The entity hierarchy for the Event Dispatcher module is:

                               _Outbound_Stream
                              |
    Node___Event_Dispatcher___|_Relay____________Logging
                              |
                              |_Sink_____________Inbound_Stream

    The EVENT DISPATCHER entity is the top-level entity in the
    hierarchy of entities belonging to the Event Dispatcher module.
    Each DNA node must implement an event dispatcher.

    An EVENT DISPATCHER OUTBOUND STREAM entity represents an outgoing
    connection to a sink on a local or remote node. An outbound
    stream entity manages the connection to the sink, and it filters,
    processes, and transmits events to the sink. The simple-name
    refers to the outbound stream managed by this command.

    The EVENT DISPATCHER RELAY entity is used for processing events
    from Phase IV DECnet systems. It receives Phase IV format events
    and posts them into the DECnet-Plus logging system.

    Three EVENT DISPATCHER RELAY LOGGING entities are automatically
    created and enabled whenever an event dispatcher relay entity
    is enabled. The logging entities (console, file, and monitor)
    control the destination of Phase IV events. Each logging entity
    can be individually diabled and reenabled. All three logging
    entities are automatically deleted when the Phase IV relay entity
    is disabled.

    An EVENT DISPATCHER SINK entity represents a sink. A sink manages
    incoming connections and filters incoming events. Each sink
    maintains a filter that is applied to all streams that are
    assigned to that sink. The simple-name refers to the sink managed
    by this command.

    The EVENT DISPATCHER SINK INBOUND STREAM entity is the sink-side
    end of communication between an event dispatcher and a sink. An
    inbound stream entity is dynamically created, enabled, disabled,
    and deleted in tandem with the connection it represents.