A controlled cutover, not a swap.
The failure mode in a copper migration is rarely the new technology. It is a legacy line released before anyone confirmed the replacement path actually carries the call or the signal.
The appropriate path is chosen per line — remove, migrate native, Cline, or endpoint upgrade — then coordinated across vendors, monitoring providers and the carrier, with end-to-end testing before legacy service is released.
“Replacement” is one of four outcomes.
After Discovery and Assessment each line already has a disposition. Many lines can simply be removed. Some belong on modern native services. Some critical legacy endpoints are best preserved on managed connectivity. Some need a coordinated endpoint upgrade with the vendor who owns the device.
Migration is the execution of those decisions, in an order that never leaves a critical endpoint dark.
- 01PATH SELECTED PER LINE
- 02WAVE & CHANGE-WINDOW PLAN
- 03NUMBER & PORTING RECORD
- 04END-TO-END TEST EVIDENCE
- 05AS-BUILT DOCUMENTATION
- 06DISCONNECT CONFIRMATION
The disposition, then the execution.
The line no longer supports anything. It is cancelled and the saving is documented.
The function moves to a modern service that already meets the requirement established at Assessment.
Managed connectivity preserves a POTS-like interface for the endpoint that genuinely needs one.
Coordinated with the vendor who owns the device, when the endpoint itself has to change.
Facilities, the alarm company, the monitoring provider and the carrier all work from the same record.
Legacy service is released only after end-to-end testing and documentation are complete.
How the cutover is controlled.
- 01Sequence the work
Waves ordered by criticality and carrier deadline, life safety first.
- 02Coordinate the stakeholders
Your alarm, elevator and access vendors stay. We run the communications workstream between them, monitoring and the carrier.
- 03Cut over
Install, preserve numbers where required, and bring the new path into service while the legacy line is still available.
- 04Test, document, then release
Signals, call paths and entry functions tested end to end. Only then is the old line disconnected.
Questions we hear first.
Can we keep our existing phone numbers?
In most cases numbers can be preserved through the migration. We confirm it per line during Assessment rather than promising it up front.
When does the old line get disconnected?
Only after the new path has been tested end to end and the documentation is complete. Controlled cutover is the entire point of the process.
Do we have to change vendors?
No. Your alarm, elevator, access and monitoring vendors stay in place. Critical Line runs the communications workstream between them and the carrier.
What happens if a site fails testing?
The legacy service stays up. A line is not released until its replacement path has demonstrably carried the call or the signal.
Plan the cutover.
Start with the lines that already have a deadline. We'll sequence the rest.