Plan a Cisco Unified CM to Zoom Phone migration
Moving from Unified CM to Zoom Phone changes how sites, routing and devices are organized. The work is in the mapping, and it is easier when done in this order.
1. Inventory what exists
Export users, lines, devices, hunt groups, queues, auto attendants, voicemail boxes and shared lines. Separate direct inward dial numbers from extension-only users, and flag anything unused.
2. Decide how calls reach the PSTN
Zoom Phone can provide numbers and calling itself, or you can keep your own carrier and connect it to Zoom through session border controllers you operate. Keeping your carrier defers number porting and lets Unified CM and Zoom coexist during the move. It also means the border controllers must be sized and tested before the first user moves.
3. Map sites and extensions
Zoom Phone groups users into sites, each with its own short extension range and main number. Decide whether each Unified CM location becomes a site, and resolve extension overlaps between locations before provisioning anything.
4. Map call handling
Hunt groups and queues become call queues. Call handlers become auto receptionists. Lobby, break-room and conference phones become common area phones. Shared lines become shared line groups or delegation. Write the mapping down per item and have its owner confirm it.
5. Check the devices
Confirm each desk phone model against Zoom's supported device list. Plan replacements, and decide who moves to the Zoom desktop and mobile clients.
6. Plan coexistence
Unless everyone moves on one night, users on both systems must call each other by extension. Decide how those calls route during the migration and test it with the first group.
7. Migrate in groups and keep a way back
Begin with a group that includes one queue, one auto receptionist and one common area phone. Verify inbound, outbound, internal and emergency calling. Record what was created so the group can be reversed.
Test emergency calling for every site before users move, and record the result.
Where Vector helps
Vector reads the Unified CM inventory through an on-site collector, maps it to Zoom Phone sites, users, queues and devices, provisions in groups, verifies the result, and records each change so it can be rolled back.