Yes, the ResNet network is behind the ATU perimeter firewall.
For security reasons, incoming connections started from sources on the Internet are not allowed through the firewall to ResNet.
Outgoing connections from ResNet to the Internet, and the return traffic, is allowed. While certain protocols, such as ICMP ping, may be restricted, for outgoing connectivity the firewall does not actively block specific ports or filter content unless it has been identified as malicious (malware, virus, phishing, etc) or is causing a network issue.