ETSI TS 185 003 V2.3.1 (2009-06)

Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Customer Network Gateway (CNG) Architecture and Reference Points

RTS/TISPAN-05023-NGN-R2

General Information

• Status: Published
• Publication Date: 24-Jun-2009
• Technical Committee: TISPAN 5 - TISPAN NGN Home Networking
• Current Stage: 12 - Completion
• Due Date: 03-Jul-2009
• Completion Date: 25-Jun-2009

Standards Content (Sample)

Technical Specification
Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN);
Customer Network Gateway (CNG)
Architecture and Reference Points

2 ETSI TS 185 003 V2.3.1 (2009-06)

Reference
RTS/TISPAN-05023-NGN-R2
Keywords
architecture, gateway, IMS, interface, network
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ETSI
3 ETSI TS 185 003 V2.3.1 (2009-06)
Contents
Intellectual Property Rights . 5
Foreword . 5
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 7
3 Definitions and abbreviations . 8
3.1 Definitions . 8
3.2 Abbreviations . 8
4 The CNG Architecture . 9
4.1 Introduction . 9
4.2 CPN and NGN side requirements . 10
4.2.1 Analogue phone connected to the NGN through a CNG . 10
4.2.2 IMS Customer Network Device connected to the NGN through a CNG. 11
4.2.3 SIP-non IMS Customer Network Device connected to the NGN through a CNG . 12
4.3 CNG functions . 13
4.3.1 The transfer level functions . 13
4.3.1.1 CNG-NFF: CNG-NAPT and Firewall Function . 13
4.3.2 The transport level functions . 13
4.3.2.1 CNG-CSMF: CNG-Communication Services Media Function . 13
4.3.2.2 CNG-IPTVF: CNG-IPTV Function . 13
4.3.3 The CNG Network Attachment Subsystem entities (CNG-NASS) . 13
4.3.3.1 CNG-CMF: CNG-Configuration and Management Function . 13
4.3.3.2 CNG-AtF: CNG-Attachment Function . 14
4.3.3.3 CNG-PCF: CNG-Policy Control Function . 14
4.3.3.4 CNG-AuF: CNG-Authentification Function . 14
4.3.3.5 CNG-LF: CNG-Location Function . 14
4.3.4 The CNG-Resource and Admission Control Functional entities (C-RACF) . 14
4.3.4.1 CNG-ACF: CNG-Admission Control Function . 14
4.3.5 The CNG-Service-related Functional entities (CNG-SF) . 15
4.3.5.1 VGCF: Voice Gateway Control Function . 15
4.3.5.2 CNG-SIP Proxy B2BUA Function . 15
4.3.5.3 CNG-PPF: CNG-Plug and Play Function . 15
4.3.5.4 CNG-UIF: CNG-User Interface Function . 16
4.3.5.5 ISIM module . 16
5 The CNG Reference points . 17
5.1 CND side Reference points . 17
5.1.1 Network attachment reference points . 17
'
5.1.1.1 e reference point . 17
'
5.1.1.2 e reference point . 17
5.1.1.3 a reference point . 18
u
5.1.2 Transport level reference points. 18
5.1.2.1 D reference point . 18
j
5.1.2.2 Dj' reference point . 18
5.1.3 Service-related reference points . 18
'
5.1.3.1 G reference point . 18
m
5.1.3.2 u reference point . 18
5.1.3.3 C reference point . 19
5.2 NGN side Reference points . 19
5.2.1 Network attachment reference points . 19
ETSI
4 ETSI TS 185 003 V2.3.1 (2009-06)
5.2.1.1 e reference point . 19
5.2.1.2 e reference point . 19
5.2.2 Service-related reference points . 19
5.2.2.1 G reference point . 19
m
5.2.2.2 U reference point . 20
t
6 The CNG Data Model . 20
7 Information flows . 20
7.1 Attachment flows . 21
7.2 Configuration and management flows . 21
7.3 Signalling flows . 22
7.3.1 CND attachment and local/IMS registration . 22
7.3.2 Outgoing call . 24
7.3.2.1 SIP non-IMS CND . 24
7.3.2.2 IMS CND . 25
7.3.3 Internal call . 25
7.3.4 Admission Control . 26
7.4 Remote Access flows . 28
7.4.1 Remote Access Connection Set-up . 28
7.4.2 Download of content using HTTP . 29
7.4.3 Upload of content using HTTP . 30
Annex A (informative): Bibliography . 32
Annex B (informative): Change History . 33
History . 34

