In-Place Server—Hybrid Migration Unified CM 4.X to 7.1 Existing Backup Subscriber Existing backup subscriber is not the call processing server Be careful about duplicate IP addresses New Publisher TFTP 2 Can use new IP addresses in new cluster New DHCP option 150 points to new TFTP server Phones can re-home to new TFTP and new active subscriber *Make sure existing 4.X active sub is off Existing TFTP New Active Subscriber 3 New backup subscriber is online for redundancy Existing Active Subscriber New Backup Subscriber 4 Save the Existing Publisher for last in case of downgrade Once upgrade is deemed acceptable Change DHCP option 150 back to new TFTP server Revise activated services as required Existing Publisher New TFTP 1