Joint 3GPP

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Joint 3GPP TISPANWorkshop on NGN-IMSAgenda
item 6

• Issues related to the reuse of IMS for NGN
• and ADSL access to IMS features

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Potential Topic issues

• 6.1 Subscription, Databases and Terminals
• 6.2 IMS Enablers
• 6.3 Security requirements and solutions
• 6.4 Charging requirements and solutions
• 6.5 Bearer QoS classes
• 6.6 Resource allocation and Policy Control
• 6.7 Capabilities and Services
• 6.8 IP Version and related Interworking issues
• 6.9 Interconnection to External Networks
• 6.10 Potential impacts on SIP profile
• 6.11 Potential impacts on DIAMETER profiles
• 6.12 Management requirements and solutions
• 6.13 Other topics

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Service offering related issues

• 6.1 Subscription, Databases and Terminals
• 6.2 IMS Enablers
• 6.4 Charging requirements and solutions
• 6.7 Capabilities and Services

Dick Knight (BT Group plc)TISPAN WG1
Chairmandick.rr.knight_at_bt.com
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(6.1) Subscription Databases Terminals

• UICC in NGN
• NGN needs to uniquely identify users
• not all terminals will be UICC compliant
• soft identities
• Requirements
• flexibility
• Identity Issues
• SIP URLs
• who will allocate domain names?
• 3GPP approach?

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(6.1) Customer Networks (1)
3GPP IP-CAN
3GPP TE
Customer Environment
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(6.1) Customer Networks (2)
TISPAN NGN
TISPAN NGN Access Network
Core
DSL modem router App layer NAT/FW
SIP-aware layer (e.g. SIP ALG or proxy)
Gm
P-CSCF
UA
Security requirements !
Gq
PDF/Gate Controller
Go
ME
B-RAS (MAG)
DSLAM
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(6.2) IMS Enablers

• Presence Messaging Group Management
  Conferencing
• issues related to identity
• Presence needs to identify network type
• not currently in Release 6
• Could Presence be extended to PSTN/ISDN?
• Conferencing
• 3GPP approach?
• IETF (XCON)?

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(6.4) Charging Requirements and Solutions

• Fixed Networks charge on Access Lines
• But individual services (e.g. Presence) may need
  to charge User
• Requirements
• Flexible approach to charging
• allow access line, individual subscriber and any
  combination of both
• 3GPP approach
• Does this impact WLAN support?

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(6.4) Charging Example

• Customer A has ADSL
• pays access (rental)
• all family can use ADSL communications
• may be an individual charge
• Customer B uses A line
• pays for personalised services
• could pay usage charges
• Combination of
• access line charge
• usage/service charge

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(6.7) Services Issues

• Standardised Services
• Service Capabilities
• key drivers for Services
• Presence Messaging Push to Talk Gaming
• Interoperability Issues
• Supplementary Services
• enhancements to voice services
• Service Management Issues
• Managed at capability level
• What are 3GPP plans?

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Security issues

• 6.3 Security requirements and solution

Martin Euchner (Siemens AG)Work Item Rapporteur
martin.euchner_at_siemens.com Scott Cadzow (C3L)STF
Leaderscott.cadzow_at_c3l.com
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(6.3) NGN Security Objectives

• TISPAN NGN has to meet a set of comprehensive and
  fundamental NGN security requirements
• to ensure a secure and trustworthy environment
  for customers, network operators and service
  providers
• TISPAN NGN Security Release 1 is based upon IMS
  security
• needs to enhance IMS security as appropriate and
  necessary

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NGN Security - Status Quo

• There is a real need to investigate on overall
  security of NGN
• is being addressed in the TISPAN NGN Security
  Architecture Requirements TS
• Current status
• capturing NGN security goals, objectives and
  requirements
• Security requirements and NGN-IMS security gap
  analysis expected to be stable by September 2004

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Some crucial NGNSecurity Issues of Joint Interest

• There will be new IMS security requirements from
  TISPAN NGN
• from fixed NGN space
• due to convergence
• Some potential hot areas
• Security for supporting xDSL (cable?) scenarios,
• Interdomain security,
• interworking of various security mechanisms,
• Terminal or user authentication (or both),
• HW-based (UICC/USIM/ISIM/SIM) and/orSW-based
  authentication,
• Smooth NAT/FW traversal,
• Various, unique identities in the NGN
  environment,
• Single-sign on?
• (E2E) media protection,

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Process for NGN Security Standardisation
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Desired Collaboration with 3GPP

• What is the most productive way of collaboration
  on NGN-IMS security affairs?
• SA3 could be the primary point of contact for
  liaison activity on security
• other 3GPP SA groups may need to be involved too
• Liaisons with IMS security requirements are
  expected from September 2004 onwards...

