Transcript TISPAN_NGN_2004 - Docbox

Converged Fixed-Mobile solutions:
The TISPAN_NGN approach
(Sophia, 22 November 2004)
Christian Julien
(ETSI Secretariat)
TC TISPAN TO
[email protected]
1
Agenda
1. TISPAN_NGN Project: Steps and
Requirements
2. TISPAN_NGN Status: architecture outline
3. How the use of 3G UMTS IMS in NGN will help
Fixed-Mobile convergence for Multimedia
4. Some important issues to be taken care of
5. Summary
2
TISPAN_NGN Genesis
TISPAN: Telecommunication and Internet
converged Services and Protocols for Advanced
Networking
results from the combination, in September 2003, of :
 SPAN, formed as a Technical Body from the joining of SPS
(Services, Protocols & Switching) and NA (Network Aspects)
SPAN = Services and Protocols for Advanced
Networks
 TIPHON, formed in 1997 as an ETSI Project to study VoIP and
subsequently extended to any Telecom (including Multimedia)
services over IP
TIPHON = Telecommunications and Internet
Protocol Harmonization Over Networks
3
TISPAN_NGN Synergy
 The working groups of the TC TISPAN have been
carefully defined to cover the needs of the industry in
specific technical areas of competence
 Each project follows a particular technical subject and
co-ordinates across the competence groups
 The following slide gives an summary of the way the
new TC leads the way in standardisation
4
PROTOCOLS
NUMBERING &
ROUTEING
QoS
TESTING
ARCHITECTURE
F-MMS
SERVICES
8 Working
Groups
DTM (Dynamic asynchronous
Transfert Mode)
OSA (Open Service Access)
EMTEL
(EMergency TELecommunication)
NETWORK
MANAGEMENT
Telecom Equipment Identity
SECURITY
Tispan_NGN
TISPAN_NGN Synergy
Projects
Etc… as needed
5
Technical approach
Goals
Services
Security
Architecture &
Requirements
Testing
Specification
Protocols,
Interworking etc.
Definition
QoS
Naming &
Addressing
Network & Service Management
Capabilities



Typical Services and basic
features
Service Capabilities
(building blocks)
QoS, Security, Naming and
Addressing

Architecture and
Requirements

Network and Service
Management (NGN OSS)

Protocol Selection and
Profiling

Evaluation & Modification
(“fit for purpose”)

Test Specification and Test
Suites (to facilitate
interoperability)
6
_NGN goals & Technical overview
 The Next Generation Network will eventually
provide:

A multi-service multi-protocol, multi-access, IP based network
- secure, reliable and trusted
• Multi-services: delivered by a common QoS enabled core
network.
• Multi-access: diverse access networks; fixed and mobile
terminals,
• Not one network, but different networks that interoperate
seamlessly

An enabler for Service Providers to offer
• real-time and non real-time, communication services
• between peers, or in a client-server configuration.

