The Simulation Engine site preference identifies the Process Simulator. The Process Simulator is an optional component. If this component is installed, you must set the Simulation Engine preference with a three-part name in the format host:port/name.
CAUTION RMI requests to a server with an underscore (_) in the DNS name fail due to a limitation in Java™ Runtime Environment (JRE)1.4 and greater. If your server has a name containing an underscore, you must use the IP address or localhost if appropriate.