I nternational Telecom m unication Union ITU-T IMS based NGN IMS based NGN Architecture Architecture and its application and its application Dick Knight BT Group plc I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6
Outline ITU-T IP Multimedia S ubsystem o • Overview & Key Features • Use in NGN • Benefits Support for PSTN/ ISDN Replacement o • Simulation • Emulation Overall Architecture o • ITU-T S G13, ETS I TIS PAN & BT 21CN I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 2
I P Multim edia Subsystem ITU-T o S IP-based control system to enable media- agnostic service delivery in IP networks • Secure registration • Secure communications • Location independence • Separation from Service providing application • Specified by 3GPP o Control system for a flexible service delivery platform I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 3
Key Elem ents ITU-T HSS AS P-CSCF S-CSCF UE NACF & RACF Transport Network I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 4
Key Elem ents Functionality 1 ITU-T o UE – User Equipment o HS S Home S ubscriber S erver o P-CS CF • Mobility Management • Proxy Call Session • User security Control Function • First contact point • Service Provisioning & authorisation support • Forward SIP messages • Call / Session from UE to S-CSCF and establishment support vice-versa • Generation of CDRs. • GUP Data Repository • Maintain security • Identification handling association to UE • Access authorisation • Authorisation of • Application Services bearer resources S upport I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 5
Key Elem ents Functionality 2 ITU-T • Obtain Address of o S -CS CF entry point for • Serving Call Session network serving the Control Function destination user • Control for registered • Modify t he SIP request UE sessions according to HSS and • May behave as Proxy service control Server or User Agent interactions • Interaction with • Perform preference Services Platforms and capability • Provide endpoints matching with service event related information I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 6
I MS in NGN ITU-T o Performs Service Control Functions • Within the service stratum • Meets the requirements of Y.2001 o Flexible approach to services • Service delivery using Internet applications, services and protocols o Provides inherent mobility support o Already exists! o BUT – specific to IP Connectivity Access networks I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 7
I MS Adaptations in NGN ITU-T S pecific adaptations to NGN – generic access IMS UE NACF RACF Transport Network I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 8
I MS Adapted to NGN ITU-T o Control of IP Transport Networks (admission control, QoS, authentication, etc.) o Co-ordination of multiple control components to a single core transport o Interworking and interoperability with legacy and other networks o Mutual de-coupling of applications from session/ call control and transport o Access technology independence of session/ call control and applications I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 9
Architecture of I MS for NGN ITU-T Figure 1 of draft ITU-T Recommendat ion Y.IFA AS Other IP Multimedia Networks PSTN ISC Sh Mm HSS MGW BGCF CSCF (AAA+DB) PSTN Mk Cx Mw BGCF Dh Mj Mn Mi Mb Mg Mb SLF MGCF CSCF Dx MRFP Mr Mw Mb MRCF Mp P-CSCF Gq Gm Mb UE IP Connectivity Access Network I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 0
PSTN/ I SDN Replacem ent ITU-T Simulation Emulation o Interactions between o PS TN/ IS DN service AS and UE provide capabilities and “ PSTN/ ISDN-like” interfaces using services to NGN Users adaptation to an IP infrastructure o IP “ Terminals” o Legacy user equipment o Includes terminal and interfaces adapters unchanged o Network and UE based o Two approaches: services • Call Server (S oftswitch) o Example use of IMS • IMS -based I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 1
I MS-Based Em ulation ITU-T AS HSS (ISUP-aware) AGCF S-CSCF H.248 Access NACF & RACF PSTN Media ISDN G/W Transport Network UE I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 2
Advantages of I MS PES ITU-T Preserves common interface to RACS & o transport network Common service control functions o Common Routing and configuration data o between emulated PS TN/ IS DN Users and NGN Users Economy of scale o • Consider effects of reducing numbers of emulated users • Provision of advanced services I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 3
Service Control Architecture ITU-T Applications Application ANI ANI Based on Y.FRA Fig. 3 Application Support Functions & Service Support Functions Application Support Functions & Service Support Functions (may include own Authentication, Authorization and Accounting) (may include own Authentication, Authorization and Accounting) Authentication Network Sig. User User User Profile Media Res. Broker & authorisation Interworking Subscription I/C Border I-CSCF Subscription Subscription Other NGN Locator G/W Control Multimedia Service FE Breakout P-CSCF other IP MM G/W Control S-CSCF Network User Access Media G/W (e.g. IMS) Signalling I/W Gateway Media Resource Control Function Control Internet NACF RACF NGN UNI PSTN/ISDN Access Packet Core Packet Transport End-User Functions Transport Functions Function I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 4
ETSI TI SPAN Architecture ITU-T (* apart from IMS-based PSTN Emulation) Rf/Ro Ut Rf/Ro Charging Ut Application Servers Functions Sh Rf/Ro ISC Dh UPSF Iw SLF Cx IWF Dx Ib P3 IMS / PSTN Mw PSTN Mw/Mk/Mm IBCF Emulation (R2) Ic I/S-CSCF Simulation Mk Mi AGCF P2 Mk BGCF Mw Other IP Networks Mr Mj Gq' Mg e2 SGF P-CSCF MGCF MRFC Ie P1 PSTN/ISDN Gq' Gq' Network Gm SPDF Attachment SPDF Resource & Mp Mn Subsystem Admission RACS A-RACF e4 Control MG Re Ia MRFP T-MGF I-BGF UE BGF RCEF IP Transport (Access and Core) CNG I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 5
BT 2 1 CN Architecture ITU-T 3 rd Party AE Applications & Services SIP Application SIP Application Server External Servers AS AS AS OSA AS Application Call OSA AS s Application Service Assembly Servers OSA SCS SIP Stack ISC SBR Sh IMS (ENUM) Presence SCIM Cx HSS ISC Messaging plus PSTN Mw Call Server P2 AGC I-CSCF S-CSCF CAC F Other e2 BWM BCF Mw e4 IMS P- CSCF Mw SPDF Mr Mg Gm Gq’ Rq POTs A-RACF SPDF MRFC SGF MGCF C7 H248 SIP e1 Mp Re Ia Mn Media M Server PSTN S Media Border Other TDM MPLS/IP IAD Backhaul Gateway Networks Gateway A Network BRAS Border N Other IP Gateway Networks MSAN and Access Metro and Core WiMax/WLAN I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 6
I nternational Telecom m unication Union ITU-T Thank You Thank You I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6
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