Providing remote users with access to on-premises file systems, such as Microsoft DFS or Windows CIFS / SMB shares, can be a hard task, especially as multiple security layers often exist, like firewalls and VPNs.
Some companies have opted to solve this challenge by deploying the Microsoft Forefront Unified Access Gateway (UAG) as a bridge to provide users who are remote with access to these on premise systems. The UAG was a software solution, facilitating access to file shares, intranets and corporate systems.
The Microsoft Forefront Unified Access Gateway is now officially deprecated.
by 
