BlackBerry Enterprise Transporter

So lets talk about the Transporter

The transporter has two different modes

In live mode, you can move user accounts when the BlackBerry® Enterprise Server instances
in both the destination BlackBerry Domain and the source BlackBerry Domain are running. If
you choose this mode, the BlackBerry Enterprise Server instances in both BlackBerry Domain
instances must use different SRP IDs.
In this mode, the BlackBerry Enterprise Server instances in the destination BlackBerry Domain
must be running. This must occur so that the BlackBerry Enterprise Transporter can monitor
the organizer data synchronization and calendar synchronization processes and IT
administration commands (such as Resend IT Policy or Switch Service) that the destination
BlackBerry Enterprise Server instances send to the BlackBerry devices to complete the
migration process.

In bulk mode, you can move all user accounts on a BlackBerry Enterprise Server. During the
migration process, you must turn off the BlackBerry Enterprise Server instances in both the
source BlackBerry Domain and the destination BlackBerry Domain. In the destination
BlackBerry Domain, however, you must turn on the BlackBerry Administration Service.