Does EJB 1.1 support mandate the support for RMI-IIOP ? What is the

Question :Does EJB 1.1 support mandate the support for RMI-IIOP ? What is the
meaning of "the client API must support the Java RMI-IIOP programming
model for portability, but the underlying protocol can be anything" ? (EJB)
Answer :EJB1.1 does mandate the support of RMI-IIOP.
OK, to answer the second question:
There are 2 types of implementations that an EJB Server might provide:
CORBA-based EJB Servers and Proprietry EJB Servers. Both support the
RMI-IIOP API but how that API is implemented is a different story. (NB: By
API we mean the interface provided to the client by the stub or proxy).
A CORBA-based EJB Server actually implements its EJB Objects as CORBA
Objects (it therefore encorporates an ORB and this means that EJB's can
be contacted by CORBA clients (as well as RMI-IIOP clients)
A proprietry EJB still implements the RMI-IIOP API (in the client's stub) but
the underlying protocol can be anything. Therefore your EJB's CANNOT be
contacted by CORBA clients. The difference is that in both cases, your
clients see the same API (hence, your client portability) BUT how the stubs
communicate with the server is different.