Distributed Component Object Model (DCOM)

DCOM, or Distributed Component Object Model, is a technology for component-based development of software that is network-aware.

What is DCOM (Distributed Component Object Model)?

A technology for component-based development of software that is network-aware. Using Distributed Component Object Model (DCOM), developers can create network-aware applications using Component Object Model (COM) components. DCOM works under various network transports, including TCP/IP.

How it works

DCOM is a client/server protocol that provides distributed network services to COM, allowing DCOM-enabled software components to communicate over a network in a similar fashion to the method by which COM components communicate among themselves on a single machine.

DCOM client objects make requests for services from DCOM server objects on different machines on the network using a standard set of interfaces.

Graphic D-32. Distributed Component Object Model (DCOM).

The client object cannot call the server object directly. Instead, the operating system intercepts the DCOM request and uses interprocess communication mechanisms such as remote procedure calls (RPCs) to provide a transparent communication mechanism between the client and server objects. The COM run time provides the necessary object-oriented services to the client and server objects. The COM run time also uses the security provider and RPCs to create network frames that conform to the DCOM standard.

In Microsoft Windows NT and Windows 2000, DCOM requests are sent using RPCs. Windows NT and Windows 2000 use security features such as permissions to enable software components to securely and reliably communicate over the network.

DCOM was formerly known as ┬źNetwork OLE┬╗.