2008 KNOM Conference IMS (IP Multimedia Subsystem)/ SDP (Service Delivery Platform) 네트워크 / 응용서비스구조및적용 한국기술교육대학교 (KUT) 이재오
Contents Related Standards Bodies IMS (IP Multimedia Subsystem) Network Architecture SDP (Service Delivery Platform) IMS Prototype Summary 2
Related Standards Bodies 3
Standards Bodies Standards Body Description SDP-related Standards Open Mobile Alliance 3GPP (3 rd Generation Partnership Project) Formed in June 2002 by almost 200 companies to develop a service-enabler architecture and interfaces Set up in 1998 to produce technical specifications relating to the evolution of GSM networks to 3G Location, presence, notification, messaging, address list management, presentation, synchronization, browsing, user profiling, device management, authentication, policy, payment, charging, digital-rights management Presence, messaging, presentation, user profiling, streaming, authentication, policy management, charging, IMS specification Open Geospatial Consortium The Parlay Group Internet Engineering Task Force Founded in 1994 to create open and extensible software APIs for geographic information systems (GIS) and other location-based technologies Formed in 1998 to crate open, network-agnostic APIs for thirdparty services; works closely with 3GPP and ETSI Concerned with the evolution of Internet architecture and smooth operation of the Internet Location Location, presence, address list management, delivery, policy management Presence, notification, messaging, address list management, user profiling, delivery, streaming, authentication, digital-rights management 4
Standards Bodies Standards Body Worldwide Web Consortium (W3C) Java Community Process (JCP) Description Creation of Interoperable technologies (guidelines, software, and tools) to realize the full potential of the Web Set up in 1998 as the process to develop and revise Java technology specifications and evolve the Java platform SDP-related Standards Presentation, user profiling, digital-rights management Java, delivery, device management OSGi Alliance Service-Oriented Architecture/Web Services Liberty Alliance Founded in March 1999 to develop specifications for the management ad delivery of software components to networked devices An Industry-standard architectural approach to building services using web services, a standardized way to build and integrate services that run over IP-based networks Set up in 2001 to establish an open standard for federated network identity and identitybased Web services Device management UDDI, WSDL, XML Federated identity management 5
IMS (IP Multimedia Subsystem) Network Architecture 6
IMS Requirements The IMS aims to: Combine the latest trends in technology Make the mobile Internet paradigm come true Create a common platform to develop diverse multimedia services Create a mechanism to boost margins due to extra usage of mobile PS networks IMS framework requirements Support for establishing IP Multimedia Sessions The need to support the main service (audio, video communication) to be delivered by the IMS Support for a mechanism to negotiate QoS The QoS for a particular session is determined by a number of factors, such as the maximum bandwidth that can be allocated to the user based on the user s subscription or the current state of the network Support for interworking with the Internet and circuit-switched networks Internet interworks with CS networks, such as the PSTN, or existing cellular networks. Support for roaming Support for strong control imposed by the operator with respect to the services delivered to the end-user General policies applicable to all the users in the network Individual policies that apply to a particular user Support for rapid service creation without requiring standardization The IMS reduces development delay by standardizing service capabilities instead of services Access independence of the IMS: The release 6 version of 3GPP TS 22.228 added a new requirement to support access from networks other than GPRS 7
3GPP IMS Functional Architecture 8