Nomadicity and Mobility
• of both users and devices
• inter and inter-Network Domains, eventually between Fixed and
Mobile networks
 “My communications services” always reachable,
everywhere, using any terminal.
7
_NGN Wide range of services
Person-to-Person – Communication Services
Conversational
Voice call
Video call
Chat call
Multimedia call
Messaging
e-Mail
SMS
EMS
MMS
IM
Content-on-demand
Browsing
Download
Streaming
Push
Broadcast
Peer-to-Peer
8
_NGN key assumptions
Support of a wide variety of services
Conversational
TV Broadcasting
Streaming
Messaging
Web
Support of fixed and mobile converged services
Well defined
interfaces
between control
and applications
Control Functions
Independence
between
control and transport
Packet-based transfer
Backbone
DSL/ATM
DSL/Ethernet
Cable Network
UTRAN/GPRS
Support of a wide variety of terminals
WLAN
9
_NGN high level Roadmap
Towards a converged Wireline and Wireless NGN …
Release 1 Release 2
xDSL,
WLAN
FTTx
Release 3
Fully
Nomadic
???
2004 2005 2006 2007 2008 2009 2010
 Release 1 bringing Multimedia services
 Nomadicity/user-controlled roaming
 xDSL access focus; Access Network Attachment Subsystem
 Release 2 optimizing access resources usage
 According to user subscription profile and service use
 Corporate users specific requirements …
 Release 3 introducing full (inter-domain) Nomadicity
 Inter-network domain nomadicity/user-controlled roaming
 Higher bandwidth access (VDSL, FTTH, Wi-max …)
10
Agenda
1. TISPAN_NGN Project: Steps and
Requirements
2. TISPAN_NGN Release 1 Status:
architecture outline
3. Why the use of IMS in NGN will help FixedMobile convergence for Multimedia
4. Some important issues to be taken care of
5. Summary
11
_NGN Release 1 scope
 Ongoing discussion
 Being consolidated meeting after meeting
 Stabilized at TISPAN#4 (sept.) & #4bis (nov.) meetings
 Major service capabilities under consideration
 Real time conversationnal services (Voice, Videotelephony)
 Messaging (Instant Messaging, MMS), Presence Management
 Legacy services emulation enabling legacy PSTN/ISDN
migration towards NGN
 Content delivery such as VOD, Video Streaming, TV-Channel
distribution (if inputs and resources available)
 Network Architecture basis
 ADSL access prime focus, possibly WLAN (may be deferred to
Release 2)
 3G/UMTS IMS sub-system reused as basis for real-time
Conversationnal services (SIP-based session control)
 Objective: mid-2005
 Pragmatic bottom-up approach for Release 1
 Not excluding Top-down (TIPHON-like) approach for preparing
future TISPAN_NGN Releases
12
_NGN architecture design principles
 A sub-system oriented approach, enabling:
The addition of new subsystems over the time to cover new
demands and service classes.
To import subsystems from other standardisation bodies.
Flexibility to adjust the architecture.
 IP connectivity is provided using two subsystems:
Network Attachment Subsystem (NASS)
Ressource and Admission Control Subsystem (RACS)
 First service-oriented subystems include:
The 3GPP IMS suitably adapted to accomodate xDSL-based
access networks requirements (joint effort with 3GPP), supporting
multimedia services and PSTN/ISDN Simulation.
A PSTN/ISDN Emulation subsystem specifically tailored to allow
TDM equipment replacement, while keeping legacy terminals
unchanged.
13
_NGN Architecture overview
Applications
Based on
3GPP IMS R6
Other Multimedia
Subsystems …
IP Connectivity
Access Network
And related functionality
(RTSP -based)
Streaming services
Network
Attachment
Functionality
(SIP - based)
IP Multimedia Subsystem
(Core IMS)
PSTN
(SIP - I based)
PSTN/ISDN Emulation
Subsystem
Resource and
Admission Control
Functionality
GW
GW
GW
GW
Access Transport
Network
IP
Core Transport Network
3GPP IP-CAN
14
_NGN detailed overview
Applications
Based on
3GPP IMS
IP Connectivity
Access Network
And related functionality
Data
Base
Other Multimedia
Components …
Streaming Services
(RTSP based)
PSTN / ISDN Emulation
(SIP-I based)
Network Attachment
Functionality
NASS
GW
NGN
Terminals
Customer
Networks
NGN
Terminals
Resource and Admission
Control Functionality
RACS
“Go”
interface
GW
Legacy
Terminals
IP
Access Transport
Network
PSTN / ISDN
Legacy
Terminals
“Gq”
interface
Legacy
Terminals
Other Networks
ICF
IP Multimedia
Component (Core IMS)
(SIP based)
TGW
Core transport
Network
MBG
3GPP IP-CAN
3GPP Terminals
15
IMS background (1/3)
 IMS introduced in 3GPP Rel5, and further enhanced
in Rel6:
IP Multimedia domain for call control based on
SIP
3GPP specifies features to fullfill operator
requirements, e.g.:
•
•
•
•
•
QoS control
