Archetype 2 — the tier-one incumbent

At the opposite extreme are the carrier-class BNGs — the chassis-based platforms from the large incumbents, engineered for national operators terminating millions of sessions. These are formidable, mature systems. They are also built for a customer that is not you.

• You pay for a network you'll never run. The platform's cost — hardware, per-feature licensing, and the support contract — reflects PPPoE session engines, L2TP LAC/LNS, lawful intercept, MPLS L3VPNs, ATM interworking heritage, and a decade of carrier features. A WISP terminating ten thousand IPoE subscribers subsidizes all of it whether a single packet uses it or not.
• Complexity is the product. These systems assume a dedicated NOC and staff who are certified on the platform. That operational model is a poor fit — and a poor value — for a team of a handful of people.
• You are a rounding error to the vendor. Roadmap priorities, feature attention, and support responsiveness follow the tier-one accounts. Your IPoE requirements compete with the demands of operators a thousand times your size, and lose.

Where the generalist under-serves you by making you the integrator, the incumbent over-serves you by making you pay — in money and complexity — for a carrier network you don't operate.