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(6.3) Security Backup Slide
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NGN Security Requirement Areas

• Security Policy
• Authentication and Authorization
• Identity and Secure Registration
• Communications and Data Security(incl.
  integrity, replay protection, confidentiality)
• Privacy
• Security Management(incl. security event logging
  and security audit)
• Interworking with NAT/Firewall
• Non-repudiation
• Availability, DoS protection, reliability and
  assurance.
• There are many more detailed requirements

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QoS related issues

• 6.5 Bearer QoS Classes

Dave Mustill (BT Group plc)TISPAN WG5
Chairmandave.mustill_at_bt.com
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(6.5) TISPAN WG5 QoSQoS in an NGN Environment

• QoS and Network Performance
• Evolution from PSTN to NGN
• Where Are We Now?
• QoS in TISPAN_NGN R1
• Bearer Service NP Classes
• Conclusions

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QoS and Network Performance

• QoS is an end-to-end issue
• Includes terminal and users local network
• Metrics are parameters sensed by user (e.g.
  delay, echo, distortion)
• Network Performance is UNI-UNI issue
• Metrics are bit/packet related (e.g. delay,
  jitter, packet loss, error rates)
• TIPHON confused the two terms we are trying to
  be a lot more rigorous in TISPAN.

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Actual Performance

• Packet loss in high bit rate (core) networks is
  low (0.1)
• Delay variation in high bit rate core networks is
  low compared to fixed delay element
• The main NP problems are in the access networks
  which are expensive and low bandwidth
• QoS depends very much on the terminal (e.g. the
  interactions between the codec and the network)
• We have very little practical knowledge of
  effects of jitter variations on new codecs

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Evolution from PSTN to NGN
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General Principles of Apportionment

• Applies to NP not QoS parameters
• OK for fixed impairments but need to avoid
  unlikely worst cases imposing too tight limits
• Only a help if we know how to design network to
  achieve limits
• Impairments caused by random events that are not
  correlated in all networks may need to be treated
  differently (under discussion in STQ WG5)

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Where Are We Now?

• We understand
• NP for 64kbit/s circuit switched channels
• How to design circuit networks to achieve NP
• Interactions of circuit switched channels with
  low rate codecs
• QoS for 3.1 kHz speech (E-model)
• Packet handling techniques that improve
  performance
• We do NOT understand
• Interactions of packet transmission with new
  codecs
• Interactions of terminal and network signal
  processing
• How to specify NP on IP infrastructure e.g.
  jitter spectrum
• How to design packet networks to achieve NP
  (relation between network load and performance)
  particularly at bandwidth bottlenecks
• Level of improvement from packet handling
  techniques and network QoS mechanisms
• QoS for wideband speech

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QoS in TISPAN_NGN R1

• The TISPAN_NGN should be able to support a wide
  range of services with defined levels of QoS.
• In order to support the required levels of QoS
  TISPAN will define bearer service NP classes and
  means of achieving them
• QoS control mechanisms
• QoS control architecture
• QoS control signalling

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Layered Nature of NP QoS

• TISPAN WG5 will specify three levels of QoS
• Network Performance of the bearer service between
  UNIs
• End-to-end QoS of monomedia application
  components (e.g. delay, speech quality, picture
  quality)
• End-to-end QoS of some multimedia application
  specific parameters (e.g. lipsync)

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Bearer Service NP Classes

• TIPHON QoS specifications were focused on
  end-to-end QoS
• In an NGN environment, the network performance at
  the bearer service level should be taken into
  account
• Bearer services are characterised by their NP
  parameters and their bandwidth
• The initial focus of TISPAN_NGN will be on bearer
  service NP Classes, based upon the uses to which
  the bearer services will be put
• These classes should be based on the ITU-T Y.1541
  IP Network QoS classes and 3GPP TS 23.107 UMTS
  QoS classes

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ITU-T and 3GPP QoS Classes (1)

• TISPAN WG5 views both ITU-T and 3GPP approaches
  to IP QoS classes as classes of network
  performance
• There are discrepancies between the two sets of
  classes which both set out to define a minimum
  set of QoS classes for the support of a variety
  of applications on an IP bearer
• The main discrepancy is the fact that the 3GPP
  classes place no requirement on the control of IP
  packet delay variation (jitter)