Charging
Security
Subscription profiles
Interworking with other networks (CS/PSTN)
 IMS provides building blocks allowing faster
integration and deployment of IP multimedia
services
16
IMS background (2/3)
 IMS allows operators to have more control on the
service level than with GPRS only:
Service level awareness
Correlation between the SIP application layer and
the transport in PS domain
Access to services in correlation with a
subscription profile (e.g. basic, silver, gold…)
Better control on the packet resources used
 3GPP IMS Releases:
Release 5: frozen since March 2003
Release 6: freezing in December 2004
Release 7: Starting. Stage 1 requirements being
currently defined
17
IMS background (3/3)
User Ids
User profile
roaming
security
QoS
policy
control
SIP
InterWorking
CS/PSTN
Basic
Call
Control
charging
Service logic
APIs
18
IMS Registration and Call
Legend
Call Flow
IMS SIP: CSCF Call State
Control Functions
Proxy- UE Interface, Local
Services
Interrogating- Home Network
Contact Point
Serving- Session Control,
Service Invocation, AS &
HSS Trigger, Charging,
…
Signaling path
1
Register & find user Home
4
Register & Download IMS user Profile
2
Register & Retrieve required SCSCF & it’s capabilities
5
INVITE UE#2 into call
3
Choose correct S-CSCF
6
Upon Acceptance, Data Path is Set-up
Application
Servers
Content path
I-CSCF
2
HSS
3
P-CSCF
4
IP MULTIMEDIA
SUBSYSTEM
S-CSCF
1
5
SGSN
GGSN
6
GGSN
SGSN
UE #2
UE #1
UMTS PACKET DOMAIN
UMTS PACKET DOMAIN
20
IMS Architecture
Control Plane
HSS
IMS
I-CSCF
S-CSCF
P-CSCF
Go
UTRAN
GGSN
Gi
Other IP/
IMS network
Cx
Mw
SGSN
I-CSCF
Cx
Traffic Plane
UE
The HSS holds the IMS service profile
of the subscribers.
Mm
Gi
CSCFs are the IMS entities responsible of the call control:
S-CSCF
to external IP networks
there are 3 types of CSCFs depending on
theirinterconnects
role:
and other IMS networks.
•P-CSCF (Proxy CSCF)
If THIG is used by the operator to hide its
•S-CSCF (Serving CSCF)
internal configuration, the connection to
•I-CSCF (Interrogating CSCF)
The PSnetworks
domain goes
provides
the IPanbearer
to
external
through
I-CSCF.
access to the IMS, i.e. a PDP context.
PS Domain
21
IMS Architecture
Control Plane
HSS
IMS
Traffic Plane
Cx
I-CSCF
In Release 6, the PDF can be
separated from the P-CSCF. Those
two entities are then connected
through the Gq interface.
I-CSCF
Other IP/
IMS network
Cx
Mw
The MRF is used for
multiparty
P-CSCFcall control
Mm
S-CSCF
Mk
Mr
Gq Go
Mi
MRF
Gi
Mg
BGCF
Mj
UTRAN
Gi
Go
UE
SGSN
PS Domain
IMSMGW
PDF
Gi
GGSN
MGCF
Mn
SGW
Those entities are
responsible for
interworking between
IMS and CS
domain/PSTN
Legacy/
PSTN
22
_NGN IMS-based subsystem
Applications
Other
subsystems
Service Layer
PSTN/ISDN
Emulation
subsystem
Resource and
Admission Control
Subsystem
PSTN/ISDN
Cust omer Premises Equipment
IMS
Network
Attachment
Subsystem
Transport Layer
Transport Functions
23
Core IMS use in the NGN architecture
NGN
specific
Rf /Ro
impacted
Sh
AS
Network
Attachment
Subsystem
Dh
ISC
SIP
Cx
« Core
Core IMS
IMS
»
SLF
S-CSCF
Mw/Mk/Mm
Mi
Ic
BGCF
Mj
Id
Mg
MRFC
MGCF
Ie
Mn
Resource and Admission Control Subsystem
MRFP
SGF
PSTN/ISDN
Mp
A-BGF
IBCF
Mi
Gq
Gm
IWF
Other IP Networks
P-CSCF
Dx
I-CSCF
Mw
Mr
H.248
UE
Ia
Rf /Ro
Ib
Mw
DIAMETER
HSS
Cx
Mw
If
Charging
Functions
T-MGF
IP Transport (Access and Core)
I-BGF
24
_NGN standards built on 3GPP IMS specs
 Use the “core” IMS as one of the high-level
components of the overall NGN architecture,
with initial focus on xDSL
xDSL-based access networks provide access to IMS and
other subsystems (e.g.; streaming)
xDSL-based access networks as a new type of IPConnectivity Access Network for the IMS
 Complement the IMS with other subsystems
A resource and admission control subsystem
A network attachment subsystem
A PSTN/ISDN Emulation Subsystem
Other multimedia subsystems and applications
25
Differences between xDSL and
3G Radio Access
 Differences which impact the IMS-SIP specifications:
Wireline versus Wireless: The constraints in terms of bandwidth
scarcity, security, transmission delay are different
Terminals: Less stringent requirements are likely to be placed on NGN
terminals (e.g. support of IPv6, availability of USIM/ISIM, codecs...)
Location Information: Location information is different in nature and
usually not available at the UE
Resource management:: Explicit resource reservation signalling not
available in terminals and access network edge points; no dedicated
channel for signalling
Regulatory issues: Different contexts leading to different constraints
Terminals vs Users: Users are not always tied to terminals

