Earlier the corporate network was relatively simple and easier to secure as the applications were confined within the organization's perimeter. Users accessing the network were provided a secure connection through on-premises VPN solutions. However, with the introduction of the cloud, infrastructure became borderless, and the corporate network got extended to the internet. 

The tables have turned today. Users can now access applications anytime, anywhere and on any device. VPNs backhaul traffic through a data center just to access cloud-based applications. This results in a poor user experience and an increase in MPLS costs. Gartner recommends that enterprises adopt a zero-trust network access (ZTNA) service instead. Remote access VPNs met the security requirements in the network-centric world, but in the age of cloud and mobility, application access needs to be independent of the network.