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ITU-T and 3GPP QoS Classes (2)

• Long term harmonisation of the two sets of
  classes is desirable
• In the shorter term the TISPAN WG5 view is that
  there are two possible approaches that could be
  adopted in TISPAN
• support of both sets of classes (giving ten in
  all)
• defining an interworking/mapping function (where
  3GPP class x would map to ITU-T class y as a call
  passed from a 3GPP to an NGN domain)
• Even in the short term it will be necessary to
  determine a way of assessing how much jitter and
  delay a call will have when handed over from a
  3GPP network to an NGN

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QoS Summary

• Almost all of our knowledge on QoS and NP is
  based on circuit-switched narrowband speech.
• We need implementation experience to develop our
  knowledge of the QoS and NP requirements of
  packet-based networks.
• There is an urgent need to work on the
  harmonisation of the 3GPP and ITU-T bearer QoS
  classes.

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Gq interface ssues

• 6. 6 Resource allocation and Policy control

Leonardo Finizola e Silva (Alcatel)
leonardo.finizola_e_silva_at_alcatel.be Jörg
Ottensmeyer (Siemens) joerg.ottensmeyer_at_siemens.c
om
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(6.6) Using Gq in TISPAN

• 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 function
• Resource reservation
• Admission Control
• NAT Control
• Gate and Policy Control

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(6.6) Gq 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

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SIP Profile issues

• 6.10 Potential impacts on SIP profile

Sébastien Garcin (France Telecom)TISPAN SIP Work
Item Rapporteursebastien.garcin_at_francetelecom.com
Ray Forbes (Marconi)TISPAN WG3 (Protocols)
Chairmanraymond.forbes_at_marconi.com
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Inherent differences between NGN IMS and 3GPP IMS

• Wireline versus Wireless
• Constraints in terms of bandwidth scarcity,
  security, transmission delay are different.
• Terminals
• Different requirements placed on NGN terminals
  (e.g. support of IPv6, availability of UICC
  device)
• Location Information
• Location information different in nature and
  usually not available at the terminal.
• Resource management
• Explicit resource reservation signalling not
  available in terminals and access network edge
  points
• Common ressources shared between the signalling
  and media flows
• Regulatory issues
• Different constraints

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Potential impacts on 3GPP TS 24.229

• Relaxing the constraint on IPv6
• Potential impact on P-CSCF procedures
  (modification of IP adressing in SIP messages)
• Access call server discovery since IPv4 is
  supported, extensions to DHCPv4 should be
  considered
• Relaxing the constraint on UICC availability in
  UE
• Alternative (probably weaker) SIP authentication
  procedures may have to be taken into account
• Impact on trust placed in the terminal
• Difference in bandwidth and transmission delay
  constraints
• SIP compression seen as optional for the UE
• Indication of RTCP stream bandwidth in SDP
  usually seen as optional for UE
• SIP timers to be re-considered
• Geographic location information
• Need to update SIP information format (currently
  P-Access-Network info)
• P-CSCF may have to insert this information in SIP
  messages
• Should not be systematically removed by the
  S-CSCF (for location-dependent services triggered
  from the called partys S-CSCF)

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Potential impacts on 3GPP TS 24.229

• Administrative domain of the P-CSCF
• Not only sent at registration phase but also at
  session establishment phase
• Subject to privacy
• Differences in resource reservation procedures
• P-Media-Authorization headers not required,
  impact on Preconditions signalling
• Need for SIP body filtering procedures in P-CSCF
• No dedicated transport channel/resources for
  signalling in xDSL access
• Overriding presentation restricted user
  information to authorized parties
• Due to regulatory reasons
• Support of SIP-aware residential gateways
• Impact on security association and NAPT scenarios
• SIP support for overlapp sending?

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Other NGN-IMS issues ?

• 6.13 Other Requirements/Topics, e.g.
• Common Application Servers access from IMS and
  from other Subsystems?
• Need for direct interactions between resource
  control entities
• Relationships between the IMS and NGN modelling
  (i.e. service/transport split)
• .

No specific input available at this stage ?
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Summary NGN-IMS requirements and issues

• Requirements
• Agreed ones
• Those requiring further joint work
• Issues impacting IMS
• Which specifications
• Issues requiring further joint work

For discussion and Possible consensus reach !