ETSI
5 ETSI TS 185 003 V2.3.1 (2009-06)
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).
Introduction
The present document defines Release 2 of an anticipated series of releases of TISPAN NGN. Release 2 extends the
capabilities of Release 1, enhances some Release 1 capabilities and provides some new services. The TISPAN NGN is
described in terms of the content capabilities and this release (Release 2) is defined by the documentation set and the
features that these support.
The general objective of Release 2 is to extend Release 1 through enhancements and new services. The present
document focuses on additional capabilities and services and continues to enable an NGN to be a flexible platform
allowing future enhancements and releases. The TISPAN NGN is specified using a release mechanism. The present
document provides an overview of the capabilities in the second release. No assumptions should be made about future
releases.
Throughout the present document, references to NGN are assumed to be references to TISPAN NGN unless otherwise
indicated.
ETSI
6 ETSI TS 185 003 V2.3.1 (2009-06)
1 Scope
The present document provides an overview of Customer Network Gateway (CNG) functional architecture and
reference points and the way it interacts with an NGN, as described in ETSI TISPAN Release 1 and Release 2 standards
(see ES 282 001 [1]).
The present document describes architectural building blocks to be included in the CNG to support the interworking
with an NGN, both at the transfer, transport and service layers. It also defines the reference points between the CNG
internal architectural blocks involved and a CND.
The WG5 does not address the layer 1 issues, as such studies refer to the AT&TM Group.
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.
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".
[2] ETSI ES 282 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Resource and Admission Control Sub-System (RACS):
Functional Architecture".
[3] ETSI ES 282 004: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN Functional Architecture; Network Attachment
Sub-System (NASS)".
[4] ETSI ES 282 007: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Subsystem (IMS); Functional architecture".
[5] 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]".
ETSI
7 ETSI TS 185 003 V2.3.1 (2009-06)
[6] ETSI TS 182 012: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IMS-based PSTN/ISDN Emulation Sub-system (PES);
Functional architecture".
[7] ETSI TS 183 019: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Network Attachment; User-Network Interface Protocol
Definitions".
[8] IETF RFC 3261: "SIP: Session Initiation Protocol".
[9] ETSI TS 131 103: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); Characteristics of the IP Multimedia Services Identity
Module (ISIM) application (3GPP TS 31.103)".
[10] IETF RFC 2131: "Dynamic Host Configuration Protocol".
[11] 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)".
[12] ETSI TS 185 006: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Customer Devices architecture and Reference Points".
[13] ETSI TS 185 009: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Architecture and reference points of a customer network device
for IMS based IPTV services".
[14] IETF RFC 2617: "HTTP Authentication: Basic and Digest Access Authentication".
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.
[i.1] ETSI TR 185 007: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Analysis of protocols for customer networks connected to
TISPAN NGN".
[i.2] ETSI TR 185 004: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); High level customer network architectures".
[i.3] Broadband Forum TR-069: "CPE WAN Management Protocol".
[i.4] Broadband Forum TR-098: "Data Model for TR-069".
[i.5] Broadband Forum TR-104: "Provisioning Parameters for VoIP CPE".
[i.6] ETSI TS 185 005: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Services requirements and capabilities for customer networks
connected to TISPAN NGN".
[i.7] ETSI TR 180 001: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN Release 1; Release definition".
ETSI
8 ETSI TS 185 003 V2.3.1 (2009-06)
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
CPN Device: device that is physically installed in the CPN allowing user access to network services; this can be a
Customer Network Gateway with gateway functionalities towards the NGN, or a Customer Network Device being the
end user terminal
Customer Network Device (CND): CPN device enabling the final user to have direct access to services through a
specific user interface
NOTE: CNDs can be dedicated to the internet, conversational and audio-video services. But they could be also
Consumer Electronics equipment and other devices which may have nothing to do with these premium
services (e.g. services performing a content sharing within a CPN, typically between a PC and a music
system).
Customer Network Gateway (CNG): CPN device acting as a gateway between the CPN and the NGN
NOTE: CNG is able to perform networking functions from physical connection to bridging and routing
