It would have to be an awfully small hospital to use DSL. I would imagine they would use T1 or even T3. And, I doubt they would allow you to bypass their secure network.
You are asking an awfully big question. The only way to share one database would be if all the patients were patients of one group. I don't see how that would be possible if GI or Neuro were sharing the same database. There would be HIPAA problems for sure. Maybe I am misunderstanding your question. As far as the logistics, having a terminal server at the central office to access the AC databases on the application/file server would work using RDP.
