Hi,
The Migrate Subscriber Data tool cannot be used for migrating greetings directly from Octel to Unity.
However, if there are Bridge subscribers on the Unity system that correspond to the Octel users, you can use Migrate Subscriber Data to migrate the Bridge subscribers' data to the Unity subscribers, and that includes the voice names and greetings of the Bridge subscribers.
If there aren't any Bridge subscribers, then after you create the subscriber accounts on Unity, the new Unity subscribers will need to record their voice names and greetings the first time they log on to their Unity mailboxes.
Nancy