Choosing a BNG: chassis, MikroTik or software
The broadband network gateway is where every subscriber session lives, so the platform an ISP chooses sets its cost, its scale ceiling and how it operates. There are three realistic choices, and they suit different operators.
What a BNG does, and why the choice matters
A BNG terminates subscriber sessions, PPPoE, IPoE or L2TP, authenticates each one against RADIUS, assigns addresses, enforces the subscriber's speed, applies carrier NAT and accounts for usage. It is the busiest and most load-bearing box an ISP runs. The platform you build it on decides your capital cost, how you scale, how long you wait for capacity, and how much of the system you control.
Three ways to build a BNG
| Platform | Strengths | Trade-offs |
|---|---|---|
| Chassis router | Very high port density and capacity, deep-buffer line cards, mature feature set | High capital cost and per-subscriber licensing, long lead times, vendor lock-in |
| MikroTik | Low cost, quick to start, familiar to many small operators | CPU-bound termination, scales by adding boxes, limited deterministic CGNAT logging |
| Software BNG on x86 | Commodity servers, scales on cores and NICs, integrated CGNAT, operational flexibility | You size and operate the hardware; raw port density is lower than a chassis |
Matching the platform to the operator
A chassis earns its place where raw port density and deep buffering are the deciding factors, and the budget and lead times are acceptable. MikroTik is a reasonable start for a small network, until session counts, CGNAT scale or deterministic logging begin to strain it. A software BNG on standard x86 suits an operator that wants to scale on commodity hardware, keep integrated CGNAT, and avoid per-subscriber licensing, accepting that it sizes and runs the servers itself.
Netavo BNG is a software BNG for x86: it terminates PPPoE, IPoE and L2TP, includes carrier-grade NAT, and scales to large subscriber counts on standard servers. If you are weighing a move from an existing platform, the Netavo BNG site has detailed guides on replacing a chassis BNG and outgrowing a MikroTik edge, and a full engineering library on the data-plane and protocol detail.
Software or hardware: what actually differs
The comparison that decides most choices between a chassis BNG and a software BNG on x86 servers.
| Chassis (hardware) BNG | Software BNG on x86 | |
|---|---|---|
| What you buy | A vendor's chassis, line cards and licences | Software, on standard servers you choose |
| How it scales | By line cards and chassis, in large steps | By cores, network cards and more servers, in small steps |
| Licensing | Often per subscriber, per feature and per port | Per subscriber; Netavo BNG includes CGNAT and routing |
| Lead time | Weeks to months for hardware | As long as it takes to source a server |
| Failure domain | One large box carries many subscribers | Several smaller boxes, so one failure touches fewer |
| Upgrades | Vendor release cycles, often with downtime planned around the chassis | Software releases; Netavo BNG keeps forwarding while its control plane restarts |
| CGNAT | Often a separate service card or appliance | Built in, with port-block logging, on Netavo BNG |
| Where it wins | Very high port density and deep buffers in one place | Cost per subscriber, flexibility and gradual growth |
When hardware still makes sense
A chassis remains the right answer where very high port density in one location matters more than cost, or where an operator's existing tooling and staff are built around one vendor. For most growing ISPs, altnets and wireless operators, the deciding factors are cost per subscriber, how gradually capacity can be added, and how much is included in the licence, and those favour software.
The two can also coexist: a software BNG for new areas or for L2TP from wholesale suppliers, alongside a chassis that already serves an established footprint.
Common questions
What access protocols does Netavo BNG terminate?
Netavo BNG terminates PPPoE, IPoE and L2TP sessions, authenticating each subscriber against RADIUS and assigning IPv4 and IPv6 addressing.
Does a software BNG include CGNAT?
Netavo BNG includes integrated carrier-grade NAT with deterministic port blocks, so NAT is part of the same platform rather than a separate appliance.
Do I have to replace everything at once?
No. A BNG migration can be staged, running the existing and new platforms side by side and moving subscribers in groups. The Netavo BNG migration guides cover this in detail.
Weighing up a BNG platform?
Tell us about your access model and subscriber numbers, and an engineer will talk through whether a software BNG fits and how a migration would be staged.
Work with us →