Building our fibre network

At Openreach, we’re using the latest cable technology to build our fibre networks, especially Fibre-to-the- Premises. 

We’re using two primary cable designs.

Slippery Fish


A 12-fibre small profile oval cross-sectional cable (8 x 4mm) that we insert into our underground duct network. It’s strengthened inside so it can be pushed by hand up to 50m into a duct. It’s flexible and easy to handle. And because it’s so small, we can also easily clip it to poles or slip it behind other cables or trunking.

Ultra-light weight cable


This cable punches well above its weight, carrying 36 fibres within its slim 7mm diameter. That small diameter makes it perfect for aerials as well as lots of other applications, including our underground network.

We combine it with modern wiring clamps and port seal closures so we can use it to meet demanding fibre network requirements. And we’re working with our suppliers to come up with a cable that can carry up to 48 fibres without increasing the diameter.