Use this procedure to make adjustments to your dial plan in the case of a Numbering Plan Area (NPA) overlap.
Prerequisite: The baseline dial plan is defined and you are adding no additional gateways, and you are in the Design View.
Locate the affected zone.
Set up the following for the zone:
Add new (overlap) zone prefix to the zone.
Create egress routes for the new prefix. (Create new route scopes, if necessary.)
Create ingress routes, if necessary.
Commit your changes to the baseline dial plan.