Soap, WSDL, UDDI: Digesting The Alphabet Soup - InformationWeek

InformationWeek is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.


Soap, WSDL, UDDI: Digesting The Alphabet Soup

Ask five CIOs to define Web services and you'll probably get five different answers. That's no surprise. Web services are a new and complex set of technologies, even though the phrase has been used generically for years to describe a broad range of Internet technologies.

But one definition is rising to the top: A Web service is a piece of software that can communicate with another application over a network by using a specific set of standard protocols--Simple Object Access Protocol, the Universal Description, Discovery, and Integration framework, the Web Services Description Language.

Soap is the fundamental message-passing protocol that defines how to send data, typically in XML format, among applications across a network. Soap is reminiscent of previous message-passing protocols that didn't quite deliver--the Common Object Request Broker Architecture and Microsoft's Distributed Component Object Model are perhaps the two best-known examples.

Soap can be used to build connections between applications. Those connections can then be described using WSDL. A developer can use the description to design an application to connect to the Web service. When Web services become more sophisticated, an application will be able to use a WSDL description to automatically configure itself to connect to other Web services.

Those Web services have to be found, and that's where UDDI comes in. UDDI is a set of protocols and APIs that define a registry repository where Web services and their associated WSDL descriptions can be catalogued and searched. In the future, businesses or even automated-agent software may first search UDDI registries to find suppliers.

Soap, WSDL, and UDDI are platform-independent technologies that make extensive use of XML, a standard language that's used to define protocols and encode the data stream that applications employ to communicate with each other.

Though Soap, WSDL, and UDDI are frequently referred to as standards, they haven't been blessed by a recognized organization such as the World Wide Web Consortium. Today, Soap is a draft standard within the consortium that will likely be superseded by a specification called XML Protocol, or XMLP. WSDL isn't as far along, but has been submitted to the consortium. UDDI is being guided by the UDDI Project, but it's likely that only parts of that specification will be submitted to the consortium.

Without widely accepted vendor-neutral standards, Web services could end up in the junkyard of also-ran attempts to unify business logic, along with Corba, DCOM, EDI, Java Remote Method Invocation, and Unix Remote Procedure Call. Only Web services have come close to succeeding.

We welcome your comments on this topic on our social media channels, or [contact us directly] with questions about the site.
Comment  | 
Print  | 
More Insights
The State of IT & Cybersecurity Operations 2020
The State of IT & Cybersecurity Operations 2020
Download this report from InformationWeek, in partnership with Dark Reading, to learn more about how today's IT operations teams work with cybersecurity operations, what technologies they are using, and how they communicate and share responsibility--or create risk by failing to do so. Get it now!
IT Careers: 10 Industries with Job Openings Right Now
Cynthia Harvey, Freelance Journalist, InformationWeek,  5/27/2020
How 5G Rollout May Benefit Businesses More than Consumers
Joao-Pierre S. Ruth, Senior Writer,  5/21/2020
IT Leadership in Education: Getting Online School Right
Jessica Davis, Senior Editor, Enterprise Apps,  5/20/2020
Register for InformationWeek Newsletters
Current Issue
Key to Cloud Success: The Right Management
This IT Trend highlights some of the steps IT teams can take to keep their cloud environments running in a safe, efficient manner.
White Papers
Twitter Feed
Sponsored Live Streaming Video
Everything You've Been Told About Mobility Is Wrong
Attend this video symposium with Sean Wisdom, Global Director of Mobility Solutions, and learn about how you can harness powerful new products to mobilize your business potential.
Sponsored Video
Flash Poll