In-Depth

UML and IIOP

While the OMG proceeds with its plans for UML 2.0, some observers say it is a waste of time. They contend that UML is merely a rehash of IIOP, the Internet Inter-ORB Protocol of the OMGÕs Common Object Request Broker Architecture (CORBA).
IIOP lies at the core of network-based distributed computing. It maps General Inter-ORB Protocol (GIOP) messages to TCP/IP so the ORB uses the Internet as an ORB communication bus. GIOP is the methodology that ORBs need to communicate. It maps ORB requests to different network transports. Thus, IIOP is an implementation of GIOP.

"With IIOP there was the CORBA Interface Definition Language [IDL]. That was fine for specifying structures of large distributed systems in terms of specifying their interfaces, but UML goes beyond that," said Cris Kobryn, chief technologist at Telelogic, Irvine, Calif. UML allows users to specify interactions between distributed objects or components, what Kobryn calls complex distributed behavior. It takes IDL further "in that you can completely specify an architecture so that it's model-driven," Kobryn said.

About the Author

Richard Adhikari is a widely published high-tech writer based in Silicon Valley. He can be reached via e-mail at [email protected].