If you’re just stepping into the world of fiber optics, all the technical terms and abbreviations can feel overwhelming. That’s why I created this fiber glossary series — to help you understand what these terms really mean, in the simplest way possible.

I’ll explain everything from an industry insider’s point of view, using real photos whenever I can (not just fancy renders). I also avoid overly complex explanations, keeping the language clear and direct, so you can be confident you’ll understand the real meaning of these terms after reading.

Related Fiber Optic Terms

Here are some other fiber optic glossary entries you might find useful. Click to learn more:

Today, we’re going to talk about: FTTB.

TABLE OF CONTENTS

So What Is FTTB？

Let’s start with the basics:

FTTB stands for Fiber to the Building — or sometimes, Fiber to the Basement. It means the fiber optic cable runs all the way from your service provider to the building, but not into each individual apartment or office.

Instead, the fiber usually stops at a central point like the building’s equipment room, basement, or communication cabinet. From there, existing copper (or Ethernet) cables are used to bring the internet into each unit.

So, you’re not getting full fiber inside your home — but you’re still much closer than with older setups like DSL or cable.

What Does FTTB Look Like in Real Life?

Here’s a quick example:

  • You live in a multi-story apartment building.

  • The telecom company installs fiber to the basement or utility room.

  • A shared device (often called an ONU or network switch) converts the fiber signal.

  • That signal travels through existing LAN cables, phone wires, or coaxial lines to each room.

It’s like bringing fiber to your doorstep — but the last few meters are handled by simpler, older wiring.

FTTB vs FTTH: What’s the Difference?

Feature FTTB (Fiber to the Building) FTTH (Fiber to the Home)
Fiber Reach
Up to the building
All the way into each home
Last Connection
Copper / Ethernet / coax
Full fiber connection
Speed Potential
Good, but limited by last cable
Maximum speed and stability
Installation Cost
Lower
Higher

FTTB is a great balance — especially for retrofitting older buildings where re-cabling every unit would be costly or disruptive.

How Does FTTB Work Technically?

Here’s the simplified process:

  1. Fiber is deployed to a shared building location (usually a telecom room or MDF).

  2. The signal is handed over to devices like:

    • ONU (Optical Network Unit)

    • Ethernet switches

    • VDSL or MoCA converters, depending on the in-building cabling

  3. The signal is then distributed through existing infrastructure to each user.

Curious about terms like ONU or VDSL? I’ll explain them in other glossary entries soon, and link them back here for easy reference.

Is FTTB Fast Enough?

Yes — in most cases.

FTTB can support hundreds of Mbps, or even gigabit speeds, especially if the internal wiring is high-quality Ethernet (like Cat5e or Cat6). However, the overall speed is still limited by the “last leg” — the part between the building entry point and your room.

If your building has old phone lines, performance may be reduced compared to full FTTH.

Why is FTTB Used?

FTTB is a popular solution for:

  • Apartment buildings, condos, or dormitories

  • Commercial office towers

  • Places where rewiring every unit with fiber is difficult or too expensive

It’s a cost-effective way to offer high-speed internet access while reusing existing in-building infrastructure.

In Summary

FTTB = Fiber to the Building — not quite full fiber to your room, but a huge step up from traditional networks.

It delivers faster speeds, better stability, and is especially useful in large buildings where individual fiber installations aren’t practical.

If someone asks, “Does FTTB mean fiber to the basement?” — the answer is yes, that’s often exactly where it ends.

Still Have Questions?

If you’re still unsure about something, feel free to reach out.

Want to explore more fiber optic terms? Head over to our blog section.

If the term you’re looking for isn’t covered yet, let me know — I’ll add it to the priority list!

And lastly — if you’re a telecom provider, network operator, or involved in fiber infrastructure development and looking for a reliable partner in fiber optic components — feel free to contact to us.