Dell FC4500 Hardware Reference Manual page 15

About the Rackmount Disk-Array Processor Enclosure
1
You can place the DAEs in the same cabinet as the DPE, or in one or
more separate cabinets. The DPE connects to the external Fibre
Channel environment using GBIC connectors on the storage
processor. High-availability features are standard.
The EMC Access Logix™ option provides Storage Group
functionality for the FC4500 DPE.
Introduction
1-3