Deploying zero trust software-defined perimeter (SDP) architecture is not about completely replacing virtual private network (VPN) technologies and firewalls. By and large, the firewall demarcation points that mark the inside and outside are not going away anytime soon. The VPN concentrator will also have its position for the foreseeable future.
A rip and replace is a very aggressive deployment approach regardless of the age of technology. And while SDP is new, it should be approached with care when choosing the correct vendor. An SDP adoption should be a slow migration process as opposed to the once off rip and replace.
