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IP networking MEDIACOM-2004 ITU Workshop IP
networks towards NGN Geneva, 24-27 April
2001(Edition 2 du 18 04 01)

• Gaël Fromentoux
• Renaud Moignard
• Christine Pageot-Millet
• André Tarridec
• FT RD/DAC

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Outline

• Introduction
• Proposed definitions
• IP services network current state
• VoIP
• Control plane architecture QoS
• Mobility nomadism
• IPv6 migration.
•  
• Conclusion
• References Glossary

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Introduction

• In this paper, it is first proposed a set of
  definitions to characterise NGN solutions
• in particular a so-called " target NGN ".
• It is then applied to the services and network
  evolution of an IP domestic network
• whose final state would be compliant with the
  proposed " target NGN ".
• Important matters related to this evolution are
  briefly evoked
• IP services network current state,
• control plane architecture QoS,
• VoIP,
• Mobility nomadism ,
• IPv6 migration.

• As a conclusion, possible synergies between IP,
  mobile and telephony networks
• evolution towards NGN are pointed out.

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Proposed definitions NGN

• A set of definitions based upon functional
  architecture principles
• Proposals aim at helping to provide a common
  understanding and vocabulary related to NGN
  matters.

• NGN solutions are characterised by the following
  main attributes
• A services control layer independent from the
  bearer resources,
• A network service layer in packet mode (ATM,
  IP...),
• Open and better standardised interfaces, between
  the services control the resources control,
• The externalisation of part of the control
  functions with regards to the transfer layer.

• The expected advantages from architectures
  compliant with those principles are
• The set up of a business model on line with the
  fast moving telecommunications environment
• The ability to support any kind of services to
  make them evolve at their own pace,
• Architecture flexibility gained from the
  independence between services and bearer
  resources,
• Resources mutualisation stemming from the two
  preceding points,
• The use of any kind of transmission support
  (ADSL, SONET, SDH, WDM, radio...).
• Note that some solutions are already labelled NGN
  ones although they do not respect the whole
• set of rules proposed here.

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Proposed definitions Target, Telephony Data
NGNs

• Definition a NGN is a Target NGN " in case it
  supports all kinds of telecommunications services
  and meets the proposed NGN features.

• Definition a NGN will be labelled
• Telephony NGN " when it is at least able to
  support the whole set of existing telephony
  services (plain, enhanced and IN services) with
  matching Quality of Services, QoS.

• A Target NGN includes services supported
• by Telephony NGNs those by Data NGNs.
• Target NGNs can be considered as
• the final evolution of these two ones.

• Definition a NGN will be labelled Data NGN
  when it is not able to support the whole set of
  existing telephony services (plain, enhanced and
  IN services) with matching Quality of Services.

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Proposed definitions Core Transit NGNs

• A  transit NGN  interconnects local networks to
  packet network cores.
• gt great interest for inhomogeneous networks,
  for migration, when traffics sources are
  scattered etc

• A  core NGN covers core network part. It
  interconnects edges offers access to
  international networks

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Proposed definitions Local NGN

• A network solution will be labelled a Local NGN
  when it covers the access and edge network
  parts.
• To support a large range of services
• To collect various accesses of different kind

• To emulate LEX functions is just not enough.

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IP services and network current state IP
network

• IP networks provide best effort data services
• gt to residential customers, professional
  customers
• companies.
• gt Internet, Intranet and Extranet connectivity
  is possible.

• Two main services
• gt aggregation services to collect the traffic of
  
• Not always on customers to deliver it to
  IAPs/ISPs,
• gt transport services to convey the traffic of
  always connected users between sites directly
  attached to the IP network and towards Internet.

• Only best effort services based on the IPv4
  protocols are available.
• gt No service differentiation through
  differentiated
• Service classes, no QoS guarantee.
• Over provisioning is the remedy.
• Voice services such as VoIP, Internet Call
  Waiting,
• Centrex IP may be supplied

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IP network current state

• 3 parts access, edge and core.
• The access part collects and concentrates
  customers
• traffic through 2 Access Server types
• NAS for narrowband switched connections
• BAS for broadband permanent connections.
• 2 kinds of NAS data-oriented and voice-oriented
  NAS.

