FTTB, which stands for “Fiber-to-the-Building” (sometimes also referred to as “Fiber-to-the-Business”), is a type of broadband network architecture in which an optical fiber is run directly to a commercial, multi-dwelling unit (MDU) or office building. Once the fiber reaches the building, the signal can be further distributed to individual units or offices using various methods, including Ethernet or even older infrastructures like copper lines.

Here’s an overview of FTTB:


  • Optical Line Terminal (OLT): Located at the service provider’s central office, it’s responsible for connecting the FTTB network to the broader internet.
  • Optical Network Terminal (ONT) or Optical Network Unit (ONU): Positioned at the building or inside it, these devices convert optical signals to electronic signals suitable for traditional business/residential devices.


  • Speed: FTTB networks can deliver high-speed internet, often gigabit-level, depending on the internal distribution method after the fiber endpoint.
  • Reliability: Optical fiber is less prone to interference and signal degradation than copper lines.

Internal Distribution:

  • Once the fiber reaches the building, it’s essential to distribute the signal to individual units or offices. This distribution can be achieved through:
    • Ethernet: For distributing high-speed internet.
    • DSL over existing phone lines: Utilizing existing infrastructure but with reduced speeds.
    • Coaxial cables: In some scenarios, existing coaxial infrastructure may be repurposed for internet distribution.


  • Efficiency: Bringing fiber directly to the building ensures high-speed internet for all occupants without the need for individual connections.
  • Cost-effective: For service providers, connecting an entire building through FTTB can be more cost-effective than running individual lines to every single unit.
  • Improved Services: Besides internet, FTTB can enhance other services like VoIP, IPTV, and more.


  • Internal Wiring: If the internal infrastructure of the building is outdated, it may need an upgrade to fully take advantage of fiber speeds.
  • Deployment Cost: While FTTB is more cost-effective than individual connections, initial setup costs can still be high, especially if the area lacks existing fiber infrastructure.

Comparison with Other Fiber Solutions:

  • FTTH (Fiber-to-the-Home): Direct fiber connections to individual homes.
  • FTTP (Fiber-to-the-Premises): A broad term that includes both FTTH and FTTB.
  • FTTN (Fiber-to-the-Node/Neighborhood): The fiber ends at a local node, and then other infrastructures like copper take over for the “last mile” to homes or businesses.

In essence, FTTB is an effective way of providing high-speed internet to MDUs like apartment complexes or office buildings, leveraging the capabilities of fiber optics up to the point of the building and then utilizing other means to ensure connectivity within.