Small BNGs#

Fiona Weber - WDZ GmbH // Wobcom GmbH

• Why: A contrarian architecture decision with a completed migration to show for it: instead of the industry trend of terminating subscribers on a few huge central routers, AS9136 pushed small white-box BNGs to the edge. A genuine postmortem-flavored operator story — exactly the kind of hard-won, transferable lesson the PM's field values.
• What: Migration from 2 central to 25 distributed BNGs on RtBrick software on UfiSpace and EdgeCore hardware (MPLS/IS-IS + SR, BGP, PPPoE/IPoE, QinQ, RADIUS, CGNAT, L2/L3VPN), plus the migration experience: the topology change turned into a major fiber and infrastructure cleanup, strange CPEs in the field, "bugs, bugs, bugs," and subscriber migration pain.
• How: Distributed termination removes centralized failure points, simplifies backbone/fiber planning, enables direct routing and service flexibility, and avoids "major vendor tax" with pay-as-you-grow boxes. The costs: IP pool management and config automation get harder, and you're running more complex hardware deep in the field with a new software vendor. The speaker's guidance on fit: it depends on physical footprint and org structure, and is especially attractive for medium-sized networks — but even if decentralization isn't right for you, shrink your failure domains ("huge chassis routers need to die").
• Where applicable: The migration specifics are AS9136/WDZ-specific; the failure-domain reasoning and the honest challenge list are broadly applicable to any access-network operator.