Fiber to the Node (FTTN) Overview

Fiber to the Node (FTTN) is a fiber and copper local loop architecture for delivering broadband Internet to subscribers. With FTTN, fiber is installed only to copper local loop aggregation points known as Feeder Distribution Interfaces (FDIs). FTTN has the advantage that, compared to FTTH, it dramatically reduces the amount of fiber that must be installed to serve a subscriber and requires substantially less capital to install. However, FTTN does not provide the bandwidth potential of network architectures like FTTH or even Fiber to the Curb (FTTC).

A typical FTTN network architecture is shown in the drawing above.  Fiber from a CO (or could be from an RT DLC cabinet, not shown) serves a DSLAM or BBDLC installed adjacent to a Feeder Distribution Interface, which provides copper loop concentration (typically 2:1) and cross-connect functions.  Local loops from the FDI to its subscribers are typically less than 5000 feet, which is a reasonably good match to the distances over which VDSL2 provides bandwidth advantages over ADSL2+.  The picture below shows what a typical FDI looks like, though this cross-connect cabinet is installed next to a DLC (beige cabinet to the right).

FDI

AT&T and Qwest are big proponents of FTTN.  AT&T’s U-verse service offering is based on an FTTN architecture.  In 2007, Qwest committed $300 million to delivering broadband services across an FTTN architecture.

© 2009, The Product Group LLC. All rights reserved.

Related posts:

1. Fiber to the Cabinet or FTTCab What used to be called Fiber to the Node or FTTN is now called Fiber to the Cabinet or FTTCab in the ITU standards. The...
2. Fiber to the Curb (FTTC) Overview Fiber to the Curb (FTTC), like Fiber to the Node (FTTN), is a fiber and copper local loop architecture for delivering broadband Internet to subscribers. With...
3. Fiber in Broadband Access Networks The most expensive element in delivering broadband Internet services over fiber optic cable is the access network, and its architecture largely determines how much bandwidth...
4. VDSL2 Versus DOCSIS Smackdown Light Reading is reporting that Cox is offering 50 Mbps DOCSIS cable modem service in Arizona on Cisco gear to counter Qwest’s 40 Mbps VDSL2...
5. VDSL2 Overview and Tutorial VDSL2 (Very high bit rate Digital Subscriber Line 2), a performance-improved version of the original VDSL now known as VDSL1, is standardized by the ITU in...