We are right now building an application for quilaty assuarance in X-ray diagnosises based on J2EE on JBoss. The individual JBoss servers at the different hospitals needs to communicate some user inforamtion and also a limited amount of patient data. Security is therefore of most importance. Since all hospitals have firewalls, I was thinking about a central message router. In Sweden this is sent through a private encrypted network called sjunet (hospital is sjukhus in Swedish).
Now for my question: Can I use EJBs transported by HTTPS to communicate with the central router. The router will be clustered. Since the number of installations on the hospitals are increasing, we can not be sure of having the same version of the product and thereby also JBoss deploy everywhere at the same time. We aim for it, but major upgrades must be planned and can't be introduced at all hospitals at the same time. Can I access e.g. EJBs on a JBoss 4.x from a JBoss 3.2.1 server?