Web services gateway Overview

This topic provides an overview of the Web services gateway:

What are Web services?
Web services are modular applications that interact with one another across the Internet. Web services are based on shared, open and emerging technology standards and protocols (such as SOAP, UDDI, and WSDL) and can communicate, interact, and integrate with other applications, no matter how they are implemented.

What is the IBM Web services gateway?
The gateway is a middleware component that bridges the gap between Internet and Intranet environments during Web service invocations. You use it to manage:

• Web services.
• channels that carry requests to and responses from the services.
• filters that act upon the services.
• references to UDDI Registries in which services can be registered.

How does the Web services gateway work?
The gateway builds upon the Web services Definition Language (WSDL) and the Web Services Invocation Framework (WSIF) for deployment and invocation.
You deploy a Web service to the Web services gateway by deploying a WSDL file which describes how the Web services gateway should access it. The WSDL file can be deployed to a UDDI Registry or to a URL. You can send requests passing through the Web services gateway to a Java class, an enterprise bean, or a SOAP server (including another gateway).
A request to the Web services gateway arrives through a channel, is translated into an internal form, then passed through any filters that are registered for the requested service, and finally sent on to the service implementation. Responses follow the same path in reverse.

What problems are solved by the Web services gateway?

• Securely externalizing Web services: Business applications that are exposed as Web services can be used by any Web service-enabled tool, regardless of the implementation details, to create new applications. To better integrate your business processes, you might want to expose these assets to business partners, customers and suppliers who are outside the firewall. The Web services gateway lets clients from outside the firewall use Web services that are buried deep inside your enterprise. The gateway also allows you to set access control on each of these deeply-buried services.
• Better return on investment: A process that you develop as a Web service can be reused by any number of partners.
• Use of existing infrastructure: With the Web services gateway, you can use your existing messaging infrastructure to make Web service requests, and use your existing Web services for external process integration.
• Protocol transformation: You might use one particular messaging protocol to invoke Web services, while your partners use some other protocol. Using the Web services gateway, you can trap the request from the client and transform it to another messaging protocol.

Who should use the Web services gateway?
Any enterprise that chooses to share its resources selectively with its business partners and customers. IT Managers and Developers, who deploy resources, can also benefit from this technology.