MPG Gateway Network Topology illustrates a multi-tier payment processing network with edge firewall, load balancing, and core routing feeding a message broker (mpg.exchange TOPIC) that distributes requests, callbacks, and errors across isolated VLAN segments. Traffic flows from the Unified Layer through the DMZ, Core Router, and WebService-Interface validation layer, then branches via the Distribution Switch into three request-routing paths serving IPS (VLAN 30), Host/CBS (VLAN 40), and Callback (VLAN 50) segments. Each segment runs dedicated Rest-Handlers and web service interfaces (MPG-WS-H-IN/OUT) that process transactions and return responses through a unified outbound WebService-Interface. This architecture enforces network segmentation, centralized validation, and asynchronous callback handling—critical for PCI-DSS compliance and high-availability payment systems. Fork and customize this topology on Diagrams.so to model your own payment gateway, adjust VLAN ranges, or add additional security zones. The design demonstrates best practices for isolating payment processing workloads while maintaining a single validation and response-shaping layer.