For environments requiring an Internet-facing capability, the SharePoint application server upon which Central Administration is installed, must not be installed in the DMZ.
Information flow control regulates where information is allowed to travel within an information system and between information systems (as opposed to who is allowed to access the information) and without explicit regard to subsequent accesses to the information.
SharePoint installed Central Administrator is a powerful management tool used to administer the farm. This server should be installed on a trusted network segment. This server should also be used to run services rather than user-oriented web applications.