1. Web Services Architecture Presentation for ECE8813 Spring 2003 By: Mohamed Mansour

2. What is a Web Service Any piece of software that makes itself available over the Internet and uses a standardized XML messaging system

4. Roles Service Provider Service Requestor Discovery Agencies

6. Wire Protocol Transport  HTTP (or other Internet protocols) Packaging  SOAP (or other packaging protocols) Extensions  Context, routing, policy

9. SOAP Example <SOAP:Envelope xmlns:SOAP=http://schames.xmlsoap.org/soap/envelope/http://schames.xmlsoap.org/soap/envelope/

10. End-to-End Scenario Requestor SOAP run-time SOAP message Network Layer HTTP Request Server (Provider) SOAP run-time Network Layer Deliver HTTP Dispatch to appropriate runtime

12. Description Stack Interface, Implementation  Described in a WSDL (Web Service Description Language) document  Minimum layers for any web service

13. Stack Components

14. WSDL Example

15. WSDL Example – contd.

16. WSDL Example – contd.

17. WSDL Example – contd.

18. Description Stack – contd. Policy  additional description to specify the business context, qualities of service, security requirements and offerings, and management requirements. Presentation  how to render the input and output messages on a screen for a user to interact with. This is particularly useful for rendering Web services to users on many different types of devices. Orchestration  An orchestration description reflects a simple choreography of Web service invocations between two business partners to complete a multi-step business interaction. Composition Service Level Agreements Business Level Agreements

20. Discovery Stack Publication  Providers produce their service descriptions in a UDDI document.  Direct publish (ftp, CD-ROM, …)  UDDI registry Discovery  Discovery methods parallel publication methods Inspection  Web Service Inspection Language (WSIL)  a de-centralized, light weight method

21. Resources http://www.w3.org/TR/2002/ http://www.xmethods.com http://www.alphaworks.ibm.com/webservices http://www.microsoft.com/webservices http://java.sun.com/webservices http://www.borland.com/webservices