A. Users internal to an organization access the internal RMS URL. Licensing for internal users is based on RMS CALs, which must be purchased for any user or device that creates or views protected RMS content. When RMS validates a user’s credentials, it issues a usage license. This CAL is in addition to the Windows CAL required to communicate with the Windows Server OS. You can opt to license CALs based on users or devices.
To enable external users to access content, you must purchase a Windows Server 2003 External Connector (EC) License and an RMS EC License for each RMS server that will be accessed. The EC licenses remove the need for per-user CALs for external users. If you have an RMS trust relationship with another organization that has RMS CALs for its users, you’ll still have to buy an RMS EC License for your RMS servers.