What is Openreach Dark Fibre Access (DFA)?
Openreach Dark Fibre Access (DFA) is a wholesale telecoms product that gives communications providers access to an unlit fibre optic connection within the Openreach network.
Instead of buying a managed Ethernet service from Openreach, the provider leases the physical fibre strand and supplies its own optical equipment at each end. That makes DFA a useful option when a customer needs dedicated point-to-point fibre performance and the premises sits in an eligible area.
What 'dark fibre' means
Dark fibre is fibre-optic cable that has been installed but is not carrying any light signal. The network owner provides the fibre path, while the customer or communications provider installs and operates the transmission equipment.
In practical terms, the fibre is "dark" until the provider lights it with its own optics, switches, routers or transmission platform.
How Openreach DFA works
Openreach DFA is designed as:
- An uncontended fibre connection.
- Unlit and unmonitored by Openreach.
- A point-to-point optical path between two network locations.
- A passive service: Openreach provides the fibre, but not the equipment needed to transmit data over it.
The communications provider is responsible for the active service built on top of that fibre, including the optical equipment, monitoring, capacity and customer handoff.
How does DFA differ from a traditional EAD?
A traditional Openreach Ethernet Access Direct (EAD) is an active Ethernet service. Openreach provides and manages the underlying service and presents Ethernet connectivity to the provider.
DFA is different because it is not an active service managed by Openreach. It is a passive fibre path that the communications provider lights and operates themselves.
- DFA fault repair SLA is typically 18 clock hours.
- Openreach does not monitor the active data service, because the optical equipment is provider-managed.
- DFA can be much more cost effective than a traditional EAD.
Can I order a DFA leased line to my premises?
The key point is that DFA is not available everywhere. Ofcom limited dark fibre remedies to less competitive business connectivity markets so they would not discourage alternative network investment.
Under the 2021 Wholesale Fixed Telecoms Market Review, Openreach was required to offer Dark Fibre Access in Area 3 locations: areas where Ofcom concluded there was little or no prospect of effective network competition. The area-based approach continues under the 2026-31 Telecoms Access Review.
- Area 3: generally eligible for DFA.
- Area 2: generally not eligible for DFA.
- Highly competitive urban areas: generally not eligible, especially where multiple fibre operators already serve the business market.
The complication is that eligibility is not simply decided by town or county. It can vary by postcode sector and exchange area, so one location may qualify while a nearby location does not.