FTTH Network Levels NE3 to NE5 Explained

Last updated: 2026-07-22 · FEMOtech GmbH

The network levels (NE) structure German fiber infrastructure: NE3 is the last mile from the exchange to the building, NE4 the in-building cabling to the apartment, NE5 the section inside the apartment to router and devices. For connecting homes, installation technique (blowing, pulling, pushing) and termination technique (splicing or plugging) decide speed and cost per home.

The five network levels at a glance

Network levels of fiber infrastructure
Level	Section	Typical technology
NE1	National backbone between cities and regions	Carrier trunk lines
NE2	Regional distribution to points of presence (PoP)	Feeder networks
NE3	Last mile: PoP to building entry point	Buried microducts, closures, blowing technique
NE4	Building: entry point to apartment	Risers, floor distributors, outlets
NE5	Apartment: outlet to router/device	Patch cables, in-home fibers

For connector manufacturers NE3 to NE5 are the relevant levels: this is where terminated and field-installable connections are set, often under time pressure and in large numbers.

FTTB, FTTH, FITH: where does the fiber end?

FTTB (fiber to the building) takes the fiber to a central point in the building; the last metres run over legacy copper. FTTH (fiber to the home) extends the fiber into the individual unit and is the future-proof full build-out. FITH (fiber in the home) completes the idea and cables the apartment itself with fiber.

Blowing in or pulling in: what protects the fiber?

When blowing in, compressed air carries the cable through a pressure-tight microduct; it floats on an air cushion and stays almost tension-free. A common size for building connections is the 7 × 1.5 mm microduct (7 mm outer, 4 mm inner diameter). When pulling in, the rope's tensile force acts directly on the cable, limiting length and cable choice.

The FEMOtech system ELC/ESC is designed for both methods plus pushing in; the fully terminated connector travels with the cable. Blowing distances above 300 m are achievable with the OD 7 mm / ID 4 mm microduct.

Splice or plug?

A fusion splice remains first choice where connections are permanent and loss budgets are tightest: in closures and distributors of NE3. In NE4 and NE5 the picture flips: many locations, few connections per location, tight time windows. Pluggable systems save the splicer, the training and installation time per home. With the FEMOtech system, standard equipment suffices for termination, grinding and polishing; completion on site is housing plus latch.

Frequently asked questions about FTTH and network levels

What do the network levels NE1 to NE5 mean?

German fiber infrastructure is divided into five network levels: NE1 (national backbone), NE2 (regional distribution), NE3 (last mile to the building), NE4 (in-building cabling to the apartment) and NE5 (inside the apartment to router and devices).

What is the difference between FTTB and FTTH?

With FTTB (fiber to the building) the fiber ends in the basement or utility room; distribution continues over existing copper. With FTTH (fiber to the home) the fiber runs all the way into the individual unit, without any copper section.

Is blowing in or pulling in better?

When blowing in, the cable floats on an air cushion and is carried almost tension-free; that protects the fiber and allows long distances. When pulling in, the tensile force acts directly on the cable, limiting length and cable choice. The FEMOtech system supports both plus pushing in.

Why does a splice-free connector system pay off?

A fusion splice offers very low loss but requires a splicer, trained staff and time per connection. In NE4 and NE5, where many locations each need only a few connections, pluggable systems such as ELC/ESC by FEMOtech save installation time per home and free crews from the splicer.