capabilities (L1 to L3), but also possibly implementing functions related to the service support (up to L7).
Customer Premises Network (CPN): in-house network composed by customer network gateway, customer network
devices, network segments, network adapters and nodes
NOTE: Network segments are physical wired or wireless connections between customer premises network
elements); network adapters are elements performing a L1/L2 conversion between different network
segments; nodes are network adapters with L3 routing capabilities.
IMS CND: CND whose external behaviour complies with the IMS specifications
NOTE: See [1], [2], [3], [4] and [5].
"Multiple" Play Services (can be: double, triple, quadruple etc.): delivery by a single service provider of different
types of concurrent services to one or multiple users within the same CPN
NOTE: Services can be categorized in the following way: data (e.g. Web browsing, best effort traffic etc.),
person(s) to person(s) communication, entertainment.
Non-IMS SIP IETF CND: SIP-based CND whose external behaviour conforms to RFC 3261 [8] but do not fully
conform to the IMS specifications
Many scenarios are expected to provide one service from a service provider to a customer device (case of multiple
service providers, one or several CNG, etc.). They are presented within the TR 185 004 [i.2] and TS 185 005 [i.6].
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ACS Auto-Configuration Server
AKA Authentication and Key Agreement
ALG Application Layer Gateway
A-MGF Access-Media Gateway Function
ARF Access Relay Function
B2BUA Back-to-Back User Agent
BC Broadcast Content
CLF Connectivity session Location and repository Function
CND Customer Network Device
CNG Customer Network Gateway
CNG-ACF CNG-Admission Control Function
CNG-AtF CNG-Attachment Function
ETSI
9 ETSI TS 185 003 V2.3.1 (2009-06)
CNG-AuF CNG-Authentication Function
CNGCF CNG Configuration Function
CNG-CMF CNG-Configuration and Maintenance Function
CNG-CSMF CNG- Communication Services Media Function
CNG-LF CNG-Location Function
CNG-NFF CNG-NAPT and Firewall Function
CNG-PCF CNG-Policy Control Function
CNG-PPF CNG-Plug and Play Function
CNG-UIF CNG-User Reference point Function
CoD Content on Demand
CPN Customer Premises Network
DHCP Dynamic Host Configuration Protocol
NOTE: http://www.ietf.org/rfc/rfc3235.txt?number=2131
DLNA Digital Living Network Alliance
EF Elementary Files
ETH ETHernet
IGMP Internet Group Multicast Protocol
IMPU IMS PUblic identity
IMS IP Multimedia Subsystem
IP Internet Protocol
IPTV IP TeleVision
ISIM IMS Subscriber Identity Module
MGC Media Gateway Controller
NACF Network Access Configuration Function
NAPT Network Address and Port Translation
NOTE: http://www.ietf.org/rfc/rfc3235.txt?number=3235
NASS Network Attachment Subsystem
NAT Network Address Translation
NDN Next Generation Network
P-CSCF Proxy Call Session Control Function
PLT Power-Line Telecommunication
RADA Remote Access Discovery Agent
RATA Remote Access Transport Agent
RTSP Real Time Streaming Protocol
SDP Session Data Protocol
SIP Session Initiation Protocol
SSID Service Set IDentifier
UE User Equipment
UICC Universal Integrated Circuit Card
VGCF Voice Gateway Control Function
VoIP Voice over IP
4 The CNG Architecture
4.1 Introduction
The following clauses present the functional entities for the CNG. Examples of Customer Network Devices may be
connected to the CNG:
a) Analogue phones connected through the CNG to the NGN network.
b) IMS Customer Network Devices connected through a CNG to the NGN network [5].
c) Non IMS SIP IETF Customer Network Devices [7].
d) ISDN Customer Network Devices through the CNG to the NGN network.
ETSI
10 ETSI TS 185 003 V2.3.1 (2009-06)
Different types of Customer Network Devices may be involved in Intra CPN communication through a CNG.
The list of Customer Network Devices which are likely to be connected to the CNG is provided by the
TS 185 006 [12].
The general overview of the CPN Architecture is provided by the TR 185 004 [i.2]. The CNG functional entities are
described in the following parts of the document, as well as the reference points between each function.
4.2 CPN and NGN side requirements
The list of the CNG requirements is provided by the TS 185 005 [i.6]. specification for Service requirements and
capabilities for customer networks connected to TISPAN NGN.
4.2.1 Analogue phone connected to the NGN through a CNG
In this case, the CNG includes all the CPN functionalities necessary to fulfill a service between the analogue phone and
the NGN, as shown in figure 1.
TThhe CPNe CPN Env Enviirroonmnmentent tthhe NGe NGNN and and IIMMS enS enttiittiieses
CusCusttomomerer Ne Nettwworkork Gat Gateewwaayy
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ee
CCNNGG--PPooliliccyy Co Connttroroll FuFunncctitioonn (C(CNGNG-P-PCCFF))
CNCNGGCCFF
CCNNGG--CCoonnffiigurguraattiioonn & & MManaanagemgemenentt Fun Funccttiioonn ((CCNNGG--CCMMFF))
ee
ARARFF
CCNNGG--LLooccaatitioonn Fu Funncctitioonn (C(CNGNG--LLF)F)
CNCNG-G-AtAttatacchhmemenntt FFuunnccttiioonn ((CNG-CNG-AAttFF))

