Published on November 28, 2007
Joint 3GPP & TISPANWorkshop on NGN-IMSAgenda item 6:: Joint 3GPP & TISPAN Workshop on NGN-IMS Agenda item 6: Issues related to the reuse of IMS for NGN and ADSL access to IMS features Potential Topic issues: 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 Service offering related issues: Service offering related issues Dick Knight (BT Group plc) TISPAN WG1 Chairman [email protected] 6.1 Subscription, Databases and Terminals 6.2 IMS Enablers 6.4 Charging requirements and solutions 6.7 Capabilities and Services (6.1) Subscription Databases & Terminals: (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 URL’s who will allocate domain names? 3GPP approach? (6.1) Customer Networks (1): (6.1) Customer Networks (1) 3GPP IP-CAN 3GPP TE Customer Environment (6.1) Customer Networks (2): (6.1) Customer Networks (2) TISPAN NGN Core TISPAN NGN Access Network ME DSL modem + router App layer NAT/FW DSLAM PDF/Gate Controller B-RAS (+MAG) P-CSCF UA SIP-aware layer (e.g. SIP ALG or proxy) Security requirements ! Gq Go Gm (6.2) IMS Enablers: (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)? (6.4) Charging Requirements and Solutions: (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? (6.4) Charging Example: (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 (6.7) Services Issues: (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? Security issues: Security issues Martin Euchner (Siemens AG) Work Item Rapporteur [email protected] Scott Cadzow (C3L) STF Leader [email protected] 6.3 Security requirements and solution (6.3) NGN Security Objectives: (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 NGN Security - Status Quo: 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 Some crucial NGNSecurity Issues of Joint Interest: Some crucial NGN Security 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/or SW-based authentication, Smooth NAT/FW traversal, Various, unique identities in the NGN environment, Single-sign on? (E2E) media protection, … Process for NGN Security Standardisation: Process for NGN Security Standardisation Desired Collaboration with 3GPP: 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... (6.3) Security Backup Slide: (6.3) Security Backup Slide NGN Security Requirement Areas: 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 QoS related issues: QoS related issues 6.5 Bearer QoS Classes Dave Mustill (BT Group plc) TISPAN WG5 Chairman [email protected] (6.5) TISPAN WG5 QoSQoS in an NGN Environment: (6.5) TISPAN WG5 QoS QoS 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 QoS and Network Performance: QoS and Network Performance QoS is an end-to-end issue Includes terminal and user’s 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. Actual Performance: 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 Evolution – from PSTN to NGN: Evolution – from PSTN to NGN General Principles of Apportionment: 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) Where Are We Now?: 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 QoS in TISPAN_NGN R1: 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 Layered Nature of NP & QoS: 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) Bearer Service NP Classes: 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” ITU-T and 3GPP QoS Classes (1): 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) ITU-T and 3GPP QoS Classes (2): 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 QoS Summary: 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. Gq interface ssues: Gq interface ssues 6. 6 Resource allocation and Policy control Leonardo Finizola e Silva (Alcatel) [email protected] Jörg Ottensmeyer (Siemens) [email protected] (6.6) Using Gq in TISPAN: (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 (6.6) Gq Extensions: (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 SIP Profile issues: SIP Profile issues 6.10 Potential impacts on SIP profile Sébastien Garcin (France Telecom) TISPAN SIP Work Item Rapporteur [email protected] Ray Forbes (Marconi) TISPAN WG3 (Protocols) Chairman [email protected] Slide36: 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 Inherent differences between NGN IMS and 3GPP IMS Potential impacts on 3GPP TS 24.229: 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 party’s S-CSCF) Slide38: 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? Potential impacts on 3GPP TS 24.229 Other NGN-IMS issues ?: 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 ? Summary NGN-IMS requirements and issues: 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 !