hi, a cp-7911g can works on a router 2801 voice bundle Fl 50 ?, or just works with the CP-7911G-CCME, someone told me that the ccme licence are "honor based licence, aren't load into the router" so just the voice bundle fL licence is necesary, the ccme phone licence aren't.
As Paolo suggested what you have been told is correct.
CP-7911G-CCME (CCME License) is honor based and technically even if you don't purchase it the setup will work just fine. Its just a paper license which certifies you to use the phone.
But from ordering perspective you should purchase this license because that's the correct way of ordering cosidered by Cisco.
If you look at it, even the Feature License on Router is not required. You don't enforce it anywhere on the router. But you should purchase the same.