IBM to Propose Addition to WS-I Profiles

By Tony Baer

IBM Corp will next week propose a new Web Services Interoperability profile for dealing with asynchronous business-to-business messages, which could represent a new direction for the organization to go higher up the web services technology stack.

After a somewhat stormy birth four years ago, WS-I has become one of the success stories in the web services standards world. Its role is devising profiles, or test cases, for determining if web services middleware from different vendors are truly interoperable.

IBM is expected to propose the Reliable Asynchronous Messaging Profile, RAMP, at this year's first major WS-I gathering.

RAMP will consist of snippets of three recent or pending web services standards: WS-Addressing, for specifying how an address is represented in the header of a SOAP message; WS-ReliableMessaging, which covers whether a message was received only once and, if applicable, whether it was received in the right sequence; and WS-SecureConversation, which authenticates the series of messages that occur in an exchange between two or more parties.

IBM developed the proposed RAMP profile in conjunction with Ford and Chrysler, and has recently drawn backing from other customers, such as Citibank.

WS-I profiles are not standards per se, but test cases that vendors accept as their standard for testing the interoperability of their web services middleware products. To keep the tests manageable, they do not necessarily exercise every aspect of the technology stack.

For instance, the WS-Basic Profile determines whether a SOAP message sent by Microsoft BizTalk Server could be read by a Mercury/Systinet UDDI registry, and then bind to a WSDL web services description exposed by SAP.

In so doing, the WS-I basic profile specifies only a select number of elements of the headers of SOAP messages, UDDI registry listings, and WSDL service descriptions.

To date, WS-I has only developed two profiles: the Basic Profile, which covers SOAP 1.1, WSDL 1.1, USSI 2.0, XML Schema 1.0, HTTP 1.1, and XML 1.0 second edition and the Basic Security Profile, which covers X509, SAML, Kerberos and other user token profiles.

Arguably, the strength of WS-I is that it has stuck to its knitting with a couple of very basic interoperability profiles, and therefore drawn virtually universal industry support. The weakness is that WS-I's lowest common denominator approach has caused the organization to stay behind the times.

For instance, the Basic Profile does not even test for the latest version of UDDI, which is supported in moist current registry products. And in four years, it only has only finalized one profile, although it is close to finishing the second.

Consequently, IBM's proposal carries risks for the organization as it seeks to introduce testing profiles that are higher up in the web services technology stack.

"We need a more complete stack that people can have confidence in," urges Bob Sutor, who directs IBM's web services standards efforts.

In fact, one of the pieces of IBM's RAMP proposal, WS-ReliableMessaging, is not quite a done deal in the standards world. Although ratified by Oasis, there remains a rival, closely related WS-Reliability proposal from Sun, Fujitsu, Oracle and others.

According to IBM''s Sutor, both specs come from "separate camps with a common heritage." Both originated from ebXML, a complex specification predating web services that never gained market traction.

According to WS-I chair Tom Glover, who is also from IBM, in all likelihood, there will be compromise on this issue, as some members want the WS-Addressing component of IBM's RAMP proposal to be added instead to the Basic Profile, which already exists.

The other elements of RAMP might end up broken out in a separate profile, as IBM is proposing.

Although RAMP is likely to be a major item on the agenda, Glover expects that the hot topic next week will actually focus on when to update the Basic Profile to include SOAP 2.0.

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