Simple Question on protocol

[HanMing Low]

Hi,
I'm confused over the protocol used for EJB.
From the client and the developer point of view, how do we know which protocol is used for the communication of the distributed object.
I understand that by looking at the stubs file, I should be able to know if it is a CORBA or RMI stubs.
Is there any difference in the code?
And, I'd apprecitate if there is any reference to some code sample.
As I've only come across RMI-IIOP, how would a EJB client using JRMP looks like?
And, which are the EJB Server that supports JRMP?
Thanks for any advice.
Cheers.

Han Ming