Details being discussed between 3GPP (IMS R6 and R7) and
TISPAN
26
IP Connectivity control
 IP connectivity is provided using two control subsystems,
which play a role similar to the 3GPP GPRS procedures
 Network Attachment Subsystem
IP address allocation (e.g.; using DHCP).
Authentication, taking place at the IP layer
Authorisation of network access
Location management, taking place at the IP layer,
...
 Ressource and Admission Control Subsystem
Admission Control
Gate Control
...
27
_PSTN/ISDN Emulation Subsystem
Applications
Other
subsystems
Service Layer
PSTN/ISDN
Emulation
subsystem
Resource and
Admission Control
Subsystem
PSTN/ISDN
Cust omer Premises Equipment
IMS
Network
Attachment
Subsystem
Transport Layer
Transport Functions
28
Emulation vs Simulation
PSTN/ISDN service continuity in NGN:
 PSTN/ISDN Simulation
 "Provides PSTN/ISDN service capabilities and interfaces using
adaptation to an IP infrastructure"
 The provision of PSTN/ISDN-like services to advanced terminals (IPphones) or IP-interfaces. There is no strict requirement to make all
PSTN/ ISDN services available or identical, although end users expect
to have access to the most popular ones, possibly with different
ergonomy.
 PSTN/ISDN Emulation
 "Provides PSTN/ISDN-like service capabilities using session
control over IP interfaces and infrastructure"
 Mimicking a PSTN/ISDN network from the point of view of legacy
terminals (or interfaces) by an IP network, through a gateway. All
PSTN/ISDN services remain available and identical (i.e. with the same
ergonomics); such that end users are unaware that they are not
connected to a TDM-based PSTN/ISDN.
29
_PSTN/ISDN Emulation subsystem
 Two approaches under discussion:
 Softswitch approach ('Monolithic architecture')
• A shortcut to refer to (often already existing) implementations based
on use of call control software (ported from legacy switches).
• Not requiring standardisation of the internal structure of the
PSTN/ISDN emulation subsystem, only external interfaces
 IMS-like approach
• Re-use (all or part) of the IMS functional architecture to specify the
internal structure of the PSTN/ISDN Emulation subsystem
 Towards a compromise agreement:
 Functional architecture, physical implementation examples
• Standardisation of external interfaces: H.248 profile, network SIP-I
An IMS-like functional architecture does not prevent the
implementators to build a physical architecture using only
softswitches (MGC) and media gateways (MGW).
30
IMS and PSTN/ISDN Emulation
 Many similarities
 Two session-based control subsystems:
• For supporting multimedia conversational services and
PSTN/ISDN services simulation (IMS)
• For supporting PSTN/ISDN services emulation
 Above a managed IP network
 Supporting operators’ requirements
• Quality of service, Security, Charging capabilities, Regulatory
constraints....
 Clear Benefits
 Enables the deployment of common control platforms
• Towards a unique infrastructure for supporting multimedia services
and TDM- switches replacement
 Enables service convergence
• new voice services available to all types of subscribers
 Enables the scope of nomadism to be extended to legacy
access lines.
31
_Emulation typical configurations
Z
H248
