can someone clarify what these two apporaches are? How they may be appropriate for different requirements?
'Typically' in a core / edge network the edge is utilized for host and core for storage connectivity. Though this isn't true in all environments. The scale-out at the edge addresses network capacity expansion for additional host connectivity. One example would the concept of a data centre POD layout. As a new infrastructure POD is deployed for servers the network edge would scale to accommodate this infrastructure change assuming the core is built to hand the scale.