Hi
I think Tirthankar is referring to JRMP (
Java Remote Method Protocol).
Java's native RMI technology uses JRMP as the wire level protocol. It can support only java clients calling remote java objects (in a different JVM).
Whereas
EJB (and CORBA) use IIOP (Internet Inter ORB Protocol) as the wire level protocol. IIOP is designed to be implementation language neutral, that is even a C++ client can invoke java object and vice versa. IIOP can propogate security and transaction related information along with the method invocation.
I don't know anything more about them.