Easy to answer my friend. This phones are SIP you will need configure the (voice register global) and (voice register pool 1) to register them. Note that in voice register pool in the first line ( id network) is your local voice network. The secound line will be CUCM address . when this address is reachable again, the phones back to register on CUCM.
!The Callmanager fallback will used only for your skinny phones. So try to added correct number of DN and PHONES !and remmember that the license of SRST will deduct the amount of phones that you declare as sip and skinny.