Exchanges inside the CNG
Network attachment functions
Transport plane functions
Service plane and applicative functions

Figure 1: Analogue phone connected to the NGN-IMS network through a CNG
ETSI
11 ETSI TS 185 003 V2.3.1 (2009-06)
4.2.2 IMS Customer Network Device connected to the NGN through a
CNG
In this case, the Customer Network Device includes all the CPN functionalities necessary to fulfilll a service between
itself and the NGN-IMS network, as shown in figure 2:

LALANN s siidede : : WAWANN s siiddee : :

tthhee Us Useerr EEquipmquipmeenntt thethe NGNGN aN annd IMd IMSS
eenntitititieses
CCuustomer Nstomer Neetwtwork Gork Gaatewtewaayy
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CCuustomer Nstomer Neetwtwork Dork Deevviicece
CCNNG-G-PPllugug anandd P Pllaayy F Fuuncncttiionon (C(CNNGG-P-PPPFF))
CNDCND
CCNNG-G- SSIIPP   pprrooxxyy B2 B2BUABUA
CC
CND-CND-PPlluugg a anndd P Pllaayy Fu Funnccttiioonn ((CCND-ND-PPPPFF)) UIUICCCC
SISIPP
ReReggiiststrraarr
PrProxoxyy ISISIIMM
GG ''
mm
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mm mm
CuCuststoommeerr
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AAppplicplicaattioionn
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FuFunnccttiioonn ((CND-CND-CSCSMF)MF)
CNCND-D-NANAPPTT T Trraavveerrsasall FFuunnccttioionn ((CND-CND-NTF)NTF)
DjDj
UIUICCCC CCNNGG--IPIPTTVV Fu Funncctitioonnss ((CCNNGG--IIPPTTVVFF))
CCNNDD--CConfonfiguratiguration & ion & MMaanagnagememenentt AAcceccessss n nooddee
FuFunnccttiioonn ((CND-CND-CMFCMF))
ISISIMIM
ee
CCNNGG--AdAdmmiissssiioonnCCononttrroollFFuuncncttiionon ((CCNNGG-A-ACCFF) )
ee ''
CND-CND-LLooccaal Al Auutthheenntticaicattioionn FFuunnccttioionn ((CCND-ND-LLAAF)F)
CNGCNG--PPooliclicy Coy Connttrrool l FuFunnccttiioonn ((CNGCNG--PPCF)CF)
ee
CND-CND-AAttttaachchmmeenntt FFuunnccttiioonn ((CND-CND-AAttF)F) CNCNGGCCFF
CCNNG-G-CCoonnffiguratiguration & ion & MManaanagegemmeenntt F Funcuncttiioonn (C(CNNGG-C-CMMFF))
aa
uu
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ee
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CCNNG-G-AAttattacchhmmeenntt FFuunnccttiioonn ((CCNNGG--AAtFtF))
ee
CCNNGG--LocLocatatiioonn F Funcuncttiionon (C(CNNGG-L-LFF))
LALANN WWANAN
Exchanges inside the CNG
Network attachment functions
Transport plane functions
Service plane and applicative functions

NOTE: The IMS CND functions are described within TS 185 006 [12] dedicated to Customer Network Devices.

Figure 2: IMS Customer Network Device connected to the NGN-IMS network through a CNG
ETSI
12 ETSI TS 185 003 V2.3.1 (2009-06)
4.2.3 SIP-non IMS Customer Network Device connected to the NGN
through a CNG
In this case, the Customer Network Gateway includes all the CPN functionalities necessary to fulfilll a service between
itself and the NGN-IMS network, as shown in figure 3.

