Transcript Document
IMS Workshop Summary James Rafferty August 10. 2006
Agenda
• Recap – Goals of IMS – Key Elements of Architecture – Applications – Relevance for the Enterprise – Best Practices • Resources • Your Takeaways • Q & A
What is IMS…
• IP Multimedia Subsystem (IMS) is an architecture that enables wireline, wireless and cable operators to offer a new generation of rich multimedia services – Across both circuit switched and packet switched networking infrastructures • IMS defines a architecture of logical elements using SIP for call signaling between network elements – Provides a layered approach with defined service, control, and transport planes
Mb Mb
The IMS Architecture
IP Multimedia Networks Legacy mobile signalling Networks CS Network
Mm Mb CS CS BGCF Mj IM MGW Mc MGCF Mk BGCF Mg Mk I-CSCF Mw Mm ISC Cx AS Mi Sh C, D, Gc, Gr Cx HSS S-CSCF Dx SLF Mb Mr Mw Dx P-CSCF MRFP Mb Mp Mb MRFC Gm UE IMS Subsystem Ut 3GPP TS 23.228 V7.2.0 (2005-12)
IMS – Simplified View
Application Server Application Server SCIM Application Server MRFC MRFP MRF
SIP
S-CSCF I-CSCF P-CSCF CSCF
RTP
BGCF MGCF MGW HSS/HLR Key Elements:
AS – Application Server
SCIM - Service Capability Interaction Manager
MRFC - Multimedia Resource Function Controller
MRFP - Multimedia Resource Function Processor
MRF – Media Resource Function
CSCF- Call Session Control Function
BGCF - Breakout Gateway Control Function
MGCF - Media Gateway Control Function
MGW - Media Gateway
HSS - Home Subscription Server
HLR - Home Location Register
Other Key IMS Concepts
• Multiple Plane Architecture – Makes use of separate planes: • Application, Transport and Session Control • Common Security and Login functions – Makes use of Diameter protocol and HSS (Home Subscriber Server) to validate users • Applications and Services are independent of Access Method – Enables support for 3G mobile, WiFi, DSL, etc.
IMS Benefits
• • • •
Converged Applications Across Networks Reduced development costs and time Voice, Video and data services Write once / use many Shared Resources
• • • •
Media server resources Common user data Single user profile across applications Integrated applications
• • •
Session Control Common Session Control (SIP) Provides common service policies Leverages investments across multiple applications
• • •
Access Network Agnostic Eliminates multiple service solutions Network transparency Consistent services across networks DSL Applications Video Data Voice Control SIP Transport Hosted Services Win Media MP3 Web Content Text CMTS Access Mobile PSTN
Why IMS?
• Need a better environment for creating and deploying high value multimedia services • Transform business models from voice-driven to service-driven businesses • Fixed-Mobile Convergence on a common IP application and service delivery architecture • Grow and protect subscriber base, increase ARPU (Average Revenue Per User) • Deliver a differentiated portfolio of value-added services • Provide more subscriber focused offerings • Controlling CAPEX and OPEX • Maturity and adoption of SIP and XML • Web model development model shortens the required investment of a programmer to develop new applications • Enables best-of-breed solutions with focus on new IP application services • Faster time to market with new services • Develop on standards-based technology • Reduce time to market for new applications with web development model
IMS Applications
3G Unified Messaging Pre-Paid IMG 2.5G
IP MSC IMG PSTN MGW Cable CMTS Announcements Video Mail Video Conferencing Sponsored Calling
SIP
Voice Mail
SIP
Conferencing
SIP MSCML
Video Ringback
SIP VoiceXML
Gaming
SIP
IP Phones S-CSCF / SCIM
RTP SIP Routing Cloud SIP SIP w/ VoiceXML SIP w/ MSCML HTTP
MRF
FTP NFS
Win Media mp3 Web Content Text MPEG-4 (MRFC/MRFP) Network Storage
Other Likely IMS Applications
• FMC – Fixed Mobile Convergence • IP Centrex Hosting for Businesses • Audio and Video combined with other services – For example, conferencing, push-to-communicate, Multimedia over Broadband, Multimedia IM • Legacy Migration – Voice mail, conferencing, SMS, Prepaid Services
IMS and the Enterprise How will IMS affect the Enterprise?
1. IMS will be the preferred hosted services environment for carriers 2.
Enterprises can borrow “best practices” from IMS for its own services 3. Service orientation of IMS echoes and complements Enterprise driven approaches such as SOA (Service Oriented Architecture)
IMS Best Practices
• IMS includes “lessons learned” from many predecessor architectures • Best Practices include: – Separation of signaling from media – Separation of Applications from underlying sessions and transport – Services provided are independent of underlying transport – Common mechanisms for authenticating users and securing sessions • Review Call Center Example
Local Campus (Traditional)
Agents on IP Phones
Enterprise LAN
Call Center Server w/ Voip Gateway
H.323
RTP T1/E1 ISDN/CAS PSTN
Customer Agent on Soft Phone • All Agents in single location • Uses all-in-one system to handle all calls • Signaling and Media combined in one system Customer
Application of IMS Best Practices Contact Center Example
• Separate the application server apart from the Media • Use a separate Media Resource Function – Single MRF can support multiple applications • Use XML + markup languages for fast development and flexible, mid-call agent interactions • Use SIP as the protocol which ties the pieces together
Case Study: Distributed Contact Center
Remote Agent Application Server Agents on IP Phones Customer Media GW
Enterprise LAN Signaling Gateway Internet RTP
SIP/
RTP
VoiceXML MSCML MRF
PSTN
Agent on Soft Phone Web Customer Email Customer Customer • Improved Scalability: Separate Application from Media • Ability to add new media such as video as needs evolve • Fast development using SIP + XML
Resources • IMS Forum – www.imsforum.org
• 3GPP –
www.3GPP.org
• Internet Engineering Task Force –
www.ietf.org
• ETSI TISPAN -
http://portal.etsi.org/portal_common/home.asp?tbkey1=TISPAN