The web services architecture is based on interactions between three components: a service provider, a service requester, and an optional service registry.
The registry is an optional component of the web services architecture because service requesters and providers can communicate without it in many situations. For example, the organization that provides a service can distribute the service description directly to the users of the service in a number of ways, including offering the service as a download from an FTP site.
Using a service registry offers a number of advantages to both the requester and provider; for example, using the IBM® WebSphere® Service Registry and Repository (WSRR) can help the requester to find services more quickly and can help the provider to enforce version control of the services being offered.
CICS® provides direct support for implementing service requester and service provider components. However, you need additional software to deploy a service registry in CICS. If you use the IBM WebSphere Service Registry and Repository (WSRR), CICS provides support for WSRR through the web services assistant. Alternatively, you can deploy a service registry on another platform.