LALAN N sidsidee : : WAWAN N sisiddee : :
ththe Ue Userser Eq Equuiippmmenentt ththe Ne NGGNN anandd I IMMSS
enentittitiieses
CCuussttomomerer N Neettwwoorrkk GGaatteewawayy
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uu
-- --
CNGCNG UUsseerr In Inteterrffaaccee FuFunnccttiioonn (CNG(CNG UIUIFF))
CustCustoommerer N Neettwworork k DeDevviiccee
CNGCNG --PPllug anug andd PPllayay FuFunnccttiioonn (CNG(CNG --PPPPFF))
CCNNDD
CNGCNG-- SSIIPP   pprrooxxyy B2BUA B2BUA
CC
UIUICCCC
CNDCND --PPlluugg an and Pd Pllaayy FuFunnccttiioonn (CND(CND --PPPPFF))
SISIP P
RegiRegissttrraarr
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GG '' PrProoxxyy
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B2B2BBUUAA
GG GG
AAppplplicicaattioionn
mm mm
CuCussttomomeerr
GG
mm
AAppplplicicaattioionn
CNDCND --SeSellff PPrrovoviissiionioninngg (C(CNNDD -- SPSP))
ASAS
UU
tt
UU
CNDCND --CoCommmmuniuniccaattiioonn S Seerrvviicceess M Mediediaa
tt
CNGCNG --NANAPPTT an and d FFiirreewwaall ll FFuncuncttiionon (CNG(CNG --NNFF)FF)
FFuncuncttiionon (CN(CNDD --CSCSMMFF))
DjDj''
CNDCND --NANAPPTT TrTraavveerrssaall FFuncuncttiionon (CND(CND --NTNTFF))
DjDj
UIUICCCC CNGCNG --IPIPTVTV FFuncuncttiionsons (CNG(CNG --IIPPTVTVF)F)
CNDCND --CoConfnfiigurguratatiion &on & M Maanagenagemmentent AAcceccess ss nonodede
FuFunnccttiioonn (CND(CND --CMCMFF))
ISISIIMM
ee
CNGCNG --AAddmmiissssiioonnCContontrroolFlFununccttiioonn (CNG(CNG --ACACFF))
ee ''
-- --
CNCNDD LocLocalal AAuutthhenenttiiccaattiionon FFuunnccttiionon (CND(CND LALAFF))
CNGCNG -- PPooliliccyy Cont Contrrooll FuFunnccttiioonn (CNG(CNG --PCPCFF))
ee
CNCNDD -- AAttttaacchhmmentent FFuncuncttiionon (CND(CND -- AtAtFF)) CNGCNGCFCF
CNGCNG -- Conf Confiigguurratatiioon &n & MMaannagemagementent FuFunnccttiioonn (CNG(CNG --CMCMFF))
aa
uu
CNGCNG --AAuutthenthentiiccatatiioonn FFuncuncttiionon (CNG(CNG --AuAuFF )) ee ARARFF
ee ''
CNCNGG --AAttttacachmhmentent FFuunnccttiionon (CNG(CNG -- AtAtFF))
ee
CNGCNG --LocLocatatiioonn FFuunnccttiionon (CNG(CNG --LFLF))

Exchanges inside the CNG
Network attachment functions
Transport plane functions
Service plane and applicative functions