IMS Protocol Session Control Protocol Bear Independent Call Control (BICC) H.323 SIP (Session Initiation Protocol, RFC 3216): Not differentiate the UNI from a NNI Text-based protocol: easier to extend, debug, and use to build services Transaction and Dialog AAA Protocol Diameter (whose base protocol is specified in RFC 3588) An evolution of RADIUS Other Protocols COPS (Common Open Policy Service, RFC 2748) H.248 and it packages: used by signaling nodes to control nodes in the media plane (e.g., a media gateway controller controlling a media gateway), MEGACO (Media Gateway Control) XCAP Media Plane RTP: RFC 3550 RTCP: RFC 3550 9
Overview of IMS Architecture IMS architecture is a collection of functions linked by standardized interfaces. IP Multimedia Core Network Subsystem One or more user database, called HSSs (Home Subscriber Servers) and SLFs (Subscriber Location Functions) One or more SIP servers, collectively known as CSCFs (Call/Session Control Functions) One or more ASs (Application Server) One or more MRFs (Media Resource Functions), each one further divided into MRFC (Media Resource Function Controllers) and MRFP (Media Resource Function Processors) One or more BGCFs (Break Gateway Control Functions) One or more PSTN gateways, each one decomposed into an SGW (Signaling Gateway ), an MGCF (Media Gateway Control Function), and an MGW (Media Gateway) 10
UE (User Equipment) Contains the SIP user agent Establishes a GPRS PDP Context (e.g., UMTS Network) for Signaling (either dedicated or a general one) Media transport UICC (Universal Integrated Circuit Card) Logical application : SIM (Subscriber Identity Module), USIM (Universal SIM), and ISIM ((IP multimedia Services Identity Module) Contains for authentication Private User Id and Public User Ids User Network address Security algorithms and keys At least a USIM Correlates between session control and QoS (Quality Of Service) reservation 11
P-CSCF (Proxy Call Session Control Function First contact point for the UE (outbound proxy) Forward registration to I-CSCF Forward requests to the S-CSCF (with the lowest load) Forward replies and incoming requests to UE Maintain security association with UE Responsible for compression/decompression Maintain session and registration information Can terminate registrations or session if deemed necessary Correlation between SIP and QoS Enforce local policies Generate CDR (Charging or Call Data Record) Possible support routing to local service infrastructure Emergency call handling Discovered through DHCP or during GPRS PDP establishment State-full Proxy 12
I-CSCF (Interrogating Call Session Control Function) Contact point within an operator Discovered through DNS Assign S-CSCF to a user by contacting the HSS May act as a THIG (Topology Hiding Inter-Network Gateway) Always on the path (Record-Route and Service-Route) of any message leaving the network Encrypt all entries added by the hiding network in outgoing messages Starting with release 7, this functionality has moved to the IBCF (Interconnect Border Control Function) Generate CDR State-less and State-full proxy 13
S-CSCF (Serving Call Session Control Function) Acts as a registrar Acts as a SIP Proxy (forward messages,...) Allocated to a user during registration Always on the path of the user s SIP messages (Record-Route and Service-Route) Enforces service policies based o the user s subscription profile Collects session information for billing Interacts session information for billing Interacts with application service platform (e.g. SDP) Choose the appropriate AS based on user profile (IFC (Initial Filter Criteria)) Forward to AS using ISC interface Acts as user agent when required (Notifications about deregistrations and re-authentication, call termination) State-full proxy 14
HSS (Home Subscription Server) Functions. To locate an already allocated S-CSCF to the user To download the authentication vectors of the user To authorize the user to roam in a visited network To record in the HSS the address of the S-CSCF allocated to the user To inform the HSS about the registration state of user s identity. To download from the HSS the user profile To push the user profile from the HSS to the S-CSCF To provide the I-CSCF with the necessary information to select an S-CSCF User Profile Private User Identity + Service Profiles Service Profile Public Identifications (1 to n) Barring Identification Flag SIP URI TEL URI Core Network Service Authorization ( 0 to 1) Initial Filter Criteria (0 to n) Shared Initial Filter Criteria (0 to n) 15
