Access to any internal server from the internet creates major security issues unless you understand what your doing. Without being critical or condescending you are asking a questions that a BES admin should know. The IP will not present itself outside of any firewall without configuration. I have added two links with some info as a start only.
KB11028-How to configure a proxy server for BlackBerry MDS Connection Service
KB19713-"Cannot connect to server" appears on the BlackBerry smartphone after Microsoft Office Communications Server 2007 is installed