DGCAckHandler Holds strong references to a set of remote objects, or live remote references to remote objects, after they have been marshalled (as remote references) as parts of the arguments or the result of a remote invocation. 
LiveRef NOTE: There is a JDK-internal dependency on the existence of this class and its getClientSocketFactory method in the implementation of 
ObjectTable Object table shared by all implementors of the Transport interface. 
StreamRemoteCall Stream-based implementation of the RemoteCall interface. 
Target A target contains information pertaining to a remote object that resides in this address space. 
Transport Transport abstraction for enabling communication between different VMs.