MRF (Media Resource Function) A source of media in the home network Play announcements, mix media stream (e.g., in centralized conference bridge), transcode between different codecs, obtain statistics, and do any sort of media analysis Further divided into MRFC (Media Resource Function Controller): signaling plane MRFP (Media Resource Function Processor): media plane Acts as a SIP UA and contains a SIP interface towards the S-CSCF The MRFC controls the resources in the MRFP via an H.248 interface. MRFP: all the media-related functions, such as playing and mixing media Location Home network 16
IBCF (Interconnect Border Control Function) Optional component. If used then replaces the I-CSCF as the entry point to the network Support Topology hiding IMS ALG: Translation between IPv4 and IPv6 Packet screening Is source/destination address OK Is SIP content OK CDR generation Usually built as a B2BUA 17
BGCF (Breakout Gateway Control Function) Routing functionality based on telephone numbers IMS terminal, addressed to a user in a circuit-switched network, such as PSTN or the PLMN The main functionality To select an appropriate network where inter-working with the circuit-switched domain is to occur Or, to select an appropriate PSTN/CS gateway, if inter-working is to occur in the same network where the BGCF is located. 18
PSTN/CS Gateway SGW (Signaling Gateway) Lower Layer protocol conversion Replacing the lower MTP transport with SCTP over IP MGCF (Media Gateway Control Function) The central node of the PSTN/CS gateway Translates SIP messages in appropriate PSTN signals and vice versa MGW (Media Gateway) Interfaces the media plane of the PSTN or CS network Perform transcoding, if necessary 19
3GPP2 IMS Functional Architecture 20
SDP (Service Delivery Platform) 21
OMA Definition The OMA specifies enablers, which provide standardized components to create an environment in which services may be developed and deployed. The OMA enablers, the decomposition into these components and the interactions between them comprise OSE. OSE- The primary intention: promote common architectural principles, across the whole OMA, for how OMA Enablers are specified and how they interact with one another whilst ensuring architecture integrity, scalability and interoperability all of which strive to reduce Architecture silo design and hence reduce integration and deployment complexities 22
OMA- OSE (Open Service Environment) Applications OSE Context I0+P SP Domain Execution Environment (Life Cycle Mgmt, Load balancing, Caching, O&M, Etc.) I1 I0 WAP Serv. Bind. Enabler implementation Policy Enforcer Other bindings.. Enabler implementation Enabler implementation Enabler implementation Execution Environment (Life Cycle Mgmt, Load balancing, Caching, O&M, Etc.) I2 ISC Sh Ut Ro Rf Gm Mb Non- IMS 23
Parlay- OSA APIs The OSA specifications define an architecture that enables service application developers to make use of network functionality through an open standardized interface, i.e., the OSA API. The network functionality is described as Service Capability Features or Services. The OSA Framework is a general component in support of Services (Service Capabilities) and Application The purpose of the OSA API is to shield the complexity of the network, its protocol and specific implementation from the applications. Documents UML: specify the interfaces classes IDL and WSDL: specify the interfaces Java API specification: for the reference 24
Parlay- OSA Interfaces Enterprise Operator Admin tool Not in scope Client Application Framework operator admin 4 1 2 Parlay- OSA APIs 3 5 6 Service supplier admin tool Telecom Network 25
SDP 특징 주요목적 IMS 와같은서비스인비결정적인 (non-deterministic) 서비스들을준비 (provisioning) 원격동적서비스구성 서비스들을관리할수있는동적인동작들 (Load, Unload, Start, Stop 동작 ) 응용환경의자원공유및접근제한 네트워크자원할당 / 정보 : QoS 관리및 AAA 서버 역할 상이한컨텐츠제공자와의수많은관계를관리 컨텐츠제공자가개발할서비스를전개할수있는네트워크능력을일관되고표준화된방법으로제공 서비스개발자로하여금다양한디바이스형태의복잡성을감춤으로개발을용이하게제공 컨텐츠제공자로하여금안정된과금사용정보를제공받을수있는환경제공 효과 네트워크를사용하려고하는다양한 Third-Party 와의공존을통한신규인터넷서비스창출 Third-Party 컨텐츠제공자가원하는다양한단말사용자서비스를위한서비스의 create/capture/provision/deliver/control 의수행환경제공 26
