A phased migration from an existing CS 1000 solution to an Avaya Aura® solution involves dividing the existing endpoints into groups and migrating them in batches instead of everything together. Phased migration is the preferred migration strategy as it ensures the following:
All endpoints in a solution are not affected by a migration activity.
Less downtime during a migration activity.
Less likelihood of a catastrophic fault during the migration activity.
The following must be addressed if a phased migration is planned:
Group features such as Multiple Appearance Directory Numbers (MADN) can be lost if all endpoints and participants in the feature group are not migrated in the same migration phase. If MADN members are spread across multiple Media Gateway Controllers, all MGCs must be migrated simultaneously.
PSTN access to migrated endpoints must be configured so that the migrated endpoints can initiate or receive PSTN calls. This configuration can be done by moving the migrated users to the centralized SIP trunks of the Avaya Aura® solution. You can also keep the existing CS 1000 TDM DID trunks and use them with the Vacant number routing administered on the CS 1000 solution. Vacant number routing is administered to route calls to vacant numbers in the Avaya Aura® solution.
Routing of internal calls to the migrated endpoints must be configured by using Vacant number routing to route calls from CS 1000 to the Avaya Aura® solution. You can also use specific digit manipulation tables on the CS 1000 solution to route calls to the migrated endpoints on the Avaya Aura® solution.
You must route internal calls to the endpoints in the CS 1000 solution from the migrated endpoints in the Avaya Aura® solution. On the Avaya Aura® solution, you must configure SIP routing into the CS 1000 solution for the range of extensions still deployed there. Alternately, if a SIP endpoint and a SIP route exist for a number, the Avaya Aura® solution delivers the call to the SIP endpoint.
The Avaya Aura® solution must be configured with the resources necessary to accommodate the increased number of endpoints. A CS 1000 endpoint requires the same resource allocation in an Avaya Aura® solution as any other Avaya Aura® SIP endpoint.
