How should you type cast a remote object ? Why ?

A client program that is intended to be interoperable with all compliant EJB Container implementations must use the javax.rmi.PortableRemoteObject.narrow(?) method to perform type-narrowing of the client-side representations of the remote home and remote interfaces.

Programs using the cast operator for narrowing the remote and remote home interfaces are likely to fail if the Container implementation uses RMI-IIOP as the underlying communication transport.