A demilitarized zone (DMZ) in a network architecture is typically associated with providing a buffer zone between the internal network and external sources like the internet. The primary characteristic of a DMZ is that it allows controlled access to external resources such as the internet, typically by placing web servers or other public-facing applications within the DMZ. This setup ensures that the internal network remains protected while allowing some level of interaction with the outside world through the firewall. Therefore, the characteristic most closely associated with the deployment of a DMZ is that Internet access through the firewall is allowed.