Here is as usual a basic configuration that you can perform to enable your CME router.

!
tftp-server flash:<<firmware>>
telephony-service
max-ephones <<X>>
max-dn <<Y>>
load <<phone_type>> <<firmware_load>>
ip source-address 10.1.2.1 port 2000
create cnf-files
transfer-system full-consult
!
ephone-dn <<tag-number>> <dual-line>
number 1234
name technical
!
ephone <<tag-phone>>
mac-address <<AAAA.BBBB.CCCC>>
type <<phone_type>>
button 1:<<tag-number>>