Array-based: Solution dependent
VR: Data Compression
Array-based: Deduplication and compression techniques aimed at reducing remote replication traffic is entirely dependent on what the specific storage solution or what a 3rd party WAN acceleration solution can provide.
vSphere Replication (VR): Data compression can be enabled to save network bandwidth between sites. For this VR utilizes the FastLZ compression library. Bandwidth is not monitored, and there is no way to configure bandwidth throttling. The data replicated is not encrypted, enabling 3rd party WAN acceleration solutions to provide some benefit.