Hi,
there is no datasheet on the Homepage, its only listed in the Access Point Matrix.. But normally most of the Campus Access Point (CAP) can run as a Remote Access Point (RAP) too. The Instant Access Point (IAP) can do evertyhing, IAP, CAP and RAP. I can't imagine that Aruba Networks would change something there with the new AP-21X Series. Maybe some smaller Access Points doesn't support the RAP-Mode.
Regards,
Thomas