Title: A Scalable SIP-based Architecture to Offer Value-added Services in a Converged IN/IP Environment
1A 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
2Outline
- 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
3The 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.
4Existing IN Service Architecture (1)
5Existing 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)
6Existing 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).
7Existing 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)
80800 IN Service Example Flow
9VoIP 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
10Limitations from existing IN
- The service logic is based on specific
manufacturers 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.
11Convergence 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
12Services 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)
13GEMINI proposed architecture
PSTN
IP
14Multiple 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_at_domain.com for accessing IN/PSTN services
- in_ip_at_domain.com for accessing SIP-based services
15Multiple Zones (2)
- Each zone has direct connection with the SS7
world
16Multiple Zones (3)
- Alternatively, there is one IP-SSP that
communicates directly with the Signaling Gateway
17IP-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) PCM??RTP
4.Softswitch (MGC) MEGACO ??SIP
5.Conference bridge Low class (3rd Party)
6.H.323 to SIP For supporting existing H.323
infrastructure
18IP-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.
19IP-SSP Protocol Stack
20IP-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.
21IP SCP Architecture
22E-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.
23Hybrid Call Forwarding (1)
24Hybrid Call Forwarding
- MSC for the Hybrid
- Call Forwarding in
- GEMINI architecture
25Hybrid Conference Call
26Conclusions
- 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
27Acknowledgments
IST-2001-33465 Project GEneric Architecture for
custoMised IP-based IN services over hybrid
Voice over IP and SS7