1. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Introduction to Softswitch Architectures Bob Ehlers Director, Business Development Performance Technologies

2. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Definition Overview Elements of Softswitch –Media Server –Feature Server –Media Gateway Controller Summary

3. August 3-4, 2004 San Jose, CA www.voipdeveloper.com What is a Softswitch? First - Softswitch is an ambiguous term –Softswitch can refer to only the media gateway controller. This is the device that handles all of the call control. This definition does not include the media services, application services or media gateway functions. –Softswitch can also refer to the entire set of functions included in the media gateway controller, media server, application server, signaling gateway and media gateway. We’ll use the entire set of functions.

4. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Basic Definitions Media Gateway is a transition device for moving data from one network topology to another. In our definition it usually means IP to TDM and back. Can include vocoding or can treat the stream as raw. The media gateway translates between circuit-switched voice traffic and packet-based traffic. Media Gateway Controller runs the call control and application- level calling features in a server that supports easy software upgrades and expansion of features. It is also called the "call agent" and it controls the media gateway. Signaling Gateways convert and/or relay network SS7 call signaling between the circuit network and the packet backbone Media Server is a device for storing and serving streams of data to a feature server, media gateway, or media gateway controller. Feature Servers provide less frequently used but more processor intensive services such as voicemail, call center routing, advanced billing and the like, freeing the media gateway controller to focus on call control functions

5. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Basic Softswitch Elements Media Gateway Call Control Services Traditional Proprietary Single Platform (Tandem) Next Generation Modular, Open Platform (Local Exchange) Services MG IPPBXRASIAD MGCSGMSFS

6. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Media Gateway Signaling Gateway Softswitch Architecture Media Gateway Controller (Softswitch) IP Network with IP based control SS7 Network PSTN Media Server Feature/ Application Server Broadband IAD IP PBX IP Wireless Device Border Agent/ Session Controller Firewall SOFTSWITCH

7. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Architecture Choices Purpose built or general purpose Centralized or decentralized –One Platform running many processes –One Chassis with dedicated processes –Many platforms or chassis at the same location What services? What scale?

8. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Next Gen Architecture Adjuncts SIP –Proxy/Redirector –Session Border Controller –STUN, TURN, ICE –Back to Back P2P And much more….

9. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Tandem versus Local Exchange Tandem Softswitches –Have existed for several years –Switch long haul, intra and inter-lata traffic (tandem) –Can be call feature ignorant for the most part – they just route the call –Relatively simple to program and maintain Local Exchange Softswitch –Relatively new –Provide local switching AND calling features –Can be extremely complex to program and maintain (Today)

10. August 3-4, 2004 San Jose, CA www.voipdeveloper.com What must a local exchange Softswitch do?

11. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Why is a local exchange Softswitch cool? But, there is much much more to a softswitch… –Move a voice session from a hard-wired, circuit switched connection to a software serviced session and you can add value… Adjust the quality of the call…echo cancellation, jitter buffering, QoS, latency adjustment Process the call content…record it, translate it, transcribe it, store it for replay Distribute the call content…multicast, call routing Add multimedia services…video, text messaging, subtext Bill for differentiation…quality of call, content of call, priority of the call

12. August 3-4, 2004 San Jose, CA www.voipdeveloper.com New services enabled by local exchange Softswitch Distributed Multi User Gaming Virtual reality Web-pages and applets Links in e-mails Web-IVRs Click-to-dial Directory Services Video conferencing Instant Messaging Voicemail notifications Stock notifications Callback notification Calendars Pre-arranged conference calls Unified Messaging Voicemail to Email

13. August 3-4, 2004 San Jose, CA www.voipdeveloper.com What is SIP and why is it Hot? Session Initiation Protocol enables a low cost, well understood, cohesive, OPEN session establishment and control method over IP for streams of media, including voice and video. Leverages widely deployed underlying technologies such as DNS. Broadly available open source SIP protocol stack makes VoIP using SIP commonplace Lots of open source applications that use SIP Competition to embellish and support open stacks Service Providers embrace open source concept When you hear SIP think “open VoIP” – that is the implied meaning of SIP.