SIP -I
SIP may also be used if the set
of services to be emulated is
limited and/or « downgraded »
emulation is considered
acceptable (e.g. second line).
Z
H248
RGW
or
AGW
RGW
or
AGW
DSS1/IUA
Z
H248
S/T
SIP -I
H248
RGW
or
AGW
V5.2/V5UA
V5.2
Z
H248
SIP -I
AN
H248
RGW
or
AGW
Z
H248
RGW
or
AGW
SIP -I
H248
ISUP
PSTN
/
ISDN
TGW
32
_Network Attachment Subsystem
Applications
Other
subsystems
Service Layer
PSTN/ISDN
Emulation
subsystem
Resource and
Admission Control
Subsystem
PSTN/ISDN
Cust omer Premises Equipment
IMS
Network
Attachment
Subsystem
Transport Layer
Transport Functions
33
_Network Attachment Subsystem
 Main functionalities
IP address allocation (e.g.; using DHCP).
Authentication and authorisation, taking place at the IP layer
Access network configuration, based on user profiles.
Location management, taking place at the IP layer
 Replaces the 3GPP PS Domain / GPRS procedures
for authentication and location management
 Outstanding Issues
Interactions between authentication at the network attachment
level and at the SIP level.
Alignement with DSL Forum Architecture
One NASS per access network or one NASS for several
access networks?
34
_NGN NASS current architecture
Service control
subsystems and
applications
Resource
and
Admission
Control
Subsystem
e2
e4
CLF
a2
CDCF
CNG
UAAF
NACF
e3
TE
a4
a1
e1
PDBF
a3
AMF
35
_Resource and Admission Control
Applications
Other
subsystems
Service Layer
PSTN/ISDN
Emulation
subsystem
Resource and
Admission Control
Subsystem
PSTN/ISDN
Cust omer Premises Equipment
IMS
Network
Attachment
Subsystem
Transport Layer
Transport Functions
36
_NGN RACS description
 Main Functionalities:
Session Admission Control.
Gate Control (including NAPT)
 TISPAN R1 : No interactions between RACS in
different networks
 Need to support both push and pull procedures
Push mode required for ADSL-based access networks
 Issues for future releases:
Admission control at core network boundaries.
Cooperation between peer ressource control subsystems
37
_NGN RACS status
 Provides a Gq-like interface to TISPAN
Subsystems and applications
 Controls transport ressources at the boundary
between the access and core networks
Using a Gate Control Protocol
 May also control NAPT at core network boundaries
 TISPAN has recently approved an H.248-based
Gate Control Profile
An alternative COPS-based or SNMP-based
standards may be pushed by some vendors at a
later stage
38
Agenda
1. TISPAN_NGN Project: Steps and
Requirements
2. TISPAN_NGN Release 1 Status: architecture
outline
3. Why the use of IMS in NGN will help FixedMobile convergence for Multimedia
4. Some important issues to be taken care of
5. Summary
39
Why IMS in NGN ?
 IP Multimedia Substem generally fulfills the NGN
requirements for conversational services
For managed, carrier operated telecom network
With Release 6 becomes applicable to a range of access
network types (3G RAN, WLAN)
IMS access (technology) independence
 Whole Telecom industry benefit
Will enable simple and effective interworking between
Cellular and Wireline
Growing IMS market, encouraging greater usage
Wider choice of IMS suppliers
Market stimulation, decreasing costs (thanks to shared
development/deployment costs)
…
40
Benefits of IMS use in NGN

