This invention is a system and method for a high-performance Diameter Routing Agent (DRA) platform with a three-tier architecture. The DRA platform consists of a Diameter Connection Router (DCR), a Diameter Load Balancer (DLB), and multiple DRA Instances. DCR is a front-end to all external Peers and distributes Diameter connections to a DLB. DLB is a Diameter transaction load balancer and distributes individual Diameter transaction to a DRA. DRA is a Diameter Routing Agent to implement business logic to determine routing of an incoming request to a destination peer as well as message mediation. A public Internet Protocol (IP) address of the DCR is exposed to the external peers as a single point of contact between the peers and the computer network, wherein an internal topology of the computer network remains hidden from the peers.