SDP Interface No consensus to date on what architectural elements constitute an SDP Some vendors use the term SDP for their application servers or content delivery solutions, whereas other vendors and service providers tend to include a whole portfolio of products and components such as CRM systems or rating engines in their SDP offering. In general, an SDP should be seen as a commercial bundle of different products, possibly offered by different vendors. Some comment elements of SDPs are :- Service Execution Platform (e.g. Application Server) - a core element of an SDP providing the deployment and execution environment for broad range of voice and data applications. Network Abstraction Layer (e.g. Parlay GW ) - a core element of an SDP providing standardized interfaces to core network elements and services. Service Exposure Layer (e.g. Parlay X GW) - an optional element exposing service capabilities (usually via Web Services) to 3rd party service providers and enterprises. Content Delivery Platform - an optional element usually present in mobile SDPs for the provisioning of multimedia content to mobile devices. Service Delivery Platforms SDP Web Services Service Exposure Layer Service Execution Platform Content Delivery Platform Network Abstraction Layer Network Elements 27
Alcatel OSDE Framework Open Service Delivery Environment End-User CPE IMS Client TV Client Streaming Client Video Player Mail Client GUP/ HSS Softswitch Network Services SIP,ISC,LDAP, Diameter,HTTP INAP,CAP, Parlay-X Services Enablers Presence GLMS Rating Server SIP,LDAP Diameter,HTTP/SOAP End-User Services Mobile Video SDP IPTV SDP IMS SDP IN SDP HTTP,Others SOAP/WSDL WS Parlay-X WS Services Orchestration HTTP,Others SOAP/WSDL,WS Any Application, Any Content MMS Client OSS/BSS Integration HTTPS,SOAP/XML Self-Mgt SNMP,FTP,SOAP/XML OSS Ad-hoc,SOAP/XML BSS Customer Self-mgt Provisioning/Activation Service Fulfillment Inventory, Alarm handling, QoS, Performance, Traffic Service Assurance CDR handling Billing 28
Service Enablers and Application Services Application Service Common Service Enabling Platform Network Transport Switching OMA Service Environment OSA Financial, Banking, Weather, Maps and Directions, MP3Music, Streaming Video, Information Services, Location Services, M-Commerce Conferencing Services, VPN, MMS, Messaging, Push to Talk/VoIP SMS-C, Rating, Location Info, Preferences, Presence, QoS, SIP App Server, Policy Server, HLR/HSS. AAA, MMS, GLMS, Content Servers Node B, RNC, SGSN/GGSN, MSC, BSC, CSCF, BS 29
Service Components Service Creation & Execution Environment (JAIN SLEE WEB AS) Portal, system mgmt, etc 3 rd Party Parlay-X(WS) Third Party Call, Call Notification, Short Messaging, Multimedia Messaging, Payment, Accounting Management, Terminal Status, Terminal Location, Call Handling, Audio Call, Multimedia Conference, Address List management, Presence) XCAP&HTTP SIP RTP CDN, Games, Music&Videos, News, Mobile Commerce and Charging, Mobile Web Services, PoC SDP Service Composition & Orchestration: SOA, BPEL-compliant ESB - SDPs: Mobile Data/Video, IMS, IPTV, IN Service Enablers: Parlay API(UML, IDL/WSDL, Java RMI) call controller, user interaction, content management, device management, policy control, authentication, accounting, identity management, address list management, notification, policy, payment, charging, DRM, subscriber/profile management, location, presence/availability, messaging, streaming, etc Multi services execution environment: J2EE/.NET, SIP Servlet, SLEE, Web Service Network Integration Using Resource Adapters/ Event Broker (SIP, Diameter, MGCP, INAP, MAP, CAP, etc.) MRFC MRFP SIP RTP SIP SIP CSCF Diameter Diameter CCF/OCF HSS SIP Diameter H.248 MGW MGCF IMS Core Network ISUP OSS/BSS Access & Core Transport Networks IP Access Network RTP,HTTP Internet PSTN 30
IMS/SDP/Third-Party SDP: service centric Parlay X: Through SDP IMS: network centric Parlay: Directly interfaced to IMS Service Layer to IMS and Transport Network Layer: XCAP, SIP, RTP, Diameter New API: Third Party and Application Developer SDP: OMA, Parlay 를기초로중첩및부가기능 31
IMS Prototype 32
Reference-JAIN Technology: IMS architecture and the applicability of the SIP specifications 33
SIP Message Routing REGISTER/ OK REGISTER SDP AS SUBSCRIBE/OK SUBSCRIBE NOTIFY/OK NOTIFY INVITE/ RING/ OK-INVITE/ ACK P-CSCF S-CSCF SUBSCRIBE/OK SUBSCRIBE NOTIFY/OK NOTIFY I-CSCF REGISTER/ OK REGISTER P-CSCF S-CSCF S-CSCF P-CSCF I-CSCF I-CSCF SDP AS SDP AS 34
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Summary SDP (Service Delivery Platform) 통합적 / 효율적으로운영 OMA 를기반의 SDP 는서비스의생성, 전개, 전달, 관리에집중 IMS 는표준화된제어기반구조를제공. 기존서비스의재사용 Third-Party 서비스의융합 OSA Parlay 와 Parlay X OSA 인터페이스와주요응용서비스모델 39