TISPAN_NGN has taken the lead in adopting 3G IMS as a key
base component in the NGN architecture



A promissing major step to enable smooth Fixed-Mobile
convergence for Multimedia:




Consolidating the IMS and Service Platforms access & transport
technology independence
Enabling seamless service interworking
An effective basis to support Nomadicity and Mobility features
Still a number of challenges ahead




It needs adaptions to support xDSL access (on-going)
Still a number of issues to be addressed (Identifiers, Security,
IPv4/v6 interworking and transition …)
Resource optimization and transport technology evolution
QoS insurance for Real time services …
Identifiers, Security …
But a significant step is being taken to enable the Multimedia
Fixed-Mobile convergence in TISPAN_NGN Release 1
41
Agenda
1. TISPAN_NGN Project: Steps and
Requirements
2. TISPAN_NGN Release 1 Status
3. Why the use of IMS in NGN will help FixedMobile convergence for Multimedia
4. Some important issues to be taken care of
5. Summary
42
_NGN IMS-related issues
A promissing approach but many challenges, e.g.

Resource and QoS control in access (and end-end)


QoS insurance (IP flow differenciation)
Policy control (G0) interface
 Services interoperability




Terminals


IP addresses, (Line & Personal) Identifiers, SIP Client (Profile) …
IT adaptation and integration



Services are not (yet) standardized in 3GPP
TISPAN_NGN is intending to standardize a minimum set
Interworking with Legacy networks and Platforms
Flexible NGN-OSS
Provisioning, Charging and Billing
To enable use of IT(IP)-based technology in Telecom carriers
grade environment.
43
Using Gq interface in NGN
 Gq Interface is located between Multimedia
Subsystem(s) and Resource and Admission
Control Subsystem (RACS)
 Gq is used by different subsystems (not only IMS)
and multiple Access Networks
 Gq is used to access the following functions:




Resource reservation
Admission Control
NAT Control
Gate and Policy Control
44
Gq interface Extensions
 Support for network initiated resource reservations
 Besides Pull Model the Push model shall be supported.
 Support for requesting Address and Port Translation
 Parameters for NAT type of scenarios., e.g.
• interworking of different (private/public) IPv4 address spaces,
query and allocate NAT bindings
• Possibly IPv4/IPv6 interworking
 Gate control and service and network policy control
 Parameters to access those functions
45
Agenda
1. TISPAN_NGN Project: Steps and
Requirements
2. TISPAN_NGN Release 1 Status: architecture
outline
3. Why the use of IMS in NGN will help FixedMobile convergence for Multimedia
4. Some important issues to be taken care of
5. Conclusion
46
_NGN summary
 A strong industry demand
 For new generation Multimedia services on xDSL access
 For preparing replacement of soon becoming obsolescent PSTN
 For a first Release of specifications by mid-2005
 Giving main standards directions
 With realistic and implementable solutions
 ETSI TISPAN taking the lead to propose an architecture basis
consisting of a range of subsystems:
 Maximizing Wireline and Cellular convergence, through adoption of
3G/UMTS IMS component for support of conversational services
 Access network attachment Subsystem, Resource and admission
control sub-system … preparing for next Releases
 TISPAN collaborating with 3GPP to accommodate Wireline
access network requirements by IMS
 A 1st Workshop held last June, a further one next year
 To coordinate the IMS specifications evolutions to support various
Wireless and Wireline access technologies
 Other collaborations very welcome
 ITU-T NGN Focus Group, ATIS is eager to cooperate
 European IST projects e.g.
which is considering IMS in
the scope of their system architecture too.
47
Acronyms











CSCF
IMS
IWF
GPRS
HSS
MRF
MGCF
SIP
SLF
UMTS
UTRAN
Call State Control Function
IP Multimedia Services
Inter-Working Function
General Packet Radio Service
Home Subscriber Function
Multimedia Resource Function
Media Gateway Control Function
Session Initiation Protocol
Subscriber Location Function
Universal Mobile Telecom. System
Universal Telecom. Radio Access Net.
48
THANKS FOR YOUR ATTENTION
Questions/Comments ?
ETSI TISPAN Portal:
http://portal.etsi.org/Portal_Common/home.asp
49