Service Publication in Active Directory
Service Publication in Active Directory |
|
A Connection Point object represents one or more instances of a service that is available in a network. The Active Directory schema defines a variety of object classes for use in service publication. All objects representing resources that accept connections are derived from the object class Connection Point.
Figure 5.2 shows the hierarchy of the Connection Point class.
Figure 5.2 Connection Point Class Hierarchy
Some examples of objects that are derived from Connection Point and that accept connections are as follows:
Print Queue and Volume The Print Queue and Volume objects are the standard connection points used by print and file services respectively.
RPC Entry Points Windows 2000 supports two sets of networking APIs that provide transport independence: the Microsoft® Windows® Sockets interface and the RPC interface. RPC provides a mechanism for calling functions in other processes, even processes running on remote computers on a network. RPC provides a threading model, provides an endpoint (socket/pipe/port) mapping service, and connects to a name service. Services that currently publish themselves by using the RPC Name Service (RpcNs) APIs are published in Active Directory using the RPC-Entry object and other RPC object classes.
Service Instance Windows Sockets services that publish themselves using the registration and resolution (RnR) APIs are published in Active Directory using the Service-Instance object class.
Service Connection Point Service Connection Point is used by services that need to explicitly publish themselves in Active Directory, rather than use an existing abstraction, such as RPC Name Service or RnR.
A service that uses Service-Connection-Point needs to provide an abstraction layer to hide service location details from client applications. This abstraction can be implemented as a dynamic-link library (DLL), or as part of the client application. The abstraction queries Active Directory for a connection point object representing the service requested by the client application and uses the binding information from that object to connect the client application to the service.
A client application queries Active Directory for connection point objects that represent the services that the application wants to use. The client then selects one of those objects and uses the binding information from that object to connect to the service. In the case of RpcNs and RnR, the query is performed by the abstraction layer. In the case of the serviceConnectionPoints class, the query is performed directly by the client.
Note
COM-based services do not use Connection Point objects to advertise themselves. These services are published in the class store. The Windows 2000 class store is a directory-based repository for all applications, interfaces, and APIs that provides for the publishing and assigning of applications.
For information about COM-based services and Windows 2000 Class Store, see the MSDN™ link on the Web Resources page at http://windows.microsoft.com/windows2000/reskit/webresources.
