Fiber to the x (FTTX) is a generic term for any network architecture that uses optical fiber to replace all or part of the usual copper local loop used for telecommunications. The four technologies, in order of an increasingly longer fiber loop are:

• Fiber to the node / neighborhood (FTTN) / Fiber to the cabinet (FTTCab)
• Fiber to the curb (FTTC) / Fibre to the kerb (FTTK)The American word curb means the same thing as the U.K. word kerb. For more information see American and British English spelling differences.
• Fiber to the building (FTTB)
• Fiber to the home (FTTH)

In the actual deployments, the difference between FTTN and FTTC is quite subtle and is mostly that the latter is nearer the customer than the former.

The broadly-defined term fiber to the premises (FTTP) is sometimes used to describe FTTH and/or FTTB.

Fiber to the node

Fiber to the Node (FTTN), also called fiber to the neighborhood or fiber to the cabinet (FTTCab), is a telecommunication architecture based on fiber-optic cables run to a cabinet serving a neighborhood. Customers connect to this cabinet using traditional coaxial cable or twisted pair wiring. The area served by the cabinet is usually less than 1,500 m in radius and can contain several hundred customers. (If the cabinet serves an area of less than 300 m in radius then the architecture is typically called fiber to the curb.)

Fiber to the node allows delivery of broadband services such as high speed internet. High speed communications protocols such as broadband cable access (typically DOCSIS) or some form of DSL are used between the cabinet and the customers. The data rates vary according to the exact protocol used and according to how close the customer is to the cabinet.

Unlike the competing fiber to the premises (FTTP) technology, fiber to the node can use the existing coaxial or twisted pair infrastructure to provide last mile service. For this reason, fiber to the node costs less to deploy. However, it also has lower bandwidth potential than fiber to the premises.

Fiber to the Telecommunications Enclosure

Fiber-to-the-Telecommunications-Enclosure (FTTE) is a standards-compliant structured cabling system architecture that extends the optical fiber backbone network from the equipment room, through the telecom room, and directly to a telecommunications enclosure (TE) installed in a common space to serve a number of users in a work area. Its implementation is based on the TIA/EIA-569-B “Pathways and Spaces” standard, which defines the Telecommunications Enclosure (TE), and TIA/EIA-568-B.1 Addendum 5, which defines the cabling when a TE is used. The FTTE architecture allows for many media choices from the TE to the work area; it may be balanced twisted pair copper, multimode optical fiber, or even wireless if an access point is installed in or near the TE.