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A Scalable SIP-based Architecture to Offer Value-added Services in a Converged IN/IP Environment. F.S.Salloum, Tasos Dagiuklas, Maria Skoura 16 January 2003 International SIP 2003. Outline. The Problem Existing IN Service Architectures SSP, SCP Limitations from existing IN architecture
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A Scalable SIP-based Architecture to Offer Value-added Services in a Converged IN/IP Environment F.S.Salloum, Tasos Dagiuklas, Maria Skoura 16 January 2003 International SIP 2003
Outline • The Problem • Existing IN Service Architectures • SSP, SCP • Limitations from existing IN architecture • Convergence between IP & PSTN • Services in a converged environment • GEMINI proposed Architecture • Multiple zones,IP-SSP,IP-SCP,E-SCP • Examples • Conclusions
The Problem • To offer in a converged environment existing and next generation customized personalized services that meet the demands of multiparty multi-connection and multimedia calls.
Existing IN Service Architecture (2) • Service Switch Point (SSP) • Physical embodiment of the Service Switching Function (SSF) • Connects through INAP with the Service Control Function (SCF) which is embodiment on the Service Control Point (SCP) • Includes an instance of a special Basic Call Process Service Independent Building Block (BCP-SIB)
Existing IN Service Architecture (3) • Service Control Points (SCP) • Physical embodiment of the Service Control Function (SCF) which controls the execution of services. • SCF contains the Service Logic Execution Environment (SLEE) • The incoming SIBs are executed in the form of Service Logic Programs (SLPs).
Existing IN Service Architecture (4) • Service Creation Environment (SCE) • Physical embodiment of the Service Creation Environment Function (SCEF) • The SCEF is actually an offline function for the creation of service logic from the SIBs • Service Management Platform (SMP) • Physical embodiment of the Service Management Function (SMF) and of the Service Management Access Function (SMAF)
The SCP Using the Service key executes the Associated SLP 5 INAP initial-DP INAP ETC or CON 6 4 ISUP 0800XX 3 Interruption Of the basic Call routing Software (BCSM) 2 1 0800 IN Service Example Flow
VoIP Value-Added Services Roadmap Service Driven Networks(PSTN, SS7) Hybrid networks CTI Data networks NGN networks VoP networks Access Networks (wireless, Cable) Now Migration Path
Limitations from existing IN • The service logic is based on specific manufacturer’s SLEEs • Not always write once run everywhere • Variations of IN call models • IN cannot be supported fully with existing IP infrastructure only partially through ISUP signalling • Problem to integrate with 3G and future mobile IP users • Primitive User Interfaces • Limited capabilities regarding multimedia support.
Convergence between IP & PSTN • Technical Drivers • IP has been adopted as a unified transport in the corporate, enterprise, access and core networks • Use of Open APIs to rapidly deploy and customise personalised services • Regulatory Drivers • Deregulation of the telecommunication market • New entranets (i.e. greenfield operators, service providers) • Business Drivers • New Players in the Value Chain • New Business Model
Services in a converged environment • PSTN user access to IP services • IP user access to PSTN services (Call waiting,3rd party conference, voting) • Presence and redirecting services • Multiple Call Handling • Click to services (dial,fax etc)
GEMINI proposed architecture PSTN IP
Multiple Zones (1) • Under each IP-SSP responsibility there is a certain number of hierarchical SIP servers, within a zone. • Service requests are forwarded at the SIP server residing at the top of this hierarchy • Two service categories • 800@domain.com for accessing IN/PSTN services • in_ip@domain.com for accessing SIP-based services
Multiple Zones (2) • Each zone has direct connection with the SS7 world
Multiple Zones (3) • Alternatively, there is one IP-SSP that communicates directly with the Signaling Gateway
IP-SSP System Overview IP-SSP in GEMINI architecture is a decomposed architecture consisting of existing of the self equipment (MG,SG,SCG) and glue modules (Soft switch with H.323toSIP and conference bridge). 1.SCG (Service Control Gateway) Transports INAP 2.SG (Signaling Gateway) Transports ISUP/Q931 3.MG (Media Gateway) PCMRTP 4.Softswitch (MGC) MEGACO SIP 5.Conference bridge Low class (3rd Party) 6.H.323 to SIP For supporting existing H.323 infrastructure
IP-SSP Functionalities • Service Control Gateway • Handles the transportation of INAP messages from the SS7 world to the IP world (using SIGTRAN) and vice versa • Media Gateway • Handles the transcoding between PCM and RTP • Signalling Gateway • Handles the trasnportation of ISUP messages from the SS7 world to the IP world (using SIGTRAN) and vice versa • Softswitch • Contains the equivalent SSF and BCP-SIB logic of the SSP in the PSTN world • MEGACO for controlling the MG and SG • SIP for connection to the SIP network • ISUP to SIP and INAP to SIP handlers • Conference Bridge • Low class for supporting 3rd party conference calls. • SIP to H.323 translation • For connecting with an existing H.323 network either with an H.323 GK or directly. Fast start is preferred to be used for minimizing call setup.
IP-SCP Overview • Provides an application execution environment to the services • By using Java and standard Service Creation APIs we support “write once run everywhere” concept • The Service Creation Environment can be IP-everywhere.
E-SCP Functionalities • Extension of a current SCP supporting capability set 4 (CS4) enabling multimedia and multiparty support • Forwards INAP SS7 messages to the IP world according to SIGTRAN using SCTP • Provisioning of IN service logic and the IP/IN extension services • Provisioning of IN service-customization capabilities for the IP domain.
Hybrid Call Forwarding • MSC for the Hybrid Call Forwarding in GEMINI architecture
Conclusions • Converged Architecture to support existing IN and next generation services in a converged SS7/PSTN and IP environment • This convergence has been addressed using SIP technology
http://gemini.otenet.gr http://www.intracom.gr/ http://www.otenet.gr/ http://www.telekom.at/ http://www.com.dtu.dk/ http://www.alcatel.de/ http://www.solinet.com/ Acknowledgments IST-2001-33465 Project GEneric Architecture for custoMised IP-based IN services over hybrid Voice over IP and SS7