Hi Andres
Cisco2901-v/k9 does not include any licenses for CUCME. As soon as you try and configure max-ephones under telephony-service you will be forced to activate an eval license which will expire after a certain number of days.
You need to order the UC license PAK to get CUCME. Your part code is correct:
C2901-CME-SRST/K9 | 2901 UC Bundle w/ PVDM3-16,FL-CME-SRST-25, UC License PAK |
HTH. Barry