When running Oracle Multi-Threaded Server, one or more dispatcher processes (named D001, D002, and so on) are responsible for receiving connection requests from the listener and directing each request to the least busy Shared Server process. If the listener cannot find an available Dnnn process, a dedicated server process is created instead. The actual number of Dispatcher processes running is determined by the setting of the INIT.ORA parameter MTS_MAX_DISPATCHERS.