A company has 25 small shops needing basic routing, two regional hubs aggregating 500 Mbps of encrypted traffic with services, and a data center needing multi-gigabit throughput and redundancy. Budget limits overprovisioning. Which edge platform selection aligns throughput and feature needs to each site role?

The tiered selection matches forwarding capacity, services, and availability to each role while respecting budget, with low-cost fixed routers sufficient for basic shop routing, mid-range aggregation platforms providing the CPU, crypto acceleration, QoS and stateful services needed to sustain 500 Mbps of encrypted hub traffic, and modular high-throughput chassis delivering multi-gigabit fabrics with redundant supervisors, power and fabric resilience required at the data center. The variant using mid-range routers without crypto offload for hubs fails on encrypted throughput because plain forwarding numbers collapse under IPsec when encryption is done in software, so hub aggregates would drop or add latency. The variant using stacked fixed routers at the data center to save budget fails on scalability and hardware redundancy because stacking adds ports but does not provide chassis backplane capacity, nonstop forwarding or supervisor redundancy for multi-gigabit core load. The variant standardizing mid-range routers across shops and hubs to simplify sparing fails on economic fit because deploying aggregation-grade hardware with unused performance and licensing to 25 low-demand sites violates the constraint against overprovisioning. As an exam caveat, distinguish nominal interface speed from sustained IMIX and encrypted throughput with services enabled, since data sheets list ideal conditions that rarely hold with NAT, ACLs and VPN active. As a practical check, validate vendor IMIX IPsec throughput and PPS with features on, plus redundancy mechanisms and sparing cost before committing to platform tiers.