OST Hardware

Hello, I wanted to get some more information regarding OST. Here is the hardware layout we have planned.

Server1 - CAS only to manage from

Server2 - Media Server1

Server3 - Media Server2

My question..

Q:  Do we need to purchase OST storage devices if we want to copy deduplicated data from Media Server1 to Media Server2 over the network? If not is their an advantage?

Thanks,

Dominic