Web service Gateway continued

What is the Web services gateway?

The gateway provides you with a single point of control, access and validation of Web service requests, and allows you to control which services are available to different groups of Web service users.

You use the gateway to make available controlled sets of Web services for use within your organization and by external users. The services that each gateway instance makes available as Web services can be a mixture of internal services that are directly available at service integration bus destinations and external Web services.

This approach provides the following benefits:

1. The gateway service is made available at a different Web address to the target service, so you can replace or relocate the target service without changing the details for the associated gateway service.
2. 
   You can have more than one target service (that is, more than one implementation of the same logical service) for each gateway service.
   The gateway service can be made available on a different service integration bus to the target service.
3. 
   The gateway provides a common interface to the services in each set. Your gateway service users need not know where each underlying service is located, or whether the underlying service is being provided internally or sourced externally, or whether there are multiple target services available for a single gateway service.
   
   How does the Web services gateway work?

• When you create a gateway service, you map an existing destination that hosts a target service (either an internal service or an external Web service) to a new Web service that seems to be provided by the gateway.
  
  Who should use the Web services gateway?

An enterprise that chooses to share its resources selectively with its business partners and customers, or an enterprise that uses external Web services and wants to make them available internally. IT managers and developers, who deploy resources, can also benefit from this technology.

What business problems are solved by the Web services gateway?

The gateway solves the following business problems:

• 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 better integrate your business processes, you might want to expose these assets to business partners, customers and suppliers who are outside the firewall. The gateway lets clients from outside the firewall use Web services that are hosted within your enterprise. Using the gateway, you can control access to each of these services.
  Better return on investment: Any number of partners can reuse a process that you develop as a Web service.

• Use of existing infrastructure: With the gateway, you can make readily available as Web services any combination of your existing internal services and external Web services, no matter how each of those existing services are currently accessed (for example through a service integration bus destination, a Web address or a UDDI registry).
  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.