
the scope of the present document.
The IMS public user identity used at registration is in the form of a SIP URI. This SIP URI can include a user name in
the form of a telephone number with a user=phone parameter where the telephone number is either a public e.164 or a
private number; if private numbers are used, the private numbering plan shall be uniquely identifiable by the NGN.
ETSI

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13 ETSI TS 182 024 V2.1.1 (2008-08)
6.2 Originating session procedures
Originating communication setup procedures shall comply with TS 182 006 [8] or TS 182 012 [3] depending on the
type of endpoint.
In addition to the procedures specified in this clause, the UE shall comply with the requirements identified in
TS 124 229 [20], clause 4.1 as modified by ES 283 003 [15].
In addition to the procedures specified in the following clauses, the AGCF shall comply with the procedures specified in
TS 183 043 [16] appropriate to this entity.
In addition to the procedures specified in the following clauses, each IMS functional entity shall comply with the
procedures specified in the clauses of ES 283 003 [15] and TS 183 028 [17] appropriate to this entity.
An AS providing the logic of an originating HES may provide communication admission control in terms of number of
simultaneous communications to/from this particular HES.
Support of private numbering is described in clause 6.5.
Certain services require that the UE or an AGCF can be configured to insert a default session destination in the Request
URI when a dialstring is not entered by the end user. In the case of the UE, the default session destination may be
manually configured by the user or received from the CNGCF. This configured default session destination can either
point to the terminating end point for the session or a value independent from the actual destination. In the latter case,
the AS acting as the originating HES determines the actual session destination from local configuration data and
...