Based on the best security design principles, the campus network was segregated into different security zones.  The network communication among security zones are established by various interconnecting routers and firewalls. The firewall security rules, deployed in the interconnecting firewalls, control the firewall to allow or deny the flow of specific network traffic between security zones. Through the firewall security policies service, IT service owners can request for appropriate firewall security rules to provide security protection and the controlled network traffic to deliver an IT service. With reference to the industrial security best practices, principles as well as the existing security policies, the network security team will review the firewall security policy service request.  Further discussion with the requestor and Information Security Unit (ISU/OCIO) will be carried out to refine the security policy before actual deployment.