CentreStack is a managed file sync and share solution. It can help a remote file server sync folders to cloud and also maintain same set of permission control with same set of Active Directory users.
This video demonstrates how to use server agent to connect remote file server to CentreStack over the Internet without using VPN (virtual private network).
The end result is business continuity as the file server content is replicated to the cloud and maintain two-way synchronization. At the same time, the folder permission is maintained with Active Directory user identity. Business users when they are in the local office, they can continue to access the local file server as it was before; and the same business user can access file server now from mobile devices, web browsers and remote PC/Mac without using a VPN.
Sometimes, this is also called hybrid cloud with local network performance and cloud productivity combined.