Figure 3: Non IMS SIP Customer Network Device connected to the NGN-IMS network through a CNG
'
In this case G is used, the SIP proxy B2BUA shall perform an adaptation of the non-IMS SIP profile from a CND
m
which requests for an IMS session.
ETSI
13 ETSI TS 185 003 V2.3.1 (2009-06)
4.3 CNG functions
4.3.1 The transfer level functions
4.3.1.1 CNG-NFF: CNG-NAPT and Firewall Function
The CNG-NFF entity shall provide gate control functionality i.e. dynamic NAPT and firewall functions at the boundary
between the CPN and the NGN.
4.3.2 The transport level functions
4.3.2.1 CNG-CSMF: CNG-Communication Services Media Function
The CNG-CSMF is the termination point for the access node, it shall perform an adaptation so as to deliver media flows
from the NGN network to an analogue or IP Customer Network Device.
The CNG-CSMF is used for analogue (or digital in the case of ISDN CNDs) to IP media conversion - in which case it
corresponds to the R-MGF identified in ES 282 001 [1] or it is used for IP-IP media traffic.
In case the CPN is provided with analogue or ISDN CNDs and the media gateway function is not implemented in the
NGN (as an A-MGF, c.f. ES 282 001 [1]), the CNG-CSMF shall be used.
As a result, this functionality is recommended.
4.3.2.2 CNG-IPTVF: CNG-IPTV Function
When supporting IPTV services, the CNG shall be able to forward inbound multicast packets only to the physical
interfaces connected to devices that have joined the specific multicast group. This mechanism should be implemented
acting on layer 2 and layer 3 multicast signalling flows (e.g. IGMP based).
The CNG shall be able to perform a link layer multicast to unicast translation, if the CPN segment, which the IPTV
CND is connected to, is not able to support multicast; specifically, when sending an IP multicast packet to a
host received on an NGN reference point, the CNG can send the packet to the unicast MAC address of the host
(contained in the multicast signalling message without any change in the IP destination address). This mechanism is
also of interest for example when the IPTV CND is connected to the CNG through Powerlines technology (directly or
using ETH-to-PLT bridges).
4.3.3 The CNG Network Attachment Subsystem entities (CNG-NASS)
4.3.3.1 CNG-CMF: CNG-Configuration and Management Function
The CNG-CMF shall manage a mutual authentication between the CNGCF and the CNG.
The CNG-CMF shall enable the CNG configuration and firmware upgrade.
The CNG-CMF entity should enable transmission of configuration information to CNDs, obtained from the CNGCF.
As a result the CNG-CMF should be able particularly to store configuration information dedicated to several CND, after
sending only one request to the CNGCF. As soon as a CND is connected, the CNG-CMF should be able to deliver
configuration parameters to it.
Furthermore, the CNG-CMF should allow maintenance of any CPN device (CNG/CND) from the NGN network,
through the CND-CMF, that is to say the opportunity to do diagnostic and performance tests too. Functionalities should
be added to the CNGCF, whether this latter entity could perform the CPN maintenance.
For instance, the CNG-CMF could provide the functionality and reference points of a Broadband Forum Auto
Configuration Client (see TR-069 [i.3]).
ETSI
14 ETSI TS 185 003 V2.3.1 (2009-06)
Moreover, the CNG-CMF may be able to perform management activities related to remote access. The remote access
allows the user to access a CND from another device via the Internet through the G reference point, and work on it
m
remotely.
Some authentication parameters may be stored in a UICC (containing the ISIM).
4.3.3.2 CNG-AtF: CNG-Attachment Function
The CNG-AtF entity shall be responsible for allocation of IP addresses to user premises equipment (CND), and to the
CNG from the NACF via the ARF.
4.3.3.3 CNG-PCF: CNG-Policy Control Function
The CNG-PCF may integrate a database containing the access profile.
This includes bandwidth and QoS parameters for the CNG Customer Network Device side applications and terminals,
which could be configured by a user. For instance, congestion issues within the CPN may be solved defining resources
for several SSID.
4.3.3.4 CNG-AuF: CNG-Authentification Function
The CNG-AuF shall manage the authentication of CNDs to be connected to the CPN. A CND requesting for a CPN
Wireless attachment should be authorized by the access point embedded in the CNG.
The CNG-AuF may thus be configured by the user for such a case, using the CNG-User Interface Function (CNG-UIF).
4.3.3.5 CNG-LF: CNG-Location Function
The CNG-LF functional entity may allow an internal application providing location information, to perform for instance
emergency calls or deliver some local video content.
This information may be configured by the owner of the CNG, received from the CLF or obtained from the network,
via the CNG-AtF (typically through DHCP option 82).
The information should also come from the CLF. In this case the CNG-LF may not be used.
4.3.4 The CNG-Resource and Admission Control Functional
entities (C-RACF)
4.3.4.1 CNG-ACF: CNG-Admission Control Function
The CNG-ACF should receive and send QoS messages from/to the CNG-SIP proxy B2BUA Function. In particular it
should:
