the solution licensing guide found here http://www.cisco.com/web/partners/downloads/partner/WWChannels/technology/ipc/downloads/Solution_Bundle_Licensing_Config_VoD.pdf
shows that a 7912 needs 2 DLUs, however the solution expert tools shows that you need 3 DLUs for each 7912. From your experience which is true?
The correct number is 3 DLU's. Here is the best reference document I have found for accuracy.
Hope this helps!