14. August 3-4, 2004 San Jose, CA www.voipdeveloper.com What does Open VoIP need to take off? Support!!! –There are many open source projects for everything from IP PBX to SIP Proxy/redirectors to QoS managers, to Media Servers –The applications are well written and very complete, but… –They are very complex. Complex protocols, complex configurations, complex interfaces –Need for new channels of support are clear

15. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Opportunities Abound Voice Over Broadband –Cable Operators –DSL Operators –Fixed Wireless –Power Line Operators Hosted IP PBX Enterprise PBX

16. August 3-4, 2004 San Jose, CA www.voipdeveloper.com The Elements of Local Exchange Softswitch

17. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Softswitch Hardware Building Blocks Computing Elements: Intel ® -based SBCs Intel ® -based SBCs PPC and Sparc SBCs SS7 Elements Signaling gateway blades Signaling gateway blades Rack components OS Software & Middleware: Operating systems Linux dev. environments Communications protocols Media (DSP) tools SS7/IP signaling software I/O & Communications Elements T1/E1/J1 T3 Serial access Media Processing Elements: DSP resource HW platforms Development tools Platform Elements: Packet-based chassis platforms Layer2/Layer3 Ethernet switching System management Power and cooling Network Processing Elements: PPC XScale

18. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Media Gateway Controller (What some vendors call Softswitch) Call set upCall Tear downIn call featuresCall Agent - SIP Call Agent – H.323Audit sessionsRestartMultipoint Functions of a Media Gateway Controller

19. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Media Gateway Controller Ethernet Switch ISMISM Storage Controller TDM Link to MG MGCP Translator Call Control - IPPBX Signaling Gateway

20. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Media Server AnnouncementsDTMFAudio BridgingRecording Speech Recognition Text to SpeechFaxVideo Functions of a Media Server

21. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Media Server Ethernet Switch ISMISM Storage Controller Vocoding/Encoding DTMF Detection/Control Streaming Server TDM Call Bridging

22. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Feature/Application Server QoS ManagementBilling Fault Detection/ Response Advanced Call Routing Web Client Interface Advanced Conference Features Unified Messaging Voicemail Call Center Functions of a Feature/Application Server

23. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Feature Server Ethernet Switch ISMISM Storage Controller Vocoding/Encoding – Voice Rec IVR DTMF Detection/Control Converged Messaging Video Conference Service

24. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Media Gateway Protocol TranslationPhysical Interface Voice Encode Decode Functions of a Media Gateway

25. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Media Gateway Ethernet Switch ISMISM Voice Decoding (IP Net In) Voice Encoding (PSTN In) TDM Link to PSTN TDM Link to MGC

26. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Session Border Controller (not a softswitch element per se) Protocol TranslationSecurity Billing/ Traffic Reporting Lawful Interception IP Phone Management Failover Reroute Functions of a Border Agent/Session Controller QoS PolicyNAT Traversal

27. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Session Border Controller Ethernet Switch ISMISM Turn STUN SBC CALEA/Lawful Intercept

28. August 3-4, 2004 San Jose, CA www.voipdeveloper.com OR

29. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Because it is all software, functions can be combined into one hardware platform or even one computer Ethernet Switch ISMISM Media Gateway Controller SBC/STUN/TURN Media Server CALEA/Lawful Intercept Media Gateway Feature Server Signaling Gateway

30. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Conclusion A softswitch is a platform for routing and delivering multi-media services on a packet switched network (IP) A softswitch replaces traditional circuit switching A softswitch serves as the basis for a whole new range of product offerings Softswitches have existed for over a decade, but are only now finding popular adoption thanks in large part to SIP Softswitch architectures can be centralized or distributed Softswitches are enabling competitive carriers to enter the market…VoDSL, VoCable, VoWiFi

31. August 3-4, 2004 San Jose, CA www.voipdeveloper.com Where to Learn More IEC Tutorials http://www.iec.org/online/http://www.iec.org/online/ Whitepapers http://www.pt.com/Industries/Market_Communic ations.html http://www.pt.com/Industries/Market_Communic ations.html Call us: Performance Technologies Bob Ehlers, Director of Business Development 805-783-6153bob.ehlers@pt.com