The edge part concentrates the traffic and
performs specific edge functions ( flow
classification conditioning, external routing
protocols processing network-based VPN
handling). Edge and border routers support
interfaces with the access network, internal
servers, ISPs/IAPs Internet.
The core part routes and forwards aggregated
flows over core routers. MPLS improves the
traffic engineering and supports network-based IP
VPNs.
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IP network NGN like features
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VoIP (H.323 SIP) general architecture

• VoIP H323 (ITU) SIP (IETF).
• The GK is the control platform.
• It controls end points (GW terminal) of a
• H.323 domain performs call request
• (call admission).
• GWs perform IP/PSTN inter-working
• for media stream
• SGs for SS7/IP signaling inter-working.
• Supplementary services services could be
  performed within a SCP via an INAP/IP interface
  or within an application server via API or
  proprietary interfaces.

• VoIP can be considered as a Data NGN MM
  services i.o telephony services. No absolute QoS
  is available.
• VoIP architectures may reach Target NGN by
  introducing QoS telephony services. Mobility is
  still missing.

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Control plane architecture QoS

• Control Plane Services Resources
• Services control to analyze services requests
  independently from the resources
• Resources control to select monitor resources
  after the request (routing path algorithms)
• Resources mediator to be found

• QoS
• It is a major requirement for the next generation
  IP networks. Voice, videoconf streaming cannot
  cope with best effort. Customers have
  differentiated needs requiring differentiated QoS
  levels
• IP networks to support several QoS levels
  absolute QoS, relative QoS and best effort.
• Unlimited bandwidth is not ready yet
• The Integrated Differentiated Services models
  as first steps whereas MPLS is under deployment

• QoS is an end-to-end issue, concerns every layer
  of the transfer plane, requires coordinated
  mechanisms procedures in the transfer, control
  management planes
• A full QoS support is very complex to implement
• Its introduction will be progressive

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NGN introduction in CS and PS domains post R5
architecture.

• 2 domains PS CS in UMTS R5
• An Internet Multimedia Subsystem (IMS) is
  introduced. The PS domain associated with the IMS
  allows UMTS R5 to offer VoIP services
• CSCF controls admission, incoming calls and
  communicates with HSS, (Home Subscriber Server),
  which is a customer database dealing with
  mobility and service profile
• MGCF controls gateways that perform PSTN/IP
  network inter-working between
• SIP protocol has been chosen by 3GPP for UMTS R5.
  From a strict functional viewpoint, except for
  the mobility aspect, a CSCF is a SIP server
• Post R5 release proposes an evolution of PS
  domain towards NGN externalization of some
  control functions in SGSNserver GGSNserver

Application servers
SCP
Application
API
CAP
Network Service Control
CSCF
HSS
MGCF
T-SGW
Transport
MGW, GSN
UTRAN

• 3GPP2 is considering IP for the mobility
  management.
• Mobile IP is a key component of "full IP"
  scenarios.

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Mobile IP architecture principles

• 3 main elements compose the
• mobile IP architecture
• Mobility function within the terminal to
• perform moving detection function
• registration functions to a HA or a FA.
• HA function in the router that
• connects the H sub-network of the mobile
• is in charge of updating the information
• DB for mobile location reemitting to
• data to its current location
• FA function in the router that connects
• the V sub-network of the mobile. It
• registers visiting mobiles offers services
• such as datagrams routing to
• visiting mobiles.

• Mobile IP to manage macro-mobility
• at the IP level. Mobile IP mainly allows
• communication hold-on when a mobile moves from an
  IP sub-network to another,
• the use of the same IP address attached to a
  mobile and valid in all IP networks.

• As a conclusion IP network could both handle
  macro-mobility
• (e.g. in target NGN and partly in UMTS networks)
  and telephony services, thanks to respectively
  mobile IP and to SIP or H323 architectures.

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VHE a distributed user profile

• To trace a user to know its profile and how to
  recognize it the Virtual Home Environment (VHE)
  concept a system concept for personalized
  service portability across network boundaries and
  between terminals ". ( ETSI 3GPP )
• These concept have been designed in the UMTS
  networks context to allow users to always have
  a common look and feel of their service. No
  difference for users while they roaming in other
  networks.
• VHE will be created by a combination of
  capabilities handled by service providers,
  network operators and located within terminal
  equipments.
• The initial definitions still hold in a non UMTS
  context (a global service provider for a
  consistent view of its customers being
  potentially mobile, fixed and Internet customers.
• With regards to this perspective global operators
  would gain to share a common understanding of
• The models that describe their customer (i.e.
  data attached to their customer),
• The functions that allow services to be delivered
  to their customer (i.e. applications dealing with
  customers),
• The equipment running these applications and the
  associated databases.

