Web Services Interoperability

The Web Services Interoperability Organization (WS-I) is an industry consortium chartered to promote interoperability amongst the stack of web services specifications. WS-I does not define standards for web services; rather, it creates guidelines and tests for interoperability.

It is governed by a Board of Directors consisting of the founding members (IBM, Microsoft, BEA Systems, SAP, Oracle, Fujitsu, Hewlett-Packard, and Intel) and two elected members (currently, Sun Microsystems and webMethods).

The organization's deliverables include profiles, sample applications that demonstrate the profiles' use, and test tools to help determine profile conformance.

WS-I Profiles

According to WS-I, a profile is

A set of named web services specifications at specific revision levels, together with a set of implementation and interoperability guidelines recommending how the specifications may be used to develop interoperable web services.

* WS-I Basic Profile
* WS-I Basic Security Profile
* Simple Soap Binding Profile

WS-I Test tools

The WS-I issued a test tool suite in 2004. Two tools are included :
*A monitor designed to intercept live SOAP messages and the associated HTTP headers during a test session. This functionality is ensured through the use of the man in the middle principle.
*An analyzer designed to analyze profile conformance of a Web Service artifacts. The profile is chosen with a Test Assertion Document (*.TAD) file. The different artifacts are :
**The Web Service description file, actually a WSDL file
**The Web Service discovery artifact, actually an UDDI entry
**The messages and associated envelopes exchanged during a test session and captured with the test tools

These test tools are not designed to be used as a full certification tool. As stated in the user guide ("WS-I Testing Tools version 1.1 User Guide") bundled with the [http://www.ws-i.org/deliverables/workinggroup.aspx?wg=testingtools test tools.] , they can only be used as indicator of profile compliance:

Question: Can testing tools certify that a Web Service is conforming to the Profile?
Answer: The tools can only verify the conformance of Web Service artifacts that are produced during a testing session. Some artifacts belong to the definition of the Web Service (WSDL); some others result from the observable behavior of the Web Service at run-time. It is rather difficult to test all possible behaviors that a Web Service can exhibit, mostly because exercising these behaviors is application-dependent and requires an application-level understanding of theWeb Service. For these reasons, the Testing WS-I working group has not attempted to provide certification criteria.

The testing tools are then an indicator of conformance of a Web Serviceto the Profiles selected, based on the artifacts produced. In turn, this is an indicator ofinteroperability with other business partners who also have tested as conforming to the Profiles.

WS-I Profile Compliance

The WS-I is not a certifying authority thus every vendor can claim to be compliant to a profile. However the use of the test tool is required before a company can claim a product to be compliant. See [http://www.ws-i.org/docs/20031021_trademark.pdf WS-I Trademarks and Compliance claims requirements]

In a 2003 interview , the WS-I spokesman said even if every companies are free to claim compliance unfaithfully, he expects companies to be honest:

"We expect enforcement of that brand to be market-driven. We suspect no one wants to be the first person to be called on for making a bad claim." [http://www.internetnews.com/dev-news/article.php/2247551]

ee also

*Web Services Resource Framework

External links

* [http://www.ws-i.org/ WS-I Home Page]