Fibre Broadband: The Basics

Making sense of next generation broadband


Fibre Broadband Overview

Explaining the various forms of Fibre to the...

To demonstrate the effect that fibre has on a broadband circuit we have provided diagrams showing how the traditional ADSL model differs from both FTTC and FTTP. Essentially, by removing part or all of the copper cables you are reducing the resistance on the line which gives way to significant improvements in the speeds achieved.

Traditional Broadband

For comparison here is a very basic view of how ADSL broadband operates over existing copper cables. Fibre broadband sees part or all of the copper being replaced, and in doing so the speeds can increase owing to the near infinite capabilities that fibre optics can deliver.

Traditional ADSL circuit diagram

Fibre to the Cabinet

The Fibre to Cabinet (FTTC) technology sees the DSLAM (Digital Subscriber Line Access Module) moving from it's traditional location at the local exchange to a street cabinet in your area. Fibre is run to the enabled cabinet, and the remaining connection to your premises is run over the existing copper cables. By replacing a large proportion of the copper cables to the cabinet with fibre, it means the speeds that can be achieved are significantly higher.

Fibre to the Cabinet circuit diagram

Fibre to the Premises

The Fibre to Cabinet (FTTP) technology doesn't make use of the copper phone network. Instead it delivers incredible speeds utilising fibre from the local exchange. Lots of roads already have BT laid fibre already which is spliced and then run into your premises using existing ducts or overhead cable infrastructure. In trials the process has been straight forward for most customers, however should it be the case that the ducts used for your copper cables are damaged, or additional engineering works are required, the customer needs to be aware that further costs may apply to run the fibre successfully.

Fibre to the Premises circuit diagram

FTTC Installation

Fibre to the Cabinet Delivery

In much the same way that ADSL is supplied, all the hard work is completed external to the premises. An engineer doesn't need to attend your premises, they will simply move the line to use fibre at the street cabinet.

You may already have an ADSL modem router, sadly this is unlikely to be compatible with FTTC. For a definitive answer check with the manufacturer. If needed, you can purchase a VDSL modem router for as little as £30. However, the filters you use for ADSL, are also needed and usable with FTTC. They allow you to connect your phone and your router to the line, and ensure that the two don't interfere with each other.

Recommended Routers

Tried and tested routers our customers are using



A wireless VDSL2/ADSL modem router providing you with a very basic router suitable for basic home user applications. If you have over 10+ devices using this, then we would recommend you invest in something a little larger.

TP-LINK Archer VR400 V3 AC1200


This provides VDSL2/ADSL modem router capabilities with far reaching WiFi coverage suitable for more demanding home and business users.

FTTP Installation

How Fibre to the Premises is Installed

Unlike ADSL and FTTC, whereby traditional phone lines are used to supply the broadband connection to your premises, FTTP sees a new fibre connection run directly to your home, ignoring any existing cables. Engineers do require access to your building to complete the installation.

We will always give our clients access to the soonest possible installation date. However, should this prove to be unsuitable, it can be changed. There are two parts to the installation process, the first, you don't need to be present, but you will need to be present for the second stage.

Step 1

ENGINEER VISIT 1 - This installation visit doesn't require you to be present as long as the engineer can access the outside of your building. An Openreach engineer will install a small box (approximately 15cm x 10cm x 3cm) close to your existing phone lines. It is this box which will allow the fibre to enter your building and is known as the Customer Splicing Point (CSP). The engineer will call before attending and it is important this call is answered otherwise the appointment cannot go ahead.

Where a customer's phone lines are supplied using overhead cables, an outage of up to an hour may occur. The FTTP installation process involves replacing the drop wire with a new hybrid cable to avoid overloading. It is important to plan for this interruption, especially if you are a business reliant on making and receiving calls.

Step 2

ENGINEER VISIT 2 - An engineer will visit again on an agreed date to complete the fibre installation. It is important that on this date, you are present and know roughly where you would like the fibre modem and router to be placed. The engineer can offer you advice on this including running up to 30 meters of fibre within your premises. Their job is to connect the Openreach supplied modem to the CSP. The engineer will call before attending and it is important this call is answered otherwise the appointment cannot go ahead.

Step 3

The engineer will ensure that the fibre is connected correctly into the Openreach supplied fibre modem (also known as a Optical Network Termination - ONT). This will present you with up to 4 RJ45 sockets for your network to connect to the Internet feed.

FTTP Modem      FTTP Modem

Openreach supplied FTTP modem

The Internal Fibre Setup

Once complete, this is how the setup should look.

FTTP Internal Setup