1.3 Overview

The Distributed Component Object Model (DCOM) Remote Protocol extends the Component Object Model (COM) over a network by providing facilities for creating and activating objects, and for managing object references, object lifetimes, and object interface queries. The DCOM Remote Protocol is built on top of Remote Procedure Call Protocol Extensions, as specified in [MS-RPCE], and relies on its authentication, authorization, and message integrity capabilities. The DCOM Remote Protocol is also referred to as Object RPC or ORPC. The following diagram shows the layering of the protocol stack.

Figure 1: DCOM protocol stack

The following diagram presents an overview of the protocol.

Figure 2: DCOM protocol overview

Higher-level applications use the DCOM client to obtain object references and make ORPC calls on the object. The DCOM client in turn uses the Remote Procedure Call Protocol Extensions, as specified in [MS-RPCE], to communicate with the object server.

The object server constitutes an object resolver service and one or more object exporters. Objects are contained in object exporters. Objects are the target of the ORPC calls from the client.