We are looking at a CER 1.3 TO 7.1 upgrade in addition to upgrading call manager from 4.1.3 to 7.1.3. Our plan is new hardware for both systems so we would like to uprade CER first given the backward compatibility and then build out a parrallel CUCM cluster of 7.1.3 that we would perform the DMA from the 4.1.3 system. My question is, can we reconfigure the CER 7.1.1 after the migration of the 4.1.3 CUCM system to point the CUCM 7.1.3 system without any issues. The CUCM 7.1.3 system will essentially be a new cluster when done, with likely different IP addresses.