The CentraSite Application Server Tier (CAST) hosts CentraSite components that are provided as web applications in an application server. The components of the CentraSite Application Server Tier function as clients of the CentraSite Registry Repository component.

CentraSite Control is CentraSite's browser-based user interface, providing general purpose features for administrators, designers, and end users. Because this interface is built on Software AG's pluggable UI infrastructure, it can be easily extended and customized. For more information about the CentraSite Control pluggable architecture, see the CentraSite Developer’s Guide. The pluggable infrastructure also enables you to plug into CentraSite additional user interfaces from the CentraSite Community.

The Business UI is a lightweight alternative toCentraSite Control, offering high-level features for business users.

The CentraSite Server performs authorization of communication from client applications to the CentraSite Registry Repository.

The CentraSite Application Server Tier hosts the UDDI services that client programs use to interact with CentraSite using the UDDI V3 API.

The CentraSite Control and UDDI services interact with the Registry and Repository component using the CentraSite API for JAXR (registry) and HTTP (repository).

The CentraSite Registry Repository component manages the content of the registry and the repository. Besides housing the data that makes up the registry and repository, this component controls access to CentraSite and ensures that the data objects in the registry conform to the CentraSite information model.

Client programs interact with the registry portion of this component using the CentraSite API for JAXR and the CentraSite API for XQuery. Client programs interact with the repository portion of this component using HTTP.

Client programs do not interact directly with the CentraSite Registry Repository. Instead, the communication from the client is always routed via the CentraSite Server component of the Application Server Tier.

UDDI clients interact with CentraSite using the UDDI V3 services that reside on the Application Server Tier. UDDI clients include developer tools supplied by Community partners, third-party UDDI browsers, UDDI-compliant IDEs and UDDI registries that are federated with CentraSite.

XQuery and JAXR-based clients interact with the CentraSite Server component of the Application Server Tier. These clients include the CentraSite plug-in for Eclipse, third-party applications developed by CentraSite Community and (potentially) applications developed by your own organization.

Authentication of the client communication is performed by CentraSite Server. Therefore, the clients do not send their requests directly to the Registry Repository but instead to the CentraSite Server. The CentraSite Server forwards authenticated client requests to the Registry Repository.