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IPv6 to fix IPv4 limitations

• IPv6 to meet the requirements for a large-scale
  worldwide deployment.
• IPv6 supports a number of enhanced features, such
  as
• larger unicast and multicast address space,
• anycast address,
• aggregatable addressing for hierarchical routing,
• host address auto configuration,
• easy site renumbering,
• flow identification for QoS support,
• streamlined packet formats for improved
  forwarding performance,
• multicast support (explicit scope),
• extension headers used for supplementary
  capabilities,
• security providing packet authentication and
  encryption,
• mobility improvement through auto configuration,
  security, anycast address and destination
  options.
• Given the large amount of IPv4 equipment
  currently deployed in public private networks
  both protocols
• will coexist for a long time.
• Several transition mechanisms have been
  incorporated in the IPv6 design to help with the
  migration phase.

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IP network towards a possible Target NGN
lots of work ahead !
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Conclusion

• A variety of networks have been deployed more or
  less dedicated to a particular service.
• Most of the past technical constraints are no
  longer valid given the fast evolution in
  architectures and broadband technologies
  (control/transfer plane evolution, xDSL, UMTS,
  DWDM, packet transfer)
• Many legacy networks are evolving towards Next
  Generation Networks whose architectures are based
  on the same principles.
• These new architectures will provide more
  flexibility for the support of services.
• To enable generalized multimedia mobile services
  customers should be provided with personalized
  services across networks and between terminals,
  over mobile or fixed accesses whatever their
  location is.
• This is the target.
• In this paper, technical issues to overcome have
  been more specifically addressed in the case of
  IP transport. Special attention should be paid to
  fixed and mobile service convergence.
• Many of these issues are currently under study in
  several standardization bodies and fora, to make
  this attractive future happens they should be
  consistently dealt with.

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References
"A Next generation architecture for the public
network " ISS2000 TINA-C Network Resource
Architecture, version 3.0 Feb. 1997 TIPHON
Network Architecture reference configurations,
DTS 02003 v0.0.1 ETSI March 1999 Multiservice
Switching Forum Architecture, MSF99.074 March
1999 Megaco Protocol Proposal Working draft,
draft-IETF- megaco-protocol-01.txt April 1999
Draft ITU-T Recommendation Q.BICC, Bearer
Independent Call Control protocol definition RFC
2543 SIP Session Initiation Protocol RFC 3015
Megaco Protocol v1.0 RFC 2002 IP mobility
Support (for Ipv4) Universal Mobile
Telecommunications System (UMTS) Virtual Home
Environment (VHE) in the Integrated Services
Digital Network, Evolved UMTS core network, ETSI
EG 201 717. Universal Mobile Telecommunications
System (UMTS) Service aspects Virtual Home
Environment (VHE), ETSI TR122 970, 3G TR
22.970. Eurescom Project P920, UMTS Network
Aspects (http//www.eurescom.de/public/projects/P9
00-series/p920/P920.htm RFC 1633 Integrated
Services in the Internet Architecture an
Overview RFC 2475 An Architecture for
Differentiated Services RFC 3031 Multiprotocol
Label Switching Architecture draft-ietf-mpls-diff-
te-reqts-00 Requirements for support of
Diff-Serv-aware MPLS Traffic Engineering RFC
1883 Internet Protocol Version 6 (IPv6)
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Glossary
ARF Access to the Resources Function ASF Access
to the Services Function AP Application
Part BAS Broadband Access Server CAP Camel
Application Part CS Call Server CSCF Call State
Control Function DWDM Dense Wavelength Division
Multiplexing FA Foreign Agent GGSN Gateway GPRS
Support Node GK GateKeeper HA Home Agent HSS
Home Subscriber Server IAP Internet Access
Provider IGP Interior Gateway Protocol INAP
Intelligent Network Application Part ISDN
Integrated Services Digital Network ISP Internet
Service Provider LEX Local EXchange LSP Label
Switched Path MG Media Gateway
MGC Media Gateway Control MGCF Media Gateway
Control Function MPLS MultiProtocol Label
Switching MSC Mobile service Switching
Center NAS Network Access Server NGN Next
Generation Network OTN Optical Transport
Network PHB Per-Hop Behaviour POTS Plain Old
Telephone Service PDSN Packet Data Serving
Node PS Proxy SIP PSTN Public Switched Telephony
Network QoS Quality of Service RC Resources
Control SC Services Control SGSN Serving GPRS
Support Node SGW Signalling Gateway UMTS
Universal Mobile Telecommunications System VHE
Virtual Home Environment VPN Virtual Private
Network