a) check resources availability on each link/device involved in the communication requesting a QoS
reservation/allocation, through an internal database;
b) perform the appropriate resources reservation, through the CNG-PCF.
Thus, the CNG-ACF should manage session limitations for instance or the priority of media streams. This applies to
upstream flows but there may also be an opportunity to do so for downstream flows.
The CNG-ACF is only able to take into account sessions that pass through the SIP B2BUA. Sessions using encrypted
signalling or different signalling protocols will not be included. In the latter case the CNG-ACF might allow more
sessions through the access line that it should have. As RACS has a full view on all sessions over the access line, it will
deny the session setup thus preventing an overload situation [i.7].
ETSI
15 ETSI TS 185 003 V2.3.1 (2009-06)
4.3.5 The CNG-Service-related Functional entities (CNG-SF)
Depending on the services supported, a CNG may include one or more Service-related Functions. The present version
of the present document identifies four types of SCFs intended to support SIP-based applications. It should be noted that
not all applications require a Service-related Function to be involved (e.g. P2P applications usually do not require such
functions).
4.3.5.1 VGCF: Voice Gateway Control Function
The VGCF within the CNG is the equivalent of an MGC embedding a SIP User Agent. A CNG should include several
UAs in case of multi analogue and/or ISDN Customer Network Device within the CPN. The VGCF should control the
CNG-CSMF (i.e. the R-MGF as defined in ES 282 001 [1]).
The VGCF should perform the service authentication and manage signalling flows securely.
NOTE: The VGCF together with the CNG-CSMF provides the function of a R-VGW as defined in
TS 182 012 [6].
In case of AKA authentication, the VGCF shall have access to the authentication parameters through an ISIM/UICC
functionality. To be noticed that HTTP Digest is for an early deployment whereas IMS AKA is the target solution.
4.3.5.2 CNG-SIP Proxy B2BUA Function
The CNG-SIP Proxy B2BUA should implement:
a) a Local SIP Registrar without any authentication needed;
b) an outbound SIP Proxy, a SIP access point for the P-CSCF, forwarding the register messages to the P-CSCF if
necessary.
Moreover, it may be:
c) a protocol adaptation module performing an adaptation of non-IMS compliant IETF SIP protocols towards one
IMS compliant SIP protocol. This functionality could also be performed by the NGN.
NOTE: Some adaptation may be performed by the CNG so as to support non-IETF SIP CNDs in the CPN
(proprietary SIP) but this case is out of the scope of the present document.
d) a protocol adaptation module performing remote access communication establishment. This functionality is
called Remote Access Transport Agent (RATA).
The CNG-SIP Proxy B2BUA Function should be aware of each SIP CND (could be an IMS CND) capability within the
CPN environment.
The CNG-SIP Proxy B2BUA Function shall at last be able to manage two SIP dialogues and the associated identities
(possibly through an ISIM module), from both the NGN and the CND sides. This gives the opportunity to transfer an
IMS session from a device to another or to forward an incoming call to the appropriate CNDs (forking).
The responsibility of the RATA is to provide a communication channel enabling interaction between remote and in the
home network located UPnP capable CND’s.
In case of AKA authentication, the SIP Proxy B2BUA shall have access to the authentication parameters through an
ISIM/UICC functionality. To be noticed that HTTP Digest is for an early deployment whereas IMS AKA is the target
solution.
4.3.5.3 CNG-PPF: CNG-Plug and Play Function
The CNG-PPF may obtain some CND information (service discovery, description) and allow their control.
Also, the CNG-PPF should allow a communication between many types of Customer Network Device within the CPN,
not only conversational (based on UPnP for instance).
The CNG-PPF may also support this kind of communication through the CNG between NGN devices and CND
devices.
ETSI
16 ETSI TS 185 003 V2.3.1 (2009-06)
While facilitating such communication, ALG functionality may be needed by the CNG-PPF, interfacing the CNG-NFF.
Since some of the communication sessions supported by the CNG-PPF result in media sessions, the CNG-PPF may
need to interface the CNG-ACF in order to support QoS provisioning for these types of services.
The Remote Access Discovery Agent (RADA) discovers and maintains a device-list for the services provided. The list
is continuously updated, kept and provided for facilitating communication between devices.
When sessions (for example UPnP based) are initiated between a CND and a remote NGN device, they may be
established by IMS SIP session establishment and then described in the SDP parts of the IMS SIP signalling. When
establishing the UPnP session between the NGN and CPN endpoints the CNG-PPF needs to perform ALG
functionality, by re-writing any CPN references within the UPnP messages and also control port forwarding through the
CNG-NFF. Informative flows for the Remote Access feature are detailed in clause 7.4.
4.3.5.4 CNG-UIF: CNG-User
...