Can a licensing server of RDS with 2008R2 will work with 2003&2008 R2 servers??

Hi:

We have a PDC and licensing server of RDS with 2008R2 and 2 servers with 2003 Std, when we install the licenses, we choose 2003 (Windows Server 2003: CAL by user), now the scenario works fine.

If we install another comunicationes server with 2008R2, the licensing server works fin both 2003&2008R2 servers???

If I add new licenses, can we buy CALs by device, and the new server with 2008R2 works with the new licenses??

The licenses that we have now:

1. Microsoft® Windows Terminal Svcs CAL 2008 Single OPEN No Level Device CAL Device CAL      60
2. Microsoft® Win Rmt Dsktp Svcs CAL 2008 R2 Sngl OPEN No Level Device CAL Device CAL       40

Best Regards.