1. Service-Orientation Architecture (SOA) ChangSup Keum MSE Student, School of Engineering, ICU cskeum@icu.ac.kr "Things should be made as simple as possible, but no simpler." -- Albert Einstein

2. Agenda Service-Oriented Architecture Web Services Web Services in Telecommunications Conclusion

3. What is a Service? Some functional block Implications Always assume remote use Always assume cross-platform use Ignore service's inner implementation

4. Service-Orientation PrincipleMeaning Boundaries are explicitDevelopers opt-in to exposing service- based functionality Services are autonomousIndependent deployment, versioning, and security Share schema and contract, not class or object Integration based-on message formats and exchange patterns, not classes

5. What if there exist … Technology and frameworks that allow applications to speak to each other … thru the Internet infrastructure … Just imagine an even better world Smooth heterogeneous integration Business process automation and workflow Dynamic construction of business forms Software as a service

6. How does this happen? Change architectural viewpoint Application-oriented architecture Service-oriented architecture (SOA)

7. Application-Oriented Architecture Each application has proprietary structure Need to recreate for each application No smooth interaction with other applications Applications are tightly- coupled with inflexible decisions Application User interface Executable program Scheduled Execution Business logic Procedures Data Access Data SQL Database XML Flat File

8. Mismatch Application-oriented architecture is for distributed systems that trust each other On the Internet, systems are independent, not trusted, and even autonomous Autonomy implies states, asynchrony, different languages and data formats, etc. What we need is an architecture for loosely-coupled systems Service-Oriented Architecture Solution for the tension between autonomy and interoperability

9. Towards a Service-Oriented Architecture Decouple user experience from business logic Provide a common standard allowing user experience to be delivered in any language or to any platform Application User interface Executable program Scheduled Execution Business logic Procedures Data Access Data SQL Database XML Flat File Service Messaging Interface description Publish and Find Data Access Data SQL Database XML Flat File Common Standard Business Logic Autonomous Systems Standards conforming

10. Web services A recent, practical implementation of so-called Service-Oriented Architecture Successor of CORBA for Internet and XML age Key ingredients of Web services Business logic and data aggregated as a unit Exposed as programmatic interfaces Delivered over ubiquitous internet infrastructure Using standards that are available to all parties Killer application of XML technology O riginally they were called XML Web services, or XWS for short

11. Web services Runtime Client Corp. application Desktop application Wireless device Web portal etc. Web services Server WSDL SOAP Proxy SOAP Runtime Server SOAP runtime server Code generated by WS tools SOAP Message Processor Web service Applications that implement the service WS Container SOAP and WSDL processing Application code DB Legacy

12. SOAP Syntax

13. SOAP is not enough… How to know what SOAP request body and response document have methods, parameter names, data types Data types, error codes and messages We thus need a L anguage... … for D escribing … … S ervices … Delivered over the W eb WSDL[wizdl] is an IDL for Web services

14. WSDL Syntax

15. One More Piece Pieces we ve seen so far XML provides open data description SOAP uses XML for cross-platform data transfer WSDL describes SOAP services But how do we describe our services so others can discover them? Universal Description, Discovery, and Integration (UDDI) Describe services so others can discover Speed eager adoption and interoperability

16. Web services Examples http://www.gotdotnet.com/userarea http://www.xmethods.com http://www.webservicex.net http://www.webserviceoftheday.com http://www.salcentral.com http://www.brinkster.com

17. Web Service in Telecommunications Web Service Web Service Web Services Open Service Open Service Architecture Open Service Architecture Parlay (X) Web Service IT Community Telecommunications Community

18. Web Services in Telecommunications Standardization Parlay Group Parlay/OSA Web Services : Parlay mapping of the Parlay APIs into WSDL For vendors who want to use Web Services technology (and tools) as an alternative to CORBA/IDL The first version of the Parlay X Web Services was released in May 2003 by The Parlay Group. They are intended to stimulate the development of new telecom applications by providing a standardized set of Web Services, which can be used by IT developers without telecom experience. ETSI, 3GPP, OMA, PayCircle, Microsoft and Vodafone

19. Service Requester Service Provider Service Broker Parlay Web Service Architecture OSA/Parlay Application Servers Parlay X Application Servers SCF Framework SCF Parlay Web service Gateway / Parlay X Gateway Bind Publish Find

20. Parlay X Web Services 1.Third Party Call 2.Network-Initiated Third Party Call 3.SMS 4.Multimedia Messaging 5.Payment 6.Account Management 7.User Status 8.Terminal Location

21. Conclusion Service-orientation is an evolutionary thing No radically new thinking Consolidates good things Message is the key message! Think the message instead of call or invocation XML is better than binary Asynchronous is good Get prepared for a service-oriented world

22. References http://webservices.xml.com/pub/a/ws/2003/09/30/soa.html W3C Web Services page: http://www.w3.org/2002/ws/http://www.w3.org/2002/ws/ Web Services Architecture: http://www.w3.org/TR/ws-arch/http://www.w3.org/TR/ws-arch/ Web Services Description Language (WSDL): http://www.w3.org/TR/wsdl20/ http://www.w3.org/TR/wsdl20/ SOAP Primer: http://www.w3.org/TR/soap12-part0/http://www.w3.org/TR/soap12-part0/ UDDI Technical White Paper: http://www.uddi.org/pubs/Iru_UDDI_Technical_White_Paper.pdf http://www.uddi.org/pubs/Iru_UDDI_Technical_White_Paper.pdf Web Services Listings: http://www.xmethods.net/http://www.xmethods.net/ Amazon.com Web Service: http://www.amazon.com/gp/browse.html/102-6115969- 6708167?%5Fencoding=UTF8&node=3435361 http://www.amazon.com/gp/browse.html/102-6115969- 6708167?%5Fencoding=UTF8&node=3435361 Google Web Service: http://www.google.com/apis/http://www.google.com/apis/