As institutions expand, and grow, surging interference malware and attacks; large portions of the Internet at a time impinge and create large amounts of service disruption. So, their IT infrastructure needs to be updated and expanded to accommodate the changing demands of their business. The project's main objective is to improve and enhance the network infrastructure design for communication institutions. In this work, we tried to present a meliorating plan for the infrastructure of enormous communication systems inside institutions. It implemented the network topology so it has established an on-premises infrastructure constituting two sites with three different networks: LAN, data center, and DMZ. The LAN network was reserved for client devices. In contrast, the data center network is intended for servers such as the domain controller, additional domain controller, file storage server, network-attached storage, DHCP server, DNS server, and WDS server (used for deploying operating systems on devices). The DMZ network included servers for hosting public websites (IIS server) and public DNS, as well as a DFS server for replicating files between the two sites. To ensure the security of the infrastructure, a Fortigate firewall is used to separate the DMZ network from the LAN and data center networks. It connected firewall A to Firewall B to enhance security and filter traffic. It connected firewall B to a router, which is then connected to the ISP network.The on-premises infrastructure provides a reliable, secure, and scalable solution for institutions. The layered security approach with Fortigate firewalls helps to ensure that data and resources are protected from unauthorized access. Also, we performed the trap and IP security technology on the sites. The infrastructure is flexible enough to accommodate the organization's future growth and expansion needs. The combination of on-premises infrastructure and layered security measures provides a solid foundation for critical business operations. The infrastructure is well-suited to meet the needs of a modern enterprise with its advanced threat protection capabilities and ability to scale up or down as required.