I will be upgrading my CallManager 4.13 cluster (1 pub & 2 sub) to UCM 6.0. I plan to install the UCM 6.0 on a new server and import the 4.13 data to the new server using DMA. When the new server is up, I plan to do a phased migration of the phones and gateways to 6.0.
Has anyone done a phased migration from 4.13 to 6.0? Will the phones that are registered to 6.0 UCM be able to call the phones that are registered to CCM 4.13, and vice-versa? Will inbound calls from the PSTN to the gateways that are registered to the CCM 4.13 be able to reach the phones that are registered to UCM 6.0? Will phones that are registered to UCM 6.0 be able to call to the PSTN via the gateways that are registered to CCM 4.13?
Please note that my CCM 4.13 is still up and running during the phased migration.
I look forward to any suggestions. Thank you.